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 powder paint layer formed on the plating layer, the thickness of the powder paint layer being 100 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 for preventing an intruder from entering a facility and a method for manufacturing the same.

Background Art

[0002] Conventionally, in facilities (such as military facilities, nuclear power plants, oil refineries, etc.) where it is necessary to restrict entry by unauthorized persons, 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 on 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 easy to reflect light, so it is easy to be noticed by intruders at night and the intrusion prevention effect is insufficient.

[0004] In addition, barbed iron wire using titanium or stainless steel with a higher corrosion prevention effect as a core material is also used. However, since barbed iron 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 iron wire made of titanium has lower rigidity than barbed iron wire made of iron and is easily deformed, so a sufficient intrusion prevention effect cannot be obtained. Further, barbed iron wire made of stainless steel is more likely to reflect light than barbed iron wire made of iron. Moreover, since it is difficult for coating agents such as dulling agents to adhere to barbed iron wire made of stainless steel, it is difficult to suppress light reflection. Therefore, barbed iron wire made of stainless steel is easily noticed by intruders at night and has an insufficient intrusion prevention effect.

[0005] Also, from the viewpoint of improving corrosion resistance, barbed iron wire using a resin material instead of a metal material as a constituent material of the core material or the barbs is known (for example, Patent Document 1). However, barbed iron 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 iron 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 iron 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 iron wire that can easily manufacture such barbed iron wire.

Means for Solving the Problems

[0008] Such an object is achieved by the following (1) to (13) of the present invention. (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 powder coating layer formed on the plating layer, and the barbed wire is characterized in that the thickness of the powder coating layer is 100 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, which satisfies the relationship of 1.25 ≦ T1 / T2 ≦ 8, where T1 [μm] is the thickness of the powder coating layer and T2 [μm] is the thickness of the plating layer.

[0011] (4) The barbed wire according to (1) or (2) above, wherein the powder coating layer contains inorganic particles and a thermosetting resin.

[0012] (5) The barbed wire according to (4) above, wherein the inorganic particles contain silica, barium sulfate, and calcium carbonate.

[0013] (6) The barbed wire according to (4) above, wherein the thermosetting resin contains a thermosetting polyester resin.

[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 zinc-containing plating layer on the surface of the base material, and a step of forming a powder coating layer 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 powder coating layer is 100 μm or more.

[0015] (8) The step of forming the powder coating layer includes the step of adjusting the powder coating, the step of spraying the powder coating onto the plating layer to adhere the powder coating onto the plating layer, and the step of heating the powder coating to form the powder coating layer, and is the method for manufacturing barbed wire according to the above (7).

[0016] (9) The step of adhering the powder coating includes the step of spraying the powder coating onto the plating layer using an electrostatic powder sprayer provided with a discharge port and a corona electrode at the discharge port, and the step of generating an electric field between the electrostatic powder sprayer and the plating layer by applying a voltage to the corona electrode of the electrostatic powder sprayer to charge the powder coating, and is the method for manufacturing barbed wire according to the above (8).

[0017] (10) The step of forming the powder coating layer is carried out at 200 to 285 °C, and is the method for manufacturing barbed wire according to the above (9).

[0018] (11) The step of preparing the base material includes the step of preparing a long plate material on which the barbs are formed, and the step of wrapping and fixing the wire with the plate material, and is the method for manufacturing barbed wire according to the above (7).

[0019] (12) The base material is formed in a cylindrical shape in which the wire is wound in a spiral shape, the step of forming the plating layer and the step of forming the powder coating layer are carried out on the cylindrical base material, and is the method for manufacturing barbed wire according to any one of the above (7) to (11).

[0020] (13) 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, and is the method for manufacturing barbed wire according to the above (12).

Advantages of the Invention

[0021] According to the present invention, in addition to a plating layer containing zinc on the surface of the barbed wire, a powder coating layer with a thickness of 100 μm or more is formed, so that a barbed wire that is less likely to rust and has suppressed light reflection can be obtained. Such barbed wire is excellent in corrosion resistance, is less conspicuous at night, and maintains the intrusion prevention effect over a long period of time.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0023] 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).

