JP2004073979A - Drain pipe regeneration method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drain pipe regeneration method which can line a drain pipe irrespective of a vertical main pipe, a horizontal main pipe, and a branch pipe continuously at a practical cost by a single apparatus and a method. <P>SOLUTION: In the method, an indoor drain pipe for a condominium is regenerated by resin-lining the inner surface of the drain pipe. a liquid resin composition is put in the suction side heat-insulating tank 20 of a gear pump device 18 to be kept at a prescribed temperature to be prepared to be able to be supplied to a spray gun device 10 for coating the inside of a pipe. Next, the spray gun device 10 is inserted into a small caliber pipe 13 from its terminal. After the spray gun device 10 reaches a large caliber main pipe 11 by using a propulsion device 14 and a direction control device 15, the propulsion device 14 is rotated reversely, while the device 10 is pulled from the main pipe 11 toward the terminal of the small caliber pipe 13, the resin composition supplied from the gear pump device 18 is ejected from the spraying tip ejection hole of the device 10, and a resin coating film of a prescribed thickness is adhered to the inner surface of a pipe to be coated. The resin coating film is dried and cured for the resin lining of the inner surface of the pipe. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a method for rehabilitating an internal drainage pipe for an aged apartment house by lining it with a resin.
[0002]
[Prior art]
In recent years, apartment buildings such as apartments and condominiums have become aging, and many problems such as corrosion, clogging, and water leakage of indoor drainage pipes have occurred. However, replacing a drain pipe with a new one is extremely difficult in terms of the construction period when people live in a house, and the cost burden is large. Therefore, there is a demand for the development of a method for rehabilitating drainage pipes in a relatively short time and at low cost by using existing pipes as they are and lining the inner surfaces of the pipes with resin paint.
[0003]
The diameter (nominal diameter) of a drain pipe to be rehabilitated is generally in the range of 50 mm to 200 mm in an apartment house or the like. Lining of the inner surface of these drainage pipes with a resin has been conventionally performed, and as such a method, a ball pig method, a hose lining method, a reflow (Re-Flow) method, or the like is known. The liquid resin paint used in these methods is a thermosetting resin such as an epoxy resin, an unsaturated polyester resin, or an acrylic resin, and a mixture of these with glass flakes.
[0004]
In the ball pig method, a resin paint with flowability is poured into a pipe, and then a polyurethane resin or rubber pig (of various shapes such as a sphere or an ellipse) having a size suitable for the inner diameter of the pipe is put into the pipe. While inserting and moving with a rope or suction, a liquid resin paint is applied to the pipe wall on the surface of the pig, and then the pig is taken out and the resin coating is waited for curing. It seems that this method is often used for relatively small diameter pipes, but if the pipe diameter is different or there is a curved pipe part, it is necessary to replace the pig each time, and the construction will continue There is a drawback that you can not.
[0005]
In the hose lining method, a polyester fiber jacket (cylindrical woven fabric) impregnated with epoxy resin, unsaturated polyester resin, etc. is inserted into the tube while turning it over, and is cured with ultraviolet light etc. to line the inner wall of the tube It is a construction method. This method is considered to be suitable for the rehabilitation method of sewer pipes, but it is considered to be inappropriate for rehabilitation method of indoor drainage pipes for condominiums and other condominiums because it is expensive and expensive.
[0006]
In a recently developed reflow method (Japanese Patent Application Laid-Open No. 2001-219121), a lining device having a resin injection hole at the tip is inserted into the pipe from the upper part of the vertical main pipe of the drain pipe, and the resin is rotated by rotating a built-in small motor. This is a method of spraying, lining, and curing. This construction method is inconvenient in that the horizontal main pipe and the horizontal branch pipe cannot be lined simultaneously with the vertical main pipe. A complicated construction method is adopted in which a liquid resin paint is applied to the horizontal branch pipe by a normal spraying method, and the horizontal main pipe is rehabilitated by a reflow method again.
