JP2733411B2 - Seal lining method for pipe inner surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for sealing and lining the inner surface of a pipe, for example, by filling a defective portion of an existing pipe such as a gas pipe with a seal and uniformly covering the inner surface of the pipe with a corrosion-proof lining (lining or lining). ) On how to do that. More specifically, the present invention relates to a lining method for easily repairing and repairing gas pipes, particularly, gas pipes such as an inner pipe, a supply pipe, and a branch pipe from the inner surface. The method of the present invention is characterized in that a lining seal can be performed over a long distance of 20 to 30 m with a simple blower having a low pressure of 0.01 to 1 kg / cm ² , and the cured lining film has excellent gas resistance and sealing properties. And a seal lining method capable of protecting a buried gas pipe for a long time.

[0002]

2. Description of the Related Art Many methods for lining the inner surfaces of gas pipes and water pipes using air (compressed air) have been proposed and applied in the past. In particular, when lining only the inner surface of a pipe, construction methods such as a pig method, a high-pressure air method, and a low-pressure air method and materials thereof have been proposed and applied. However, any of these methods can uniformly or uniformly line the inner surface of the pipe, but cannot seal and seal a hole, a pinhole, or the like without a backup among the defective portions of the pipe. This is because, if a certain pressure or more is applied to transport the lining resin, the lining resin will come out of the defective portion through the hole. On the other hand, attempts have been made to apply a suitable lining material at a low pressure to seal and seal holes and defects, and various proposals have been made. Even if the resin is air-lined at 0 kg / cm ² ), such a resin may have a low viscosity thixotropy in its composition itself. The seal could not be sealed. In addition to the above, a special composition that can seal a defective portion, that is, a composition in which the resin cures instantaneously can be considered, but this is limited to a part of the material and limited tube. It was impossible to seal the lining over a long distance. Therefore, a resin composition containing glass flakes has been proposed as a composition that can seal and seal such defective portions, and is applied as a seal lining on the inner surface of gas pipes, etc. And is being constructed. This method is referred to as a simple processing method, and it is possible to line the inner surface of the seal of a defective portion of a small diameter pipe (20 to 30φ) of a gas pipe with a simple blower. As a practical example of the use of the resin composition containing glass flakes, it is said that a defective portion of an inner tube having a diameter of 25 mm at a distance of 5 to 6 m can be sealed and sealed with glass flakes and lining can be performed.

[0003]

However, in the lining method using the conventional glass flake-containing resin composition, the lining distance is at most 5 to 6 m,
Longer distances, e.g.
There is a problem that it is impossible to apply φ) to pipe repair.

That is, when lining 20 to 30 m with a low-viscosity thixotropic composition containing glass flakes at low pressure, firstly, the lining distance does not advance more than 6 m because the frictional resistance of the resin itself is also large. thing. Second
In addition, there are two drawbacks in that the usable time of the resin comes halfway and hardens and ends in a short distance, so that lining over a long distance was impossible. These factors include:
Although glass flakes have a large sealing effect on hole defects,
It is considered that the lining distance does not increase due to the weight of itself and the difficulty of sliding.

[0005] Next, it is considered that the cause of the resin curing during the lining can be solved by increasing the pot life of the resin. However, in actual tests, it is possible to form the lining coating film only by increasing the pot life. Was not uniform, and the sealing property still had a problem.

[0006] In order to improve these disadvantages, for long distances (2
Development of a seal lining composition (0 to 30 m × 25 φ) and a method thereof has been awaited.

Therefore, the present invention provides a safe, simple, and economical lining method capable of sealing and lining the inner surface of a pipe such as a gas pipe over a long distance of 20 to 30 m using a simple blower. An object is to solve the above problems.

[0008]

From the above, the present inventor has made various investigations and found that a lining method capable of easily sealing lining in a short time at a low pressure with a simple blower over a distance of 20 to 30 m is as follows. Was found to be the most desirable.

