JP6749259B2 - Conductive paint tape - Google Patents

Description

The present invention relates to a conductive paint tape in which a conductive paint is continuously applied in the longitudinal direction.

As disclosed in Patent Documents 1 and 2, a method is known in which a conductive paint is applied to the surface of a concrete structure made of reinforced concrete to detect the occurrence of deformation such as cracks.

That is, the electric circuit is formed by applying the conductive paint to the surface of the concrete structure, and the electric circuit is detected when the electric circuit is broken due to cracking or expansion.

JP, 2016-24139, A JP, 2016-24138, A

However, the configurations described in Patent Documents 1 and 2 in which the conductive coating is applied have been configured using a blend of a conductive coating and a tape that is easily cut, such as a non-woven double-sided tape or a masking tape having a cut.

In short, the conductive paint protective tapes disclosed in Patent Documents 1 and 2 are used as the detecting portion, and it is an essential requirement that the conductive paint protective tape or the like breaks due to cracking or the like.

On the other hand, in order to detect the occurrence of cracks at a specific location, it is necessary to connect the detection unit and the detection device with a lead wire or the like. If the distance between the detection unit and the detection device is large, there are problems such as where it is difficult to wire the lead wires and the aesthetic appearance is deteriorated.

In addition, at the connection portion between the detection portion formed of the conductive paint and the lead wire, which is an electric wire, problems such as difficulty in joining different materials and corrosion of the electric wire may occur.

Therefore, an object of the present invention is to provide a conductive paint tape coated with a conductive paint that is easily broken and that can be easily connected to a detection portion formed of the conductive paint.

In order to achieve the above-mentioned object, the conductive paint tape of the present invention is a conductive paint tape in which a conductive paint is continuously applied in the longitudinal direction, and a tape main body portion having a stretchability formed in a strip shape, A conductive paint layer having elasticity formed on the surface of the tape body is provided.

Here, the conductive paint layer may be a mixture containing silver powder, a urethane resin, and an organic solvent. Preferably, the blending ratio is 55-65% by weight of the silver powder, 5-15% by weight of the urethane resin, and 25-35% by weight of the organic solvent.

The surface of the conductive paint layer may be covered with a coating layer. Further, the tape body may be made of polyolefin or nylon.

In the conductive paint tape of the present invention thus configured, the conductive paint layer having elasticity is formed on the surface of the tape main body part having elasticity. For this reason, even if a crack occurs at a place where detection is not planned or the crack opens and closes, it does not break, and the electric state of the electric circuit can be maintained.

Further, when the detection unit is configured by applying a conductive paint, it is easy to connect to the detection unit and the appearance can be made uniform. Furthermore, by coating the surface of the conductive paint layer with the coating layer, it is possible to make the conductive paint layer difficult to peel off even if the conductive paint tape expands and contracts.

It is sectional drawing explaining the structure of the electrically conductive coating tape of this Embodiment. It is explanatory drawing which illustrated the application location of a conductive paint tape. It is sectional drawing explaining the structure of a conductive paint tape and a detection part.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view illustrating the configuration of the conductive paint tape 1 of the present embodiment, FIG. 2 is a schematic diagram illustrating an application portion of the conductive paint tape 1, and FIG. 3 illustrates a specific structure of FIG. FIG.

Conductive paint tape 1 of the present embodiment is mainly composed of elastic tape main body 3 formed in a strip shape and elastic conductive paint layer 2 formed on the surface of tape main body 3. To be done.

The tape body 3 is made of a material having high elasticity. For example, a polyolefin resin material can be used for the tape body 3. Specifically, fine line tape (product number 2800, manufactured by 3M Company) having high heat resistance can be used. Also, the tape body 3 can be formed of an elastic material such as nylon.

The tape body 3 formed of such a synthetic resin material having excellent stretchability can follow the deformation without breaking even when the stretch is repeated. Also, the compatibility with the conductive paint layer 2 and the undercoat material 5 described later is good, and the adhesiveness can be improved and peeling can be made difficult.

On the other hand, the conductive paint layer 2 has a composition with excellent elasticity. In order to detect cracks with the conductive paint, it is necessary to reduce the tensile resistance to facilitate breakage. For example, the conductive paint used at the detection location is blended with polyester having poor elasticity.

On the other hand, the conductive paint layer 2 contains a resin having excellent elasticity. For example, the conductive paint applied to form the conductive paint layer 2 contains silver powder as a filler, a highly stretchable urethane resin, and an organic solvent. A diluent such as thinner is used as the organic solvent.

The conductive paint composition for forming the conductive paint layer 2 is, for example, 55 to 65% by weight of silver powder, 5 to 15% by weight of urethane resin, and 25 to 35% by weight of organic solvent. It can be %.