[0007]
[Problems to be solved by the invention]
As can be seen from the above, despite the strong demand for a method that can easily rehabilitate indoor drainage pipes for apartments, condominiums, and other condominiums, various existing methods are unsatisfactory in many aspects. Therefore, the present invention provides that the entire process can be completed within a permissible time zone that does not interfere with life while a person lives in the target housing, and a drain pipe having a nominal diameter of 50 mm to 200 mm. It is an object of the present invention to be able to continuously line the vertical main pipe, the horizontal main pipe, and the branch pipe with a single device and a method without distinction, and to realize a durable inner lining surface at a practical cost.
[0008]
[Means to solve the problem]
The above problem can be solved by the drain pipe rehabilitation method described below. That is, the present method prepares a liquid resin composition to a predetermined composition, puts the liquid resin composition into a suction-side heat-retention tank of a gear pump device, keeps it at a predetermined temperature, and can immediately supply it to a spray gun device for in-pipe coating as needed. Preparation and a step of inserting the spray gun device from the end of the small-diameter pipe of the indoor drainage pipe to be coated into the inside and propelling it up to the large-diameter main pipe or the medium-diameter pipe in front of it, and the spray-gun apparatus After reaching the target pipe, the liquid resin composition supplied from the gear pump device is sprayed by the spray tip of the spray gun device while pulling and moving the spray gun device from the arrival position toward the end of the small-diameter pipe. Injecting from the injection hole to apply a resin film of a predetermined thickness to the inner surface of the pipe to be coated, and drying and curing the resin coating obtained in this way to apply resin to the inner surface of the pipe to be coated And a step of subjecting the inning. Prior to the implementation of this method, it is desirable to inspect and clean the inside of the pipe to be coated.
[0009]
The present invention relates to a method for applying a resin lining to an inner surface of a pipe by using a “spray gun apparatus for coating in a pipe” (Japanese Patent Application No. 2000-126969) to which a patent application was previously filed by the present applicant.
[0010]
First, a liquid resin composition is prepared to a predetermined composition, and a preparation is made to supply the liquid resin composition to a spray gun device for in-pipe coating at a predetermined temperature and pressure. When ready, feed the spray gun device into the tube to be coated. In this case, the spray gun device is fed from the end of the minimum diameter pipe, and is propelled to the vertical main pipe having the maximum diameter or the medium diameter pipe in front of the vertical main pipe by using appropriate propulsion means. When the spray gun device reaches the target position, the gear pump is activated to supply the liquid resin composition to the spray gun device, and the spray gun device is pulled along the reverse path to the time of feeding and moved. The liquid resin composition is sprayed from the spray holes of the spray tip on the way to form a thick resin coating on the inner surface of the pipe to be coated. The resin coating film thus formed becomes a solid resin thick film after being left for a certain time due to the effect of the curing / drying agent contained in the composition. This problem solving means corresponds to claim 1.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
(1st Embodiment)
In the first embodiment of the present invention, in a step of feeding a spray gun device into a pipe to be coated in the above-mentioned problem solving means, a propelling force is applied to the spray gun device by feeding out a paint hose from a propulsion device, and spraying is performed. When the tip of the gun device reaches the branch of the tube, the tip is controlled by a direction controller so as to face a desired direction. These propulsion devices and direction controllers have been referred to above as "suitable propulsion means".
[0012]
With reference to FIG. 1, the spray gun device for coating in a pipe (this device) will be described. FIG. 1A is an exploded view showing each part of the apparatus 10. In this apparatus 10, a rotary type automatic spray tip 1 is attached to a nipple 5 at a tip, a paint hose 2 is connected to a nipple 7 at a trailing end, and a band spring 4 is connected between the two via a movable nipple 6. It is attached in a spherical shape. The band spring 4 changes the degree of curvature according to the diameter of the pipe to be coated, and the coil spring 3 connecting the three nipples 5, 6, 7 expands and contracts accordingly. With this configuration, as shown in FIGS. 1B and 1C, the spray gun apparatus main body 10 is supported so as to always coincide with the center axis of the pipe regardless of the diameter of the pipe. In this case, the tip of the spray tip 1 does not come into contact with the tube wall, and a gap for properly performing spraying is secured.
