JPS589317B2 - pipe lining - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an improved pipe lining coating.

Recently, red water outbreaks have been occurring frequently due to rusting of existing water pipes due to pollution of water sources, and countermeasures are urgently needed.

Therefore, the present applicant previously proposed in Japanese Patent Application No. 47-7819 (Japanese Patent Publication No. 51-40595) that it is suitable as a pipe lining material with excellent strength and chemical resistance, and that the above-mentioned rusted piping can be recycled. The present invention provides a novel pipe lining coating material that can be used as a reinforcing material for existing pipe materials.

As a result of further intensive studies, the inventors of the present invention have found that the construction results are further improved by using a heat-resistant cylindrical film with good peelability and a moisture-proof cylindrical film in two layers.

That is, the gist of the present invention is that a fibrous material impregnated with a viscous thermosetting resin composition is interposed between an outer cylindrical film and an inner cylindrical film in the form of a sandwich. In the coating material for pipe lining,
The inner cylindrical film is made of a heat-resistant cylindrical film impregnated with the thermosetting resin composition and has good peelability from the fibrous material, and the inner cylindrical film is made of a highly moisture-proof cylindrical film. A pipe lining coating material comprising at least two layers of cylindrical film.

The inner cylindrical film, which is a feature of the pipe lining coating material (hereinafter simply referred to as lining material) of the present invention, has at least two layers of cylindrical film, as shown in the schematic perspective views of FIGS. 1 and 2 of the accompanying drawings. The outer cylindrical film (1 in Figures 1 and 2) is a fibrous material (hereinafter referred to as F) containing a thermosetting resin composition having viscosity.
The inner cylindrical film (2 in Fig. 1 and 3 in Fig. 2) is press-fitted for the purpose of having good heat resistance and good releasability from the FRP base material because it contacts the RP base material (referred to as RP base material). F
This is a cylindrical film for internal pressurization that has the dual function of moisture-proofing against high-temperature steam for RP heat curing.

That is, in the lining material of the present invention, for example, as shown in Fig. 1, tubes (1 in Fig. 1) made of polyamide, polyester, or fluorine resin, etc., which have good heat resistance and mold releasability from FRP, are used. The inside is made of polyolefin, polyvinyl chloride, polyester, which has excellent moisture resistance.
A double-layered tube made of polyvinylidene chloride, fluororesin, etc. (2 in Figure 1) is inserted, or an outer layer is placed inside a tube similar to 1 in Figure 1 as shown in Figure 2. A polyamide-polyolefin laminate tube (3 in Figure 2) is made of a polyamide film with good heat resistance (3a in Figure 2), and the inner layer is a polyolefin film with good moisture resistance (3b in Figure 2). A cylindrical film for internal pressure, such as a double-layered film inserted or, in some cases, a pre-laminated composite tube such as a polyamide-polyolefin laminate tube, is used as the inner layer cylindrical film.

However, when the above-mentioned composite tube is used alone as an inner layer cylindrical film, it is desirable that the thickness be reduced in consideration of heat resistance.

The fibrous material impregnated with the viscous thermosetting resin composition used in the lining material of the present invention is so-called FRP.
It is the base material.

As reinforcing fibers used in FRP base materials, abrasion-resistant polypropylene fibers, heat-resistant, high-modulus, or high-strength fibers such as carbon fibers, graphite fibers, and whiskers are sometimes used, but the mainstream reinforcing fibers are Glass fiber is inexpensive and has a relatively good reinforcing effect.

The thermosetting resin composition used for the FRP base material must have chemical resistance, strength retention and improvement properties, and preferably be reasonably inexpensive; however, it must also have the following two performance aspects: You need to choose from.

First, by impregnating glass fiber with the above resin, FRP
The second option is to use a resin compound that has a low resin viscosity immediately after making the base material, but thickens when left at a temperature of about 30°C for a relatively short period of time (this is called B-staging). ,
A method to moderately increase the viscosity of the resin by adding additives to the above resin over a relatively long period of temperature changes and changes over time [Technology to B-stage styrene resin in a completely controlled manner - FRP Bripreg mat used for press molding, namely S. M. C(Sheet
It is important to select a resin composition suitable for the molding compound manufacturing technology.

A typical example of the thickening effect of adding additives to this resin is the case where calcium carbonate and magnesium oxide are added to a polyester resin.

The resin viscosity required for the FRP base material during pipe lining construction depends on the glass fiber material, glass content, and FRP base material.
It varies depending on the thickness of the RP base material and the size of the construction pipe, but
500,000 to 8 million cPs can be used.

