Barbed wire and method for producing barbed wire

Abstract

To provide a barbed wire which exhibits superior corrosion resistance without requiring costly materials, is inconspicuous at night, and can sustain an intrusion prevention effect for a long duration; and to provide a method for producing a rust remover that enables easy production of such a barbed wire.SOLUTION: A barbed wire according to the invention is employed in intrusion-prevention fences, and includes a base material comprising an iron or steel wire and multiple barbs attached to the wire; a zinc-containing plating layer formed on a surface of the base material; and a trivalent chromium-containing trivalent chromate layer formed on the plating layer, the thickness of the trivalent chromate layer being 1.5 μm or more.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to barbed wire and a method for manufacturing barbed wire, and more particularly, to barbed wire used for an intrusion prevention fence that prevents intruders from entering a facility and a method for manufacturing the same.

Background Art

[0002] Conventionally, in facilities where it is necessary to restrict entry by unauthorized persons (for example, military facilities, nuclear power plants, oil refineries, etc.), an intrusion prevention fence made of barbed wire has been used to prevent unauthorized entry. Such an intrusion prevention fence is obtained by stretching barbed wire wound in a spiral shape. Then, the intrusion prevention fence is laid in the facility.

[0003] The laid intrusion prevention fence needs to maintain its intrusion prevention effect over a long period of time. Therefore, it is desirable to use barbed wire that is resistant to rust and has excellent durability over a long period of time. General barbed wire is composed of an iron core material and barbs, and the surfaces of the core material and barbs are zinc-plated for corrosion prevention. Such barbed wire has the advantages of being inexpensive and easy to process into a desired shape, but there is a problem that the zinc plating peels off over time and the corrosion resistance is not sufficient. Usually, the product life of iron barbed wire is about 2 to 3 years. Also, when the barbed wire is exposed to seawater or sea breeze, the life of the barbed wire is further shortened due to salt damage. Furthermore, the barbed wire with zinc plating is likely to reflect light, so it is easily noticed by intruders at night and the intrusion prevention effect is insufficient.

[0004] In addition, barbed wire using titanium or stainless steel with a higher corrosion prevention effect as a core material is also used. However, since barbed wire made of titanium is very expensive, when laying intrusion prevention fences over a wider area, the laying cost of the intrusion prevention fence becomes too high. Also, barbed wire made of titanium has lower rigidity than barbed wire made of iron and is prone to deformation, so a sufficient intrusion prevention effect cannot be obtained. Moreover, barbed wire made of stainless steel is more likely to reflect light than barbed wire made of iron. Furthermore, since it is difficult for coating agents such as dulling agents to adhere to barbed wire made of stainless steel, it is difficult to suppress light reflection. Therefore, barbed wire made of stainless steel is likely to be noticed by intruders at night, and the intrusion prevention effect is insufficient.

[0005] Also, from the perspective of improving corrosion resistance, barbed wire using a resin material as a constituent material of the core material or the barbs instead of a metal material is known (for example, Patent Document 1). However, barbed wire formed of a resin material has problems in that its properties such as impact resistance, abrasion resistance, weather resistance, and heat resistance are inferior to those of barbed wire formed of a metal material, and a sufficient intrusion prevention effect cannot be obtained.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] An object of the present invention is to provide barbed wire that is excellent in corrosion resistance, is not conspicuous at night, and maintains an intrusion prevention effect over a long period without using expensive materials. Another object of the present invention is to provide a method for manufacturing barbed wire that can easily manufacture such barbed wire.

Means for Solving the Problems

[0008] Such an object is achieved by the present invention of the following (1) to (11). (1) A barbed wire used for an intrusion prevention fence, a base material having a wire made of iron or steel and a plurality of barbed bodies attached to the wire, a zinc-containing plating layer formed on the surface of the base material, and a trivalent chromate layer containing trivalent chromium formed on the plating layer, and having, a barbed wire characterized in that the thickness of the trivalent chromate layer is 1.5 μm or more.

[0009] (2) The barbed wire according to (1) above, wherein the thickness of the plating layer is 20 μm or more and 80 μm or less.

[0010] (3) The barbed wire according to (1) or (2) above, wherein when the thickness of the trivalent chromate layer is T1 [μm] and the thickness of the plating layer is T2 [μm], the relationship 0.019 ≦ T1 / T2 ≦ 0.15 is satisfied.

[0011] (4) The barbed wire according to (1) or (2) above, wherein the trivalent chromate layer contains the trivalent chromium, a metal other than the trivalent chromium, and a structure derived from a complexing agent.

[0012] (5) The barbed wire according to (4) above, wherein the metal contains two or more selected from alkali metals, alkaline earth metals, cobalt, titanium, zirconium, vanadium, molybdenum, tungsten, manganese, iron, nickel, gold, silver, copper, tin, and aluminum.