[0013]
The paint hose 2 includes a pressure-resistant rubber tube as the innermost layer, a metal mesh as the intermediate layer, and a soft plastic or rubber layer as the outermost layer, and has a rigidity capable of transmitting a propulsive force applied in the axial direction to the distal end portion. A monitor fiberscope 8, an optical fiber bundle 9 for illumination, and a direction controller 15, which will be described later, are attached to the outer periphery of the paint hose 2 along its longitudinal direction by fasteners (FIGS. 1B and 1C). And (D)). The inside of the tube is illuminated with light from the optical fiber bundle 9 for illumination, and the position of the spray tip 1 and the branch position of the tube in the tube can be confirmed with the fiber scope 8. The paint hose 2 is pushed or pulled by the propulsion device 14.
[0014]
The propulsion device 14 is configured to be driven by a motor with the paint hose 2 interposed between a pair of rollers rotating in opposite directions, and to reverse the rotation direction as necessary. Since the fiber scope 8 and the like are attached to the outer periphery of the paint hose 2, it is desirable that the roller is made of a soft and non-slip material such as rubber so as not to damage them.
[0015]
As shown in FIG. 1 (D), the direction controller 15 connects two thin piano wires at predetermined intervals to both sides of the center axis of the body of the nipple 5 to which the spray tip 1 is attached. Is drawn so that the direction of the axis of the nipple 5 can be swung right and left by drawing one of the piano wires. These piano wires are housed in a soft plastic or rubber sleeve of the same length as the paint hose 2 and extend along the outer periphery of the paint hose 2 to the operator's hand.
[0016]
In order to feed the spray gun device 10 into the inside of the pipe to be coated, it is fed from the end of the minimum diameter pipe, and is propelled to the vertical main pipe having the maximum diameter or a suitable medium diameter pipe. On the way, the position of the tip of the spray gun 10 in the pipe is confirmed using the fiber scope 8, and at the place where the pipe branches, the direction controller 15 is used so that the tip of the spray gun 10 is directed in a desired direction. Control. When the spray gun device 10 reaches the target position, the propelling device 14 is reversed and the liquid resin composition is discharged from the spray hole of the spray tip while pulling the spray gun device 10 at a constant speed so as to follow the above-described path in reverse. Spray toward the tube wall.
[0017]
(2nd Embodiment)
In the second embodiment of the present invention, the liquid resin composition used in the above-mentioned method is composed of a solvent-free room temperature-curable or thermosetting resin-based paint and various additives.
[0018]
The resin component in the composition is a polyurethane resin, an epoxy resin, an unsaturated polyester resin, a vinyl ester resin, or the like. Additives such as curing agents are added to these, but no solvents are added. Each of these resin components is a liquid low molecular weight polymer, and is cured by the added curing agent at the working temperature or a slight heating after the coating film is formed, and is transformed into a robust macromolecular weight polymer. On the other hand, in the case of a thermoplastic resin, the molecular weight is large, so that a large amount of a solvent must be used. In addition, the thermoplastic resin is weak to heat and soluble in a solvent, and is not suitable for lining applications.
[0019]
Since this composition is a solventless type, the resin concentration is not diluted by the solvent, so that a thick film can be formed at once by a single application. There is no sagging of the coating film, and uneven film thickness is prevented. In addition, since the generation of harmful solvent vapor is small, it is suitable for a person to work in a residential complex. The concentration of the resin in the composition varies depending on the type of the resin, but generally ranges from 50% by weight to 70% by weight, and the viscosity ranges from 10,000 CP to 50,000 CP. This embodiment corresponds to claim 2.