[0024] The barbed wire 1 of this embodiment has a base material, a plating layer formed on the surface of the base material, and a powder coating 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 perpendicular 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 formed into 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.

[0025] (Base material) The base material of the barbed wire 1 has a wire 2 and a plurality of barbed bodies 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).

[0026] 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, it is possible to obtain an intrusion prevention fence 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.

[0027] 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.

[0028] The barbed body 3 is a laser blade (razor blade) made of iron or steel, barbed wire having a sharp tip, etc. In particular, by using a laser blade as the barbed body 3, a psychological deterrent force that makes an intruder hesitate to enter the facility works greatly, 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.

[0029] As shown in FIG. 1(b), the barbed body (laser blade) 3 is provided symmetrically with respect to the wire 2 in the radial direction of the wire 2. Further, the barbed body 3 is provided at a predetermined interval 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.

[0030] 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 longitudinal length of the barbed body 3 is within the above range, the intrusion prevention effect of the barbed wire 1 can be further enhanced. Further, the predetermined interval (pitch) of the barbed body 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 body 3 is within the above range, the intrusion prevention effect of the barbed wire 1 can be further enhanced.

[0031] (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 barbs 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, it is preferable that the plating layer is 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.

[0032] 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 adhere firmly to the surface of the base material 10 and can improve 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 powder coating layer for a long period of time. As a result, the barbed iron 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 iron 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.

[0033] (Powder coating layer) A powder coating layer formed by a powder coating is formed on the plating layer. As a method for forming such a powder coating layer, a powder coating process is used. In the powder coating process, since a solvent-free powder coating is used, there are no environmental problems and risks of disasters caused by solvents as in the case of a coating method using a solvent-containing paint. Also, since it is possible to recover and reuse the paint that has been sprayed excessively during the process, there is an advantage that the loss of paint can be made very small. Specific powder coating processes will be described later.

[0034] The powder coating layer formed using powder coating treatment is formed thicker than the plating layer formed by plating treatment. Specifically, in the present embodiment, the thickness of the powder coating layer is set to 100 μm or more. Generally, the film thickness of the plating layer formed by plating treatment is at most about several tens of microns, and a film thickness of 100 μm or more could not be obtained. On the other hand, in the present invention, by forming a powder coating layer using a powder coating 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, there is also an effect that the gloss derived from the base material 10 is suppressed as the film of the base material 10 becomes thicker. That is, since a plating layer containing zinc and a powder coating layer with a thickness of 100 μm or more are formed on the surface of the barbed wire 1, the barbed wire 1 is excellent in corrosion resistance, is less conspicuous at night, and the intrusion prevention effect is maintained over a long period.

[0035] In the present embodiment, the powder coating for forming the powder coating layer contains inorganic particles, a thermosetting resin, and a curing agent for curing the thermosetting resin. As the inorganic particles, particles containing silica (SiO2), barium sulfate (BaSO4), calcium carbonate (CaCO3), titanium oxide (TiO2), aluminum oxide (Al2O3), copper oxide (CuO), zinc oxide (ZnO), tin oxide (SnO2), cerium oxide (CeO2), iron oxide (Fe2O3), magnesium oxide (MgO), barium oxide (BaO), calcium oxide (CaO), potassium oxide (K2O), sodium oxide (Na2O), zirconium oxide (ZrO2), magnesium carbonate (MgCO3), magnesium sulfate (MgSO4), etc. can be used. Among these, it is preferable that the inorganic particles contain silica particles, barium sulfate particles, and calcium carbonate particles.

[0036] The silica particles may be particles mainly composed of SiO2, and may be crystalline or amorphous. Also, the silica particles may be particles obtained by pulverizing quartz, or may be particles produced from silicon compounds such as water glass and alkoxysilane as raw materials. In particular, the silica particles obtained by pulverizing quartz have a wider particle size distribution than the silica particles obtained by a synthetic method, and thus exhibit a matting effect that suppresses the gloss of the base material 10. Therefore, by using the silica particles obtained by pulverizing quartz, the barbed wire 1 can be made less conspicuous. Also, when silica particles are contained in the powder coating, the fluidity of the powder coating is improved. As a result, even when the powder coating layer is formed relatively thick, the thickness of the powder coating layer can be made more uniform, and the corrosion resistance of the barbed wire 1 can be further improved.