[0013] (6) The barbed wire according to (4) above, wherein the complexing agent contains one or more selected from dicarboxylic acids, tricarboxylic acids, oxyacids, hydroxyl group-containing dicarboxylic acids, hydroxyl group-containing tricarboxylic acids, and salts thereof.

[0014] (7) A method for manufacturing a barbed wire used for an intrusion prevention fence, a step of preparing a base material by attaching a plurality of barbed bodies to a wire made of iron or steel, A step of forming a plating layer containing zinc on the surface of the base material; A step of forming a trivalent chromate layer containing trivalent chromium on the plating layer to obtain the barbed wire, and having: A method for manufacturing barbed wire, characterized in that the thickness of the trivalent chromate layer is 1.5 μm or more.

[0015] (8) The step of forming the trivalent chromate layer includes: A step of adjusting a trivalent chromate treatment solution containing trivalent chromium; A step of immersing the base material on which the plating layer is formed in the trivalent chromate treatment solution to adhere the trivalent chromate treatment solution onto the plating layer; A step of drying the trivalent chromate treatment solution to form the trivalent chromate layer, and The step of adhering the trivalent chromate treatment solution is carried out at 20 to 60°C, The step of forming the trivalent chromate layer is carried out at 50 to 100°C. The method for manufacturing barbed wire according to (7) above.

[0016] (9) The step of preparing the base material includes: a step of preparing a long plate material on which the barbs are formed; and a step of wrapping and fixing the wire with the plate material. The method for manufacturing barbed wire according to (7) above.

[0017] (10) The base material is formed in a cylindrical shape in which the wire is spirally wound, The step of forming the plating layer and the step of forming the trivalent chromate layer are performed on the cylindrical base material. The method for manufacturing barbed wire according to any one of (7) to (9) above.

[0018] (11) The barbed wire is formed in a cylindrical shape, The length of the cylindrical base material is the same as the length of the cylindrical barbed wire, The diameter of the cylindrical base material is the same as the diameter of the cylindrical barbed wire. The method for manufacturing barbed wire according to (10) above.

Advantages of the Invention

[0019] According to the present invention, on the surface of the barbed wire, in addition to the plating layer containing zinc, a trivalent chromate layer with a thickness of 1.5 μm or more is formed. Therefore, it is possible to obtain a barbed wire that is difficult to rust and has suppressed light reflection. Such barbed wire is excellent in corrosion resistance, is not conspicuous at night, and maintains the intrusion prevention effect over a long period of time.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0021] Hereinafter, preferred embodiments of the barbed wire of the present invention and a method for manufacturing the barbed wire will be described in detail with reference to the accompanying drawings. 1. barbed wire First, the barbed wire of the present invention will be described. FIG. 1(a) is a photograph showing a preferred embodiment of the barbed wire of the present invention wound in a spiral shape, and FIG. 1(b) is a partially enlarged photograph of FIG. 1(a).

[0022] The barbed wire 1 of the present embodiment has a base material, a plating layer formed on the surface of the base material, and a trivalent chromate layer formed on the plating layer. Such barbed wire 1 is used for an intrusion prevention fence provided to prevent intrusion by non-related persons around a facility where entry by non-related persons needs to be restricted. The barbed wire 1 is wound in a spiral shape and formed into a cylindrical shape. Such barbed wire 1 is transported to the laying site in a wound state as shown in Fig. 1(a). After arriving at the site, the barbed wire 1 can be used as an intrusion prevention fence by stretching it in a direction orthogonal to the winding direction of the barbed wire 1 to make it spiral. Also, a plurality of barbed wires 1 can be prepared, and the ends of the barbed wires 1 that are stretched and form a spiral can be joined together, or these barbed wires 1 can be stacked in the height direction and used as an intrusion prevention fence. Hereinafter, each member constituting the barbed wire 1 will be described.

[0023] (Base material) The base material of the barbed wire 1 has a wire 2 and a plurality of barbs 3 attached to the wire 2. Note that the shape of the base material is the same as the shape of the barbed wire 1 shown in Figs. 1(a) and (b).

[0024] The wire 2 is an iron or steel wire. The wire 2 preferably has a wire diameter such that the barbed wire 1 has sufficient strength and is difficult for an intruder to notice at night. Specifically, the wire diameter of the wire 2 is preferably about 1.0 to 4.0 mm, more preferably about 1.5 to 3.5 mm, and even more preferably about 2.0 to 3.0 mm. If the wire diameter of the wire 2 is within the above range, an intrusion prevention fence can be obtained that has sufficient strength, is difficult for an intruder to notice at night, and exhibits a high intrusion prevention effect. Also, the cross-sectional shape of the wire 2 is not particularly limited, and can take any shape such as circular, elliptical, rectangular, square, triangular, or other polygons.

[0025] Also, the length of the wire 2 is not particularly limited, but from the viewpoint of high portability and the ability to lay an intrusion prevention fence of sufficient length even with a small number of barbed wires 1, it is preferably about 150 to 300 m, and more preferably about 200 to 270 m.

