JP2007296774A - FRP fluid transfer pipe - Google Patents

Abstract

Provided is a fluid transport pipe made of FRP which has both chemical resistance and water pressure resistance and is excellent in durability.
An FRP fluid conveying pipe 10 includes a first thermoplastic resin layer 1 containing a chemical-resistant thermoplastic resin formed on the innermost peripheral side, and the first thermoplastic resin layer. A second thermoplastic resin layer 2 containing a styrenic thermoplastic resin formed in close contact with the outer peripheral side of 1 and a reinforcing fiber formed in close contact with the outer peripheral side of the second thermoplastic resin layer 2 And an FRP layer 3 made of a thermosetting resin, and a coating layer 4 containing a thermoplastic resin formed in close contact with the outer peripheral side of the FRP layer 3.
[Selection] Figure 1

Description

  The present invention relates to an FRP fluid transport pipe having chemical resistance and water pressure resistance, and more particularly to an FRP fluid transport pipe having excellent durability.

  The fluid conveyance pipe is for conveying a fluid such as agricultural water, and is widely used, for example, as an irrigation pipe for a greenhouse of a greenhouse. As such a fluid conveyance pipe, a pipe (polyvinyl chloride) made of PVC (hereinafter referred to as “PVC pipe”) is the mainstream and well known. However, since PVC pipes are easily deformed due to temperature changes, the watering direction tends to shift and cracks are likely to occur. Also, PVC pipes have low bending rigidity, so if the distance between support points such as a hanging element is wide, they will bend easily due to their own weight, and especially permanent changes due to long-term static loads, making repair difficult. Sometimes it ends up.

  On the other hand, a pipe made of fiber reinforced thermosetting resin (hereinafter referred to as “FRP”) (hereinafter referred to as “FRP pipe”) is also known as a fluid conveyance pipe (for example, a patent). Reference 1). FIG. 3 shows an example.

  The FRP pipe 30 shown in the figure has a three-layer structure, and is formed in close contact with the thermoplastic resin layer 11 made of ABS resin formed on the innermost peripheral side and the outer peripheral side of the thermoplastic resin layer 11. The FRP layer 12 and a coating layer 13 made of ABS resin (acrylonitrile-butadiene-styrene resin) formed in close contact with the outer peripheral side of the FRP layer 12 are provided.

  The FRP pipe 30 having such a structure has few problems as described above which the PVC pipe has, and the ABS resin is exposed on the outer surface thereof. For example, toluene, xylene, MEK and the like are used as solvents. It is easy to adapt to the adhesive and piping is easy. Furthermore, since the FRP pipe 30 is lightened by FRP, it is convenient to transport and handle, and has other excellent characteristics. In addition, as a commercial item of the pipe 30 made from FRP, there exists a UM shower (Ube Nitto Kasei Co., Ltd. (brand name)) etc., for example.

  By the way, in greenhouses and the like, there are many requests that the above-mentioned FRP pipe not only be used for water but also for transporting agricultural chemicals containing organic solvents, fluids containing insecticides, deodorants and the like. However, the conventional FRP pipe 30 cannot be used for such applications because the innermost thermoplastic resin layer 11 is made of ABS resin having no chemical resistance. In order to be able to be used for such applications, it is necessary to form the thermoplastic resin layer 11 from a thermoplastic resin whose main component is a resin having chemical resistance. However, in the case of a resin having chemical resistance, it is generally difficult to ensure the adhesion between the thermoplastic resin layer 11 and the FRP layer 12.

Therefore, conventionally, there is a technology for multilayering the core using a fiber reinforced thermoplastic resin and securing the adhesion between the core and the FRP layer 12 by anchor adhesion via a blend resin layer (for example, Patent Document 2). In such an FRP pipe, since the FRP layer 12 is adhered to the innermost layer, chemical resistance against the transportation of agricultural chemicals can be obtained.
JP-A-10-178842 JP 2002-130544 A

  However, since the above-mentioned anchor adhesion is weak against internal pressure fatigue, there has been a problem that interfacial peeling is likely to occur in a fine fog cooling application in which spraying is performed at a high pressure and durability is low.