[0037] Also, the average particle size of the silica particles is preferably about 5 nm or more and 120 nm or less, and more preferably about 10 nm or more and 100 nm or less. Also, from the viewpoint of improving the fluidity of the powder coating, the content of the silica particles is preferably about 0.1% by mass or more and 5.0% by mass or less, and more preferably about 0.1% by mass or more and 3.0% by mass or less with respect to the total mass of the powder coating. Also, the silica particles may be hydrophobically treated with a silane coupling agent or the like for the purpose of improving the affinity with the thermosetting resin.

[0038] The barium sulfate particles may be particles mainly composed of winnowed barium sulfate (barite powder), which is a pulverized product of barite minerals called natural barite, or may be particles mainly composed of precipitated barium sulfate produced by a chemical reaction. Such barium sulfate particles have a function of effectively matting. When barium sulfate particles are contained in the powder coating, the gloss derived from the base material 10 and the gloss of the powder coating layer itself can be suppressed, and the barbed wire 1 can be made less conspicuous.

[0039] Further, the average particle size of the barium sulfate particles is preferably about 10 nm or more and 100 nm or less, more preferably about 15 nm or more and 90 nm or less. Further, from the viewpoint of making the barbed wire 1 less conspicuous, the content of the barium sulfate particles is preferably about 5% by mass or more and 25% by mass or less, more preferably about 10% by mass or more and 20% by mass or less with respect to the total mass of the powder coating.

[0040] The calcium carbonate particles may be particles composed of light calcium carbonate (precipitated calcium carbonate) chemically produced from limestone as a raw material, or may be particles composed of heavy calcium carbonate produced by pulverizing and classifying limestone. Such calcium carbonate particles have a function of effectively dulling the gloss. By including calcium carbonate particles in the powder coating, the gloss derived from the base material 10 and the gloss of the powder coating layer itself can be suppressed, and the barbed wire 1 can be made less conspicuous. In addition, since the calcium carbonate (heavy calcium carbonate) particles obtained by pulverizing limestone have a wider particle size distribution than the particles of light calcium carbonate produced chemically, the gloss of the base material 10 can be suppressed more effectively. Therefore, from the viewpoint of making the barbed wire 1 less conspicuous, it is preferable to use heavy calcium carbonate particles.

[0041] Further, the average particle size of the calcium carbonate particles is preferably about 10 nm or more and 100 nm or less, more preferably about 15 nm or more and 90 nm or less. Further, from the viewpoint of making the barbed wire 1 less conspicuous, the content of the calcium carbonate particles is preferably about 5% by mass or more and 25% by mass or less, more preferably about 10% by mass or more and 20% by mass or less with respect to the total mass of the powder coating.

[0042] Further, the powder coating contains a thermosetting resin. When the powder coating contains a thermosetting resin, the powder coating is applied onto the plating layer of the base material 10 by a method such as the electrostatic powder coating method and heated, whereby the thermosetting resin is cured to form a powder coating film. As the thermosetting resin, various resins such as thermosetting polyester resins, thermosetting (meth)acrylic resins, thermosetting fluorine-based resins (e.g., fluoroethylene-vinyl ether (FEVE) copolymer resins, etc.), epoxy resins, and epoxy-polyester resins can be used. Among these thermosetting resins, from the viewpoint of particularly excellent corrosion resistance, weather resistance, and water resistance, it is preferable to use a thermosetting polyester resin.

[0043] The content of the thermosetting resin is preferably about 25% by mass or more and 90% by mass or less, more preferably about 30% by mass or more and 85% by mass or less, and even more preferably about 35% by mass or more and 80% by mass or less, based on the total mass of the powder coating. If the content of the thermosetting resin is within the above range, the powder coating layer can be firmly adhered to the plating layer, and the durability (corrosion resistance, weather resistance, etc.) of the powder coating layer can be further enhanced.