[0020]
(Third embodiment)
In the third embodiment of the present invention, a silane coupling agent for improving the adhesion of a resin coating film to a tube wall is compounded as one of the additives constituting the liquid resin composition.
[0021]
By blending a silane-based coupling agent, the adhesion between the resin coating and the inner surface of the drainage pipe can be secured without using a primer, so that the time for undercoating can be saved and the construction time can be shortened. it can.
[0022]
Examples of the silane-based coupling agent include, for polyurethane resins and epoxy resins, γ-glycidoxypropyl trimethoxysilane (NUC silane coupling agent, manufactured by Nippon Yunika, trade name A-187), or γ-glycidoxypropyl trimethoxysilane. Aminopropyl trimethoxysilane (NUC silane coupling agent, manufactured by Nippon Yunika, trade name A-1110) or the like is used. The target resin is not necessarily limited to the above-mentioned polyurethane resin and epoxy resin, but is widely used. The amount used is in the range of 0.01 part to 5.0 parts with respect to the solid content of the liquid resin, and the optimal use range is preferably 0.1 part to 2.0 parts. This embodiment corresponds to claim 3.
[0023]
(Fourth embodiment)
According to a fourth embodiment of the present invention, a metal carboxylate is blended as a desiccant for quickly drying and curing a coating film as one of the additives constituting the liquid resin composition. It is. Since the lining film thickness to be realized by this method is 50 to 100 times thicker than a normal coating film, a desiccant is blended in order to shorten the drying time and prevent a delay in the construction period.
[0024]
A small amount of a metal carboxylate (manufactured by Nippon Chemical Industry Co., Ltd.) is used as a desiccant. Examples of the carboxylic acid include naphthenic acid, octylic acid, neodecanoic acid and the like. The metal salt is a salt of cobalt, lead, manganese, zinc, calcium, tin and the like, and one or more of these are selected and used. For example, cobalt naphthenate or a mixture of this and zinc naphthenate can be used. Although the drying mechanism of the metal carboxylate has not been completely elucidated, it is conceivable that the peroxide is formed in the first stage and the radical is formed by the decomposition in the second stage. The amount used is in the range of 0.01 part to 1.0 part with respect to the solid content of the liquid resin, and the optimum use range is preferably 0.05 part to 0.5 part. This embodiment corresponds to claim 4.
[0025]
(Fifth embodiment)
The fifth embodiment of the present invention specifies the characteristic construction conditions of the present method, such as the temperature, pressure, and film thickness of the liquid resin composition used in the present method. In this method, the temperature of the liquid resin is maintained at a constant temperature between 25 ° C. and 35 ° C., preferably 30 ° C., throughout the four seasons. The reason for this is to prevent fluctuations in the viscosity and curing time of the liquid resin due to a change in temperature, and to manage the lining process so that construction can be performed under constant conditions. If the temperature is not kept at the above-mentioned constant temperature, for example, in summer, the temperature of the resin rises to 30 ° C. or higher, so that the viscosity of the liquid resin decreases. The film thickness increases. Conversely, in winter, the temperature drops to near 0 ° C. At, for example, 20 ° C, the viscosity increases and the usable time is extended to 8 hours, and the film thickness is reduced, and at the same time, the curing is slow, and the lining is completed within the scheduled time. There is a disadvantage that the work cannot be completed.
[0026]
In this method, the temperature of the liquid resin composition is maintained at a constant temperature as described above, and the pressure is increased to 10 kgf / square centimeter or more and 100 kgf / sq. Is sprayed from a spray tip spray hole to form a resin thick film having a thickness of 500 μm or more and 1200 μm or less on the inner wall of the pipe to be coated. Optimum resin film thickness ranges from 800 micrometers to 1100 micrometers.
