Film-forming agent

Abstract

To provide a coating film forming agent capable of suppressing a surfing phenomenon of wiring / piping materials, and facilitating the extracting work of the wiring / piping materials from an underground pipe.SOLUTION: A coating film forming agent 14 with respect to an underground pipe 11 embedded in the ground UG and wiring 12 inserted in the underground pipe 11 and arranged in the underground pipe 11 so as to come into contact with an inner surface 11c of the underground pipe 11 includes a resin dispersion liquid in which water-insoluble resin is dispersed, and is adhered to the inner surface 11c of the underground pipe 11 and an outer surface 12a of the wiring 12. The dried resin dispersion liquid of the coating film forming agent 14 can form a resin coating film with adhesion strength which can be peeled when film forming temperature is 0 degree or more and the adhesion between the underground pipe 11 and the wiring 12 is 2 N / cm or less.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a coating agent for underground pipes and wiring and piping materials inserted into underground pipes. [Background technology]

[0002] In recent years, for the purposes of improving safety and improving the aesthetics of cities, underground buried boxes are connected by underground pipes buried underground, and wiring and piping materials are inserted into the underground pipes. The surf-riding phenomenon has become a problem with wiring and piping materials inserted into underground pipes. The surf-riding phenomenon is a phenomenon in which wiring and piping materials inside underground pipes move in the direction of vehicle travel when a vehicle travels on the ground. If tension is applied to the wiring and piping materials or the wiring and piping materials are bent due to the surf-riding phenomenon, there is a risk of the wiring and piping materials being damaged. To prevent the movement of wiring and piping materials due to the surf-riding phenomenon, Patent Document 1 clamps the wiring and piping materials with a cleat inside the underground buried box on the side where the wiring and piping materials are pulled.

[0003] Furthermore, small animals such as termites and mice can gnaw on underground pipes and wiring / piping materials, causing damage to the pipes and wiring / piping materials. Small animal control is used to prevent damage to underground pipes and wiring / piping materials. Patent Document 2 describes a method for controlling small animals by filling the gap between an underground pipe and wiring / piping materials with a water-absorbent polymer that has absorbed a water-soluble anti-termite agent. Patent Document 3 describes a method for controlling small animals by pouring a rodent repellent and / or a soft vinyl chloride resin material containing an anti-termite agent into gaps through which mice and termites can invade, and then solidifying the material. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-39402 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-011128 [Patent Document 3] Japanese Patent Application Publication No. 3-109301 Summary of the Invention [Problem to be solved by the invention]

[0005] However, since underground pipes are generally several tens to several hundred meters long, even if the wiring and piping materials are clamped inside the underground box, it is difficult to fully suppress the surfing phenomenon of the wiring and piping materials inside the underground pipe.

[0006] During renovation work, wiring and piping materials may be pulled out of underground pipes. When small animals are controlled using the methods disclosed in Patent Document 2 or Patent Document 3, it is necessary to remove the water-absorbent polymer or flexible polyvinyl chloride resin material filled between the underground pipe and the wiring and piping material before pulling it out of the underground pipe. The removal of the water-absorbent polymer or flexible polyvinyl chloride resin material must be carried out over a length of tens to hundreds of meters, which is the length of the underground pipe. Removing the water-absorbent polymer or flexible polyvinyl chloride resin material over a long distance has hindered the progress of construction work. [Means for solving the problem]

[0007] The coating agent for solving the above problems is a coating agent for underground pipes buried underground and for wiring and piping materials inserted into the underground pipes and arranged within the underground pipes so as to abut against the inner surface of the underground pipes, the agent containing a resin dispersion liquid in which a water-insoluble resin is dispersed, and the agent is applied to the inner surface of the underground pipes and the outer surface of the wiring and piping materials around the abutting portion between the inner surface of the underground pipes and the wiring and piping materials, the resin dispersion liquid being capable of forming a resin coating at a film-forming temperature of 0 degrees or higher and having an adhesive strength of 2 N / cm or less that allows the underground pipes and the wiring and piping materials to be peeled off.