[0044] Further, the powder coating contains a curing agent according to the type of the thermosetting reactive group of the thermosetting resin. The curing agent is not particularly limited. However, when a thermosetting polyester resin is used as the thermosetting resin, for example, triglycidyl isocyanurate, β-hydroxyalkylamide, various epoxy resins (e.g., polyglycidyl ether of bisphenol A, etc.), epoxy group-containing acrylic resins (e.g., glycidyl group-containing acrylic resins, etc.), polyglycidyl ethers of various polyhydric alcohols (e.g., 1,6-hexanediol, trimethylolpropane, trimethylolethane, etc.), polyglycidyl esters of various polycarboxylic acids (e.g., phthalic acid, terephthalic acid, isophthalic acid, hexahydrophthalic acid, methylhexahydrophthalic acid, trimellitic acid, pyromellitic acid, etc.), various alicyclic epoxy group-containing compounds (e.g., bis(3,4-epoxycyclohexyl)methyl adipate, etc.) can be used. The content of the curing agent is preferably about 0.5% by mass or more and 15% by mass or less, and more preferably about 1% by mass or more and 10% by mass or less, based on the total mass of the powder coating.

[0045] In addition, the powder coating may contain a thermoplastic resin. Examples of such thermoplastic resins include vinyl resins such as polyethylene resin and polyvinyl chloride resin, and various thermoplastic resins such as polyamide resin and fluororesin. Among these thermoplastic resins, it is preferable to use polyethylene resin. When the powder coating contains polyethylene resin, appropriate flexibility is imparted to the powder coating layer, and the occurrence of cracks and the like in the powder coating layer can be prevented. In addition, since polyethylene has almost no water absorption, it does not deteriorate the weather resistance and water resistance of the powder coating layer. Therefore, by using a powder coating containing polyethylene resin, the barbed wire 1 with more excellent durability can be obtained.

[0046] The content of the thermoplastic resin is preferably about 0.5% by mass or more and 15% by mass or less, more preferably about 1% by mass or more and 10% by mass or less, based on the total mass of the powder coating. If the content of the thermoplastic resin is within the above range, the barbed wire 1 with more excellent durability can be obtained.

[0047] In addition to the above components, the powder coating may contain, as other components, additives such as a curing accelerator or catalyst, a surface conditioner, a plasticizer, an ultraviolet absorber, an antioxidant, a pigment dispersant, and an impact resistance improver.

[0048] The above-mentioned powder coating can be obtained, for example, as follows. That is, the above-mentioned inorganic particles, thermosetting resin, curing agent, and other additives used as necessary are uniformly mixed by a mixer such as a Henschel mixer, a super mixer, a ball mill, or a Banbury mixer. Next, the obtained mixture is melt-kneaded by a kneader such as an extruder or a hot roll in a temperature range where the curing reaction of the thermosetting resin does not occur, and other components are uniformly dispersed in the melted thermosetting resin. Then, the obtained mixture is formed into pellets. The obtained pellets are pulverized by an impact type pulverizer such as a hammer mill or an air flow pulverizer such as a jet mill, and then classified to obtain the above-mentioned powder coating.

[0049] 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 powder coating layer is preferably about 100 μm or more and about 150 μm or less, and more preferably about 100 μm or more and about 120 μm or less.

[0050] Further, when the thickness of the powder coating layer is T1 [μm] and the thickness of the plating layer is T2 [μm], it is preferable to satisfy the relationship of 1.25 ≤ T1 / T2 ≤ 8, more preferably to satisfy the relationship of 1.5 ≤ T1 / T2 ≤ 6, and even more preferably to satisfy the relationship of 2 ≤ T1 / T2 ≤ 4. By satisfying the above conditions for the thicknesses of the powder coating layer and the plating layer, the durability of the entire plating layer and powder coating layer becomes higher, and the product life of the barbed wire 1 can be made longer.