[0026] The barbed body 3 is a laser blade (razor blade) made of iron or steel, barbed wire with a sharp tip, or the like. In particular, by using a laser blade as the barbed body 3, a great psychological deterrent force that makes the intruder hesitate to enter the facility works, and the intrusion prevention effect can be enhanced. In this embodiment, the case where a laser blade with a high intrusion prevention effect is used as the barbed body 3 will be described.

[0027] As shown in FIG. 1(b), the barbed body (laser blade) 3 is provided symmetrically about the wire 2 in the radial direction of the wire 2. The barbed body 3 protrudes so as to spread outward from the wire 2, and its shape is a trapezoid with a narrower base end on the wire 2 side than the tip forming the blade. Also, the barbed body 3 is formed on the same plane in the radial direction of the wire 2. Also, the blades of each barbed body are preferably provided at about 60 to 90° with respect to the wire 2, and more preferably about 90°. Also, the barbed bodies 3 are provided at predetermined intervals along the longitudinal direction of the wire 2. The blade thickness of the barbed body 3 is preferably about 0.3 to 0.8 mm, more preferably about 0.4 to 0.7 mm, and even more preferably about 0.45 to 0.6 mm. If the blade thickness of the barbed body 3 is within the above range, the barbed body 3 has sufficient durability and a barbed wire 1 with a high intrusion prevention effect can be obtained.

[0028] Also, the blade of the barbed body 3 is preferably about 5 to 15 mm, more preferably about 7 to 12 mm, and even more preferably about 9 to 11 mm in the longitudinal direction of the wire 2. If the length of the barbed body 3 in the longitudinal direction is within the above range, the effect of preventing the intrusion of the barbed wire 1 can be further enhanced. Further, the predetermined interval (pitch) of the barbed bodies 3 is preferably about 17 to 35 mm, more preferably about 20 to 30 mm, and even more preferably about 23 to 27 mm. If the pitch of the barbed bodies 3 is within the above range, the effect of preventing the intrusion of the barbed wire 1 can be further enhanced.

[0029] (Plating layer) In this embodiment, a plating layer containing zinc is formed on the surface of the base material 10 to which a plurality of barbed bodies 3 are attached to the above-described wire 2. As the metal material constituting the plating layer, zinc or a zinc alloy of zinc and various metals such as nickel, aluminum, and iron can be used. In particular, the plating layer is preferably composed of zinc alone in that it has a high affinity with iron or steel constituting the base material 10 and can form a plating layer firmly adhered to the surface of the base material 10.

[0030] The thickness of the plating layer formed on the surface of the base material 10 is preferably about 20 μm or more and 80 μm or less. If the thickness of the plating layer is within the above range, the plating layer can firmly adhere to the surface of the base material 10 and can enhance the durability of the plating layer. If the durability of the plating layer is increased and peeling from the base material 10 is suppressed, the base material 10 can maintain a state of being covered with the plating layer and the trivalent chromate layer for a long period of time. As a result, a barbed wire 1 having excellent corrosion resistance and a long product life can be obtained. Also, if the thickness of the plating layer is within the above range, the gloss derived from the base material 10 can be suppressed, and the barbed wire 1 can be made less conspicuous at night. Further, from the viewpoint of enhancing the above effects, the thickness of the plating layer is more preferably about 22 μm or more and 70 μm or less, and even more preferably about 23 μm or more and 60 μm or less. Note that forming the plating layer with the above-mentioned predetermined thickness on the surface of the base material 10 means that such a plating layer is formed over the entire wire 2 and barbed body 3. In the present embodiment, since the affinity between the constituent material of the base material 10 (wire 2 and barbed body 3) and the constituent material of the plating layer is high, a plating layer with a uniform film thickness can be formed by various plating processes described later. In particular, although the shape of the barbed body 3 is such that its proximal end (the root of the barbed body 3) is narrower than the tip, even for such a barbed body 3 with a complex shape, by combining the constituent material of the base material 10 and the constituent material of the plating layer in the present embodiment, a plating layer with a uniform film thickness can be formed in all regions including the root of the barbed body 3.

[0031] (Trivalent chromate layer) A trivalent chromate layer containing trivalent chromium is formed on the plating layer. As a method for forming such a trivalent chromate layer, trivalent chromate treatment is used. Trivalent chromate treatment is a chemical conversion treatment in which the plating layer is immersed in a trivalent chromate treatment solution containing only trivalent chromium and no hexavalent chromium as chromium, causing a chemical reaction on the surface of the plating layer to form a trivalent chromate film (layer) on the surface of the plating layer. Trivalent chromate treatment can address environmental issues in that it does not use hexavalent chromium, which is harmful to living organisms. Also, such a trivalent chromate layer has the same corrosion resistance as the conventionally used hexavalent chromate layer. Specific trivalent chromate treatment will be described later.