[0009]

That is, claim 1 of the present invention.
Then, in 100 parts (weight) of the resin composition for lining, the flake diameter is 600 μm to 1400 μm and the flake diameter is 20 μm.
Mixing ratio of scale-like mica flake of ~ 300μ 1: 2
1: 1 to 20 parts in 2: 1 combined amount 1 to 15 parts in combined amount of finely divided silica and organic thixotropic agent 1 to 30 parts in reactive diluent, 30 minutes pot life The method according to claim ² , wherein the curable resin composition having the above composition is flowed through the inner surface of the pipe at a pressure of 0.01 to 1 kg / cm ² to apply a seal lining to the inner surface of the pipe. In 100 parts (by weight) of the composition, a flake diameter of 600μ to 1400μ and a flake diameter of 20μ
Mixing ratio of scale-like mica flake of ~ 300μ 1: 2
1: 1 to 20 parts in 2: 1 combined amount 1 to 15 parts in combined amount of finely divided silica and organic thixotropic agent 1 to 30 parts in reactive diluent, 30 minutes pot life A step of preparing a curable resin composition having the above, a step of injecting the prepared resin composition into a hopper connected to one end of the open both ends of the pipe, and a step of injecting the hopper. The method is characterized by comprising a step of applying a pressure of 0.01 to 1 kg / cm ^{2 to} the resin composition for a predetermined time to apply a seal lining to the inner surface of the pipe.

[0010]

[Function] Due to the slipperiness of mica flakes, fine powder silica, fluidity by organic thixotropic agent and viscosity lowering property by diluent, low pressure (0.01 to 1 kg / cm ² ), 25 m / The inner surface of the gas pipe of mφ falls 20 to 30 m, and even the rising pipe is lined uniformly, and the defective portion is sealed and sealed from the inner surface, so that maintenance of the gas pipe and the like can be secured for a long time.

[0011]

EXAMPLES (1) In the present invention, an epoxy resin, an unsaturated polyester resin, and a urethane resin are generally used as the lining resin. Since these lining resins are of a type used by mixing a main agent and a curing agent, generally, the main agent is mixed with other components (in the present invention, an organic thixotropic agent or a reactive diluent). ) Is mixed and stirred, and then a curing agent is added to prepare a lining agent in many cases.

For example, when an epoxy resin is taken as an example, the viscosity immediately after mixing is 5,000 to 50 by mixing only a main agent and a curing agent.
000CPS is good and the pot life is 15 ~
About 20 minutes are preferable.

Next, the use of mica flakes (mica flakes) instead of glass flakes improves the slipperiness of the resin as described above, and at the same time improves the sealing performance while reducing the weight. If it is less than 1 part, there is a problem in the sealing property, and if it is more than 20 parts, the bulk of the mica flakes becomes large, the viscosity of the resin, thixotropicity increases, and it is not suitable as a lining composition.
Preferably, about 5 to 15 parts can be said to be the best. Also,
Regarding the shape of the mica, only those with large particles or those with only small particles will result in a problem in the sealing performance.
This is because it is necessary to adapt to various conditions because the hole to be sealed and the defective part are not uniform, the coating film forming the hole seal concentrates on the overlapping part of large flakes,
A situation in which a coating film is formed and the lining material slightly protrudes out of the tube from the hole on the inner surface of the tube to the outside of the tube and is sealed and sealed (described later,
5a).

As the mica of the mica flakes used in the present invention, Clarite mica, Szolite mica and the like are well known as common names. There is not much difference in composition, but rather it is classified by shape size and there are various grades. The type (grade) is divided according to the mesh and flake diameter. Some grades have been surface-coupled to improve the flakes themselves. There are 30 to 200 mesh types in mesh, and 10μ to 70 in flake diameter.
There is a grade of about 0μ. The reason that the flakes are better in mica flakes than glass flakes in the present invention is that the mica flakes are considered to be smooth around the flakes and slippery. Glass flakes, on the other hand, are expected to be less smooth due to artificially hitting the glass and extending it thicker. In the present invention, the size of the mica flakes was changed variously, and a lining experiment was carried out. As a result, those having a large mica flake diameter were 600 μm to 1400 μm, and preferably 500 μm to 900 μm.
The small flakes having a size of 20 μm to 300 μm, preferably 100 μm to 200 μm were excellent in sealing property, sealing property and lining property.

