JP2513280Y2 - Pipe liner - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to an inner lining material for lining a flowing water pipe such as an existing water pipe mainly buried in the ground for the purpose of repair or reinforcement. It is a thing.

More specifically, an adhesive is applied in advance to the inner surface of a tubular flexible lining material, which is inserted into the conduit while turning the inner and outer surfaces inside out with pressure fluid, and at the same time crimped to the inner surface of the conduit with the fluid pressure. The present invention relates to an inner lining material for use in a pipeline lining construction method for adhering an inner lining material to an inner surface of a conduit via the adhesive.

[Prior Art] The lining material used in this method is not only flexible and airtight, but also in consideration of the effects of creep, earthquake, etc., which occur after lining, in the longitudinal and radial directions of the pipeline. Since a considerable amount of strength is required, a tubular cloth having a synthetic resin coating layer formed on its outer surface is used.

By the way, in the case of lining materials applied to water supply pipelines, the synthetic resin that constitutes the coating layer is required to be safe in terms of water quality, and meets the standards of the Japan Water Works Association (JWWA). It is necessary.

In this JWWA standard, regarding the materials used for the lining material, "Liquid epoxy resin paint coating method for water supply" (K-
It is required to comply with the water quality test specified in 135). In this test, details such as turbidity, chromaticity, potassium permanganate consumption, chlorine consumption, etc. are specified.Synthetic resins that meet this standard include polyolefin-based synthetic resins and fluorine-based synthetic resins. The range of resins such as resins is extremely limited.

Since this internal fluororesin is extremely expensive and has poor extrusion characteristics, it is not suitable as a resin material for the coating of the liner lining material, and what can be used for this purpose is virtually a polyolefin synthetic resin. Limited to

Polyolefin-based synthetic resins include high-density polyethylene, medium-density polyethylene, low-density polyethylene, polypropylene, polybutene, etc. However, high-density polyethylene and medium-density polyethylene lack flexibility, and polypropylene is also poor in flexibility. In that case, the heat resistance is poor, and a whitening phenomenon occurs in the inverted folded portion, which is not preferable.

Therefore, from the viewpoint of flexibility, it is limited to low-density polyethylene, but low-density polyethylene generally has poor stress cracking resistance and poor durability.

In view of such circumstances, the applicant has studied various materials mainly composed of low-density polyethylene and a modified resin suitable for the coating layer of the lining material.

The one described in Japanese Utility Model Laid-Open No. 60-85336 is one of them, in which linear low density polyethylene is used as a coating layer.

Further, Japanese Utility Model Publication No. 60-157224 discloses a blend of polyethylene and styrene-ethylenebutylene-styrene resin, in which a resin having an environmental stress cracking resistance of 1000 hours or more is used in a coating layer. Has been done.

Further, JP-A-62-92844 discloses an outer layer made of a polyolefin-based synthetic resin having an environmental stress cracking resistance of 1000 hours or more, a resin obtained by grafting an ethylenically unsaturated carboxylic acid on an α-olefin polymer, and a styrene- It is described that an inner layer made of a blend of ethylene butylene-styrene resin and an intermediate layer of styrene-ethylene butylene-styrene resin are provided between the inner and outer layers.

[Problems to be Solved by the Invention] However, even these materials are not sufficient as materials for forming the coating layer of the lining material.

Although linear low-density polyethylene is said to be more flexible than high-density polyethylene or medium-density polyethylene, it has a Shore D hardness of around 50 ° and is sufficiently flexible as a coating layer for lining materials. hard.

The lining material is a lining material that is inserted inside the pipe line while turning inside out so that the inside is the outside,
In order to easily turn the inside out, the lining material itself is required to be extremely flexible. In particular, the hardness of the coating layer has a great influence on the easiness of turning over of the lining material, so that it is required to be flexible as well as flexible.

Shore D hardness in the linear low density polyethylene
A value of 50 ° is considered to be a soft synthetic resin because the synthetic resin has a small hardness, but this is not enough for the coating layer of the lining material. The lining material formed with the coating layer of linear low density polyethylene requires a pressure fluid of a considerably high pressure to turn it over, and a material having a lower hardness is required to turn it over at a lower pressure.