Furthermore, the surface of the conductive paint layer 2 can be covered with the coating layer 4 as needed. By coating with the coating layer 4 such as an acrylic resin, durability such as ultraviolet resistance and waterproofness can be improved.

Further, by coating the surface of the conductive paint layer 2 with the coating layer 4, the conductive paint layer 2 can be made difficult to peel off from the tape body portion 3 even if the conductive paint tape 1 repeatedly expands and contracts.

An epoxy resin or the like can be used for the undercoat material 5 interposed between the tape body 3 and the surface M1. By interposing the undercoat material 5 as a primer, it is possible to adjust the unevenness of the detection target object having the unevenness on the surface M1 such as the concrete structure M, and it is possible to prevent the electric leakage to the concrete structure M side.

The conductive paint tape 1 of the present embodiment is a strip-shaped conductive material capable of forming an electric circuit. Therefore, as shown in FIG. 1, if the end portions of the lead wires 61, 61 of the detection device 6 are connected to both ends of the conductive paint layer 2 of the conductive paint tape 1, the energized state can be detected.

FIG. 2 is an explanatory diagram exemplifying application points of the above-described conductive paint tape 1. In a concrete structure M such as a PC girder (prestressed concrete girder), the degree of damage may be grasped depending on the location where cracks occur. For example, when a prestressing force is introduced into a PC girder by a plurality of PC steel materials, it may be possible to know at which position the PC steel material is in a defective state or broken depending on the location where the crack C occurs.

When such a crack C is detected, the conductive paint applied along the surface M1 of the concrete structure M is connected to the detection device 6 so that all the conductive paint is easily broken. Even if this occurs, the conductive paint will break and be detected.

Therefore, as shown in FIG. 2, the detecting portion 7 is provided only at a portion where the occurrence of the crack C is desired to be detected, and the other portions are constituted by the conductive paint tapes 1 and 1 described above. For example, one end of the conductive paint tape 1 is connected to one of the lead wires 61 of the detection device 6 and is extended to a position just before a crack C occurrence point of interest.

At the point of interest of the crack C, the detection portion 7 that is easily broken from the end of the conductive paint tape 1 is wired in a U-shape. Then, an end portion of another conductive paint tape 1 is connected to the other end of the detection portion 7 and is connected to the other lead wire 61 of the detection device 6 to form an electric circuit.

Here, the configuration of the detection unit 7 will be described with reference to FIG. The detection unit 7 is mainly configured by a tape portion 72 that is formed in a strip shape and is easily broken, and a breakable detection paint layer 73 that is formed on the surface of the tape portion 72.

Nonwoven fabric tape, polyester masking tape, or the like can be used for the tape portion 72. When the tape portion 72 is made of a material that does not easily break, a slit such as a slit is formed so that the tape portion 72 is broken when a desired force is applied.

The detection paint layer 73 contains, for example, a silver powder serving as a filler, a polyester resin having poor stretchability, and an organic solvent. A diluent such as thinner is used as the organic solvent.

On the other hand, for the undercoat material 71 and the coating layer 74 of the detection unit 7, the same material as the conductive paint tape 1 can be used. For example, an epoxy resin can be used for the undercoat material 71 and an acrylic resin can be used for the coating layer 74.

Next, a method of using the conductive paint tape 1 of the present embodiment and the operation of the conductive paint tape 1 will be described.

As shown in FIG. 2, a case will be described in which the conductive paint tape 1 is used to detect a crack C generated at a place on the side surface (surface M1) of the PC girder that becomes the concrete structure M.

The detection device 6 is installed at a place where an administrator can easily access, such as a girder end where a scaffold exists or a bridge pier position. Therefore, the detection device 6 may be far away from the place where the crack C is to be detected. A detection unit 7 having a U-shape in a side view is provided at a position where the crack C is to be detected.

Then, the conductive paint tapes 1 and 1 are extended from the folded back ends of the detection unit 7 toward the installation location of the detection device 6. The lead wire 61 of the detection device 6 is connected to the conductive paint layer 2 of the conductive paint tape 1 as shown in FIG. Since the connection between the lead wire 61 and the conductive paint layer 2 is made around the detection device 6, if a defect such as corrosion or detachment of the lead wire 61 occurs, it can be found immediately.

In order to lay the conductive paint tape 1, as shown in FIG. 3, first, an epoxy resin is applied as the undercoat material 5 on the surface M1 of the concrete structure M. Similarly, an epoxy resin is applied as the undercoat material 71 also to the surface M1 of the portion where the detection portion 7 is provided.

Then, a tape portion 72 having a width of about 5 mm is attached on the undercoat material 71 at a portion to be the detection portion 7. In addition, a tape body 3 having a width of about 5 mm is attached on the undercoat material 5 at the location where the conductive paint tape 1 is to be formed.

