JPH0374628B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to lining materials for pipelines, and in particular for pipelines buried underground, such as gas pipelines, water pipes, power lines, communication lines, etc. This relates to a lining material for lining the interior of a building. In recent years, the inner surface of the pipe has been lined for the purpose of repairing or reinforcing aging pipes as described above, and as a method of lining, the inner surface of the cylindrical flexible lining material is preliminarily lined. Adhesive is applied, and the lining material is inserted into the pipe while turning the inner and outer surfaces inside out using fluid pressure, and the turned-over lining material is crimped onto the inner surface of the pipe using the fluid pressure, and the lining material is inserted through the adhesive. The lining material is adhered to the inner surface of the pipe to form a lining. With this construction method, there is no need to dig up the entire length of the pipeline for construction, and it is possible to construct long pipelines in a short time, and it is also possible to construct pipelines with many bends. In recent years, this method has attracted particular attention as an extremely excellent method. By the way, the lining material used in this method needs to be flexible, airtight, and have considerable strength in the vertical and horizontal directions, so synthetic resin is used on the outer surface of the cylindrical fabric. Those with a film layer are used. The coating layer of this lining material is required to be flexible, have appropriate elasticity, be strong, and have good heat resistance, abrasion resistance, and trauma resistance. When applied to pipes, it is required that the synthetic resin constituting the coating layer be safe in terms of water quality. The materials used for water pipes must meet the standards of the Japan Water Works Association (JWWA). This JWWA standard requires that it conform to the water quality test specified in "Tar Epoxy Resin Paint Coating Method for Water Supply" (K-115). In this test, details such as turbidity, color, potassium permanganate consumption, chlorine consumption, etc. are specified, and the resin for the coating layer of the lining material that meets this standard is polyolefin-based synthetic resin. Limited to specific resins such as resins and fluorine-based synthetic resins. Among these, fluorine-based resins are extremely expensive and have poor extrusion properties, making them unsuitable as resins for coating layers of pipe lining materials. Therefore, this use is practically limited to polyolefin-based synthetic resins. By the way, as a polyolefin synthetic resin,
There are high-density polyethylene resins, medium-density polyethylene resins, low-density polyethylene resins, polypropylene resins, polybutene resins, etc., but materials other than low-density polyethylene resins are inferior in flexibility, and low-density polyethylene resins are inferior in durability. It's hot,
It was not necessarily suitable as a material for the coating layer of pipe lining materials. PRIOR ART Therefore, the inventors first developed a system using linear low-density polyethylene resin for the coating layer as a lining material for water supply pipes, and a combination of polyethylene resin and pure styrene containing no polypropylene or oil - ethylene butylene. A product using a blend with styrene resin was devised and filed as Utility Model Application No. 176565-1981 and Utility Model Application No. 44499-1989, respectively. The linear low-density polyethylene resin is a polyolefin-based synthetic resin whose main component is ethylene obtained by copolymerizing ethylene and α-olefin, and has a density of about 0.910 to 0.940 g/cm ³ . It belongs to the area of low-density polyethylene resins, and has a molecular structure similar to linear high-density polyethylene resins with almost no branches. The characteristics of this linear low density polyethylene resin are:
It has a high tensile strength of about 330 kg/cm ² , which is equivalent to high-density polyethylene resin, and it has excellent durability with environmental stress cracking resistance of over 1000 hours. The styrene-ethylenebutylene-styrene resin is obtained by hydrogenating the remaining double bonds of a styrene-isoprene-styrene block copolymer, and both ends of its molecular chain are polystyrene. This styrene-ethylenebutylene-styrene resin is a very flexible resin,
