JP2003006593A - Package marker and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a package marker to be directly attached to a pipe at a low cost by fusing and integrating the thermally fusion-bonding sheet of polyolefin or the like as the coating and protecting material of a small-sized resonance body marker by the probe device of high sensitivity. SOLUTION: A package marker 1 is tightly sealed and packaged by the method of covering both surfaces with the coating and protecting material 3 of a thermoplastic resin or the like such as a polyethylene film and thermally fusion-bonding the coating and protecting material at the outer peripheral part 3a of a resonance body marker when coating the sheet-like resonance body marker 2 for which a coil-like resonance circuit 2b by metallic foil such as aluminum foil is formed on both surfaces of a dielectric sheet 2 and the circuits on both surfaces of the dielectric sheet 2a are connected at the end part of the circuit 2b as needed. Thus, the package marker is in the shape of a thin and flexible sheet and can be mounted adheresively to a city water pipe or a gas pipe or the like buried in the ground with an adhesive material 4 or the like and thus, the inconvenience of being detached from a target object or the like does not occur in constructions thereafter.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a gas pipe, a water pipe,
The present invention relates to a sensor for probing an embedded object embedded in a medium such as a cable tube in the ground or a wall from the surface of the medium, and in particular, a resonator marker formed by forming an LC resonant circuit that resonates with a radio wave of a specific frequency. The present invention relates to a sensor for exploring a buried object by utilizing it. The present invention also relates to a method of manufacturing a hermetically sealed package marker including a resonator marker.

[0002]

2. Description of the Related Art Conventionally, when searching a buried position such as an underground buried object using this type of resonator marker and the searching device,
A marker of a type in which a coil is wound around a magnetic material is used as a resonator marker that forms an LC resonant circuit. Such a marker is placed in advance in or directly in the vicinity of an embedded object, and a specific frequency is measured from the surface of the medium. The AC magnetic field of
The embedded object is detected by detecting the secondary magnetic field oscillated by the electromagnetic induction action of the LC resonance circuit of the resonator marker. Furthermore, in order to obtain long-term durability (airtightness, water resistance, chemical resistance, mechanical strength, etc.) of the resonator marker in the ground, a method of covering and protecting the marker by a method such as plastic injection molding is adopted. However, the marker becomes large due to the thickness and depth performance of the covering protective material, or the cost becomes high due to the case of a marker wound with a coil on a magnetic material, etc. It is used as a marker for a detection method as a spot search for a specific site.

Further, in the case of a plastic pipe such as a polyethylene (PE) pipe, a conducting wire called a locating wire is directly attached to the pipe and a magnetic field generated by applying an electric current to the pipe is investigated. However, there is a problem that if the wire is cut due to poor wire connection, earthquake or ground change, it will not be possible to search.

[0004]

By the way, in the above-described conventional resonator marker, when performing continuous exploration, when the buried object is a long body such as a gas pipe, many are arranged along the buried object. In addition to the high cost, such a resonator marker has hardness and a size larger than the pipe diameter, so it cannot be directly attached to the buried object, and it can be used by burying it in the upper part or the lower part of the pipe apart from the buried object. It was being appreciated. in this case,
There is a drawback that the original purpose is hindered because it is dug back by another contractor's construction and moved to another position or lost.

The object of the present invention is to eliminate the above-mentioned problems of the prior art, and a high-sensitivity exploration apparatus is used to protect a small resonator marker from heat such as polyolefin as a coating protection material. It is an object of the present invention to provide a package marker which can be directly attached to a pipe at a low cost by melt-integrating a fusible sheet. Another object of the present invention is to provide a manufacturing method by fusing package markers.

[0006]

In order to solve these problems, the present invention provides resonance for a dielectric sheet used as a resonance tag or a resonance label as a resonance marker formed by forming an LC resonance circuit. A circuit-formed sheet-shaped resonator marker is used, and both front and back surfaces of the resonator marker are covered with a covering protective material such as a polyolefin film, and the covering protective material is hermetically sealed by a method of heat fusion. It provides a package marker. The present invention also provides a method for producing this package marker.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a coiled resonance circuit and a capacitor portion are formed on one surface of a dielectric film (or sheet) used as a resonance marker or a resonance label as a resonance marker. A sheet-shaped marker having a capacitor section and a conductive section formed on its surface or a slightly wide coil-shaped resonance circuit also serving as a capacitor section on both surfaces of a dielectric film is used. The resonance circuit or the like provided on the dielectric film is usually formed of a metal foil such as an aluminum foil or a copper foil, but may be formed by another method such as printing or metal deposition. The thickness of the sheet-shaped resonator marker is not particularly limited, but normally, a dielectric film having a thickness of 10 μm to 1 mm is used, and the metal foil forming the resonance circuit or the like has a thickness of about 10 μm to 50 μm. Since it is used, it is preferable that the length is 2 mm or less, usually about 1 mm or less.