  In addition, in order to improve the water pressure resistance of the FRP pipe, there is a technique of filament winding glass roving on the outer periphery of the center core (see, for example, JP-A-2004-330559). However, even if such a technique is used, the above-mentioned anchor adhesion has a similar problem because it is weak against internal pressure fatigue repeatedly received from a fluid.

  The present invention has been made in view of such conventional problems, and an object of the present invention is to provide an FRP fluid conveyance pipe having both chemical resistance and water pressure resistance and excellent durability. is there.

  In order to solve the above-described problem, the FRP fluid conveyance pipe of the present invention includes a first thermoplastic resin layer containing a chemical-resistant thermoplastic resin formed on the innermost peripheral side, and the first thermoplastic resin layer. A second thermoplastic resin layer containing a styrenic thermoplastic resin formed in close contact with the outer peripheral side of the thermoplastic resin layer, and an outer peripheral side of the second thermoplastic resin layer. It is characterized by comprising an FRP layer made of reinforcing fibers and a thermosetting resin, and a coating layer made of a thermoplastic resin formed in close contact with the outer peripheral side of the FRP layer.

  According to this configuration, the first thermoplastic resin layer having chemical resistance and the second thermoplastic resin layer made of styrene-based thermoplastic resin are formed in close contact with each other by chemical affinity. This has the effect of being able to withstand the internal pressure fatigue repeatedly received from the fluid.

  In the present invention, the second thermoplastic resin layer is formed of a styrenic thermoplastic resin such as AES resin (acrylonitrile-ethylenepropylene-styrene resin) or AAS resin (acrylonitrile-acrylic-styrene resin). Preferably it is. In particular, the styrenic thermoplastic resin preferably contains an ethylene component. In such a case, the adhesion with the PBT resin or the like increases.

  In the present invention, the first thermoplastic resin layer is a thermoplastic resin made of PEP resin (polyester engineering plastic resin) such as PET resin (polyethylene terephthalate resin) or PEN resin (polyethylene naphthalate resin). Preferably it is formed. According to this configuration, the PEP resin has good chemical resistance to organic solvents, and the FRP pipe inner surface is not attacked even when a fluid containing xylene or the like is conveyed. Does not occur.

  In the present invention, the first thermoplastic resin layer is preferably formed of a thermoplastic resin made of a PBT resin (polybutylene terephthalate resin). According to such a configuration, the PBT resin has good chemical resistance to organic solvents such as xylene, and even when a fluid containing xylene or the like is conveyed, the inner surface of the FRP pipe is not affected. There will be no decline in the water pressure resistance.

  ADVANTAGE OF THE INVENTION According to this invention, while having both chemical resistance and water pressure resistance, the fluid conveyance pipe made from FRP excellent in durability can be provided.

  Hereinafter, a fluid conveyance pipe according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic configuration diagram showing a fluid conveyance pipe according to an embodiment of the present invention. The fluid conveyance pipe 10 shown in the figure is a kind of FRP pipe, and is formed on the outermost side of the first thermoplastic resin layer 1 formed on the innermost peripheral side and the first thermoplastic resin layer 1. The second thermoplastic resin layer 2 formed in close contact, the FRP layer 3 formed in close contact with the outer peripheral side of the second thermoplastic resin layer 2, and the outer peripheral side of the FRP layer 3 And a coating layer 4 formed in this manner.

  The first thermoplastic resin layer 1 contains a chemical-resistant thermoplastic resin. Examples of such chemical-resistant thermoplastic resins include PBT resin (polybutylene terephthalate resin), PEP resin (polyester engineering plastic resin), olefin thermoplastic resin (for example, PP resin and PE resin), and fluorine resin. However, PBT resin, PEP resin, olefinic thermoplastic resin, and fluorine resin are preferable, and PBT resin is more preferable.