[0032] In the present embodiment, the thickness of the trivalent chromate layer is set to 1.5 μm or more. Generally, when forming a trivalent chromate layer on a zinc or zinc alloy plating layer by trivalent chromate treatment, the thickness of the plating layer is about several μm to 10 μm, and the thickness of the trivalent chromate layer is about 0.2 to 0.5 μm. The trivalent chromate treatment undergoes a process of causing a chemical reaction on the surface of the plating layer to form a trivalent chromate film. Therefore, when the thickness of the plating layer is thin, the amount of zinc available for reaction is small, and the maximum film thickness of the trivalent chromate layer that can be formed is about 0.5 μm. On the other hand, in this embodiment, as described above, since the thickness of the plating layer is relatively thick, the chemical reaction on the surface of the plating layer by the trivalent chromate treatment continues for a relatively long time, so the thickness of the formed trivalent chromate layer can be 1.5 μm or more. By forming a trivalent chromate layer with such a film thickness on the plating layer, the base material 10 can be covered with a thick film, the corrosion resistance of the barbed wire 1 can be improved, and the product life can be significantly extended. Further, as the film of the base material 10 becomes thicker, there is also an effect of suppressing the gloss derived from the base material 10. That is, since a plating layer containing zinc and a trivalent chromate layer with a thickness of 1.5 μm or more are formed on the surface of the barbed wire 1, the barbed wire 1 is excellent in corrosion resistance, is not conspicuous at night, and the intrusion prevention effect is maintained over a long period of time.

[0033] In this embodiment, the trivalent chromate layer contains trivalent chromium, a metal other than trivalent chromium, and a structure derived from a complexing agent. Such a trivalent chromate layer is formed using a trivalent chromate treatment solution having the composition described below. By using such a trivalent chromate treatment solution, a trivalent chromate layer with a uniform film thickness can be formed over the entire base material 10 (wire 2 and barbs 3). In particular, the shape of the barb 3 is such that its base end (the root of the barb 3) is narrower than the tip, but even for such a barb 3 with a complex shape, a trivalent chromate layer with a uniform film thickness can be formed on a plating layer with a uniform film thickness over all regions including the root of the barb 3.

[0034] <Trivalent chromate treatment solution> The trivalent chromate treatment solution contains a predetermined amount of a trivalent chromium compound, a metal compound other than trivalent chromium, and a complexing agent in water (e.g., deionized water). The trivalent chromium compound is not particularly limited, but trivalent chromium salts such as chromium nitrate, chromium sulfate, chromium chloride, chromium phosphate, and chromium acetate are used. Among these, chromium nitrate, chromium sulfate, or a combination thereof is preferably used because the color tone of the formed trivalent chromate layer is less conspicuous even at night and the corrosion resistance is good. The content of the trivalent chromium salt in the trivalent chromate treatment solution is not particularly limited, but the range of 0.1 to 100 g / L is preferable, and the range of 0.5 to 10 g / L is more preferable.

[0035] Examples of the metal compound other than trivalent chromium include chlorides, hydroxides, oxides, carbonates, nitrates, sulfates, etc. of various metals such as alkali metals, alkaline earth metals, cobalt, titanium, zirconium, vanadium, molybdenum, tungsten, manganese, iron, nickel, gold, silver, copper, tin, and aluminum. Further, the trivalent chromate treatment solution preferably contains two or more metal compounds selected from these various metal compounds. In particular, when the trivalent chromate treatment solution contains chromium sulfate as the trivalent chromium compound and a cobalt-containing compound, sulfuric acid and cobalt react during the trivalent chromate treatment to form cobalt sulfide, whereby the color tone of the formed trivalent chromate layer becomes black. Therefore, the barbed wire 1 that is less conspicuous at night can be obtained. The content of the various metal compounds in the trivalent chromate treatment solution is not particularly limited, but the range of 0.0001 to 100 g / L is preferable, and the range of 0.0001 to 10 g / L is more preferable.

[0036] In addition, the trivalent chromate treatment solution contains a complexing agent. When a complexing agent is included in the trivalent chromate treatment solution and the trivalent chromium compound, metals other than trivalent chromium, and zinc contained in the plating layer in the trivalent chromate treatment solution react, they form chelates with these various metal ions, and the formed film becomes dense. Furthermore, its thickness can be made thicker. As a result, even with a shorter treatment time, the thickness of the trivalent chromate layer can be made 1.5 μm or more. Examples of such complexing agents include dicarboxylic acids, tricarboxylic acids, oxyacids, hydroxyl group-containing dicarboxylic acids, hydroxyl group-containing tricarboxylic acids, and their salts, which are used as various chelating agents. One or more selected from these compounds can be used. Specific examples of the complexing agent include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, phthalic acid, terephthalic acid, tartaric acid, citric acid, malic acid, ascorbic acid, and their salts, etc. The content of the complexing agent in the trivalent chromate treatment solution is not particularly limited, but a range of 0.1 to 100 g / L is preferred, and a range of 1 to 30 g / L is more preferred.