Although it is suitable as a material for the film layer of the lining material used for lining with the above-mentioned lining method, on the other hand, it has poor environmental stress cracking resistance. Blended with polyethylene resin such as density polyethylene resin. Problems to be Solved by the Invention However, even these materials are not sufficient as materials constituting the coating layer of the lining material for water pipes. In other words, although linear low-density polyethylene resin is more flexible than high-density polyethylene resin or medium-density polyethylene resin, it cannot be said to be a sufficiently flexible synthetic resin because its Shore D hardness is around 50 degrees. , its flexibility is insufficient as a material to be used for the film layer of the lining material for lining the pipe by the method described above,
The lining material is difficult to turn over and requires considerable fluid pressure to turn over. Furthermore, blends of styrene-ethylenebutylene-styrene resin and linear low-density polyethylene resin are more flexible than the aforementioned linear low-density polyethylene resin alone, but they are still insufficient and durable. It has poor traumatic properties and poor environmental stress cracking resistance. Furthermore, as a general characteristic of polyolefin synthetic resins, they have poor adhesive strength and cannot sufficiently adhere to cylindrical fabrics. The present invention was developed in view of the above circumstances, and is applicable to water supply pipes without contaminating water, conforming to water quality standards, being flexible and easy to turn over, and making lining work easy. The object of the present invention is to provide a lining material with excellent adhesiveness to a cylindrical fabric. Means for Solving the Problems The first invention of the present application is, in the lining material used in the above-mentioned lining construction method, as shown in FIG. The outer surface has two layers: the outer layer 2 is a polyolefin synthetic resin with environmental stress cracking resistance of 1000 hours or more, and the inner layer 3 is a resin made of ethylene-vinyl acetate copolymer grafted with ethylenically unsaturated carboxylic acid. The second invention of the present application is characterized by forming a laminated film layer 4, and as shown in FIG. , is characterized in that an intermediate layer 5 of styrene-ethylenebutylene-styrene resin is formed and laminated into three layers. The environmental stress cracking resistance characteristics in the present invention are as follows:
It is measured using the test method specified in the ASTM-D-1693 standard, and indicates the time it takes for cracks to occur when polyethylene resin is placed under a specified environment under a certain strain. This is an extremely important property as one of the criteria for the durability of polyethylene resin, and especially as a property required for the lining material of a pipe through which water flows as in the present invention. In the present invention, the polyolefin synthetic resin used for the outer layer 2 of the coating layer 4 must have the environmental stress cracking resistance of 1000 hours or more,
If this condition is satisfied, the density is 0.941
High-density polyethylene resin with a density of g/cm3 or ^more
Examples include linear low-density polyethylene resin having a density of 0.910 to 0.940 g/cm 3 , crosslinked polyethylene resin having a density of 0.910 to 0.940 g/cm ³ , and 1-polybutene resin. In addition, the ethylene-vinyl acetate copolymer that forms the skeleton of the resin used for the inner layer 3 has a vinyl acetate content of 7.
About 30% is preferable because it has a low melting point, flexibility, and good adhesiveness. Further, the resin used for the inner layer 3 is one in which an ethylenically unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic anhydride, or a derivative thereof is grafted onto the skeleton of this ethylene-vinyl acetate copolymer. The adhesive properties are further improved by adding a carboxyl group to the ethylene-vinyl acetate copolymer. Further, the styrene-ethylenebutylene-styrene resin used for the intermediate layer 5 in the second invention is preferably a flexible resin having a Shore A hardness of 30 to 80. When manufacturing the lining material, in the conventional lining material, a synthetic resin material is directly extruded onto the outer surface of the cylindrical fabric to form a film layer, and the synthetic resin material is applied between the fibers of the cylindrical fabric. Rub it in and glue it on.
