JPS61188141A - Lining material for duct - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to lining materials for pipelines, and in particular for lining materials for gas pipelines, water pipes, power lines, communication lines, etc.
It mainly relates to lining materials for lining pipes buried underground.

In recent years, the inner surface of pipes has been lined with lining for the purpose of repairing or reinforcing the pipes as they have deteriorated.
The lining method involves applying adhesive to the inner surface of a cylindrical flexible lining material in advance, and inserting the lining material into the pipe while turning the inner and outer surfaces inside out using fluid pressure. crimping the lining material on the inner surface of the pipe with the fluid pressure;
A lining material is adhered to the inner surface of the pipe through the adhesive to line the pipe. With this construction method, there is no need to dig up the entire length of the pipe for construction, and it can be constructed in a short time, even on pipes with many bends. This construction method has attracted particular attention in recent years as an extremely superior method.

By the way, the lining material used in □ in this method is
Since it needs to be flexible, airtight, and have considerable strength in both the vertical and horizontal directions, a cylindrical fabric with a synthetic resin coating layer formed on its outer surface is used.

The coating layer of this lining material is required to be flexible, have appropriate elasticity, be strong, and have good heat resistance, eaves resistance, and trauma resistance. Furthermore, especially when applied to water supply pipes, the synthetic resin constituting the coating layer is required to be safe for water purchase.

The Japan Water Works Association (JWWA)
) standards.

In this JWWA standard, "Water supply tar epoxy resin paint coating method J'('ni'-"11'5)
It is required that the water quality test specified by In the test, details such as turbidity-1 chromaticity, permanganate power consumption, chlorine consumption, etc. are specified as 1, and the resin for the coating layer of the lining material that meets this standard is , polyolefin-based synthetic resins, fluorine-based synthetic resins, etc.; limited to specific resins.

Among these, fluororesins are extremely expensive and have poor extrusion properties, making them unsuitable as resins for coating layers of lining materials for pipes. Therefore, this use is practically limited to polyolefin-based synthetic resins.

By the way, polyolefin-based synthetic resins include high-density polyethylene resin, medium-density polyethylene resin, low-density polyethylene resin, polypropylene resin, polybutene resin, etc. However, materials other than low-density polyethylene resin have poor flexibility, and low-density polyethylene resin Resin is inferior in durability and is used as a material for pipe lining materials and coating layers.
It wasn't always suitable.

Conventional techniques/techniques - Therefore, the inventors first used a linear low-density polyethylene resin as a coating layer as a lining material for water pipes, and a polyethylene resin and pure styrene containing no polypropylene or oil. A blend of -ethylene butylene and styrene resin was devised and filed as Utility Model Application No. 58-176565 and Utility Model Application No. 59-44499, respectively.

The linear low-density polyethylene resin is a polyolefin-based synthetic resin whose main component is ethylene, which is obtained by copolymerizing ethylene and α-olefin, and has a density of 0.
．． It is approximately 910-0.940 Vc/, belongs to the low density polyethylene resin region, and has a molecular structure similar to a linear high density polyethylene resin with almost no branching. This linear low density polyethylene resin °
The properties of this resin are as follows: the tensile strength is as high as about 330h4, which is equivalent to high-density polyA' ethylene resin, and the environmental stress cracking resistance is 1000 hours or more, making it excellent in durability.

The styrene-ethylenebutylene-styrene resin is obtained by hydrogenating the remaining double bonds of styrene-isoprene-styrene block copolymerization, and both ends of the molecular chain are polystyrene. This styrene-ethylene butylene-styrene resin is a very flexible resin and is suitable as a material for the film layer of the lining material used for lining with the above-mentioned lining method, but on the other hand, it has poor environmental stress cracking resistance. Therefore, in the above invention, a polyethylene resin such as a linear low density polyethylene resin is blended with this styrene-ethylenebutylene-styrene resin.

Problems to be Solved by the Invention However, even these materials are not sufficient as materials constituting the coating layer of lining materials 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 is not a sufficiently flexible synthetic resin with a Shore D hardness of around 50 degrees. However, it is not flexible enough to be used as the material for the lining material used to line pipes using the method described above, and the lining material is difficult to turn over, requiring considerably high fluid pressure to turn it over. Must.

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.