[0037] In addition to the above components, the trivalent chromate treatment solution may also contain, as other components, additives such as a surface conditioner, a plasticizer, an ultraviolet absorber, an antioxidant, a pigment or a dye, a pigment dispersant, an impact resistance improver, etc.

[0038] Also, from the viewpoint of achieving sufficient corrosion resistance and inconspicuousness at night while suppressing the manufacturing cost of the barbed wire 1, the thickness of the trivalent chromate layer is preferably about 1.5 to 5 μm, and more preferably about 1.8 to 3 μm.

[0039] Also, when the thickness of the trivalent chromate layer is T1 [μm] and the thickness of the plating layer is T2 [μm], it is preferable to satisfy the relationship of 0.019 ≦ T1 / T2 ≦ 0.15, more preferably to satisfy the relationship of 0.02 ≦ T1 / T2 ≦ 0.1, and even more preferably to satisfy the relationship of 0.025 ≦ T1 / T2 ≦ 0.08. By satisfying the above conditions for the thicknesses of the trivalent chromate layer and the plating layer, the durability of the entire plating layer and trivalent chromate layer becomes higher, and the product life of the barbed iron wire 1 can be extended.

[0040] Also, as described above, the barbed iron wire 1 is formed in a cylindrical shape by being wound in a spiral shape. The diameter of the wound iron wire in the state where the barbed iron wire 1 is wound can be appropriately changed according to the site to be laid. For example, it can be about 500 to 1200 mm. Also, the length in the state where the wound iron wire is stretched in a direction perpendicular to the winding direction is not particularly limited, but for example, it can be about 10 to 15 m. Note that the weight of the barbed iron wire 1 with the diameter of the wound iron wire being 600 mm and the length in the state where the wound iron wire is stretched being 13 m is about 11.5 kg. Also, the weight of the barbed iron wire 1 with the diameter of the wound iron wire being 1000 mm and the length in the state where the wound iron wire is stretched being 13 m is about 19 kg.

[0041] 2. method for manufacturing barbed wire Next, the manufacturing method of the barbed iron wire 1 described above will be explained. The manufacturing method of the barbed iron wire 1 includes a step of preparing a base material 10 by attaching a plurality of barbed bodies 3 to a wire 2 made of iron or steel (the first step), a step of forming a plating layer containing zinc on the surface of the base material 10 (the second step), and a step of forming a trivalent chromate layer containing trivalent chromium on the plating layer to obtain the barbed iron wire 1 (the third step). Hereinafter, each step will be explained in detail.

[0042] (The first step) The first step is a step of preparing the base material 10 by attaching a plurality of barbs 3 to the wire 2. Here, the step of preparing the base material 10 will be described with reference to FIG. 2. FIG. 2 is a diagram for explaining the step of preparing the base material. FIG. 2(a) is a diagram showing a plate material with barbs in which barbs are formed. FIG. 2(b) is a diagram showing a state in which a wire is placed in the center of the plate material with barbs. FIG. 2(c) is a diagram showing a state in which the wire is processed so as to be wrapped with the plate material with barbs from the state of FIG. 2(b).

[0043] First, a long plate material (iron or steel) for forming the barbs 3 is prepared. Next, the plate material is press-processed using a press cutter to cut portions other than the portions that will become the barbs 3 on both edge sides of the plate material. Thereafter, by performing cutting on the plate material so that the portions that will become the barbs 3 conform to the specifications of a predetermined laser blade, a plate material with barbs 30 as shown in FIG. 2(a) is obtained. The width of the plate material to be prepared can be appropriately changed according to the specifications of the barbs 3 to be formed. However, when the wire diameter of the wire 2 is about 1.0 to 4.0 mm, it can be about 15 to 25 mm. The plate material with barbs 30 thus formed is wound around a tape rewinder and stored in preparation for assembly with the wire 2.

[0044] Next, the coiled wire 2 and the plate material with barbs 30 wound around the tape rewinder are prepared. While pulling out the plate material with barbs 30 from the tape rewinder, the wire 2 is also pulled out at the same time, and as shown in FIG. 2(b), it is placed so that the wire 2 is positioned in the center of the plate material with barbs 30. Note that the distance between both edges 31 of the plate material 30 with barbs (the distance between both edges 31 of the plate material 30 with barbs in the region where the barbs 3 are not formed) is configured to be larger than the wire diameter of the wire 2. Specifically, the distance between both edges 31 of the plate material 30 with barbs is preferably about 2.0 to 2.8 times the wire diameter of the wire 2, and more preferably about 2.2 to 2.5 times. If the distance between both edges 31 of the plate material 30 with barbs is within the above range, even if the wire 2 is slightly displaced from the center of the plate material 30 with barbs, a base material 10 with stable mechanical properties such as durability can be obtained.