[0027]
The reason why the coating film is thickened in this way is that if the film thickness is usually about 5 to 20 micrometers, the resin film may be worn out in a short time. If the film thickness exceeds 1200 micrometers, the cost increases, and furthermore, it takes a long time to dry and cure, and the construction period becomes longer, which makes practical use difficult. The pressure of the above resin composition is such that the liquid resin composition having the above-mentioned viscosity of 10,000 CP to 50,000 CP is ejected from a spray tip injection hole having a diameter of about 1 mm, and the thickness is adjusted within an allowable time. Is the pressure required to form the resin coating film. This embodiment corresponds to claim 5.
[0028]
【Example】
Hereinafter, the present invention will be described with reference to Examples 1 and 2, and the main points thereof are shown in Table 1. In the table, “parts” and “%” are numerical values on a weight basis with respect to the solid content of the liquid resin. Further, the test of the coating film was performed according to the following method.
"Coating resin material adhesion and curing test method" JIS K-5400
(1) Evaluation method of adhesion by cross-cut test (2) Evaluation method of hardness by pencil scratch value (3) Chemical resistance test is evaluated by the test according to the manufacturer's catalog.
(Example 1)
Rehabilitation work by resin lining of the drainage pipe for the indoor of the apartment was performed in the following order.
(1) Inspection and Cleaning of Inner Surface of Drainage Pipe First, a sea snake in-pipe inspection camera system KD100 (FIG. 4, sales agency: Ridge Tool Company, Ohio, USA) was installed inside the apartment interior drainage pipe shown in FIG. The in-pipe inspection camera 17 was inserted from the pipe 13 having a diameter of 50 mm. From the vertical main pipe 11 having a diameter of 200 mm to the pipes having diameters of 150, 100, 75, and 50 mm in order, the inner surface of the pipe is photographed with a camera 17 and observed with a TV monitor 16. The condition was inspected. Other drains were examined as well.
[0030]
Next, a chain knocker (FIG. 5 (B)) is attached to the end of a Coleman drainage pipe cleaning machine K375 (FIG. 5 (A), released by the same company as above), and is moved from the large-diameter pipe to the small-diameter pipe. While rotating, the scale in the tube was removed. Then, replace the chain knocker with a ball wire brush (FIG. 5 (C)) to remove foreign substances and to make the inner surface of the pipe 80-120 mesh in order to obtain an anchor effect between the coating film and the pipe wall. It was roughly roughened.
[0031]
After completion of the above operation, a 2% aqueous solution of caustic soda heated to 50 ° C. was poured from the top of a 50 mm-diameter pipe to remove oil and corrosive substances, further washed with 50 ° C. hot water, and then sent with 80 ° C. hot air. And dried for about 30 minutes.
[0032]
(2) Lining the inner surface of the tube with the liquid resin composition As a liquid resin coating composition, 100 parts of a solvent-free polyurethane resin (manufactured by Tope Corporation: New urethane 21, concentration 65%, viscosity 20,000 CP) 100 parts (base material: To the curing agent = 7: 1), 0.5 part of γ-aminopropyltrimethoxysilane A-1110 as a silane coupling agent and 0.2 part of cobalt naphthenate as a drying agent are added, and the mixture is thoroughly stirred and mixed. Then, the mixed liquid resin composition was kept at 30 ° C. in the suction-side insulated tank 20 of the gear pump device 18 (FIG. 3, manufactured by Takachiho Machine Co., Ltd.).