Subsequently, in order to form the conductive paint layer 2, a conductive paint in which silver powder, urethane resin and an organic solvent are mixed is sprayed on the surface of the tape body 3 with a spray gun having a small diameter. Further, a conductive paint containing silver powder, a polyester resin and an organic solvent is sprayed onto the surface of the tape portion 72 to form a detection paint layer 73. The thickness (film thickness) of the detection coating layer 73 by spraying is about 0.05 mm. The film thickness of the conductive paint layer 2 can be made larger than that of the detection paint layer 73.

Here, since the conductive paint layer 2 and the detection paint layer 73 are formed by spraying the same kind of conductive paint with different composition, continuity can be easily ensured. The connection point between the conductive paint layer 2 and the detection paint layer 73 may be difficult to approach after the installation work, but the connection with high integrity can reduce the management burden.

Further, coating layers 4 and 74 are formed on the surfaces of the conductive paint layer 2 and the detection paint layer 73 by spraying an acrylic resin. The durability can be improved by providing the coating layers 4 and 74.

In this way, the electric circuit formed by the conductive paint tape 1, the detecting portion 7, and the detecting device 6 is used to cause the detecting device 6 to detect the crack C1. Here, it is assumed that the crack C2 has occurred in the laying section of the conductive paint tape 1 before the crack C1 has occurred.

When the train passes through the PC girder (concrete structure M) of the railway bridge, the crack C2 may open and close due to the running load of the train. If the conductive paint fails to follow the opening and closing of the crack C2, the crack C1 cannot be detected.

On the other hand, since the conductive paint tape 1 arranged over the crack C2 has excellent elasticity, even if the crack C2 repeatedly opens and closes or the width thereof widens, it continues to be energized without being broken. be able to. For example, even if the crack C2 spreads by about 1 mm, the conductive paint tape 1 can be maintained in the energized state without breaking.

On the other hand, when the crack C1 is generated or spreads, the detection unit 7 breaks, the power supply is cut off, and the detection device 6 can immediately detect the crack. That is, since the tape portion 72 and the detection paint layer 73 of the detection portion 7 are poor in elasticity, they cannot withstand the tensile force acting due to the occurrence or expansion of the crack C1 and will break. For example, when a crack C1 of about 0.3 mm occurs, the detection unit 7 is broken. However, it is said that there is a detection error of about 25%.

In the conductive paint tape 1 of the present embodiment configured as above, the conductive paint layer 2 having elasticity is formed on the surface of the tape main body 3 having elasticity. For this reason, even if a crack is generated at a place where detection is not planned or the crack C2 is opened or closed, the electric circuit can be maintained in the energized state without breaking.

Further, when the detecting portion 7 is formed by applying the conductive coating material, it is well compatible with the conductive coating layer 2 and can be easily continued to the detection coating layer 73 of the detecting portion 7.

Further, since the conductive paint layer 2 and the detection paint layer 73 are conductive paints containing the same silver powder as the filler, they have the same appearance, and even if they are exposed on the surface M1 of the concrete structure M, the appearance is impaired. Can be suppressed.

Further, by covering the surfaces of the conductive paint layer 2 and the detection paint layer 73 with the coating layers 4 and 74, it is possible to suppress deterioration due to ultraviolet rays and improve durability.

Further, by coating the surface of the conductive paint layer 2 with the coating layer 4, even if the conductive paint tape 1 repeatedly expands and contracts due to opening and closing of the crack C2, the conductive paint layer 2 is prevented from peeling off from the tape main body 3. Can be suppressed.

Further, by limiting the range in which the detecting portion 7 is arranged in combination with the conductive paint tape 1, it becomes possible to quickly identify the location of the crack, and it is rational and economical to partially reinforced the steel sheet. It becomes possible to do it.

The embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific configuration is not limited to this embodiment, and a design change that does not depart from the gist of the present invention is Included in the invention.

For example, although the case where the conductive paint tape 1 is laid on the surface M1 of the concrete structure M has been described in the above-described embodiment, the present invention is not limited to this. The conductive paint tape 1 can also be used as a conductor or the like when detecting damage to plastic.

1 Conductive paint tape 2 Conductive paint layer 3 Tape body 4 Coating layer

Claims (2)

While being arranged along the surface of the concrete structure, the conductive coating material continuously in the longitudinal direction a conductive coating tape comprising a conductor in Rukoto applied,
A tape main body portion having a band-like shape and having elasticity,
A conductive paint layer having elasticity formed on the surface of the tape body,
The tape body is formed of a highly stretchable polyolefin or nylon so as not to be broken even when stretched repeatedly , and
The conductive coating layer contains a silver powder having a mixing ratio of 55-65% by weight, a urethane resin having a mixing ratio of 5-15% by weight, and an organic solvent having a mixing ratio of 25-35% by weight. A conductive paint tape, characterized in that it is formed by applying. The conductive paint tape according to claim 1, wherein the surface of the conductive paint layer is covered with a coating layer.