In addition, the above raw material resins include epoxy resin, phenol resin, formaldehyde resin, polyester resin,
Thermosetting resins such as styrene resins can be used depending on the intended use.

FR is made by impregnating glass fiber with the above resin product.
To make a P base material, it is necessary to use an FRP material containing a large amount of resin to prevent pinholes from forming, so one ply of matte glass fiber is necessary. The thickness of the substrate is at least 0.2m
m or more, preferably 0. The thickness is 5 mm or more, and the maximum thickness can be up to about 20 mm.

This is the maximum thickness possible in one lining construction.

If a greater thickness of the FRP base material is required, the thickness can be increased by performing a second or third lining after the first lining.

It should be noted that when roving cross-shaped glass fibers are used, the strength of the FRP material is higher than that of mat-like glass fibers, the reinforcing effect is also higher, and the thickness per pride is also greatly increased compared to cross-shaped glass fibers.

Next, the above-mentioned at least two-layer internal pressure cylindrical film of the present invention will be explained in more detail in relation to various films.

When the FRP base material is heated and cured by injecting heated steam into the inner cylindrical film of the lining material, the inner cylindrical film absorbs moisture and swells, expanding in the circumferential and axial directions, producing tortoiseshell-shaped wrinkles.

At this time, the axial wrinkles are eliminated because the lap part is stretched by 2 to 5% in the circumferential direction, but it is difficult to do anything about the axial wrinkles in other parts, so the swelling rate due to heated steam is small. It is necessary to select a tube.

Incidentally, when a nylon 6 tube is immersed in water at 20° C. for 1 hour, an elongation of 2 to 4% is confirmed.

In addition, when an FRP base material, which is a fibrous material impregnated with a polyester resin composition, which is the most typical among the thermosetting resins for FRP base materials, is cured by heated steam, the amount of water exerted on the polyester resin is The influence is significant, and the presence of water causes heat to be dissipated to the water at the peak of heat generation, preventing complete curing.

Therefore, water vapor is passed through the cylindrical film for internal pressure to prevent direct contact with the FRP base material, but since the film itself also allows some moisture to pass through, the cylindrical film for internal pressure with as low a water vapor permeability as possible is used. It is understood from Table 1 below that a polyolefin-based film is suitable as an inner layer film for an internal pressure film that is particularly excellent in that both water absorption and water vapor permeability are low. Ru.

Furthermore, the thermal factors that affect the cylindrical film for pressurizing the inner surface are the amount of heat of water vapor for curing the FRP base material and the FRP
The curing heat value of the base resin is the largest.

This heated steam temperature is the decomposition temperature (
Although it varies depending on the temperature (approximately 60° to 100° C.), curing is faster at a temperature 20° to 40° C. higher than the curing agent decomposition temperature, and complete curing occurs without localized uncured portions.

Therefore, steam is injected at a temperature of 80° to 140°C for several hours to cure and after-cure the resin, but the inner cylindrical film does not deteriorate due to this amount of heat, and the heat generated by the curing of the FBP base resin (e.g. Glass fiber-reinforced polyester must withstand heat generation (which occurs for several minutes at a temperature close to 200°C).

That is, Table 2 below shows a comparison of the heat resistance of various plastic films.

(Note) 1. These are the results according to ASTM D759-48 test method.

2. The wide range of heat resistance of nylon 6 is due to the fact that it depends on the time of use, and the heating required for this lining (2 hours)
As can be seen from Table 5 below, there is no problem even if it is used at the upper limit of the maximum operating temperature.

Next, the above-mentioned cylindrical film for internal pressure must have good peelability from the FRP base material surface. For example, polyethylene and polypropylene films do not soften or melt as shown in Table 2 above. occurs, resulting in FR
It bites into the surface of the P base material and is impossible to peel off.

In addition, after the FRP base material is completely cured, as shown in Fig. 10, there is a step of peeling off the inner surface pressurizing cylindrical film (4 in Fig. 10) inside out using a rope (9 in Fig. 10). Therefore, the cylindrical film (abbreviated as tube) is F
It is necessary to maintain the strength required to peel off from the surface of the RP base material (5 in Figure 10) and the strength to withstand the weight of the drain (10 in Figure 10) and the tube itself.

Moreover, as shown in FIG. 10, the dray 710 accumulates in the lower part of the joint of the old cast iron pipe 11 and in the part where the entire connected pipe is lower than the part where the sealing jig is attached. This is the most important factor, and it is necessary to select a cylindrical film for pressurizing the inner surface with less deterioration in strength after hardening of the FRP base material.