[0015] In addition, the ratio of the large flakes to the small flakes is preferably about 1: 1 to 2: 1 or about 1: 2.

[0016]

Example (2) Next, if the composition does not have an appropriate thixotropic property (softening of the material due to stress and hardening recovery after relieving the stress), the composition is pressed by air pressure to remove the lining material. However, once the tube rises to the upper part of the inner surface of the tube, if the blower is stopped even if it adheres, the lining coating flows down and sags, filling the defective part and making it impossible to form a uniform coating. This is an important item. For this reason, various thixotropic agents were studied in the present invention, but a combination of finely divided silica and an organic thixotropic agent is preferable (described later), and the amount of addition is 1 to 15 parts with respect to the entire resin composition 100. Preferably, 3 to 10 parts is optimal. If the amount is less than 1 part, a stable thixotropic effect cannot be obtained. If the amount is more than 15 parts, the thixotropic property is too high, and the lining composition for a long distance cannot be lined and sealed at a low pressure.

Further, a combination of an organic thixotropic agent and finely divided silica is preferred, and the finely divided silica improves the strength and adhesion of the coating film. The organic thixotropic agent is an organic substance that imparts softening of the material due to stress and hardening recovery after relieving the stress, and a known substance can be used. In particular, those which do not change the thixotropic effect for a long period of time and which can prevent sedimentation of flakes and the like and separation of pigments and form a good composition are preferable, and organic gelling agents are preferable. Therefore, it was necessary to adjust the heating temperature to adjust the compounding of the organic thixotropic agent, and to use a certain amount of unique know-how for the curing time and the dispersion and stirring.

Next, regarding the advantages of the combination of the finely divided silica and the organic thixotropic agent, the thixotropic effect of the organic thixotropic agent due to a rise in temperature is stable because it is incorporated into the thermal expansion (20 to 80 ° C.). ) The point is that the adhesive strength and the smoothness of the resin do not change.

Fine silica powder has a large thixotropic effect at room temperature and improves the mechanical strength and physical properties (such as water resistance) of the resin.

In addition, the results of investigation of fillers other than mica flakes are as follows.

Teflon powder was tested, but had poor adhesion and was NG.

The spherical powder of the foam had an improved lining property. As a result, the sealing property was NG.

Other flake materials other than mica flake include aluminum flake, Cu flake, Zn flake,
As a result of the test, glass flakes and the like showed that the lining film was not formed on the entire tube, but concentrated on the bottom (large portion) because the entire tube was heavy.

In particular, glass flakes were good among them, but the clear difference between mica flakes and glass flakes was that the sealing properties of the defective portion (where there was a hole) were such that glass flakes were once sealed and gaseous. Is stopped, but with time there is a probability of about 50% (by the time the resin is hardened), and mica flakes are 100% sealed by the time the resin hardens. Completely different.

In this regard, it seems that mica returned little when the lining material blown out from the hole slightly returned after cutting the pressure (the lining wind force), and the amount of glass was large.

(3) Next, the addition of the reactive diluent is preferably 1 to 30 parts with respect to 100 parts of the composition.
About 5 to 15 parts is more preferable, and when it is 1 part or less, the effect of lowering the overall resin viscosity is small, and when it is 30 parts or more, the gas resistance and water resistance of the reactivity and the cured resin composition itself, Since mechanical strength etc. become a problem, it is preferably 5 to 5.
About 15 parts is good. The type of the reactive diluent may be a monoepoxy or a diepoxy derivative thereof as an epoxy-based reactive diluent in the general market, and the type is not particularly limited. The use of a reactive diluent other than an epoxy-based diluent is not limited as long as the effect is obtained.