[0051] Also, as described above, the barbed wire 1 is formed in a cylindrical shape by being wound in a spiral shape. The diameter of the wound wire in the state where the barbed 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 of the wound wire in the state of being stretched in a direction orthogonal 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 wire 1 with the diameter of the wound wire being 600 mm and the length of the wound wire in the stretched state being 13 m is about 11.5 kg. Also, the weight of the barbed wire 1 with the diameter of the wound wire being 1000 mm and the length of the wound wire in the stretched state being 13 m is about 19 kg.

[0052] 2. Method for manufacturing barbed wire Next, the manufacturing method of the barbed wire 1 described above will be explained. The manufacturing method of the barbed wire 1 includes a step of preparing a base material 10 by attaching a plurality of barbs 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 powder coating layer on the plating layer to obtain the barbed wire 1 (the third step). Hereinafter, each step will be described in detail.

[0053] (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 on 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 to be wrapped with the plate material with barbs from the state of FIG. 2(b).

[0054] First, a long plate material for forming the barbs 3 is prepared. Next, the plate material is press-processed using a press cutting machine to cut portions other than the portions that will become the barbs 3 on both edge sides of the plate material. Thereafter, the plate material is subjected to cutting processing so that the portions that will become the barbs 3 conform to the specifications of a predetermined laser blade, thereby obtaining a plate material with barbs 30 as shown in FIG. 2(a). 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 formed in this way is wound around a tape recoiler and stored in preparation for assembly with the wire 2.

[0055] Next, the coiled wire 2 and the plate material with barbs 30 wound around the tape recoiler are prepared. While pulling out the plate material with barbs 30 from the tape recoiler, 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 located in the center of the plate material with barbs 30. Incidentally, 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.

[0056] 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 a part of the wire 2 is exposed to the outside from the plate material 30 with barbs. By configuring in this way, the mechanical properties such as durability are more stable than the base material 10 in which the wire 2 is completely covered by the plate material 30 with barbs.

[0057] The base material 10 formed in this way is wound around the wire 2 in a spiral shape using a bobbin machine, stretched, formed into a cylindrical shape, and cut so as to have the same length and diameter as the barbed iron wire 1 that becomes 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 that becomes the product, and the base material 10 is not cut in the subsequent steps.

[0058] (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 treatments such as hot-dip plating treatment and electroplating treatment are used. In the hot-dip plating process, first, the base material 10 is immersed in molten zinc or a zinc alloy. Then, the base material 10 is pulled out and 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.

[0059] In the hot-dip plating process, the amount of plating material adhered to the surface of the base material 10 is 400 g / m 2 or more, and the thickness of the plating layer is 56 μm or more. In the electroplating process, the amount of plating material adhered to the surface of the base material 10 is about 120 - 200 g / m 2 or so, and the thickness of the plating layer is about 15 - 30 μm. Therefore, the hot-dip plating process or the electroplating process is selected to form a plating layer on the surface of the base material 10 so as to obtain a plating layer with a desired thickness.

[0060] (The third step) The third step is a step of forming a powder coating layer made of a powder coating on the plating layer of the base material 10 to obtain the barbed wire 1. For the formation of the powder coating layer, powder coating processes such as electrostatic powder coating and fluidized dip coating are used. In the electrostatic powder coating process, the charged powder coating is ejected toward the base material 10. Thereby, the powder coating is electrostatically adhered onto the plating layer of the base material 10 to form a powder coating layer. In the fluidized dip coating process, first, a tank filled with a powder coating that is lifted and fluidized by compressed air and the heated base material 10 are prepared. Then, the heated base material 10 is put into the tank filled with the powder coating. Thereby, a powder coating layer is formed on the plating layer of the base material 10. Among these processes, it is preferable to use the electrostatic powder coating process that can suppress the usage amount of the powder coating.

[0061] The electrostatic powder coating process includes a process of spraying the charged powder paint onto the plating layer to adhere (coat) the powder paint onto the plating layer (hereinafter also referred to as the "coating process"), and a process of heating the powder paint on the plating layer to form a powder paint layer (hereinafter also referred to as the "baking process"). Hereinafter, each process will be described.