Therefore, not only does the film have high tensile strength and tear strength at room temperature, but also at high temperatures (80° to 140°C, 2
A necessary condition for the cylindrical film for internal pressurization used in the lining material of the present invention is that it sufficiently maintains the strength of the original film or a strength close to it even after undergoing a heat history of 180° to 220°C for 10 minutes). It is.

Table 3 below shows the tensile strength and tear strength of various plastic films, and Table 4 shows the results of a thermal deterioration test based on the tensile strength of the inner cylindrical film (abbreviated as tube) used in the lining material of the present invention. indicate.

As described above, it is understood that a polyamide film is most suitable as the outer layer film of the inner layer cylindrical film having good heat resistance, peelability, and strength characteristics.

In addition, as shown in Table 3, the polyamide tube that is the outer layer film of the cylindrical film for internal pressure of the present invention has a tensile strength at room temperature that is slightly larger than other tubes, and a tear strength that is about the same. Moreover, as shown in Table 4, the tensile strength after undergoing thermal history is 80% of the tensile strength at room temperature.
%, it is the best material for existing large-diameter tubes (folded diameter 500 to 1000 mm).

On the other hand, as can be seen from the results in Table 4, nylon 6-
Since the influence of polyethylene melting on the strength deterioration of polyethylene laminate tubes is very large, in order to minimize the influence, it is most desirable to use this laminate tube and a polyamide tube in two layers.

The at least two-layer cylindrical film of the present invention may be one in which two or more different types of films are inserted, or may be a laminated composite film.

Next, an embodiment in which the lining material of the present invention is manufactured using the above-mentioned at least two layers of the cylindrical film for internal pressure as the inner layer cylindrical film and the above-mentioned FRP base material is described in the third to sixth sections.
This will be explained in detail with reference to the drawings.

In the first manufacturing method, as shown in the cross-sectional diagram in Figure 3, a release film (6 in the figure) is first placed on a fixed plate (1 in the figure) such as an aluminum plate, and then A predetermined glass fiber (a mat or cloth-like material, 5 in the figure) is spread and impregnated with the above-mentioned thermosetting resin composition to form an FRP base material, and then the above-mentioned at least two-layer internal pressure cylindrical film ( Place 4) in the center of the FRP (5 in the figure).

As shown in the cross-sectional diagrams of FIGS. 4 and 5, both ends of the FRP base material 5 are successively bent at the ends of the cylindrical film 4, and the cylindrical film 4 for pressurizing the inner surface is inserted m therein.

At this time, the lap portion (5' in Fig. 6) is set to be 20 to 400 mm, but since the resin has not yet been thickened or hardened, the lining is attached in one piece.

Finally, fold the film 6 placed on the fixed plate 7 and make the FRP
The base material 5 is injected to prevent uneven distribution and outflow of the resin contained in the base material 5, and is finished as shown in the schematic cross-sectional view of the product of the present invention in FIG.

In the figure, C indicates the wrap portion of the outer surface film (release film) 6.

In addition, when layering glass fiber materials in multiple layers, the number 5 shown in FIG. 3 will be several, so each layer should be slightly bent one by one, so that even if several lap parts 5' shown in FIG. Shift it little by little to make the finished surface as smooth as possible.

When the above first method is mechanized for production, it is carried out using one example of the continuous apparatus described in the above-mentioned Japanese Patent Application No. 47-7819 to obtain a finished product as shown in the cross-sectional schematic diagram of FIG. .

The second method is to first make a bag-like object from a glass fiber material or use a commercially available bag-like object as is, and insert the above-mentioned cylindrical film for internal pressure (4 in Figure 8) into the bag-like object. The glass fiber bag is impregnated with the resin composition by either the hand lay-up method detailed in the first method or the mechanical method. The FRP base material (5 in Figure 8)
) In order to prevent the resin distribution from becoming uneven or flowing out, a film (an outer layer of release film) is applied to both surfaces of the resin.
6b and 6b) of FIG. 8 are covered or wrapped to finish as shown in the schematic cross-sectional view of the product of the invention in FIG.

The lining material of the present invention produced by the first or second method described above can be used for the length necessary for pipe lining construction as shown in the schematic cross-sectional view of FIG. Roll and store as shown in (Lining material).

The lining material of the present invention produced as described above is made into a cylindrical shape for internal pressure by inserting a polyamide (outer layer) and polyolefin (inner layer) laminate tube inside the polyamide tube used as the inner cylindrical film. The specifications for implementing the film (inner layer cylindrical film) are shown in Section 5 below.
Display in table.

Next, the structure and effects of the inner surface pressurizing cylindrical film used as the inner cylindrical film of the lining material of the present invention illustrated in FIGS. 1 and 2 will be specifically explained.