A general characteristic of polyolefin synthetic resins is that 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 causing thinning of water, meets water quality standards, is flexible, easy to turn over, and requires no lining work. The object of the present invention is to provide a lining material that is easy to use and has excellent adhesiveness to a cylindrical fabric.

Means for Solving the Problems The first invention of the present application is to provide a lining material for use in the above-mentioned lining construction method, as shown in FIG. On the outer surface, the outer layer 2 is made of a lyolefin-based synthetic resin whose environmental stress cracking resistance is longer than i ooo hours, and the inner layer 113 is made of 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 skin +1II14 laminated in two layers, and as shown in FIG. It is characterized in that an intermediate layer 5 of styrene-ethylene-butylene-styrene resin is formed between the two and three layers are laminated.

The environmental stress cracking resistance in the present invention refers to Ascho M-0
It is measured using the test method specified in the -1693 standard, and represents the time it takes for polyethylene resin to develop cracks and cracks in a specified environment with a certain amount of strain applied to the polyethylene resin. This is an extremely important characteristic as one of the indicators of the durability of a resin, especially as a characteristic required for a lining material for a pipe through which water flows, as in the present invention.

In the present invention, the polyolefin resin used for the outer layer 2 of the coating layer 4 must have the environmental stress cracking resistance of 1000 hours or more, and a material satisfying this condition must have a density of 0°. High-density polyethylene resin of 941V or higher, linear low-density polyethylene resin with a density of 0.910 to 0.940, density of 0.910 to 0.940
Vap crosslinked polyethylene resin, 1-polybutene resin, and the like.

The ethylene-vinyl acetate copolymer forming the resin skeleton used for the inner layer 3 preferably has a vinyl acetate content of about 7 to 30% because it has a low melting point, is flexible, and has good adhesive properties. Furthermore, the resin used in 1i113 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 1li5 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 skin layer, and the synthetic resin material is applied to the fibers of the cylindrical fabric. In the present invention, two or three layers of am-based synthetic resin are applied to the outside of the tubular fabric 1 by rubbing and adhering them together to form an integral film layer on the tubular fabric 1. A resin tube is extruded, and the pressure inside the cylindrical fabric is reduced to adhere the synthetic resin tube to the outer surface of the cylindrical fabric 1, and the skin P
It is preferable to form three layers 4.

According to the present invention, the outer layer 2, which is in 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 when used in a water supply pipe. It is also safe in terms of water quality without affecting water quality, 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.

In addition, since ethylene-vinyl acetate copolymer is used for the inner layer 3 of the film 114, it has excellent adhesive properties, and the outer layer 3 has excellent adhesive properties. !
i2 or intermediate 1I15 and the tubular fabric 1 are sufficiently adhered. As mentioned above, in the method of extruding the synthetic resin constituting the film 114 into a tube shape and applying pressure inside the cylindrical fabric 1 to bring it into close contact, structurally the film layer 4
Although the adhesive strength between the inner layer 3 and the cylindrical fabric 1 does not improve much, 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 skin 11i1!34, so the flexibility of the entire film layer 4 is improved and the heat resistance Sexuality also improves.

Furthermore, by manufacturing the lining material by the method of bringing the extrusion-molded tube into close contact with the inside of the cylindrical fabric 1 by reducing the pressure, the resin constituting the coating layer 4 can be spread between the fibers of the cylindrical fabric 1. The entire lining material can be made flexible without being rubbed by the lining.

ADVANTAGES OF THE INVENTION Accordingly, the present invention is safe and poses no problem in terms of water quality even when applied to water supply pipes. In addition, the lining material is flexible and the adhesive strength between the cylindrical fabric 1 and the coating layer 4 is strong, so even when used in the lining construction method described above, the lining material is flexible. The material is easy to turn over, and the coating layer 4 may be scratched or the coating 114 may be damaged.
The pipe can be completely repaired and 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 pipe line for a long period of time.

EXAMPLE Below, as an example, the specific structure of a lining material for a water pipe having a diameter of 2001φ will be shown.

The tubular fabric 1 uses 638 yarns, two yarns made by twisting four 1,100-denier polyester filament yarns, as warp yarns, and uses two 1,100-denier polyester filament yarns and 20 count yarns as weft yarns. 4 polyester spun yarns with a twist count of 2.0 to 2.
．． The mixed threads were inserted five times using a "tnch" at a ratio of 612 threads per 10 cm to weave it into a cylindrical shape.