[0008] Regarding the film-forming agent, the viscosity of the resin dispersion may be 10 mPa·s or more and 400 mPa·s or less. Regarding the film-forming agent, said film-forming agent may be in the form of a foam.

[0009] Regarding the film-forming agent, the film-forming agent may also include water-insoluble microcapsules in which the small animal control component is encapsulated. For the film-forming agent, the microcapsules may have a diameter of 1 μm to 10 μm. [Effects of the Invention]

[0010] According to the present invention, the surfing phenomenon of wiring and piping materials can be suppressed, and the work of pulling out wiring and piping materials from underground buried pipes becomes easier. [Brief explanation of the drawings]

[0011] [Figure 1] (a) is a diagram of the underground power line, and (b) is an enlarged view. [Figure 2] Cross-sectional view showing the maintenance process. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] (a) is a cross-sectional view showing the underground pipes and wiring after the discharge process, and (b) is an enlarged view of a part of it. [Figure 6] (a) is a cross-sectional view showing the drying process, and (b) is an enlarged view. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, one embodiment of the coating formation method and coating formation agent will be described with reference to FIGS. <Configuration of underground power lines> First, an underground electric line formed by an underground box, an underground pipe, and wiring will be described.

[0013] As shown in FIG. 1(a), multiple underground burial boxes 10 are buried in the ground UG. The underground burial boxes 10 are, for example, handholes or manholes. The multiple underground burial boxes 10 are buried at intervals in the ground UG. Two underground burial boxes 10 are illustrated in FIG. 1(a). Hereinafter, when it is necessary to distinguish between the two underground burial boxes 10, one underground burial box 10 will be referred to as the first underground burial box 10a and the other underground burial box 10 as the second underground burial box 10b. Each underground burial box 10 has a communication hole 10c that opens to the ground G. When construction or inspection is not being carried out, the communication hole 10c is closed with a lid (not shown). Each underground burial box 10 also has an insertion hole 10d in its side wall.

[0014] An underground pipe 11 is buried in the ground UG. In this embodiment, the underground pipe 11 is made of concrete. A first end 11a of the underground pipe 11 is inserted into the insertion hole 10d of the first underground buried box 10a, and a second end 11b of the underground buried pipe 11 opposite the first end 11a is inserted into the insertion hole 10d of the second underground buried box 10b. In other words, the underground buried pipe 11 is provided to connect the first underground buried box 10a and the second underground buried box 10b.

[0015] A wiring 12 serving as a wiring / piping material is inserted through the underground pipe 11. In this embodiment, the wiring 12 is a power cable. The sheath of the wiring 12 in this embodiment is made of polyvinyl chloride. The length of the wiring 12 is approximately several tens to several hundreds of meters. Since the wiring 12 is subjected to gravity, a lower portion of the inner surface 11c of the underground pipe 11 in the direction of gravity abuts a lower portion of the outer surface 12a of the wiring 12 in the direction of gravity. Furthermore, the lower portion of the inner surface 11c of the underground pipe 11 in the direction of gravity and the lower portion of the outer surface 12a of the wiring 12 in the direction of gravity face each other via a coating 13, which will be described later. An upper portion of the inner surface 11c of the underground pipe 11 in the direction of gravity and an upper portion of the outer surface 12a of the wiring 12 in the direction of gravity are spaced apart. Furthermore, the wiring 12 is supported in the underground burial box 10 by a support (not shown).

[0016] The underground burying tool including the underground burying box 10, the underground burying pipe 11, and the wiring 12 forms an underground electric line. As shown in FIG. 1(b), a coating 13 is formed on the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12. Note that in the drawing, the ratio of the thickness of the coating 13 to the diameter of the underground pipe 11 and the wiring 12 is illustrated higher than the actual ratio. The coating 13 contains a water-insoluble resin. In this embodiment, the water-insoluble resin is an ether-based polyurethane. The coating 13 also contains microcapsules encapsulating a small animal control component. That is, the coating 13 of this embodiment is a small animal control coating capable of controlling small animals from the underground pipe 11 and the wiring 12. In this embodiment, termites are assumed as the small animal control. Therefore, the small animal control component of this embodiment is a neonicotinoid compound. The microcapsules of this embodiment are fine particles with a diameter of 1 to 10 μm. A detailed method for forming the coating 13 will be described later.