(4) The pot life of the resin is an important factor in terms of workability, and is affected by the construction length of the lining pipe, the outside air temperature, the residual heat of the blower, and the like.
If it is desired to line a tube with a falling or rising portion of m, the required amount of resin will be 2-3 kg, so it is desirable not to cure during the lining, but to cure as soon as the lining is completed. In addition, in the case of a two-pack type epoxy resin, the pot life is short when the amount is large, and the pot life is prolonged when a thin lining coating is used because of an addition reaction.

As a result of various examinations of these points, it was found that if the pot life of the composition used in this way is 30 minutes or less, the tube should be set at 20 to 20 minutes.
It was found that it was difficult to line up 30 m, and that it could be lined up in 30 minutes or more. Therefore, if the pot life is longer, the lining work does not cause any trouble, but if the pot life is too long (for example, 3 hours), the part that has been once sealed by the pressure or vibration moves due to the uncured coating film, which may result in poor sealing. For this reason, it is preferable that about 30 minutes to 2 hours be necessary for securing the sealing property.

Next, specific examples will be described.

FIG. 1 shows the formulation examples and FIG. 2 shows the material names (marked with *). The amount (weight) of the compounded resin shown in the column of the example in FIG. 1 was provided so as to be provided to the lining, and after the mixture was sufficiently cured, mica flakes were added. The comparative example was also adjusted in the same manner.

A mixture obtained by removing the curing agent and the mica flakes from the compositions of Examples 1 to 3 above was mixed with a stirrer for 30 minutes, left to stand in a drier at 80 to 100 ° C. for 2 hours, cooled, and then mixed with 3 pieces. After kneading twice with a roll, further 60-80 ° C
In a dryer for 3 hours and mixed with a stirrer for 30 minutes to obtain a product, and then, as a curing agent, 800 μm of large particles of aromatic modified polyamine and mica flakes and 30 μm of small particles.
Were added in accordance with the mixing ratio of Examples 1 to 3 to adjust the lining material.

Further, the comparative example was adjusted similarly, and finally, a curing agent and glass flake were added according to the comparative example. The glass flakes used were of two sizes, 80μ and 20μ.

Using the resin compositions 1 to 3 of the above examples, the piping as shown in FIG. 3 was set, and a lining test was performed using two turbo blowers. All pipes are 1-2
Four holes each having a diameter of 2 m to 4 m were made, and the sealing properties of the holes and the inner lining properties were confirmed.

In FIG. 3, the pipe (c) has an inner diameter of 25 m.
/ Mφ and the length is about 22m, of which two places, a falling part (g) of 0.5m and a falling part (h) of 1m,
There is one rising part (d) of 0.5 m, and one hole (f) of 1φ is made in four places on the entire circumference at 4 m.

Further, (A) is a hopper connected to the upstream (right end) of both ends of the open cut (opening) of the pipe and into which the composition of the embodiment is injected, (B) is two turbo blowers, and (C) is (E) shows an open piping tail, (B ') shows two air hoses, (A') shows a branch pipe, and (I) shows a curan (cock).

In the lining experiment, first, the compounded resin of Example 1 was prepared, and about 2 kg of the resin was injected into a hopper (a), a hose (b ') was joined to a branch pipe (a'), and a blower (b) )
Compressed air (0.25 kg / cm ² ) is sent from the two units, and the compounded resin of Example 1 that has entered the hopper (a) is flowed to the inner surface of the pipe with the pressure of the blower (b) for lining. At this time, 4
The resin first came out above the hole (1φ) (f), which was located at one place in m, but the air leak disappeared within 2 to 3 minutes, and the compounded resin remained on the outer wall of the pipe in a granular form. The lining with a total length of 22 m was completed in about 30 minutes after the operation of the two blowers (b), and the lining was completed uniformly to the tip of the tail pipe (e). Immediately after the lining is completed, an airtight test is performed, and 300mmHg
The pressure was tested for 24 hours with no leakage, and there was no air leakage, and the holes (f) made every 4 m were also cleanly closed. At the same time, the same test was performed on the blended resins of Examples 2 and 3, but the lining was completed without any problem.