Further, since the linear low-density polyethylene has poor adhesion to the tubular cloth, the coating layer may be peeled off from the tubular cloth at the time of turning over.

The blend of linear low-density polyethylene and styrene-ethylene butylene-styrene resin can be softer than the linear low-density polyethylene, but on the other hand, it has excellent resistance to linear low-density polyethylene. It comes at the expense of trauma and environmental stress crack resistance,
Not so good.

Further, in the structure described in JP-A-62-92844, the co-extrusion moldability of the outer layer polyolefin resin is poor, and the coating layer has uniform performance over the entire length of the coating layer. Is difficult to form.

The present invention has been made in view of the above circumstances, and is applied to a water supply pipeline, does not affect the water quality, conforms to the water quality standard, is flexible and easily turned over, and is easily lined. The purpose is to provide a lining material with stable quality.

[Means for Solving the Problems] In the present invention, therefore, the flexible lining material is inserted inside from the one end to the other end of the conduit while being turned over by the fluid pressure, and at the same time, the lining material is applied by the fluid pressure to the pipe. In the lining material used in the pipeline lining method that adheres to the inner surface of the duct, the outer surface of the tubular fabric has an α-olefin content of 15
-40% by weight of a random copolymer of ethylene and an α-olefin having 3 or more carbon atoms, characterized by forming a coating layer consisting of an inner layer having a density of 0.90 and an outer layer having a density of 0.91. To do.

The present invention will be described below with reference to the drawings. FIG. 1 shows an inner lining material of the present invention in which a coating layer 2 is formed on the outer surface of a tubular cloth 1. The tubular cloth 1 is made by weaving a fiber warp yarn 3 and a weft yarn 4 into a tubular shape. The tubular fabric 1 is not limited to the tubular woven fabric as described above,
A non-woven fabric or a combination of a woven fabric and a non-woven fabric may be used.

As a material for forming the coating layer 2, a random copolymer of ethylene and an α-olefin having a carbon number of 3 or more (containing an α-olefin of 15 to 40% by weight and a density of 0.89 to 0.91) ( Hereinafter, in this specification, ultra low density polyethylene will be used).

Examples of the α-olefin which is a component constituting the ultra-low density polyethylene include propylene, 1-butene, 1-hexane, etc., and these α-olefin and ethylene are copolymerized to give an ultra-low density polyethylene. In the present invention, those having an α-olefin content of 15 to 40% by weight are used. When the content of α-olefin is less than 15% by weight, the density becomes high and the hardness becomes high accordingly. On the other hand, when the content of α-olefin exceeds 40% by weight, it is too flexible and the mechanical strength is poor, and it cannot withstand the inside out work.

This ultra-low density polyethylene has a linear structure with almost no long-chain branching in terms of molecular structure, and has a structure similar to that of high-density polyethylene. However, since ethylene and α-olefins are randomly bonded and have irregularly short side chains, there is no crystallinity, the density is even smaller than that of low-density polyethylene, and it is extremely flexible and highly stress cracking resistant. Have sex.

The linear low-density polyethylene used in the prior art is also the same as the ultra-low-density polyethylene in the present invention in that it is a copolymer of ethylene and α-olefin, but the content of α-olefin is The rate is about 5%
And small. Therefore, the molecule has a portion where an ethylene chain continues for a long time, and since that portion has crystallinity, there are many crystal regions as a whole, the material is rigid, and the stress cracking resistance is poor.

This is also clear from the following. That is,
What is linear low density polyethylene and ultra low density polyethylene?
All have a melting index of about 2 g / 10 minutes, and have a relatively high molecular weight and narrow molecular weight distribution as polyethylene. However, comparing the Vicat softening point, the linear low-density polyethylene with a density of 0.92 has a temperature of about 100 ° C, while the ultra-low-density polyethylene has a temperature of about 80 ° C. I understand that it is very low.