  The second thermoplastic resin layer 2 contains a styrenic thermoplastic resin. Examples of such styrenic thermoplastic resins include AES resin (acrylonitrile-ethylenepropylene-styrene resin), ABS resin (acrylonitrile-butadiene-styrene resin), AAS resin (acrylonitrile-acrylic-styrene resin), AS resin (acrylonitrile- (Styrene resin), PS resin (polystyrene resin), and the like, and resins containing ethylene components such as AES resin and AAS resin are preferable.

  The FRP layer 3 consists of a reinforced fiber and a thermosetting resin. Examples of the reinforcing fiber include glass fiber, carbon fiber, and aramid fiber, but are not particularly limited. Examples of the thermosetting resin include an unsaturated polyester resin, a vinyl ester resin, and an epoxy resin, but are not particularly limited.

  The covering layer 4 is made of a thermoplastic resin. Examples of the thermoplastic resin include ABS, AAS, AES, PS resin, AS resin, PSF resin, PC resin, PPE resin, and PVC resin, but are not particularly limited.

  According to the above configuration, the first thermoplastic resin layer has chemical resistance, has good adhesion with the second thermoplastic resin layer, and the second thermoplastic resin layer and coating Since the layer 4 is formed in close contact with the FRP layer 3, the effect of the present invention, that is, the chemical resistance and the water pressure resistance is provided, and the durability is excellent. The filament winding (FW) is preferably performed on the outer periphery of the core 5. In such a case, the water pressure resistance of the FRP pipe 10 is also improved, so that an FRP pipe having both chemical resistance and water pressure resistance and further excellent durability can be obtained.

  Next, a confirmation test was conducted to confirm the effect of the present invention. That is, the chemical resistance and the water pressure resistance of each of the FRP pipes of Examples 1 and 2 and Comparative Examples 1 to 3 shown in FIG. 2 were examined.

  Specifically, each FRP pipe is cut to 50 cm, a vinyl chloride cap and a valve socket are attached, and then a pesticide containing xylene (Sumithion and Marathon mixed insecticide). (Trade name) was diluted 50 times, 100 times, and 200 times, respectively, and filled, and the valve socket was sealed with a silicon stopper. After leaving this at room temperature for one month, changes in the pipe inner surface and water pressure resistance were measured. In the water pressure resistance test, first, the inner surface of the FRP pipe was washed with water and left at room temperature for 24 hours. Thereafter, the water pressure was manually increased to perform a destructive test (using a Kyowa water pressure tester, T-300N), and the water pressure at the time of destruction was read. The results are shown in Table 1. In addition, the "water pressure strength retention rate" in the same table indicates the strength retention rate when no pesticide is added.

<Example 1>
First, as Example 1, an FRP pipe (outer diameter 18.0 mm, inner diameter 12.6 mm) having a side structure as shown in FIG. The FRP pipe shown in FIG. 1 includes a first thermoplastic resin layer 1 (layer thickness; 0.2 mm) made of PBT resin formed on the innermost peripheral side, and the first thermoplastic resin layer 1. A second thermoplastic resin layer 2 (layer thickness; 0.9 mm) made of AES resin formed in close contact with the outer peripheral side of the second thermoplastic resin layer 2 and in close contact with the outer peripheral side of the second thermoplastic resin layer 2 The formed FRP layer 3 (layer thickness; 0.95 mm) and a coating layer 4 (layer thickness; 0.65 mm) formed in close contact with the outer peripheral side of the FRP layer 3 It is configured.

  The core 5 has a double layer structure composed of the first thermoplastic resin layer 1 and the second thermoplastic resin layer 2 and has an outer diameter of 14.8 mm and an inner diameter of 12.6 mm.