[0017] The underground pipe 11 and the wiring 12 are bonded together by a coating 13. More specifically, a portion of the inner surface 11c of the underground pipe 11 that is lower in the direction of gravity and a portion of the outer surface 12a of the wiring 12 that is lower in the direction of gravity are bonded together by a resin contained in the coating 13. The underground pipe 11 and the wiring 12 are bonded together with an adhesive strength that allows the underground pipe 11 and the wiring 12 to be peeled off at 2 N / cm or less. In this embodiment, the underground pipe 11 and the wiring 12 are bonded together with an adhesive strength that allows the underground pipe 11 and the wiring 12 to be peeled off at 1.96 N / cm.

[0018] 2 N / cm is the upper limit of adhesive strength that can be pulled out with an 8-ton towing machine, assuming that the wiring 12 has the largest diameter that is generally used and is laid over a maximum distance of 200 m between underground buried boxes 10. Furthermore, the strength of the underground buried pipe 11 may decrease due to deterioration of the underground buried pipe 11 or multiple attempts to retrieve the wiring 12, and if the adhesive strength is too high, the underground buried pipe 11 may be damaged, so the adhesive strength is preferably 2 N / cm or less.

[0019] <Film formation method> Next, a coating forming method for forming the coating 13 on the inner surface 11c of the underground buried pipe 11 and the outer surface 12a of the wiring 12 will be described.

[0020] Before starting to form the coating 13, a preparation step is carried out to prepare the underground buried pipe 11. As shown in FIG. 2 , the maintenance process involves checking for clogging inside the underground pipe 11 and, if a clogging is found, removing the clogging. In this embodiment, the presence or absence of a clogging inside the underground pipe 11 is checked by blowing air into the underground pipe 11. Specifically, a blower 20 is inserted into the first end 11a of the underground pipe 11, and then air is blown from the blower 20. As a result, air is blown from the first end 11a to the second end 11b inside the underground pipe 11. Note that when forming the coating 13 on an already-installed underground electric power line, a sealing material such as mortar may be filled between the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12 at the first end 11a and the second end 11b of the underground pipe 11. In this case, the sealing material is removed, and then air is blown using the blower 20.

[0021] If there is no clog in the underground pipe 11, air will come out from the second end 11b of the underground pipe 11. If there is no clog in the underground pipe 11 but water W has accumulated inside the underground pipe 11, the water W inside the underground pipe 11 may be discharged from the second end 11b of the underground pipe 11 by the air blown by the blower 20. The discharged water W accumulates in the second underground box 10b. If air comes out from the second end 11b of the underground pipe 11, it is determined that there is no clog in the underground pipe 11, and coating formation begins. On the other hand, if there is a clog in the underground pipe 11, no air will come out from the second end 11b of the underground pipe 11. If no air comes out from the second end 11b of the underground pipe 11, the clog in the underground pipe 11 is removed. Then, after it is confirmed that air is coming out of the second end 11b of the underground buried pipe 11, the film formation is started.

[0022] The coating formation method includes a kneading step, an adhesion step, and a drying step. The kneading process is a process for preparing a film-forming agent 14 containing a resin dispersion in which a water-insoluble resin is dispersed. In the kneading process of this embodiment, the film-forming agent 14 is prepared by kneading water-insoluble microcapsules in which a small animal control component is encapsulated with a resin dispersion in which a water-insoluble resin is dispersed. That is, the film-forming agent 14 of this embodiment contains water-insoluble microcapsules in which a small animal control component is encapsulated and a resin dispersion in which a water-insoluble resin is dispersed. In this embodiment, since termite control is intended, the small animal control component is a neonicotinoid compound. The resin dispersion of this embodiment is a polyurethane emulsion composed of an ether-based polyurethane and water. In this embodiment, the resin content in the resin dispersion is 1%. The viscosity of the resin dispersion of this embodiment is 20 mPa·s. The film-forming temperature of the resin dispersion of this embodiment is 0°C or higher.