Therefore, the ultra low density polyethylene used by the present invention is
It is much more flexible than linear low-density polyethylene and has a high degree of stress cracking resistance.

Note that the stress cracking resistance referred to here is JI
S-K-6760 "Polyethylene test method", which was measured by the test method defined as "constant strain environmental stress crack test", and which was placed in a predetermined environment with a certain strain applied to polyethylene, It represents the time until a crack occurs, and is one of the indicators of the durability of polyethylene.

Generally, polyethylene has good chemical resistance, but it may crack when it is exposed to certain liquids or vapors under stress or in the state where strain during processing remains. Is the stress cracking resistance.

In particular, in the lining material for water supply, distortion occurs when the coating layer is extruded, and when lining, the lining material having a diameter slightly smaller than the inner diameter of the pipeline is expanded and pressure-bonded to the inner surface of the pipeline. Therefore, in the lined lining material, the coating layer is in a stressed and distorted state. In such a state, since it is constantly exposed to water, the stress cracking resistance is one of the extremely important characteristics as a material for the coating layer.

Generally, a resin having a low degree of crystallinity is likely to cause stress cracking due to crystallization and shrinkage during use, and in the case of polyethylene, it is said that the higher the density, the higher the stress cracking resistance.

However, the ultra-low density polyethylene used in the present invention basically has a structure that is difficult to crystallize despite its low crystallinity, and even if some crystallization occurs, it is highly flexible and stress It is thought that stress cracking is unlikely to occur because it does not transform into stress.

The ultra low density polyethylene used in the present invention is
It is flexible and has excellent resistance to stress cracking, and also has excellent adhesiveness to the tubular fabric 1, and is excellent as the coating layer 2 of the lining material. However, since the Vicat softening point is low as described above, the coating layer 2 softens when the heating and pressurizing fluid is fed into the lining material to cure the resin liquid applied to the lining material in the lining work. The internal pressure may cause a penetration.

In the coating layer 2 of the present invention, the density of the ultra-low density polyethylene is particularly low, 0.89 to 0.905.
The resin is used as the inner layer, and the resin having a relatively high density of 0.905 to 0.91 which is close to that of linear low density polyethylene is used as the outer layer to form a two-layer structure.

[Embodiment] As an embodiment of the present invention, a concrete configuration of a lining material for a water pipe having a diameter of 200 mm will be described below.

The tubular fabric 1 uses, as the warp yarn 3, two 638 yarns obtained by twisting four 1100 denier polyester filament yarns, and aligns and uses 638 yarns. As the weft yarn 4, six 1100 denier polyester filament yarns are twisted. Using the combined yarn, drive it into 10 cm so that it becomes 42 threads,
Weaved into a tubular shape.

Next, the specific structure of the coating layer 2 formed on the outer surface of the tubular cloth 1 will be described.