  The FRP pipe of Example 1 was manufactured as follows. First, a PBT resin (Polyplastic Co., Ltd. 600 JP (trade name)) that forms the first thermoplastic resin layer 1 and an AES resin (Technopolymer Co., Ltd. AW 270 (trade name) that forms the second thermoplastic resin layer 2. )) Are extruded by a predetermined two-layer coextrusion apparatus so as to be laminated in this order from the innermost layer side, and an outer diameter sizing by vacuum sizing is performed to create a core 5 of a predetermined size. Next, a glass fiber impregnated with an unsaturated polyester resin to be the FRP layer 3 is coated on the inner core 5 in an annular shape with a predetermined thickness, and this is passed through a crosshead die to obtain an ABS resin (GSE450 manufactured by UMG ABS Co., Ltd.). Product name)). And after cooling these glass fiber and ABS resin, it was made to harden with 95-100 degreeC hot water, and the FRP layer 3 and the coating layer 4 were formed. Thereby, the FRP pipe shown in Example 1 was obtained.

<Example 2>
Further, as Example 2, a FRP pipe (outer diameter 18.0 mm, inner diameter 12.6 mm) having a side structure as shown in FIG. The FRP pipe shown in FIG. 1 includes a first thermoplastic resin layer 1 (layer thickness: 0.2 mm) made of PET resin formed on the innermost peripheral side, and the first thermoplastic resin layer 1. A second thermoplastic resin layer 2 (layer thickness; 0.9 mm) made of AES resin formed in close contact with the outer peripheral side of the second thermoplastic resin layer 2 and in close contact with the outer peripheral side of the second thermoplastic resin layer 2 The formed FRP layer 3 (layer thickness; 0.95 mm) and a coating layer 4 (layer thickness; 0.65 mm) formed in close contact with the outer peripheral side of the FRP layer 3 It is configured.

  The core 5 has a double layer structure composed of the first thermoplastic resin layer 1 and the second thermoplastic resin layer 2 and has an outer diameter of 14.8 mm and an inner diameter of 12.6 mm.

  The FRP pipe of Example 1 was manufactured as follows. First, a PET resin (Unitika polyester resin SA-1346P (trade name)) that forms the first thermoplastic resin layer 1 and an AES resin (Technopolymer Co., Ltd. AW270 (product) that forms the second thermoplastic resin layer 2. And a core 5 of a predetermined size was prepared by extruding with a predetermined two-layer co-extrusion device so that the layers were laminated in this order from the innermost layer side, and by performing external diameter sizing by vacuum sizing. . Next, a glass fiber impregnated with an unsaturated polyester resin to be the FRP layer 3 is coated on the inner core 5 in an annular shape with a predetermined thickness, and this is passed through a crosshead die to obtain an ABS resin (GSE450 manufactured by UMG ABS Co., Ltd.). Product name)). And after cooling these glass fiber and ABS resin, it was made to harden with 95-100 degreeC hot water, and the FRP layer 3 and the coating layer 4 were formed. Thereby, the FRP pipe shown in Example 2 was obtained.

<Comparative Example 1>
On the other hand, as Comparative Example 1, an FRP pipe having a side structure as shown in FIG. That is, after forming a single-layer structure core using only ABS resin (Toray Industries, Inc. T600 (trade name)), the FRP layer 3 and the coating layer 4 were formed in this order from the outer periphery side. . As in Example 1, the FRP pipe had an outer diameter of 18.0 mm, an inner diameter of 13.0 mm, and a center core thickness of 0.9 mm. The core was manufactured by extruding with a single layer die and sizing the inner diameter with a mandrel. The FRP layer 3 and the coating layer 4 were formed by the same method as in Example 1.

<Comparative example 2>
As Comparative Example 2, an FRP pipe having a side structure as shown in FIG. That is, after forming a core with a single layer structure using only an AAS resin having chemical resistance (AE77 (trade name) manufactured by Techno Polymer Co., Ltd.), an FRP layer 3 and a coating layer 4 are formed on the outer peripheral side of the core. Were formed in order from the outer peripheral side. As in Example 1, the FRP pipe had an outer diameter of 18.0 mm, an inner diameter of 13.0 mm, and a center core thickness of 0.9 mm. The core was manufactured by extruding with a single layer die and sizing the inner diameter with a mandrel. The FRP layer 3 and the coating layer 4 were formed by the same method as in Example 1.