In order to ensure the strength of the lining material and the adhesion with the skin Il layer 4, it is recommended to use spun yarn as part of the threads constituting the tubular fabric 1 as in this example. preferable.

Next, a specific structure of the film layer 4 formed on the outer surface of the cylindrical fabric 1 will be shown.

Example 1 Outer layer: High density polyethylene resin (Mitsui Petrochemical Co., Ltd. HIZEX 500H1 density 0.950VC113,
Shore D hardness 60 degrees, melting point 132 degrees Celsius, tensile strength 37
0kg4, elongation at break 900%, environmental stress cracking resistance>
1000 hours) Inner layer: Resin made of ethylene-vinyl acetate copolymer grafted with ethylenically unsaturated carboxylic acid (Modic 3008 manufactured by Mitsubishi Yuka Co., Ltd. Vinyl acetate content 125%, density 0.950$'a IP1 Shore-D hardness 34 degrees, melting point 8
8℃, tensile strength 110kg4. Elongation at break: 850%) Thickness of film layer: Q, 7 mm Thickness ratio of inner and outer layers: outer layer/inner layer = 1/1 Example 2 Outer 1! Bilinear low-density polyethylene resin (Mitsui Petrochemical Co., Ltd. Ultrasex 2021L, density 0.918
V rubber, Shore D hardness 50 degrees, melting point 120 degrees Celsius, tensile strength 330k14, elongation at break 740%, environmental stress cracking resistance > 1000 hours 1 it) Inner layer: Ethylene-vinyl acetate copolymer with ethylenically unsaturated carboxylic acid Grafted resin (mentioned 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: Crosslinked low density polyethylene resin (Linklon XLE700A manufactured by Mitsubishi Yuka Co., Ltd., Density 0°928V♂, Shore D hardness 53 degrees, tensile strength 200Ic114, elongation at break 500%, environmental stress cracking resistance >1000 hours) Inner layer: Ethylene-vinyl acetate copolymer grafted with ethylenically unsaturated carboxylic acid Thickness of film layer: Q, 7 mm Thickness ratio of inner and outer layers: outer layer/inner layer - 1/1 Example 4 Outer layer: 1-polybutene resin (manufactured by Adeka Argus Chemical Co., Ltd. Witsutron 1210A1 density 0°905V -,
Shore D hardness 52 degrees, melting point 115 degrees Celsius, tensile strength 28 degrees
81q4, elongation at break r! 1.350%, environmental stress cracking resistance > 5000 hours) Inner layer: Resin made of ethylene-vinyl acetate copolymer grafted with ethylenically unsaturated carboxylic acid (see above) Thickness of film layer: 0.7 + 11111 Thickness of inner and outer layers Ratio: outer layer/inner layer = 1/1 Example 5 Outer layer: high-density polyethylene resin (listed above) Intermediate layer: styrene-ethylenebutylene-styrene resin (Lavalon ME6302 manufactured by Mitsubishi Yuka Co., Ltd., density 0.90 Vc/, Shore A hardness 68 degrees, melting point 130 degrees Celsius, tensile strength 1611
61 wood, elongation at break 850%) Inner II: Resin made of ethylene-vinyl acetate copolymer grafted with ethylenically unsaturated carboxylic acid (listed above) Thickness of 1 layer of Skin II: 0.7 mm Thickness ratio of each layer: Outer layer /Intermediate layer/Inner layer-Example 6 Outside [l: Linear low density polyethylene resin (listed above) Intermediate layer:
Styrene-ethylene butylene-styrene resin (listed above) Inner layer: Resin obtained by grafting ethylenically unsaturated carboxylic acid onto ethylene-vinyl acetate copolymer (listed above) Thickness of film layer: 0.7IllI11 Thickness ratio of each layer: Outer layer/middle layer Layer/Inner layer = Comparative Example 1 Single layer Comparative Example 2 using high density polyethylene resin (listed above) Single layer Comparative Example 3 using linear low density polyethylene resin (listed above) Linear low density polyethylene resin and styrene-ethylenebutylene-styrene resin , 50:・50 blend (
Lavalon 9200C manufactured by Mitsubishi Yuka Co., Ltd., density 0.92
Single layer performance test with Vd, Shore D hardness 40 degrees, melting point 130 degrees Celsius, tensile strength 270 degrees, elongation at break 750%, environmental stress cracking resistance over 1000 hours) Characteristic hardness of each resin: ASTM-D-2240 Shore D hardness or Shore A hardness (degree) was measured according to .