[0023] The adhering step is a step of adhering the coating agent 14 to the inner surface 11 c of the underground pipe 11 and the outer surface 12 a of the wiring 12 . As shown in FIG. 3, the adhering step of this embodiment includes a filling step of filling the underground buried pipe 11 with a coating agent 14.

[0024] Before starting to fill the underground pipe 11 with the coating agent 14, cement 21 is filled as a temporary blocking member between the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12 at the first end 11a and the second end 11b of the underground pipe 11. This blocks both ends of the underground pipe 11.

[0025] A first air vent pipe 22 and an injection pipe 23 are inserted into the cement 21 filled in the first end 11a of the underground pipe 11. A first air vent valve 22a is provided at the end of the first air vent pipe 22 that protrudes into the first underground box 10a. When the first air vent valve 22a is open, the inside of the underground pipe 11 and the inside of the first underground box 10a are connected. A first opening / closing valve 23a is provided at the end of the injection pipe 23 that protrudes into the first underground box 10a. A container 24 that stores the coating agent 14 is prepared on the ground G. A submersible pump 25 is placed in the container 24. The submersible pump 25 and the injection pipe 23 are connected by a hose 26. When the first on-off valve 23a is in an open state, the coating agent 14 in the container 24 is sent by the submersible pump 25 through the hose 26 into the underground pipe 11. When the first on-off valve 23a is in a closed state, the coating agent 14 is not sent into the underground pipe 11.

[0026] A second air vent pipe 27 and a discharge pipe 28 are inserted into the cement 21 filled in the second end 11b of the underground pipe 11. A second air vent valve 27a is provided at the end of the second air vent pipe 27 that protrudes into the second underground box 10b. When the second air vent valve 27a is open, the inside of the underground pipe 11 and the inside of the second underground box 10b are in communication. A second opening / closing valve 28a is provided at the end of the discharge pipe 28 that protrudes into the second underground box 10b.

[0027] In the filling step, the first on-off valve 23a, the first air vent valve 22a, and the second air vent valve 27a are opened, and the second on-off valve 28a is closed. Subsequently, the submersible pump 25 is operated to fill the underground pipe 11 with the coating agent 14 from the container 24. This causes the coating agent 14 to be sequentially filled into the space defined by the inner surface 11c of the underground pipe 11 and the cement 21. In other words, the coating agent 14 is filled between the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12. Once the space defined by the inner surface 11c of the underground pipe 11 and the cement 21 is filled with the coating agent 14, the coating agent 14 is ejected from the second air vent pipe 27. When the film forming agent 14 is sprayed out from the second air vent pipe 27, it is determined that the filling of the underground buried pipe 11 with the film forming agent 14 is complete, and the first opening / closing valve 23a is closed.

[0028] 4, the attachment step of this embodiment includes a discharge step of discharging the coating agent 14 filled in the filling step from the underground pipe 11. Before starting to discharge the coating agent 14 from the underground pipe 11, a container 24 is placed in the second underground box 10b, and a submersible pump 25 is provided in the container 24. In addition, a collection bottle 29 is provided on the ground G. The submersible pump 25 and the collection bottle 29 are connected by a hose 26.

[0029] In the discharge step, the first on-off valve 23a, the first air vent valve 22a, and the second air vent valve 27a are closed, and the second on-off valve 28a is opened. The coating agent 14 filling the space defined by the inner surface 11c of the underground pipe 11 and the cement 21 is then discharged through the discharge pipe 28. In other words, the coating agent 14 is discharged from between the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12. The coating agent 14 discharged from the discharge pipe 28 is then collected in the container 24. The coating agent 14 collected in the container 24 is then collected by the submersible pump 25 through the hose 26 into the collection bottle 29.