[0062] <Coating Process> In the coating process, the charged powder paint is sprayed to electrostatically adhere (coat) the powder paint onto the plating layer to form an adhesion layer. Specifically, in the coating process, for example, in a state where an electrostatic field is formed between the discharge port of the electrostatic powder sprayer and the plating layer (conductive surface) of the base material 10, the charged powder paint is sprayed from the discharge port of the electrostatic powder sprayer, and the powder paint is electrostatically adhered to the plating layer of the base material 10 to coat the adhesion layer. For example, when a voltage is applied with the plating layer of the grounded base material 10 as the anode and the electrostatic powder sprayer as the cathode, an electrostatic field (electrostatic field) is formed between the two electrodes. In this state, when the powder is sprayed, the powder becomes charged. The charged powder paint flies from the discharge port to the plating layer and is electrostatically adhered to the plating layer. Thereby, a film of the powder paint is formed.

[0063] In this way, in the electrostatic powder coating process, the powder paint and the plating layer which is the object to be coated are charged with opposite polarities. Therefore, even if the shape of the base material 10 is complicated, the entire base material 10 can be covered with a film of the powder paint through the plating layer. For example, the root part of the barbed body 3 is a part where coating unevenness is likely to occur in general coating processes, but by using the electrostatic powder coating process, coating unevenness does not occur even in such fine parts. Also, in the process of forming the film of the powder paint, the polarity becomes weaker as the film thickness increases. By utilizing this property, the powder paint is more likely to adhere to the part with a thinner film thickness. As a result, the film thickness of the entire powder paint layer becomes uniform. Due to the above-described effects, the obtained barbed wire 1 has the characteristic that its entirety is excellent in corrosion resistance.

[0064] As the electrostatic powder spraying machine, for example, well-known electrostatic powder spraying machines such as a corona gun (a spraying machine that sprays a powder coating charged by corona discharge) and a tribo gun (a spraying machine that sprays a powder coating charged by friction) are used. Among these, it is preferable to use a corona gun in that it can be used regardless of the material of the paint.

[0065] The corona gun is provided with a corona electrode at the discharge port. By applying a voltage from an external power source to this corona electrode, an electrostatic field is formed between the corona gun (the discharge port of the corona gun) and the plating layer. At the same time, corona discharge occurs from the corona electrode. The powder coating is charged by the ions generated by this corona discharge.

[0066] The voltage applied to this corona electrode can be appropriately changed in order to obtain the target film thickness of the powder coating layer, but it is preferably about 30 to 90 kV, and more preferably about 45 to 85 kV. If the voltage applied to the corona electrode is within the above range, coating unevenness does not occur even in fine places such as the root part of the barbed body 3. As a result, a powder coating layer having a uniform film thickness of 100 μm or more can be formed more stably and in a short time.

[0067] Also, the adhesion amount of the powder coating adhered to the plating layer of the base material 10 is preferably 100 g / m 2 or more. Thereby, the thickness of the finally formed powder coating layer becomes 100 μm or more.

[0068] <Baking process> In the baking process, the powder coating on the plating layer is heated to form a powder coating layer. Specifically, by heating, the particles constituting the film of the powder coating are melted and cured to form a powder coating film. The heating temperature (baking temperature) is selected according to the type of powder coating. As an example, the heating temperature is preferably about 200 to 285 °C, more preferably about 220 to 280 °C, and even more preferably about 240 to 270 °C. The heating time (baking time) is adjusted according to the heating temperature. As an example, it can be about 10 to 30 minutes.

[0069] Through the above steps, the barbed 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 and foreign matter removal treatments can be performed as necessary. As described above, the barbed wire and the manufacturing method of the barbed 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 components of any configuration can be added.

Example

[0070] Next, specific examples of the present invention will be described. 1. Manufacture of barbed wire (Example) <The first step> As a long plate for forming barbs, a plate with a width of 18 mm and a thickness of 0.5 mm was prepared. By pressing this plate using a press cutter, the parts other than the parts that become barbs on both edges of the plate were cut. Then, the parts that become barbs were machined on the plate so that the blade was 10 mm and the interval between the blades was 25 mm. Thereby, a plate with barbs as shown in Fig. 2(a) was obtained. The obtained plate with barbs was wound around a tape recoiler.