[0033]
The paint hose 2 is connected to the discharge pipe connection port 19 of the gear pump device 18, the spray tip 1 is attached to the spray gun device 10 for coating in the pipe, and the spray gun device 10 is fed from the end of the smallest diameter pipe 13 shown in FIG. While pushing the paint hose 2 with the propulsion device 14, the position in the pipe at the tip of the spray gun device 10 is checked with the fiber scope 8, and the tip of the spray gun device 10 is directed to the desired direction using the direction controller 15 at the branch of the tube. It was controlled so as to face, and was propelled to the maximum diameter pipe 11 through the medium diameter pipe 12. When the maximum diameter pipe 11 has been reached, the propulsion device 14 is reversed, and the paint hose 2 is pulled in the direction of the medium diameter pipe 12 and the small diameter pipe 13 by following the reverse path to that described above. While moving 10, the discharge pressure of the gear pump device 18 was adjusted to 50 kgf / cm 2, and the liquid resin composition was sprayed onto the inner surface of the pipe from the spray hole 1 mm in diameter of the spray tip 1, and on average, 1, A lining thickness of 050 micrometers was obtained. When the lining was completed, hot air at about 80 ° C. was sent for about 30 minutes to sufficiently cure the lining.
[0034]
The construction time was about 8 hours in total. As a result of the lining, a step at the pipe joint is eliminated, so that foreign matter is less likely to be caught, and at the same time, a reinforcing effect of improving the mechanical strength of the pipe itself was recognized. Separately, a test piece was prepared by lining the same liquid resin on a vinyl chloride plate and an iron plate under the same conditions, and an adhesion and hardness test and a chemical resistance test were performed. Table 1 shows the results. The drainage pipes are mostly iron pipes in old apartment buildings, and PVC pipes in relatively new apartment houses.
[0035]
(Example 2)
In the same manner as in Example 1, the inner surface of the drainage pipe is inspected by a Sea Snake in-pipe inspection system (FIG. 4), and then cleaned and dried by a Coleman drainage pipe cleaner (FIG. 5). Co., Ltd .: for acid-resistant lining, resin: curing agent = 8: 2, concentration 65%, viscosity 15,000 CP) 100 parts of γ-glycidoxypropyl trimethoxysilane A-187 as a silane coupling agent 0.5 parts and 0.2 parts of cobalt naphthenate as a drying agent were added and mixed, and the mixture was kept at 30 ° C.
[0036]
This liquid resin composition was put into the suction-side heat-retaining tank 20 of the gear pump device 18 and lining work was performed in the same manner as in Example 1 to obtain an average lining film thickness of 1,010 micrometers. The time required for the construction was about 9 hours in total. Test pieces were prepared in the same manner as in Example 1, and the results are shown in Table 1.
[0037]
【The invention's effect】
(Invention of claim 1)
According to the drain pipe rehabilitation method according to the invention of claim 1, the lining can be continuously performed from a large-diameter pipe having a diameter of 200 mm to a small-diameter pipe having a diameter of 50 mm. The pipe rehabilitation work can be completed. Therefore, there is a great feature that the resin lining work of the drainage pipe can be performed in a state where residents live in an apartment house such as an apartment. In addition, the lining reduces the amount of foreign matter caught and enhances the mechanical strength of the drain pipe. Comparing these features with the conventional ball pig method, hose lining method, reflow method, etc., the construction period is very short, it is extremely advantageous in terms of economy, and the application range is extremely wide in society. It can be said that the rehabilitation method for indoor drainage pipes for houses has been established.
[0038]
(Invention of claim 2)
According to the composition of the liquid resin composition provided by the invention of claim 2, the main component is a non-solvent type, room temperature curing type or thermosetting type liquid resin. Since these liquid resin compositions generate less harmful solvent vapor, they are suitable for work in apartment houses where people live. In addition, since it is a room temperature curing type or a thermosetting type, a robust lining film can be formed quickly after injection by the temperature of the working environment or slight heating.
[0039]
(Invention of claim 3)
According to the third aspect of the present invention, an additive for improving the adhesion between the pipe wall and the resin lining layer is provided. Therefore, in the drain pipe rehabilitation method according to the first aspect of the present invention, a primer undercoat layer is previously formed on the inner wall of the pipe. There is no need to form it, and it is possible to perform resin lining all at once, and a significant reduction in construction time is realized.