[0030] FIG. 5(a) shows the underground pipe 11 and the wiring 12 after the discharging step. As shown in FIG. 5(b), after the discharging step, the coating agent 14 is attached to the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12. Specifically, the coating agent 14 is present between the lower portion of the inner surface 11c of the underground pipe 11 in the direction of gravity and the lower portion of the outer surface 12a of the wiring 12 in the direction of gravity. Furthermore, although the coating agent 14 is attached to the upper portion of the inner surface 11c of the underground pipe 11 and the upper portion of the outer surface 12a of the wiring 12 in the direction of gravity, they are separated from each other.

[0031] As shown in FIG. 6(a), the drying step is a step of drying the coating agent 14 attached to the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12. Specifically, after removing the cement 21 filled in the first end 11a and the second end 11b of the underground pipe 11, a blower 20 is inserted into the first end 11a of the underground pipe 11 and air is blown from the blower 20. As a result, air is blown from the first end 11a to the second end 11b inside the underground pipe 11. The coating agent 14 is dried by the air blown from the blower 20. Specifically, the resin contained in the coating agent 14 hardens.

[0032] 6(b), the coating agent 14 is dried in the drying step, whereby a coating 13 containing microcapsules encapsulating small animal control ingredients and a water-insoluble resin is formed on the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12. The lower portion of the inner surface 11c of the underground pipe 11 in the direction of gravity and the lower portion of the outer surface 12a of the wiring 12 in the direction of gravity are bonded together by the hardened resin.

[0033] The operation and effects of this embodiment will be described. (1) The coating agent 14 applied to the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12 is dried, whereby the resin contained in the coating agent 14 is hardened. As a result, the coating 13 is formed on the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12.

[0034] The inner surface 11c of the underground buried pipe 11 and the outer surface 12a of the wiring 12 are bonded together by the hardened resin, thereby restricting the movement of the wiring 12. This makes it possible to prevent the wiring 12 from surfing.

[0035] The coating agent 14 uses a resin dispersion capable of forming a resin coating with an adhesive strength that allows peeling at 2 N / cm or less between the underground pipe 11 and the wiring 12. Therefore, the portion that bonds the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12 also has an adhesive strength that allows peeling at 2 N / cm or less. This allows the wiring 12 to be peeled from the underground pipe 11 simply by pulling the wiring 12 with an 8-ton towing machine that is commonly used in the construction of underground electric power lines. This makes it easy to pull out the wiring 12 from the underground pipe 11.

[0036] (2) In this embodiment, the underground pipe 11 is filled with the coating agent 14, and then the filled coating agent 14 is discharged from the underground pipe 11, thereby adhering the coating agent 14 to the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12. Therefore, compared to, for example, using a sprayer to spray the coating agent 14 onto the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12, the coating agent 14 can be more easily adhered to the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12. In particular, when an underground electric power line has already been installed, it is difficult to insert a sprayer into the underground pipe 11, which is several tens to several hundreds of meters long, and therefore the method of this embodiment is effective.

[0037] Furthermore, since the application of the coating agent 14 to the underground pipe 11 and the application of the coating agent 14 to the wiring 12 can be carried out simultaneously, the coating 13 can be formed efficiently. Furthermore, when forming an underground electric cable after applying the coating agent 14 to the underground pipe 11 and the wiring 12, it is necessary to carefully insert the wiring 12 into the underground pipe 11 so that the coating agent 14 formed on the outer surface 12a of the wiring 12 does not fall off. In contrast, in this embodiment, the coating agent 14 is applied after the underground electric cable is formed, so there is no need to worry about the coating agent 14 falling off from the outer surface 12a of the wiring 12.

[0038] (3) The viscosity of the resin dispersion contained in the coating agent 14 is 20 mPa·s. Therefore, the coating agent 14 can be pumped into the underground pipe 11 by the submersible pump 25.

[0039] (4) The coating agent 14 contains microcapsules in which small animal control ingredients are encapsulated. Therefore, the coating 13 formed on the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12 also contains microcapsules in which small animal control ingredients are encapsulated. This enables small animal control of the underground pipe 11 and the wiring 12. Furthermore, as the resin hardens, the outflow of the small animal control ingredients is suppressed, thereby maintaining the small animal control effect.

[0040] (5) When resin dispersion alone is applied to the outer surface 12a of the wire 12, the resin dispersion is water-repellent to the outer surface 12a of the wire 12, and therefore drips from the wire 12. In contrast, in this embodiment, the resin dispersion is mixed with microcapsules in the form of fine particles of 1 to 10 μm and then applied to the outer surface 12a of the wire 12. In this case, the microcapsules are attached to the outer surface 12a of the wire 12, which prevents the resin dispersion from dripping from the wire 12.

[0041] (6) When the wiring 12 is a power transmission cable, the heat resistance temperature of the wiring 12 is set assuming that the temperature will rise to around 60°C. Furthermore, water may enter the underground pipe 11. Therefore, if an ester-based polyurethane, which begins to hydrolyze at temperatures above 65°C, is used as the water-insoluble resin, there is a possibility of hydrolysis. The amines generated by hydrolysis may damage the sheath of the wiring 12. In contrast, ether-based polyurethane has a hydrolysis start temperature of approximately 150°C and is water-resistant. In this embodiment, ether-based polyurethane is used as the water-insoluble resin, so damage to the sheath of the wiring 12 due to hydrolysis can be suppressed.

[0042] (7) In the prior art, for example, when inspecting the underground pipe 11 or the wiring 12, if it was necessary to insert an inspection device between the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12, it was necessary to remove the water-absorbent polymer or the soft vinyl chloride material. In contrast, in the present embodiment, the upper portion of the inner surface 11c of the underground pipe 11 in the direction of gravity is separated from the upper portion of the outer surface 12a of the wiring 12 in the direction of gravity. Therefore, during inspection, it is possible to insert an inspection device between the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12 without removing the water-absorbent polymer or the soft vinyl chloride material. This allows for smooth inspection.

[0043] (8) Costs can be reduced compared to when termite control of the wiring 12 is performed using anti-termite cables covered with an anti-termite layer made of nylon. (9) In the drying process of this embodiment, the coating film forming agent 14 is dried by air blown from the blower 20. Therefore, the coating film 13 can be formed more quickly than when the coating film forming agent 14 is dried by natural drying.

[0044] This embodiment can be modified as follows: This embodiment and the modifications can be combined with each other within the scope of technical compatibility. Piping material as wiring and piping material may be inserted into the underground pipe 11.

[0045] The wiring 12 may be a communication cable such as an optical fiber cable. If the only purpose is to suppress the surfing phenomenon of the wiring 12, the coating agent 14 does not need to contain microcapsules encapsulating small animal control ingredients. In this case, the coating 13 will be a simple resin coating, not a small animal control coating.

[0046] In this case, the coating 13 only needs to be formed on the lower portion of the inner surface 11c of the underground pipe 11 in the direction of gravity and the lower portion of the outer surface 12a of the wiring 12 in the direction of gravity so that the underground pipe 11 and the wiring 12 are bonded together by the resin. In other words, the coating 13 does not need to be formed on the entire inner surface 11c of the underground pipe 11 or the entire outer surface 12a of the wiring 12. Therefore, in the filling step, the coating agent 14 only needs to be filled into the underground pipe 11 up to a water level where the lower portion of the inner surface 11c of the underground pipe 11 in the direction of gravity and the lower portion of the outer surface 12a of the wiring 12 in the direction of gravity are immersed in the coating agent 14.

[0047] In this way, when it is not necessary to fill the underground pipe 11 to the full with the coating agent 14, the maintenance process can be omitted. For example, if the coating agent 14 is filled from the first end 11a of the underground pipe 11 and does not flow out from the second end 11b, it is determined that a blockage has occurred inside the underground pipe 11, and the coating agent 14 is then filled from the second end 11b as well. This also reduces the amount of coating agent 14 used.

[0048] In the above embodiment, termites are assumed to be small animals that cause damage to the underground pipes 11 and the wiring 12. However, small animals such as cockroaches and mice may also cause damage to the underground pipes 11 and the wiring 12. In other words, small animal control is not limited to termite control, but also includes cockroach control and mouse control.

[0049] The small animal control component for termite control is not limited to neonicotinoid compounds, but may also be a pyrethroid. The small animal control component may be changed depending on the small animal to be controlled. For example, capsaicin may be used as the small animal control component for rodent control.

[0050] The water-insoluble resin is not limited to polyurethane, but may be acrylic, epoxy, or silicone. Because acrylic, epoxy, and silicone are water-resistant, the small animal control effect of the coating 13 is likely to be maintained even if water flows into the underground buried pipe 11.

[0051] The viscosity of the resin dispersion may be varied as appropriate. However, the higher the viscosity of the resin dispersion, the greater the amount of film-forming agent 14 adhering to the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12, i.e., the greater the amount of resin adhering to the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12. Therefore, the higher the viscosity of the resin dispersion, the greater the adhesive strength between the underground pipe 11 and the wiring 12. On the other hand, the lower the viscosity of the resin dispersion, the less the amount of film-forming agent 14 adhering to the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12. For example, if the viscosity of the resin dispersion is lower than 10 mPa·s, the film-forming agent 14 will flow off the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12, and the microcapsules will no longer be retained on the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12. Therefore, the viscosity of the resin dispersion is set so that a resin coating is formed that can hold the microcapsules on the underground pipe 11 and the wiring 12 and has an adhesive strength that allows the adhesion between the underground pipe 11 and the wiring 12 to be peeled off at a tensile speed of 2 N / cm or less.

[0052] Furthermore, if the viscosity of the resin dispersion is 400 mPa·s or less, the coating agent 14 can be sent into the underground pipe 11 using an underwater pump 25, or the coating agent 14 can be sprayed onto the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12 using a high-pressure sprayer.

[0053] In addition to the resin dispersion, the film-forming agent 14 may contain, for example, a thickener to increase the viscosity of the film-forming agent 14 . The resin content of the resin dispersion may be changed as appropriate. However, if the resin content of the resin dispersion is less than 1%, there is a risk that the coating agent 14 will not adhere to the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12. Furthermore, the higher the resin content of the resin dispersion, the higher the adhesive strength between the underground pipe 11 and the wiring 12. For this reason, the resin content of the resin dispersion is set so that a resin coating having an adhesive strength of 2 N / cm or less that allows peeling between the underground pipe 11 and the wiring 12 is formed.

[0054] In the above embodiment, the underground pipe 11 is made of concrete and the sheath of the wiring 12 is made of polyvinyl chloride, but the materials of the underground pipe 11 and the sheath of the wiring 12 may be changed as appropriate. The resin content, etc. of the resin dispersion is set according to the materials of the underground pipe 11 and the wiring 12 so that a resin coating having an adhesive strength that allows the adhesion between the underground pipe 11 and the wiring 12 to be peeled off at 2 N / cm or less is formed.

[0055] In the maintenance process, the method for checking for the presence or absence of a clog in the underground pipe 11 may be changed as appropriate. For example, the presence or absence of a clog in the underground pipe 11 may be checked by running water through the underground pipe 11. In this case, if there is a clog in the underground pipe 11, the clog may be washed away by the water, and the clog may be removed. Alternatively, the presence or absence of a clog in the underground pipe 11 may be checked by inserting a camera into the underground pipe 11.

[0056] The kneading step may be carried out before the conditioning step or simultaneously with the conditioning step. The coating film forming method may further include a foaming step of foaming the liquid coating film forming agent 14 to form a foamed coating film forming agent 14. The foaming step may be performed after the kneading step or simultaneously with the kneading step.

[0057] In this case, in the adhesion step, the foamed film-forming agent 14 is filled into the underground pipe 11. The foamed film-forming agent 14 defoams inside the underground pipe 11, and thereby adheres to the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12. By using the foamed film-forming agent 14, the amount of the film-forming agent 14 used can be reduced compared to when a liquid film-forming agent 14 is used.

[0058] The film-forming agent 14 may be a liquid that is filled into the underground pipe 11 and then foams naturally inside the underground pipe 11 . In the adhering step, the method for adhering the coating agent 14 to the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12 may be changed as appropriate. For example, the coating agent 14 may be adhered to the inner surface 11c of the underground pipe 11 and the outer surface 12a of the wiring 12 by spraying the coating agent 14 with a high-pressure sprayer.

[0059] In the filling step, the coating agent 14 may be filled into the underground pipe 11 from both ends of the underground pipe 11 . The coating agent 14 uses a resin dispersion liquid with a film-forming temperature of 0° C. or higher. Therefore, the method for drying the coating agent 14 in the drying step is not limited to blowing air with the blower 20, and natural drying may also be used.

[0060] The technical ideas that can be understood from the above-described embodiment and modified examples will be described. <Appendix 1> A method for forming a coating on an underground pipe buried in the ground and a wiring / piping material inserted into the underground pipe, comprising: an adhering step of adhering a coating agent containing a resin dispersion liquid in which a water-insoluble resin is dispersed to the inner surface of the underground buried pipe and the outer surface of the wiring and piping material; a drying step of drying the coating agent adhered to the inner surface of the underground pipe and the outer surface of the wiring and piping material, The coating forming method is characterized in that the resin dispersion is capable of forming a resin coating having a film-forming temperature of 0 degrees or higher and an adhesive strength of 2 N / cm or less that allows peeling between the underground buried pipe and the wiring / piping material.

[0061] <Appendix 2> The attaching step includes: a filling step of filling the film-forming agent between the inner surface of the underground buried pipe and the outer surface of the wiring / piping material; A coating forming method as described in Appendix 1, comprising a discharging step of discharging the coating forming agent filled in the filling step from between the inner surface of the underground buried pipe and the outer surface of the wiring / piping material.

[0062] <Appendix 3> The coating method according to claim 1 or 2, wherein the coating agent in foam form is applied to the inner surface of the underground buried pipe and the outer surface of the wiring / piping material in the application step.

[0063] <Appendix 4> The coating method according to any one of claims 1 to 3, wherein the adhesion step comprises adhering the coating-forming agent containing water-insoluble microcapsules encapsulating small animal control components and the resin dispersion. [Explanation of symbols]

[0064] 11...underground buried pipe, 11c...inner surface, 12...wiring as wiring / piping material, 12a...outer surface, 13...coating, 14...coating forming agent.

Claims

1. A coating agent for an underground pipe buried in the ground and a wiring / piping material inserted into the underground pipe and arranged inside the underground pipe so as to abut against the inner surface of the underground pipe, It contains a resin dispersion in which a water-insoluble resin is dispersed, the adhesive tape is attached to the inner surface of the underground pipe and the outer surface of the wiring / piping material around the contact portion between the inner surface of the underground pipe and the wiring / piping material; The resin dispersion is a film-forming agent characterized in that it is capable of forming a resin coating having a film-forming temperature of 0 degrees or higher and an adhesive strength of 2 N / cm or less that allows peeling between the underground buried pipe and the wiring / piping material.

2. 2. The film-forming agent according to claim 1, wherein the viscosity of the resin dispersion is 10 mPa·s or more and 400 mPa·s or less.

3. The film-forming agent according to claim 1 or 2, wherein the film-forming agent is in the form of a foam.

4. The coating agent according to any one of claims 1 to 3, further comprising water-insoluble microcapsules in which a small animal control component is encapsulated.

5. 5. The film-forming agent according to claim 4, wherein the microcapsules have a diameter of 1 μm to 10 μm.

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