Density: Measured according to JIS-7112.

(I'CI") Tensile strength and elongation at break: Measured according to ASTM-D-6381.<k+14.%) Environmental stress cracking resistance of resin constituting the outer layer = According to ASTM-D-1693 (Time) Softening temperature (Picat softening point): A
Measured according to STM-D-1525. ('C) Characteristics of the 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 were determined for the laminate. , ASTM-D-6
It was measured according to 381.

(-49%) Characteristics of Lining Materials Lining materials having film layers formed thereon according to each of the Examples and Comparative Examples were manufactured, and their properties as lining materials were determined.

In the example, immediately after extruding the laminated tube, the inside of the cylindrical fabric is depressurized and adhered to the outer surface of the cylindrical fabric,
In a comparative example, a synthetic resin was rubbed onto the outer surface of a cylindrical fabric to form a film layer 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: Measured in accordance with the JWWA-115 standard. (■4) Residual chlorine consumption: J
Measured according to the WWA-115 standard. (1
)pm・) Adhesive Peeling Strength=The peeling force (kg/25mm+width) between the cylindrical fabric and the film layer was measured by 180 degree beering.

Trauma resistance: A lining material is pasted on the surface of an iron pipe with a diameter of 400 to 500+U+, and a cloth belt with a load of 500- is applied to the lining material so as to touch it over a range of 5 to 10 cm. The belt was slid for 50 m at a speed of 10 m/1 n, and the degree of damage to the film layer of the lining material was examined.

The self-propelled reversing pressure crab lining material was turned over with fluid pressure over 5IIl, and the minimum fluid pressure (kg4) required for turning over was measured.

Test results The test results are shown in Table-1.

Water quality tests and JWWA-
The turbidity, color, potassium permanganate consumption, residual chlorine consumption, phenols, amines, cyanide, and odor and taste were tested in accordance with ISO-115.

Test results The test results are shown in Table-2.

[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...Coating
iim5・・・・・・middle class

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 materials used in the lining method for lining pipes,
On the outer surface of a cylindrical fabric made of woven or knitted synthetic fiber threads,
The outer layer is a polyolefin synthetic resin with an environmental stress cracking resistance of 1000 hours or more, and the inner layer is a resin made of ethylene-vinyl acetate copolymer grafted with ethylenically unsaturated carboxylic acid. A lining material 2 for a pipe line, characterized in that the polyolefin synthetic resin is a high-density polyethylene resin; Lining material 4 for pipes according to claim 1, characterized in that the polyolefin-based synthetic resin is a linear low-density polyethylene resin.The polyolefin-based synthetic resin is a crosslinked polyethylene resin. , the lining material 5 for a pipe line according to claim 1; the lining material 6 for a pipe line according to claim 1, characterized in that the polyolefin synthetic resin is a 1-polybutene resin; In a method for lining pipes, the 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 to line the pipe. In the lining material used,
On the outer surface of a cylindrical fabric made of woven or knitted synthetic fiber threads,
The outer layer is a polyolefin synthetic resin with an environmental stress cracking resistance of 1000 hours or more, the middle layer is a styrene-ethylenebutylene-styrene resin, and the resin is made of an ethylene-vinyl acetate copolymer grafted with ethylenically unsaturated carboxylic acid. A pipe lining material 7 characterized in that it is formed of a three-layered film layer as an inner layer.Claims of claims, characterized in that the polyolefin-based synthetic resin is a high-density polyethylene resin. The lining material for pipes according to claim 6 8 The lining material for pipes according to claim 6 , wherein the polyolefin synthetic resin is a linear low-density polyethylene resin 9 The polyolefin synthetic resin The pipe lining material 10 according to claim 6, characterized in that the resin is a crosslinked polyethylene resin.The claim 10, characterized in that the polyolefin synthetic resin is a 1-polybutene resin. Lining material for pipes as described in item 6