[0040]
(Invention of Claim 4)
According to the invention of claim 4, since an appropriate drying agent is provided according to the type of the liquid resin to be used, in the method of rehabilitating the drainage pipe according to the invention of claim 1, even though the resin film is extremely thick, It is possible to harden in a short time, and the construction time is significantly reduced.
[0041]
(Invention of claim 5)
According to the fifth aspect of the invention, in the drain pipe rehabilitation method according to the first to fourth aspects of the invention, a combination of construction conditions that can exhibit the most advantageous features is provided. In particular, the formation of a thick film eliminates pinholes, improves the acid resistance, alkali resistance, and hot water resistance of the water distribution pipe, thereby eliminating water leakage, and significantly improving the durability combined with the above-mentioned reinforcing effect, improving usability. You.
[Brief description of the drawings]
FIG. 1 is an assembly view of a spray gun apparatus for coating in a pipe (A), a schematic view when a diameter of a pipe to be coated is large (B), a schematic view when a diameter of a pipe to be coated is small (C), and a direction controller. It is a conceptual diagram (D).
FIG. 2 is a conceptual diagram of a drain pipe rehabilitation method using an in-pipe coating spray gun device.
FIG. 3 is a front view showing the gear pump device.
FIG. 4 is a perspective view showing an example of an in-pipe inspection camera system.
FIG. 5 is a perspective view of a main body in an example of a drain pipe cleaning machine (A), a view of a chain knocker (B), and a view of a ball and wire brush (C).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Spray tip 2 ... Paint hose 3 ... Coil spring 4 ... Band spring 5, 6, 7 ... Nipple 8 ... Fiberscope for monitoring 9 ... Optical fiber bundle 10 for illumination 10 ... Spray gun device for in-tube coating 11-13 ... Coated pipe 14: Propulsion device 15: Direction controller 16: TV monitor 17: In-pipe inspection camera 18: Gear pump device 19: Discharge piping connection port 20 of the gear pump device

Claims (5)

A method of rehabilitating the inner surface of an aging apartment house indoor drainage pipe by applying resin lining,
A step of preparing the liquid resin composition to a predetermined composition, putting it into a suction-side heat retaining tank of a gear pump device, maintaining the temperature at a predetermined temperature, and preparing immediately so that it can be supplied to a spray gun device for in-pipe coating as needed,
A step of feeding the spray gun device from the end of the small-diameter pipe of the indoor drainage pipe to be coated into the inside, and propelling the main pipe of the large diameter or the medium-diameter pipe in front of the large-diameter main pipe,
After the spray gun device reaches the target pipe, the liquid resin composition supplied from the gear pump device is supplied to the spray gun device while pulling and moving the spray gun device from the arrival position toward the end of the small-diameter pipe. By spraying from a spray tip spray hole, to adhere a resin film of a predetermined thickness on the inner surface of the pipe to be coated,
Curing and drying the resin coating thus obtained, and applying a resin lining to the inner surface of the pipe to be coated. The drain pipe rehabilitation method according to claim 1, wherein the liquid resin composition comprises a solvent-free room temperature-curable or thermosetting resin-based paint and various additives. 3. The drain pipe rehabilitation method according to claim 2, wherein a silane coupling agent that improves the adhesiveness of the resin coating film to the pipe wall is compounded as one of the additives constituting the liquid resin composition. The drain pipe according to claim 2 or 3, wherein a metal carboxylate is blended as one of the additives constituting the liquid resin composition, as a desiccant for quickly drying and curing the resin coating film. Rehabilitation method. While maintaining the liquid resin composition at a predetermined temperature between 25 ° C. and 35 ° C., the pressure is increased to 10 kgf / square centimeter or more and 100 kgf / square centimeter or less by a gear pump device, and this is injected from a spray tip injection hole of a spray gun device. The drain pipe rehabilitation method according to any one of claims 1 to 4, wherein a resin coating film having a thickness of 500 micrometers or more and 1200 micrometers or less is formed on the inner surface of the pipe to be coated.

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