The cylindrical film for pressurizing the inner surface shown in FIG. 1 is composed of a polyolefin tube on the inside and a polyamide tube on the outside, and water vapor passes through the inner tube, that is, the side facing the polyolefin film.

As shown in Table 1, the water absorption and water vapor permeability of polyolefin films are considerably lower than those of other plastic films, so that the elongation due to swelling due to moisture absorption can be sufficiently suppressed.

Regarding heat resistance, for example, low-density polyethylene has a softening point of about 105° to 110°C, so if it is exposed to steam at 80° to 140°C for several hours, it will completely soften and some parts will not melt. happen.

Holes are created in the polyethylene and the steam comes into direct contact with the polyamide tube, causing the polyamide tube to swell and the melted wrinkles of the polyethylene to reach the outer layer of the polyamide film and adhere to the surface of the FRP base material. F at the point when a hole occurs in
The resin component of the RP base material has already been cured, so even if water vapor comes into contact with the surface of the FRP base material through the polyamide film, it has almost no effect and a good lining surface can be obtained.

The cylindrical film for pressurizing the inner surface shown in Fig. 2 is a polyolefin-polyamide laminate tube (with a polyolefin film on the inside and a polyamide film on the outside), and the inner tube of the double tube shown in Fig. 1 (
When used in place of 2) in Figure 1, even if the polyolefin (3b in Figure 2) melts after being in contact with heated steam for several hours, the polyamide layer (3a in Figure 2) of the outer layer of the laminate will melt.
As a result, the outer polyamide tube (1 in Figure 2) does not come into contact with a large amount of water, but only comes into contact with the water vapor that comes through the polyamide film of the outer layer of the laminate, and the polyethylene melt on the surface of the FRP base material does not change. A good lining surface can be obtained with almost no wrinkles or moisture effects.

Further, the cylindrical film for pressurizing the inner surface must be completely removed by peeling it off as shown in FIG. 10, depending on the degree of hardening of the FRP base material.

The conditions are that the tube has good releasability from the FRP base material, has strength to withstand tearing off in the event that it bites into the base material surface as described above, and has a drain (10 in Figure 10). ) and the strength to withstand the weight of the tube itself.

The cylindrical film for pressurizing the inner surface shown in Fig. 2 using the above-mentioned laminate tube uses a two-layer polyamide film consisting of the laminate outer layer (3a in Fig. 2) and the outer tube (1 in Fig. 2). Therefore, not only does it have good peelability, but as mentioned above, it is extremely easy to remove and has excellent strength, so it is possible to more reliably and easily remove FRP.
It can be peeled off from the base material surface.

As described in detail above, if pipe lining construction is performed using the lining material of the present invention, many excellent advantages such as moisture resistance, heat resistance, strength, and peelability from the FRP base material, which are possessed by at least the double inner layer cylindrical film, can be achieved. The industrial value of the present invention is great because the synergistic effect of the properties eliminates the drawbacks of current lining materials and makes it possible to line pipes extremely easily, reliably, and with a good finish.

[Brief explanation of drawings]

Figures 1 and 2 are schematic perspective views showing aspects of the inner cylindrical film of the pipe lining coating material (hereinafter referred to as lining material) of the present invention, and Figures 3 to 6 show the fabrication of the lining material of the present invention. FIGS. 7 and 8 are schematic cross-sectional views of other examples of the lining material of the present invention, and FIG. 9 is a schematic cross-sectional view showing one mode of storage of the lining material of the present invention. , and FIG. 10 is a schematic partial cross-sectional view showing an embodiment in which the inner side of an old cast iron pipe including the joints is temporarily covered with the lining material of the present invention, the FRP base material is hardened, and then the inner cylindrical film is peeled off. DESCRIPTION OF SYMBOLS 1...Tubular film, 2, 3...Tubular film for internal pressure, 4...Inner layer cylindrical film, 5...FRP base material, 6...
... Outer layer cylindrical film, 8 ... Linen material, 9 ... Loaf, 10 ... Drain, 11 ... Old cast iron pipe.

Claims (1)

[Claims] 1. A pipe lining coating material in which a fibrous material impregnated with a viscous thermosetting resin composition is interposed between an outer cylindrical film layer and an inner cylindrical film layer in a sandwich-like structure, wherein the inner layer The outer surface of the cylindrical film is made of a heat-resistant cylindrical film that has good peelability from the fibrous material impregnated with the thermosetting tree composition, and the inner surface is made of a highly moisture-proof cylindrical film. A pipe lining coating material comprising at least two layers of cylindrical film.