[0045] In this state, by passing the wire 2 and the plate material 30 with barbs through an assembly molding machine, both edges 31 of the plate material 30 with barbs are processed to wrap and fix the wire 2 (Fig. 2(c)). By this processing, the base material 10 of the barbed iron wire 1 is formed. Also, in the state where the wire 2 is wrapped by the plate material 30 with barbs, it is preferable that the distance between the opposing both edges 31 of the plate material 30 with barbs is smaller than the wire diameter of the wire 2. In other words, in the base material 10, it is preferable that the wire 2 is exposed to the outside from the plate material 30 with barbs (the wire 2 is exposed in the longitudinal direction). By configuring in this way, the mechanical properties such as durability are more stable than those of the base material 10 in which the wire 2 is completely covered by the plate material 30 with barbs. Also, when wrapping the wire 2 with the plate material 30 with barbs, it is preferable that the barbs 3 provided symmetrically in the radial direction of the wire 2 wrap around the wire 2 by about 200° to 340°. Thereby, the barbs 3 can be formed on the same plane in the radial direction of the wire 2.

[0046] The base material 10 formed in this way is wound around the wire 2 in a spiral shape using a bobbin machine, stretched and formed into a cylindrical shape, and cut so as to have the same length and diameter as the barbed iron wire 1 as the product. That is, in this embodiment, the base material 10 prepared in the first step has the same outer shape as the barbed iron wire 1 as the product, and the base material 10 is not cut in the subsequent steps.

[0047] (Second step) The second step is a step of forming a plating layer containing zinc on the surface of the base material 10. For the formation of the plating layer, plating processes such as hot-dip plating and electroplating are used. In the hot-dip plating process, first, the base material 10 is immersed in molten zinc or a zinc alloy. Then, it is pulled out and the base material 10 is left at room temperature to form a plating layer on the surface of the base material 10. In the electroplating process, first, the base material 10 is put into a plating solution of zinc or a zinc alloy. Then, a direct current is passed through the plating solution to deposit a plating layer on the surface of the base material 10.

[0048] In the hot-dip plating process, the adhesion amount of the plating material to the surface of the base material 10 is 400 g / m 2 or more, and the thickness of the plating layer becomes 56 μm or more. In the electroplating process, the adhesion amount of the plating material to the surface of the base material 10 is about 120 - 200 g / m 2 or so, and the thickness of the plating layer becomes about 15 - 30 μm. Therefore, the hot-dip plating process or the electroplating process is selected so that a plating layer of a desired thickness is obtained, and a plating layer is formed on the surface of the base material 10. By using these plating processes, a plating layer with a uniform film thickness can be formed on any of the sheet material 30 with barbs, the barbs 3, and the exposed wire 2.

[0049] (Third step) The third step is a step of forming a trivalent chromate layer containing trivalent chromium on the plating layer of the base material 10 to obtain the barbed iron wire 1. For the formation of the trivalent chromate layer, a trivalent chromate treatment is used. The trivalent chromate treatment is a chemical conversion treatment in which the base material 10 with the plating layer formed is immersed in the above-mentioned trivalent chromate treatment solution, and zinc on the surface of the plating layer, various metals in the trivalent chromate treatment solution, a complexing agent, etc. undergo a chemical reaction to form a trivalent chromate film (layer) on the surface of the plating layer.

[0050] In this embodiment, the process of forming the trivalent chromate layer includes a process of adjusting a trivalent chromate treatment solution containing trivalent chromium (hereinafter, also referred to as "treatment solution adjustment process"), a process of immersing the base material 10 having the plating layer formed thereon in the trivalent chromate treatment solution to attach the trivalent chromate treatment solution onto the plating layer (hereinafter, also referred to as "attachment process"), and a process of drying the trivalent chromate treatment solution to form the trivalent chromate layer (hereinafter, also referred to as "drying process"). Hereinafter, each process will be described.

[0051] <Treatment solution adjustment process> In the treatment solution adjustment process, the above-described trivalent chromate treatment solution is adjusted. For the adjustment of the trivalent chromate treatment solution, various known stirrers such as a vortex mixer and a homogenizer can be used. Specifically, a predetermined amount of a trivalent chromium compound, a metal compound other than trivalent chromium, a complexing agent, and other additives used as necessary are added into water (for example, deionized water), and the compounds are uniformly mixed by various stirrers, whereby a trivalent chromate treatment solution can be obtained. The treatment solution adjustment process is preferably carried out at about 20 to 40°C, and more preferably at about 20 to 30°C, from the viewpoint of uniformly mixing each compound and preventing the compounds from reacting with each other before the trivalent chromate treatment. The trivalent chromate treatment solution adjusted in this process is put into a treatment tank for performing the trivalent chromate treatment.