<Comparative Example 3>
As Comparative Example 3, an FRP pipe having a side structure as shown in FIG. That is, after forming a single-layer structure core using only PBT resin (Polyplastic Co., Ltd. 600 JP (trade name)), the FRP layer 3 and the coating layer 4 are formed in this order from the outer periphery side. did. As in Example 1, the FRP pipe had an outer diameter of 18.0 mm, an inner diameter of 13.0 mm, and a center core thickness of 0.9 mm. The core was manufactured by extruding with a single layer die and sizing the outer diameter by vacuum sizing. The FRP layer 3 and the coating layer 4 were formed by the same method as in Example 1.

  As shown in Table 1, in Examples 1 and 2, compared with Comparative Examples 1 and 2, the water pressure resistance retention rate was high, and the appearance change of the inner surface (core) was difficult to occur. Therefore, it has been confirmed that the FRP pipes according to Examples 1 and 2 have chemical resistance and water pressure resistance and are excellent in durability.

  In the case of Comparative Example 1, the innermost layer (ABS layer) is eroded and dissolved or softened by xylene contained in the pesticide, and even when the pesticide diluted 200 times in water pressure resistance is filled, The hydraulic performance retention rate was only 74%.

  On the other hand, in the case of Comparative Example 2, the degree to which the innermost layer (AAS layer) is eroded by xylene contained in the pesticide is slightly softer than Comparative Example 1, but the water pressure resistance is diluted 50 times. In the case of filling with agricultural chemicals, the water pressure resistance retention rate was only 80%.

  By the way, in the case of the comparative example 3, although the external appearance change (inner core) did not occur easily, the adhesion between the inner core 5 made of PBT and the FRP layer 3 was insufficient. For this reason, water running occurs at the interface between the core 5 and the FRP layer 3 during the water pressure resistance test, resulting in destruction at a low pressure, which is inappropriate as a pipe for transporting fluid.

It is a figure which shows an example of the pipe made from FRP in embodiment of this invention. It is a figure which shows the pipe made from FRP in the Example of this invention. It is a figure which shows an example of the conventional pipe made from FRP.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st thermoplastic resin layer 2 2nd thermoplastic resin layer 3 FRP layer 4 Covering layer 5 Core 10 FRP fluid conveyance pipe (FRP pipe)

Claims (4)

  A first thermoplastic resin layer containing a chemical-resistant thermoplastic resin formed on the innermost peripheral side, and a styrenic thermoplastic resin formed in close contact with the outer peripheral side of the first thermoplastic resin layer A second thermoplastic resin layer containing FRP, a FRP layer made of a reinforced fiber and a thermosetting resin formed in close contact with the outer peripheral side of the second thermoplastic resin layer, and an outer peripheral side of the FRP layer A fluid transport pipe made of FRP, characterized in that it is configured to include a coating layer containing a thermoplastic resin formed in close contact. The FRP fluid transport pipe according to claim 1,
The second thermoplastic resin layer is formed of a styrenic thermoplastic resin such as AES resin (acrylonitrile-ethylenepropylene-styrene resin) or AAS resin (acrylonitrile-acrylic-styrene resin). FRP fluid transfer pipe. The FRP fluid transport pipe according to claim 1 or 2,
The first thermoplastic resin layer is formed of a thermoplastic resin made of PEP resin (polyester engineering plastic resin) such as PET resin (polyethylene terephthalate resin) or PEN resin (polyethylene naphthalate resin). FRP-made fluid conveyance pipe. The FRP fluid transport pipe according to claim 1 or 2,
The first thermoplastic resin layer is formed of a thermoplastic resin made of PBT resin (polybutylene terephthalate resin), and is a fluid transport pipe made of FRP.

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