An integral coating layer is formed on the cylindrical fabric, but in the present invention, two or three layers of laminated synthetic resin tubes are extruded and molded on the outside of the cylindrical fabric 1. By reducing the pressure inside the fabric and adhering the synthetic resin tube to the outer surface of the cylindrical fabric 1,
It is preferable to form a film layer 4. Effects According to the present invention, the outer layer 2, which comes into direct contact with the fluid flowing through the pipe after lining, is made of a polyolefin synthetic resin with excellent environmental stress cracking resistance, so it can be used in water supply pipes. It is safe in terms of water quality without affecting water quality even when exposed to water, and has excellent hydrolysis resistance, heat resistance, and trauma resistance. Therefore, this outer layer 2 can effectively prevent water contamination and also prevent damage to the lining material when the lining material is turned over and inserted into the conduit. Furthermore, since the inner layer 3 of the film layer 4 uses an ethylene-vinyl acetate copolymer, it has excellent adhesive properties and is sufficiently adhered to the outer layer 2 or the intermediate layer 5 and the cylindrical fabric 1. As mentioned above, in the method of extruding the synthetic resin constituting the coating layer 4 into a tube shape and bringing the tube-shaped fabric 1 into close contact with each other by reducing the pressure within the tubular fabric 1, the coating layer 4 and the tubular fabric 1 are structurally separated. However, in the present invention, by using an ethylene-vinyl acetate copolymer for the inner layer 3, this can be covered and sufficient adhesive strength can be ensured. In the lining material of the second invention, extremely flexible styrene-ethylenebutylene-styrene resin is used as the intermediate layer 5 of the film layer 4.
The flexibility of the entire film layer 4 is improved, and the heat resistance is also improved. Furthermore, by manufacturing the lining material by applying the extrusion-molded tube to the cylindrical fabric 1 under reduced pressure as described above, the resin constituting the coating layer 4 is bonded to the fibers of the cylindrical fabric 1. The entire lining material can be made flexible without being rubbed in between. Effects of the Invention Therefore, according to the present invention, there is no problem in terms of water quality and it is safe even when applied to water pipes. In addition, since the lining material is flexible and the adhesive force between the cylindrical fabric 1 and the coating layer 4 is strong, even when used in the above-mentioned lining construction method, the lining material is easily turned over, and the coating layer 4 may be damaged or the coating layer 4 may be easily turned over. The pipe can be completely repaired or sufficiently reinforced without peeling off from the cylindrical fabric 1 or between layers of the coating layer 4. Moreover, it has excellent durability and can effectively protect the pipeline for a long period of time. EXAMPLE As an example, a specific configuration of a lining material for a water pipe having a diameter of 200 mmφ will be shown below. The tubular fabric 1 uses 638 yarns, two of which are made by twisting four 1100 denier polyester filament yarns, as warp yarns, and as weft yarns,
2 1100 denier polyester filament threads
A book and four 20 count polyester spun threads.
The yarn is mixed and twisted at a twist rate of 2.0 to 2.5 times/inch.
They were woven into a cylindrical shape by placing 62 strands in a 10 cm interval. In order to ensure the strength of the lining material and the adhesion with the film layer 4, it is preferable to use spun yarn as part of the threads constituting the tubular fabric 1 as in this example. . Next, a film layer 4 is formed on the outer surface of the cylindrical fabric 1.
The specific configuration is shown below. Example 1 Outer layer: High-density polyethylene resin (Hisex 500H manufactured by Mitsui Petrochemical Co., Ltd., density 0.950 g/
^cm3 , Shore D hardness 60 degrees, melting point 132℃, tensile strength 370Kg/ ^cm2 , elongation at break 900%, environmental stress cracking resistance >1000 hours) Inner layer: Ethylenically unsaturated ethylene-vinyl acetate copolymer Resin grafted with carboxylic acid (Mitsubishi Yuka Co., Ltd. Modelix 300S, vinyl acetate content 25%, density 0.950g/cm ³ , Shore D
Hardness 34 degrees, melting point 88 degrees Celsius, tensile strength 110Kg/cm ² ,
(elongation at break 850%) Thickness of film layer: 0.7 mm Thickness ratio of inner and outer layers: outer layer/inner layer = 1/1 Example 2 Outer layer: Linear low-density polyethylene resin (Mitsui Petrochemical Co., Ltd. Ultra Zex 2021L) ,density
0.918g/cm ³ , Shore D hardness 50 degrees, melting point 120
℃, tensile strength 330Kg/cm ² , elongation at break 740%,