Example Structure: Two-layer structure in which two kinds of ultra-low density polyethylene are used as the outer layer and the inner layer, respectively. Outer layer material: Ultra-low density polyethylene (manufactured by Mitsubishi Petrochemical Co., Ltd., trade name Yucaroncel XL-414, ethylene-1 butene copolymer) [1 butene 15%], density 0.91 g / cm ³ , Shore D
Hardness 45 °, melting point 124 ° C, tensile strength 300 kg / cm ² , elongation at break 800%, environmental stress crack resistance 2000 hours) Inner layer material: Ultra low density polyethylene (Mitsubishi Yuka Co., Ltd., trade name Yucaroncel X- 141, ethylene-1 butene copolymer [1 butene 30%], density 0.90g / cm ³ , Shore D hardness 35 °, melting point 117 ° C, tensile strength 200kg / cm ² , elongation at break 800%, environmental stress resistance Cracking property 2000 hours) Thickness: 0.7mm Thickness ratio: Outer layer / Inner layer = 1/1 Comparative example 1 Material: Ultra low density polyethylene (trade name: Yucaroncel)
XL-414) Single layer tube thickness: 0.7mm Comparative example 2 Material: Ultra low density polyethylene (trade name Yucaroncel X-141) Single layer tube thickness: 0.7mm Comparative example 3 Material: Linear low density polyethylene (Mitsubishi Made by Yuka Co., Ltd.
Trade name Yucaroncel LX-526, ethylene-1 butene copolymer [1 butene 5%], density 0.936 g / cm ³ , Shore D hardness
55 °, melting point 137 ° C, tensile strength 250 kg / cm ² , elongation at break 70
Single layer tube with 0%, environmental stress crack resistance> 1500 hours) Thickness: 0.7 mm Comparative Example 4 Material: 60:40 blend of linear low density polyethylene and styrene-ethylene butylene-styrene resin (Mitsubishi Yuka Co., Ltd., trade name Lavalon ME-9200C, density 0.92g / cm
³ , Shore D hardness 50 °, melting point 130 ° C, tensile strength 250kg /
cm ² , elongation at break 700%, environmental stress crack resistance 1200 hours)
Single layer tube by: Thickness: 0.7mm Comparative example 5 Structure: Double layer structure consisting of the following outer layer and inner layer Outer layer material: Linear low density polyethylene (trade name: Yucaroncel LX-526, above) Inner layer material: polypropylene and ethylenically unsaturated carboxylic acid A 50:50 blend of a resin grafted with styrene-ethylene butylene-styrene resin (trade name: Modic F-300V, manufactured by Mitsubishi Petrochemical Co., Ltd., polypropylene having a molecular weight of tens of thousands to 200,000, carboxylic acid application rate). 1-15%, density
0.89, Shore A hardness 70 degrees, melting point 130 ° C, tensile strength 65k
g / cm ² , elongation at break 500%) Thickness: 0.7 mm Thickness ratio: outer layer / inner layer = 1/1 Performance test Resin characteristics Hardness: Shore D hardness or Shore A hardness according to ASTM-D-2240 Was measured. (Degree) Density: Measured according to JIS-K-7112. (G / cm ³ ) Tensile strength and elongation at break: Measured according to ASTM-D-638. (Kg / cm ² ,%) Flexural modulus: Measured according to ASTM-D-747. (Kg / c
m ² ) Melting point: measured by DSC. (° C.) Environmental stress cracking resistance: Measured according to ASTM-D-1693. (Time) Properties of Laminates In Examples and Comparative Example 5, only two coating layers were extruded as a film under the same conditions as when manufacturing the lining material, and the tensile strength and the elongation at break of the film were obtained. The flexural modulus was measured, and other properties were measured only for the resin of the outer layer.

Characteristics of Lining Material Molding of Lining Material: For Examples and Comparative Examples 1, 2 and 5,
Immediately after the tube was extruded to the outside of the tubular fabric, the pressure inside the tubular fabric was reduced to bring the tube into close contact with the surface of the tubular fabric to form a coating layer, which was used as the lining material.

In Comparative Examples 3 and 4, resin was rubbed on the outer surface of the tubular cloth to form a coating layer, which was used as the lining material.

Potassium permanganate consumption, residual chlorine consumption: JWWA-
It was measured according to the K-135 standard. (Ppm) Adhesive peel strength: Peeling force between tubular cloth and coating layer by 180 degree peeling at temperature of 23 ℃ and 80 ℃ (kg / 25mm
Width) was measured.

Scratch resistance: A lining material is attached to the surface of an iron pipe with a diameter of 500 mm, and a cloth belt with a load of 500 kg is hung on the lining material over a range of 5 to 10 cm.
After sliding 50 m at a speed of 10 m / min, the degree of damage to the coating layer of the lining material was examined.

Self-propelled reversal pressure: The lining material was turned over with a fluid pressure of 5 m, and the minimum fluid pressure required to turn it over was measured. (kg
/ cm ² ) Lining characteristics Pressurized steam was fed while the lining material was turned upside down, and generation of pinholes was examined while increasing the steam pressure.
If no pinhole is generated by boosting to 0.3kg / cm ² ,
The adhesive was determined to be curable.