The dielectric film is preferably flexible so that it can be attached to a curved surface such as a gas pipe. In order to heat-bond the covering protective material inside the resonator marker, the dielectric film is preferably a heat-adhesive plastic film. Resonant circuits are usually formed on both the front and back sides of a square or rectangular sheet or film-shaped dielectric, but on one side of a metal foil by means of melt coating with an extruder (extrusion machine) or coating with a resin solution. A dielectric film layer may be formed, and the metal foil thus formed may be punched into a coil shape (resonance circuit) and then bonded to another metal foil that is similarly punched into a coil shape to form a resonator marker. In this type of resonator marker, since the dielectric film does not exist in the portion other than the coil portion, the coating protective material on the front and back of the marker can be heat-welded in the portion without the coiled metal foil in the resonator marker. . By forming the dielectric film by applying a solvent-type resin liquid, the dielectric film layer can be made as thin as about 2 to 6 μm, the package marker can be made thin, and adaptability to curved surfaces can be secured.

In the present invention, the above-mentioned resonator marker is covered and protected with a plastic film such as polyethylene having a heat-adhesive property (heat-sealing property) and not impairing the resonance characteristic. As the coating protective material, it is preferable that it has thermal adhesiveness, does not hinder the resonance characteristic of the marker, and has impact after being buried in soil or the like, durability after being buried, and water resistance. It is more preferable if it has flexibility so that it can be attached to the curved surface of an object to be probed such as a gas pipe. from these things,
A thermoplastic resin such as polyethylene, polypropylene or polyester is preferable as the coating protective material. In the case of polyethylene, polypropylene or the like, the coating protective material preferably has a thickness of 0.5 mm or more. When superior water resistance, impact resistance, and tear resistance are required, films of polyester, polyamide (nylon), polyfluorinated ethylene (Teflon (registered trademark), etc.) can be used. A film obtained by laminating heat-welding polyethylene or the like on the film can be preferably used.

In the package marker of the present invention, a sheet-shaped or film-shaped coating protective material such as a polyolefin film is arranged on both front and back surfaces of a sheet-shaped resonator marker, and the marker is surrounded by the resonator marker or partially inside the marker. Can be manufactured by melt-integrating by heat fusion. For these reasons, the covering protective material has a slightly larger area than the resonator marker, but if necessary, it may be a tape-shaped film of a certain length so that it can be wound around a gas pipe or the like.

[0011]

Since the resonator package marker of the present invention is sealed by the flexible thermoplastic and heat-fusible coating material, it can withstand vibration and ground change, and also has a particle, shape, earth pressure, etc. of buried earth and sand. It can withstand the mechanical strength of. The present inventors prefer to have a thickness of 0.3 to maintain the mechanical strength of the coating protective material, although it varies depending on the type.
It has been found that 0.4 mm is required, and that the thickness at which the influence of attenuation by the moisture in the ground on the exploration distance is not affected is 0.5 mm or more. The polyolefin film is excellent in terms of such restrictions, processability and cost. Further, it is desirable to use it together with a gas barrier film. When used in combination with the gas barrier film, a resin film such as polyester or fluororesin may be used in addition to the polyolefin film, or a film obtained by laminating a polyolefin film on one side of the gas barrier film may be used.

[0012]

Embodiments of the package marker according to the present invention will be described below with reference to the drawings, but the invention is not limited to these embodiments.

FIG. 1 is a plan view showing an embodiment of the present invention, and FIG. 2 is a sectional view thereof. As shown in the figure, the package marker 1 of the present invention is a resonator marker (LC) in which a resonance coil 2b is formed on both surfaces of a dielectric film 2a.
It is composed of a resonance circuit 2 and a film-shaped coating protection material (package material) 3. Package marker 1
Sandwich the resonator marker 2 from above and below with a slightly larger covering protective material 3, and the peripheral portion 3a of the covering protective material 3 outside the resonator marker 2 or the peripheral portion 3a and a part of the inside 3
b is melt-integrated by the method of heat fusion, and the package is hermetically sealed. 1 and 2 are examples in which the resonator marker 2 is sealed by welding at the peripheral welding portion 3a.

The resonator marker 2 used in this example is shown in FIG.
As shown in FIG. 3, a resonance coil 2b made of a metal foil is formed on both surfaces of a dielectric film (insulating film) 2a, and the structure is made of a coiled aluminum foil / insulating film / coiled aluminum foil. The coils 2b on both sides of the film 2a are thin-film resonance circuits arranged so as to face each other and also functioning as capacitors. By using a coil made of copper foil, the Q characteristic of the circuit can be improved. The resonant circuit is not limited to those shown in FIGS. 1 to 3 and may have a conventionally known configuration in which a resonant coil is formed on one surface of the dielectric film,
In addition, the coils 2b, 2 arranged to face each other
The dielectric film 2a may be present only between b.