[0052] <Attachment process> In the attachment process, the base material 10 having the plating layer formed thereon is immersed in the trivalent chromate treatment solution to attach the trivalent chromate treatment solution onto the plating layer. As a result, on the surface of the plating layer, zinc of the plating layer reacts with various metals and the complexing agent of the trivalent chromate treatment solution, and chelates of various metals are formed by the action of the complexing agent. Therefore, the formed film becomes dense, and furthermore, its thickness can be made sufficiently thick. The adhesion process is preferably carried out at a temperature of the treatment tank (temperature of the trivalent chromate treatment solution) of about 20 to 60 °C, more preferably about 20 to 50 °C. If the temperature of the treatment tank is within the above range, the chemical reaction on the surface of the plating layer will continue longer, and a trivalent chromate layer having a film thickness of 1.5 μm or more can be easily formed.

[0053] Also, the time for immersing the plating layer in the trivalent chromate treatment solution (immersion time) can be adjusted according to the composition of the trivalent chromate treatment solution and the target film thickness of the trivalent chromate layer. Specifically, the immersion time is preferably about 30 to 180 seconds, more preferably about 40 to 150 seconds, and even more preferably about 45 to 120 seconds. If the immersion time is within the above range, a trivalent chromate layer with a thicker film thickness of 1.5 μm or more can be more reliably formed. Also, in the adhesion process, the pH of the trivalent chromate treatment solution may vary due to the chemical reaction between the plating layer and the trivalent chromate treatment solution. The pH of the trivalent chromate treatment solution during the adhesion process is preferably about 0.5 to 6, more preferably about 1 to 4. If the pH of the trivalent chromate treatment solution during the adhesion process is within the above range, the chemical reaction on the surface of the plating layer will continue longer, and a trivalent chromate layer having a film thickness of 1.5 μm or more can be easily formed. Also, when the pH of the trivalent chromate treatment solution is outside the above range during the adhesion process, an appropriate acid selected from sulfuric acid, nitric acid, and hydrochloric acid and a base such as sodium hydroxide may be added to the treatment tank to adjust the pH.

[0054] Also, the adhesion amount of the trivalent chromate treatment solution adhered to the plating layer of the base material 10 is preferably 15 g / m 2 or more. Thereby, the thickness of the finally formed trivalent chromate layer becomes 1.5 μm or more.

[0055] <Drying Process> In the drying process, the trivalent chromate treatment liquid on the plating layer is dried to form a trivalent chromate layer. Specifically, by heating, volatile components such as water are removed from the trivalent chromate treatment liquid adhering to the plating layer to form a trivalent chromate layer. The drying temperature (heating temperature) is selected according to the type of the trivalent chromate treatment liquid. As an example, the drying temperature is preferably about 50 to 100 °C, more preferably about 60 to 80 °C. The drying time is adjusted according to the drying temperature, but as an example, it can be about 3 to 15 minutes. By using the above trivalent chromate treatment, a trivalent chromate layer with a uniform film thickness can be formed on the plating layer with a uniform film thickness on any of the sheet material 30 with barbs, the barbs 3, and the exposed wire 2.

[0056] Through the above steps, the barbed iron wire 1 is obtained. Note that after the second step, or after the third step, or after each of the second and third steps, various degreasing treatments, water washing treatments, and foreign matter removal treatments can be performed as necessary. As described above, the barbed iron wire and the method for manufacturing the barbed iron wire of the present invention have been described based on the illustrated embodiments. However, the present invention is not limited thereto, and each component can be replaced with any component that can exhibit the same function, or any component can be added.

Example

[0057] Next, specific examples of the present invention will be described. 1. Manufacture of barbed iron wire (Example) <The first step> As a long sheet material for forming barbs, a sheet material with a width of 18 mm and a thickness of 0.5 mm was prepared. By pressing this sheet material using a press cutting machine, the portions other than the portions that become barbs on both edge sides of the sheet material were cut. Then, the portions that become barbs were subjected to cutting on the sheet material so that the blade was 10 mm and the interval between the blades was 25 mm. Thereby, a sheet material with barbs as shown in Fig. 2(a) was obtained. The obtained sheet material with barbs was wound around a tape recoiler.

[0058] Next, a wire with a wire diameter of 2.5 mm wound in a coil was prepared together with the sheet material with barbs wound around the tape coiler. While pulling out the sheet material with barbs from the tape coiler, the wire was also pulled out at the same time, and as shown in Fig. 2(b), it was placed so that the wire was located at the center of the sheet material with barbs. In this state, by passing the wire and the sheet material with barbs through an assembly molding machine, both edges of the sheet material with barbs were processed to wrap and fix the wire (Fig. 2(c)). By this processing, the base material of the barbed wire was formed. The base material thus formed was wound in a spiral shape using a bobbin machine, stretched, formed into a cylindrical shape, and cut to have the same length and diameter as the barbed wire that becomes the product.

[0059] <The second step> Next, the base material was immersed in a tank filled with molten zinc and heated to 450°C. Then, by pulling it out and leaving the base material at room temperature, a plating layer with a thickness of 70 μm was formed on the surface of the base material. After that, the base material with the plating layer formed was immersed in an aqueous solution at room temperature of 4 ml / L of nitric acid and 0.2 ml / L of hydrochloric acid for 15 seconds, and then washed with water.