(Environmental stress cracking resistance > 1000 hours) Inner layer: Resin made of ethylene-vinyl acetate copolymer grafted with ethylenically unsaturated carboxylic acid (see above) Thickness of film layer: 0.7 mm Thickness ratio of inner and outer layers: outer layer/inner layer = 1/1 Example 3 Outer layer: High-density polyethylene resin (Linklon XLE700A manufactured by Mitsubishi Yuka Co., Ltd., density 0.928 g/cm ³ ,
Shore D hardness 53 degrees, tensile strength 200Kg/cm ² ,
Elongation at break 500%, environmental stress crack resistance >1000
Time) Inner layer: Resin made of ethylene-vinyl acetate copolymer grafted with ethylenically unsaturated carboxylic acid (described above) Thickness of film layer: 0.7 mm Thickness ratio of inner and outer layers: outer layer/inner layer = 1/1 Example 4 Outer layer: 1-polybutene resin (Uitztron 1210A manufactured by Adeka Argus Chemical Co., Ltd., density 0.905
g/cm ³ , Shore D hardness 52 degrees, melting point 115℃, tensile strength 288 Kg/cm ² , elongation at break 350%, environmental stress cracking resistance > 5000 hours) Inner layer: Ethylene-vinyl acetate copolymer with ethylene properties Resin grafted with unsaturated carboxylic acid (see above) Film layer thickness: 0.7 mm Thickness ratio of inner and outer layers: outer layer/inner layer = 1/1 Example 5 Outer layer: High-density polyethylene resin (see above) Intermediate layer: Styrene- Ethylene butylene-styrene resin (Lavalon ME6302 manufactured by Mitsubishi Yuka Co., Ltd.,
Density 0.90g/cm ³ , Shore A hardness 68 degrees, melting point
130℃, tensile strength 161Kg/cm ² , elongation at break 850
%) Inner layer: Resin made of ethylene-vinyl acetate copolymer grafted with ethylenically unsaturated carboxylic acid (see above) Thickness of film layer: 0.7 mm Thickness ratio of each layer: Outer layer/middle layer/inner layer = 1/
1/1 Example 6 Outer layer: linear low-density polyethylene resin (listed above) Intermediate layer: styrene-ethylenebutylene-styrene resin (listed above) Inner layer: ethylene-vinyl acetate copolymer grafted with ethylenically unsaturated carboxylic acid Resin (mentioned above) Film layer thickness: 0.7mm Thickness ratio of each layer: Outer layer/middle layer/inner layer = 1/
1/1 Comparative Example 1 Single-layer comparative example using high-density polyethylene resin (listed above) 2 Single-layer comparative example using linear low-density polyethylene resin (listed above) 3 Comparative example of linear low-density polyethylene resin and styrene-ethylene-butylene-styrene resin , 50:50 blend (Labaron 9200C manufactured by Mitsubishi Yuka Co., Ltd., density 0.92 g/cm ³ , Shore D hardness 40 degrees, melting point 130 degrees Celsius,
Single layer performance test (tensile strength 270Kg/ ^cm2 , elongation at break 750%, environmental stress cracking resistance over 1000 hours) Characteristic hardness of each resin: Shore D according to ASTM-D-2240
Hardness or Shore A hardness (degrees) was measured. Density: Measured according to JIS-K-7112. (g/
cm ³ ) Tensile strength and elongation at break: ASTM-D-6381
Measured according to. (Kg/cm ² , %) Environmental stress cracking resistance of the resin constituting the outer layer:
Measured according to ASTM-D-1693. (Time) Softening temperature (Vikatto softening point): ASTM-D-1525
Measured according to. (°C) Characteristics of laminate Under the same conditions as when manufacturing the lining material, only the film layer of each example was extruded to form a laminate, and the tensile strength and elongation at break of the laminate were determined. Measured according to ASTM-D-6381. (Kg/
cm ² , %) Characteristics of Lining Materials Lining materials on which a film layer was formed according to each of Examples and Comparative Examples were manufactured, and their properties as lining materials were determined. In the examples, immediately after extruding the laminated tube, the pressure inside the cylindrical fabric was reduced to adhere it to the outer surface of the cylindrical fabric, and in the comparative example, a synthetic resin was rubbed onto the outer surface of the cylindrical fabric to form a film. Layers were formed and bonded to obtain a lining material. Heat-resistant operating temperature: Live steam was introduced into the lining material, and the temperature (°C) that the film layer could withstand was measured. Potassium permanganate consumption: JWWA-K-115
Measured in accordance with the standards. (mg/) Residual chlorine consumption: Measured in accordance with the JWWA-K-115 standard. (ppm) Adhesion peel strength: The peel force (Kg/25 mm width) between the cylindrical fabric and the film layer was measured by 180 degree peeling. Trauma resistance: A lining material is pasted on the surface of an iron pipe with a diameter of 400 to 500 mm, a cloth belt with a load of 500 kg is hung on the lining material over a range of 5 to 10 cm, and the belt is It was slid for 50 m at a speed of 10 m/min, and the degree of damage to the film layer of the lining material was examined. Self-propelled reversal pressure: The lining material was turned over over a distance of 5 m using fluid pressure, and the minimum fluid pressure (Kg/cm ² ) required for turning over was measured. Test results The test results are shown in Table-1.