As shown in FIG. 2, the package marker 1 is coated with an adhesive 4 such as a pressure-sensitive adhesive on one surface, and is directly attached to an object to be probed such as a PE pipe at the time of use, so that other manufacturers The problem of loss due to construction work is eliminated, and the accuracy of exploration of the buried position can be maintained by following the PE pipe even when the ground changes. As an adhesive,
A pressure-sensitive adhesive layer 4 having a surface covered with a release paper 5 may be provided, and the release paper 5 may be peeled off and adhered at the time of use, or a heat-sensitive type heat-adhesive adhesive which is fused at a low temperature. If necessary, an elastic sheet such as a sponge sheet is attached to the lower surface of the package marker 1, and an adhesive layer and release paper are provided on the lower surface of the package marker 1 so that the elastic sheet can accommodate curved surfaces such as tubes. Good.

Furthermore, as shown in FIG.
In the case of something like, the thickness of the pipe like the pipes 6a and 6b,
That is, when the pipe diameter (curvature radius) changes, the package marker 1 attached to the surface is attached in a state close to a plane when the pipe diameter is large, but the attached package marker is attached when the pipe diameter is small. Since the surface of No. 1 is a curved surface, low-density polyethylene is excellent as a coating protective material because the flexibility of the coating protective material is required in order to support attachment to different pipe diameters with the same package marker. In the case of a slightly hard medium-high density polyethylene, polypropylene, etc., it is advisable to consider the attachability to a pipe as a package marker having a curvature. Furthermore, the degree of influence of water is due to the thickness of the coating protective material. This is because the LC resonance circuit deteriorates the Q characteristic of the circuit due to an increase in the surrounding moisture, that is, the dielectric constant, and thus the search performance deteriorates. The dielectric constant of water is about 80, and the Q characteristic deteriorates due to the dielectric loss about 40 times that of the resonant circuit. The influence of the thickness of the coating protection material on the Q of the resonance circuit is 64% at 0.1 mm, 0.5
97% for mm, 100% for 1.0 mm, 0.5 m
m is necessary, and 1.0 mm or more is desirable in view of the allowance.

Next, an embodiment of a method for manufacturing a heat-sealing package marker according to the present invention will be described with reference to the drawings. As shown in FIG. 5, in the fusing device 11, a stainless steel heater 13 having a fusing portion shape is vertically attached to a pressing device 12, and the thermoplastic resin film or sheet 14 is fused and fused by heat supply from the heater 13. It is a device that does. FIG. 6 is an external view of the heater section. The heater 13 is provided so as to face each other on the lower surface and the upper surface of the heater mounting jig 16 arranged above and below, and the LC resonance circuit 2 is supplied so as to be positioned inside the frame-shaped heater 13. At the same time, a thermoplastic resin film 14 for a package, which is stacked above and below the resonance circuit 2 supplied into the heater section.
Is a frame-shaped heater 13 having an outer peripheral portion 3a of the resonance circuit 2.
Is welded under pressure. The resonance circuit 2 is packaged without being affected by heat and pressure when the sheet 14 is melt-pressed.

As another welding method, ultrasonic welding,
There is a method of high frequency welding. Ultrasonic welding is a molded product that has a protrusion on the welded part and heats up due to vibration to weld at point-to-point or line-to-line so that the welding width is narrow, and pinholes and other irregularities easily occur when the welding area is large It is not possible to guarantee and it is disadvantageous for face-to-face welding. High-frequency welding is performed by internal heat generation due to dielectric loss, and is used for welding a thermoplastic resin or vinyl chloride resin having a large dielectric constant (ε), particularly a dielectric power factor (tan δ). Olefin resin such as polyethylene cannot be welded.

As the marker package, a thick sheet, for example, a thickness of about 1 mm is required also from the viewpoint of durability and mechanical strength, and a manufacturing method which can obtain airtightness and uniform stability of a fused portion is found. It was As the thickness increases, the heat conduction from the heater surface reaches the interface between the two sheets and reaches the fusion temperature, the heater surface melts and the weld thickness becomes extremely thin, resulting in a weak weld strength. descend. Further, in the case of a resin having a high melting point, melting at the interface is likely to be unstable, and fusing of thick sheets has not been put to practical use. As a method of fusing this thick sheet, it is possible to obtain the desired thickness and uniform stabilization of the welding state of the interface by controlling the wall thickness of the fusing part in order to keep the pressing pressure of the fusing device constant. did.