[0060] <The third step> Next, prior to forming a trivalent chromate layer containing trivalent chromium on the plating layer, a trivalent chromate treatment solution with the following composition was prepared. · Chromium sulfate: 3 g / L · Chromium nitrate: 3 g / L · Sodium nitrate: 15 g / L · Cobalt nitrate: 3 g / L · Ammonium vanadate: 2 g / L · Nickel chloride: 1 g / L · Citric acid: 8 g / L · Deionized water: 1 L The trivalent chromate treatment solution was obtained by stirring and mixing the above-mentioned respective materials in a homogenizer. The thus-prepared trivalent chromate treatment solution was put into a treatment tank for performing the trivalent chromate treatment.

[0061] Next, the base material with the plating layer formed thereon was immersed in the treatment tank set at a temperature of 35°C for 50 seconds. At this time, the pH of the trivalent chromate treatment solution in the treatment tank was 2.1. Thereafter, the base material was pulled up from the treatment tank and dried at 70°C for 5 minutes, whereby a trivalent chromate layer with a thickness of 2.0 μm was formed on the surface of the plating film, and a barbed iron wire was obtained.

[0062] 2. Salt spray test evaluation The barbed iron wire obtained in the above example was put into a test tank. With respect to this barbed iron wire, while maintaining the temperature in the test tank at 35°C in accordance with the method conforming to the KS standard: KS D 9502, a 5% NaOH aqueous solution was continuously sprayed onto the barbed iron wire with a spraying machine for 1000 hours. As a result, it was confirmed that no red rust occurred in the barbed iron wire of the example after 1000 hours had elapsed.

Claims

1. A barbed wire used for an intrusion prevention fence, a base material having a wire made of iron or steel and a plurality of barbs attached to the wire, a zinc-containing plating layer formed on the surface of the base material, and a trivalent chromate layer containing trivalent chromium formed on the plating layer, and the barbed wire is characterized in that the thickness of the trivalent chromate layer is 1.5 μm or more.

2. The barbed wire according to claim 1, wherein the thickness of the plating layer is 20 μm or more and 80 μm or less.

3. The barbed wire according to claim 1 or 2, wherein when the thickness of the trivalent chromate layer is T1 [μm] and the thickness of the plating layer is T2 [μm], the relationship of 0.019 ≦ T1 / T2 ≦ 0.15 is satisfied.

4. The barbed wire according to claim 1 or 2, wherein the trivalent chromate layer contains the trivalent chromium, a metal other than the trivalent chromium, and a structure derived from a complexing agent.

5. The barbed wire according to claim 4, wherein the metal contains two or more selected from alkali metals, alkaline earth metals, cobalt, titanium, zirconium, vanadium, molybdenum, tungsten, manganese, iron, nickel, gold, silver, copper, tin, and aluminum.

6. The barbed wire according to claim 4, wherein the complexing agent contains one or more selected from dicarboxylic acids, tricarboxylic acids, oxyacids, hydroxyl group-containing dicarboxylic acids, hydroxyl group-containing tricarboxylic acids, and salts thereof.

7. A method for manufacturing a barbed wire used for an intrusion prevention fence, comprising a step of preparing a base material by attaching a plurality of barbs to a wire made of iron or steel, a step of forming a zinc-containing plating layer on the surface of the base material, and a step of forming a trivalent chromate layer containing trivalent chromium on the plating layer to obtain the barbed wire, and the method for manufacturing a barbed wire is characterized in that the thickness of the trivalent chromate layer is 1.5 μm or more.

8. The step of forming the trivalent chromate layer includes a step of adjusting a trivalent chromate treatment solution containing the trivalent chromium, a step of immersing the base material having the plating layer formed thereon in the trivalent chromate treatment solution to attach the trivalent chromate treatment solution to the plating layer, and a step of drying the trivalent chromate treatment solution to form the trivalent chromate layer, and the step of attaching the trivalent chromate treatment solution is carried out at 20 to 60°C. The method for manufacturing a barbed wire according to claim 7, wherein the step of forming the trivalent chromate layer is carried out at 50 to 100°C.

9. The method for manufacturing a barbed wire according to claim 7, wherein the step of preparing the base material includes a step of preparing a long plate material on which the barbs are formed, and a step of wrapping and fixing the wire with the plate material.

10. The base material is formed in a cylindrical shape in which the wire is wound spirally. The method for manufacturing a barbed wire according to any one of claims 7 to 9, wherein the step of forming the plating layer and the step of forming the trivalent chromate layer are carried out on the cylindrical base material.

11. The barbed wire is wound and formed in a cylindrical shape. The length of the cylindrical base material is the same as the length of the cylindrical barbed wire. The method for manufacturing a barbed wire according to claim 10, wherein the diameter of the cylindrical base material is the same as the diameter of the cylindrical barbed wire.

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