[0071] Next, together with the plate with barbs wound around the tape recoiler, a wire with a wire diameter of 2.5 mm wound in a coil was prepared. While pulling out the plate with barbs from the tape recoiler, 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 plate with barbs. In this state, the wire and the plate material with barbs are passed through an assembly molding machine, and both edges of the plate material with barbs are processed to wrap and fix the wire (Figure 2(c)). Through 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.

[0072] <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.

[0073] <The third step> Next, prior to forming a powder coating layer made of a powder coating on the plating layer, a powder coating with the following composition was prepared. · Quartz (average particle size: 20 nm): 1% by mass · Polyethylene: 5% by mass · Barium sulfate (average particle size: 50 nm): 15% by mass · Limestone (average particle size: 50 nm): 15% by mass · Triglycidyl isocyanurate: 2% by mass · Thermosetting polyester resin: 62% by mass The powder coating was obtained by stirring and mixing the above-mentioned respective materials in a ball mill.

[0074] Next, the base material with the plating layer formed was fixed to a dedicated jig connected to the ground for electrostatic powder coating. Next, a corona gun was prepared as an electrostatic powder injector and filled with the powder coating having the above composition. Then, a voltage of 70 kV was applied from an external power source to the corona electrode of the corona gun, and an electrostatic powder coating process was performed to discharge the powder coating from the discharge port of the corona gun onto the plating layer at 25°C for 100 minutes. As a result, a film of the powder coating was formed on the plating layer.

[0075] Next, the base material with the powder coating film formed thereon was heated at 270°C for 20 minutes to form a powder coating layer with a film thickness of 110 μm on the plating layer, obtaining barbed wire.

[0076] 2. Salt spray test evaluation The barbed wire obtained in the above example was put into a test tank. For this barbed wire, while maintaining the temperature in the test tank at 35°C, a 5% NaOH aqueous solution was continuously sprayed onto the barbed wire with an injector for 1000 hours according to the method conforming to the KS standard: KS D 9502. As a result, it was confirmed that no red rust occurred on the barbed wire of the example after 1000 hours.

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 powder coating layer formed on the plating layer, wherein the thickness of the powder coating layer is 100 μm or more. The barbed wire is characterized by this.

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 powder coating layer is T1 [μm] and the thickness of the plating layer is T2 [μm], the relationship 1.25 ≦ T1 / T2 ≦ 8 is satisfied.

4. The barbed wire according to claim 1 or 2, wherein the powder coating layer contains inorganic particles and a thermosetting resin.

5. The barbed wire according to claim 4, wherein the inorganic particles contain silica, barium sulfate, and calcium carbonate.

6. The barbed wire according to claim 4, wherein the thermosetting resin contains a thermosetting polyester resin.

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 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 powder coating layer on the plating layer to obtain the barbed wire, wherein the thickness of the powder coating layer is 100 μm or more. The method for manufacturing a barbed wire is characterized by this.

8. The step of forming the powder coating layer includes a step of adjusting the powder coating, a step of spraying the powder coating onto the plating layer to attach the powder coating to the plating layer, and a step of heating the powder coating to form the powder coating layer. The method for manufacturing a barbed wire according to claim 7.

9. The step of attaching the powder coating includes a step of spraying the powder coating onto the plating layer using an electrostatic powder sprayer having a discharge port and a corona electrode at the discharge port, and a step of generating an electric field between the electrostatic powder sprayer and the plating layer by applying a voltage to the corona electrode of the electrostatic powder sprayer to charge the powder coating. The method for manufacturing a barbed wire according to claim 8.

10. The step of forming the powder coating layer is carried out at 200 to 285°C. The method for manufacturing a barbed wire according to claim 9.

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

12. The base material is formed in a cylindrical shape in which the wire is wound in a spiral shape. The step of forming the plating layer and the step of forming the powder coating layer are performed on the cylindrical base material. The method for manufacturing barbed wire according to any one of claims 7 to 11.

13. 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 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 claim 12.

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