【table】

[Table] *Resin water quality test of ethylene-vinyl acetate copolymer grafted with ethylenically unsaturated carboxylic acid Regarding the coating layer of Example 6, the lining material having the same and the pipe lined with the lining material, Turbidity, color, potassium permanganate consumption, residual chlorine consumption, phenols, amines, cyanide, and odor and taste were tested in accordance with JWWA-K-115. Test results The test results are shown in Table-2.

【table】

【table】 [Brief explanation of drawings]

1 and 2 are perspective views showing the lining material for a conduit according to the present invention. 1...Tubular fabric, 2...Outer layer, 3...Inner layer, 4
...Film layer, 5...Intermediate layer.

Claims (1)

[Claims] 1. Inserting a flexible lining material from one end of the pipe toward the other end while turning it over using fluid pressure, and simultaneously adhering the lining material to the inner surface of the pipe pipe using the fluid pressure. In the lining material used in the lining method for lining pipes, the outer surface of a cylindrical fabric made of woven or knitted synthetic fiber yarn is made of a polyolefin synthetic resin with an environmental stress cracking resistance of 1000 hours or more as an outer layer, A pipe lining material comprising two laminated film layers, the inner layer of which is a resin obtained by grafting ethylenically unsaturated carboxylic acid onto an ethylene-vinyl acetate copolymer. 2. The lining material for a pipe line according to claim 1, wherein the polyolefin synthetic resin is a high-density polyethylene resin. 3. The pipe lining material according to claim 1, wherein the polyolefin-based synthetic resin is a linear low-density polyethylene resin. 4. The pipe lining material according to claim 1, wherein the polyolefin synthetic resin is a crosslinked polyethylene resin. 5. The lining material for a pipe line according to claim 1, wherein the polyolefin synthetic resin is a 1-polybutene resin. 6. Lining of a pipe, in which a flexible lining material is inserted from one end of the pipe to the other end while being turned over by fluid pressure, and at the same time, the lining material is adhered to the inner surface of the pipe by the fluid pressure. In the lining material used in the construction method, the outer surface of a cylindrical fabric made of woven or knitted synthetic fiber threads is made of a polyolefin synthetic resin with an environmental stress cracking resistance of 1000 hours or more, and is made of styrene-ethylene-butylene-styrene. A conduit characterized by forming a three-layered film layer, the intermediate layer being a resin, and the inner layer being a resin obtained by grafting ethylenically unsaturated carboxylic acid onto an ethylene-vinyl acetate copolymer. lining material. 7. The pipe lining material according to claim 6, wherein the polyolefin synthetic resin is a high-density polyethylene resin. 8. The pipe lining material according to claim 6, wherein the polyolefin-based synthetic resin is a linear low-density polyethylene resin. 9. The pipe lining material according to claim 6, wherein the polyolefin synthetic resin is a crosslinked polyethylene resin. 10. The pipe lining material according to claim 6, wherein the polyolefin synthetic resin is a 1-polybutene resin.