The welding state is controlled by the parameters of the voltage, current, energizing time, press pressure and cooling time of the power supply unit supplied to the heater. This standardizes the condition setting depending on the melting point of the resin and the thickness of the sheet. In addition, as an air bleed inside the package, by attaching a heat-resistant elastic body to the non-welding portion, first the air is evacuated by the elastic body before the welded portion on the outer periphery by pressing, and then fused by pressing the heater portion. . Furthermore, in order to obtain a good vacuum state, a vacuuming step can be added.

As an example, the following package markers were prepared. LC resonance circuit (size: 100 × 150m
m, thickness 0.125 mm, ultra-low density PE 1.0 mm thick (metallocene catalyst polymerized density 0.903 (g
/ Cm ³ ) PE) and a low-density PE coating protective material, and the area of the fused portion is 5 mm in outer circumference and the wall thickness of the fused portion is 1.8
Package markers having a size of 5, 1.75, 1.5, and 1.3 mm were prepared, and the cross-section of the fused portion was observed and the strength was measured. The results are shown in Table 1. Since ultra-low density PE with metallocene catalyst has a low melting point, the range of conditions leading to the molten state at the interface is wide, and it is easy to control the wall thickness of the fused part and it can be made thicker, but it is suitable for low density, medium and high density PE. The narrower the condition, the thinner the thickness, and the more stable the fused portion. The strength is low, and the density is medium and high. As shown in the examples, the thickness of the welded portion can be controlled to control the desired thickness and uniform stabilization of the welded state.

[0022]

[Table 1]

[0023]

As described above, the heat-sealing package marker of the present invention has the advantages that it is sealed by a specific coating protective material and retains long-term durability, is small, has good workability, and is inexpensive.

[Brief description of drawings]

FIG. 1 is a plan view of a package marker of the present invention.

FIG. 2 is a cross-sectional view of the package marker shown in FIG.

FIG. 3 is an exploded perspective view of a resonator marker.

FIG. 4 is a perspective view showing a state in which a package marker is attached to a tube.

FIG. 5 is a cross-sectional view of a thermal fusion bonding apparatus for manufacturing a package marker.

FIG. 6 is a schematic view of a heater unit of the fusing device shown in FIG.

[Explanation of symbols]

1 Thermal fusion package marker 2 LC resonance circuit 3 Cover protection material 3a, 3b fused part 4 Pressure-sensitive adhesive 5 Release paper 6a, 6b tubes 11 Thermal fusion device 12 Press machine 13 Stainless steel heater 14 Objects to be fused 15 Elastic body 16 Heater mounting jig 17 Heater Conductor

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hideki Hayakawa             4-1-2 Hiranomachi, Chuo-ku, Osaka-shi, Osaka Prefecture               Within Osaka Gas Co., Ltd. (72) Inventor Hideki Yamaguchi             4-1-2 Hiranomachi, Chuo-ku, Osaka-shi, Osaka Prefecture               Within Osaka Gas Co., Ltd. (72) Inventor Yoshinori Hatanaka             10-33 Kamitenmacho, Nishi-ku, Hiroshima City, Hiroshima Prefecture             Company Miyake (72) Inventor Masayuki Seike             11 Fuji, 1-1 Izumi-cho, Kanda, Chiyoda-ku, Tokyo             Tecom Co., Ltd. F term (reference) 5B035 AA04 AA07 AA08 BA05 BB00                       BC00

Claims (5)

[Claims] 1. A package marker, wherein a resonator marker formed by forming an LC resonance circuit is hermetically sealed by a method of heat-sealing a coating protective material such as a thermoplastic resin. 2. The resonator marker has a resonance circuit formed of a metal foil such as aluminum foil on both sides of an insulating (dielectric) sheet, and the insulating (dielectric) sheet is formed at the end of the circuit as required. The package marker according to claim 1, wherein the package marker is a sheet-like marker to which circuits on both sides of are connected. 3. The coating protective material has a thickness of 0 in order to prevent the distance performance between the resonator marker and the exploration device from being reduced in attenuation due to underground moisture and further to maintain mechanical strength. The package marker according to claim 1, wherein the package marker is 0.5 mm or more and is packaged with a durable thermoplastic resin. 4. A front surface and a back surface of a resonator marker forming an LC resonance circuit are covered with a cover protective material sheet slightly larger than the resonator marker, and at least the protective material sheet around the resonator marker is heated. A method of manufacturing a package marker, which comprises fusing and sealing the package. 5. The cover protective material is a thermoplastic resin sheet, and the hermetically sealed package of the resonator marker is melt-integrated around the resonator marker or a part of the inside thereof by heat fusion. The method for manufacturing the package marker according to claim 4.