Test results The test results are shown in the table.

[Operation] In the present invention, since the ultra-low density polyethylene used for the coating layer of the lining material has low crystallinity, it is flexible and has excellent resistance to environmental stress cracking. Moreover, since it has a linear molecular structure, it has high strength and is stable.

Since the present invention uses this ultra-low density polyethylene as the material of the coating layer, it is safe in terms of water quality without affecting the water quality even when used in water supply pipelines, and has hydrolysis resistance, It also has excellent heat resistance and scratch resistance.
Therefore, with this coating layer, water pollution in the water supply can be effectively prevented, and even when the lining material is turned inside out and inserted into the pipeline, it can be turned over with a small pressure, and damage to the lining material can be prevented.

Further, in the present invention, since the coating layer has a two-layer structure of an outer layer made of a resin having a relatively high density and an inner layer made of a resin having a low density, it is easy to turn over due to the flexibility of the inner layer. , Because the outer layer has a relatively high softening point,
Even when a heating fluid is fed into the lining material to heat it, the outer layer (exposed to the inner surface of the lining layer after being turned over) is not heated and excessively softened, and the coating layer penetrates by internal pressure. There is no such thing.

In Comparative Example 2 in which the coating layer was formed only with the same resin as the inner layer in the present invention, the coating layer penetrated with a vapor pressure of 0.1 kg / cm ² to form pinholes, and it was difficult to cure the adhesive. Is. Further, in Comparative Example 1 in which the coating layer is formed of only the same resin as the outer layer of the present invention, the self-propelled reversal pressure is high, and if there is a complicated bend in the actual pipeline, it may be difficult to insert it by reversal.

The ultra-low density polyethylene used for the coating layer of the present invention has excellent adhesiveness by itself, and especially the low-density inner layer has excellent adhesiveness, so that it can be sufficiently adhered to a tubular fabric. are doing.

As described above, in the method in which the synthetic resin forming the coating layer is extruded into a tube shape, and the inside of the tubular cloth is decompressed and adhered, the adhesiveness between the coating layer and the tubular cloth is structurally improved. However, in the present invention, since the ultra-low density polyethylene forming the inner layer of the coating layer has excellent adhesiveness in the present invention, it is possible to cover the structural lack of adhesive strength and secure sufficient adhesive strength.

[Advantage of Invention] Therefore, according to the present invention, since the coating layer is made of a stable polyolefin-based synthetic resin, there is no problem in water quality even when applied to a pipeline for water supply, and it is safe. In addition, since the lining material is flexible and the adhesive strength between the tubular fabric and the coating layer is high, the lining material is easy to turn over even when used in the lining method, and the lining material is not damaged during turning over.

Moreover, it is particularly superior in adhesiveness to the tubular fabric than the low-density inner layer, and has sufficient heat resistance due to the relatively high-density outer layer, and cures the adhesive with a high-temperature heating fluid such as pressurized steam during lining. It is possible to

Therefore, according to the present invention, the pipeline can be effectively repaired and reinforced, and the lined pipeline has excellent durability.
The pipe can be effectively protected over a long period of time.

[Brief description of drawings]

FIG. 1 is a perspective view showing the lining material of the present invention, and FIG. 2 is an enlarged transverse sectional view of a part thereof. 1 ... Cylindrical cloth, 2 ... Coating layer 3 ... Warp yarn, 4 ... Weft yarn

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location B29L 23:00

Claims (1)

(57) [Scope of utility model registration request] 1. A flexible liner, which is turned upside down by fluid pressure, is inserted from one end to the other end of the pipeline, and at the same time the liner is adhered to the inner surface of the pipeline by the fluid pressure. In the lining material used in the lining method, the content of α-olefin on the outer surface of the tubular fabric (1) is
A coating layer (2) composed of an inner layer having a density of 0.90 and an outer layer having a density of 0.91 was formed from 15 to 40% by weight of a random copolymer of ethylene and an α-olefin having 3 or more carbon atoms. Liner lining material characterized by