FIG. 4 is a view showing a sealing mechanism. (A)
As shown in (b), when the lining material P flows while covering the inner surface of the pipe wall by the air pressure up to the hole (f) opened in the pipe (c), as shown in (b), The hole (f) begins to be closed by the mica flakes M in P, and as shown in (c), the hole is hardened and completely closed, and a uniform resin film of the lining material P can be obtained.

Next, a test was carried out for the composition 1 of the comparative example shown in FIG. 1 by setting the same piping as in FIG. 3, but the hole closing (adhesion) was 50% and only half of the hole was closed. Not
In addition, the coating film of the lining could only be lined up to 12 m. Therefore, the test for airtightness was not completed. This is considered to be due to poor lining properties because the flakes are slightly heavy due to the glass and are not smooth due to the large angles of the flakes.

That is, as shown in FIG. 5, the state of FIG. 5A is changed from the state of FIG.
The glass flakes G that have once entered the hole (f) are reduced in weight before curing, resulting in poor hole closure. On the other hand, in the case of the present invention using mica flakes, mica flakes are used as shown in (c). The flakes M are hardened as they are pushed up by pressure and are completely closed without lowering.

As described above, the mica flake lining composition of the present invention is very excellent in both sealing properties and lining properties. When repairing a defective part such as a gas pipe, the lining composition can be obtained only by cutting and opening the pipes at both ends. It was found that it was very inexpensive and easy to repair because it could repair and maintain the entire pipe, and was excellent in gas resistance and protection of buried gas pipes.

[0041]

As described above, according to the present invention, there is an effect that lining can be performed over a long distance while sealing a defective portion of an existing pipe.

[Brief description of the drawings]

FIG. 1 is a table showing a combination example in Examples and Comparative Examples of the present invention.

FIG. 2 is a table showing material names of an example and a comparative example in FIG. 1;

FIG. 3 is a piping diagram for a lining test according to the present invention.

FIG. 4 is a partial longitudinal sectional view of a pipe showing a seal lining mechanism according to the present invention.

FIG. 5 is a partial longitudinal sectional view of a pipe showing a difference between a seal lining mechanism of the present invention and a conventional seal lining mechanism.

[Explanation of symbols]

 (B) Hopper (b) Blower (c) Piping (f) Hole P Lining material M Mica flake

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Isao Saito 1-7-7 Suehirocho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Tokyo Gas Co., Ltd. Pipe Technology Development Center (72) Inventor Akio Morinaga Tsurumi-ku, Yokohama-shi, Kanagawa 1-7-7 Suehirocho Tokyo Gas Co., Ltd. Pipe Technology Development Center (56) References JP-A-63-275890 (JP, A)

Claims (2)

(57) [Claims] 1. A flake diameter of 600 μm to 1400 μm and a flake diameter of 20 μm in 100 parts (weight) of a resin composition for lining.
Mixing ratio of scale-like mica flake of ~ 300μ 1: 2
1: 1 to 20 parts in 2: 1 combined amount 1 to 15 parts in combined amount of finely divided silica and organic thixotropic agent 1 to 30 parts in reactive diluent, 30 minutes pot life A seal lining method for an inner surface of a pipe, wherein the curable resin composition having the above composition is flowed at an inner pressure of 0.01 to 1 kg / cm ^{2 on} the inner surface of the pipe to seal the inner surface of the pipe. 2. A flake diameter of 600 μm to 1400 μm and a flake diameter of 20 μm in 100 parts (weight) of a lining resin composition.
Mixing ratio of scale-like mica flake of ~ 300μ 1: 2
1: 1 to 20 parts in 2: 1 combined amount 1 to 15 parts in combined amount of finely divided silica and organic thixotropic agent 1 to 30 parts in reactive diluent, 30 minutes pot life A step of preparing a curable resin composition having the above, a step of injecting the prepared resin composition into a hopper connected to one end of the open both ends of the pipe, and a step of injecting the hopper. A process for applying a pressure of 0.01 to 1 kg / cm ^{2 to} a resin composition for a predetermined time to apply a seal lining to the inner surface of a pipe, the method comprising: