JP2008055786A - Pipe and joint system equipped with oxygen barrier layer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe equipped with an oxygen barrier layer, of which the oxygen barrier property is maintained forever by the oxygen barrier layer protected from intrusion of a claw of a pipe falling-off preventive member reaching an intermediate layer even if the claw bites into the surface of the pipe by the pipe falling-off preventive member or the like. <P>SOLUTION: The pipe is equipped with the oxygen barrier layer characterised by comprising three layers of an inner layer 11, an outer layer 12 and an intermediate layer 13 sandwiched in between the inner and outer layers and having the oxygen barrier property, which are three layers of resin materials and manufactured by a coextrusion molding. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pipe and a joint system used for water supply and hot water supply piping, and more particularly to a pipe and a joint system having an oxygen barrier layer.

  In recent years, pipes made of polybutene, cross-linked polyethylene or the like have been used as pipes for water supply and hot water supply. However, this type of pipe has a permeation of oxygen in the atmosphere, and oxygen enters the fluid in the pipe from the atmosphere. This created a problem that should be essentially improved.

  For example, in cold districts in Hokkaido and Tohoku, there have been an increasing number of cases where panel heaters are installed along walls, but the heater body through which hot water flows is made of iron. For this reason, when oxygen is contained in the warm water, there is a problem that rust is generated in the heater body due to long-term use. For this reason, an oxygen barrier layer is formed on the surface of the pipe used.

  However, when connecting the pipes to each other or connecting the pipes to various instruments, it is common to use a joint incorporating a water stop ring and a pipe removal prevention member. In particular, in the pipe removal prevention member, a claw is formed toward the pipe, and this claw bites into the pipe and is connected and fixed.

  FIG. 1 is a view showing an example of a joint. A water stop ring 1 and a pipe drop prevention member 2 are built in the joint, and a socket 3 is attached to prevent the drop. A claw 4 is formed on the inner peripheral surface of the pipe removal preventing member 2. Therefore, when the pipe 5 is inserted from the socket 3, the water stop ring 1 contacts the surface of the pipe 5 to prevent water leakage, and the claw 4 of the pipe removal preventing member 2 bites into the surface of the pipe 5 and the pipe 5 is pulled out. Is to prevent.

  However, if the oxygen barrier layer 5a is formed on the surface of the pipe 5 in order to prevent oxygen from entering, the oxygen barrier layer 5a may be destroyed by the nail 4 that has digged in. That is, since the oxygen barrier layer 5a is disposed on the outer surface of the pipe 5, there is a concern that the oxygen barrier layer 5a may be damaged by dragging during pipe handling during construction. Further, in the conventional pipe 5, it has been difficult to employ a joint using the pipe removal preventing member 2 that is widespread in the water supply / hot water supply field. This is because the joint nail 4 damages the oxygen barrier layer 5a during connection.

  An object of the present invention is to provide a pipe having a oxygen barrier layer, and to provide a pipe and a joint system that does not lose its function even if a nail bites into the surface by a pipe removal prevention member or the like. It is.

  The gist of the present invention relates to a pipe having an oxygen barrier layer (Claim 1), characterized by comprising an inner layer and an outer layer, and an intermediate layer having an oxygen barrier property sandwiched therebetween, preferably, These three layers are resin materials (Claims 2 to 3), and are obtained by coextrusion molding (Claim 4).

  And as a pipe joint system, a larger characteristic is adopted by adopting a pipe joint provided with a water-stopping O-ring such as NBR or EPDM and an oxygen-impermeable O-ring such as butyl rubber (Claims 5 and 6). It is demonstrated.

  Since the pipe obtained by the present invention has a barrier layer in the middle of the pipe (Claim 1), such a layer is protected by the inner and outer layers, particularly the outer layer. However, this intermediate layer is not reached, and the oxygen barrier property is maintained permanently.

  On the other hand, in the pipe joint system (Claims 5 and 6), the function of the O-ring contacting the surface of the pipe is divided, and the feature is further increased by using an oxygen-impermeable O-ring.

  The pipe of the present invention is optimal for pipes for water supply and hot water supply as described above, and a layer having an oxygen barrier property is arranged in the center of the pipe thickness (Claim 1). It is a type that prevents damage to the layer and is compatible with joints where pipe removal prevention members etc. are used, installation is complete, and oxygen from the atmosphere does not enter the pipe, Since unnecessary oxygen does not enter the fluid, there is a feature that defects such as rusting of an iron panel heater main body are not caused.

  Of course, there is no restriction on the location of use of the pipe of the present invention. However, when running tap water, the inner layer should be made of a material that is not affected by chlorine contained in the tap water, and the inner layer is poured into the pipe. It must not be eroded by the fluid being sunk. In addition, depending on the place of use, it is necessary to make the pipe flexible or wear-resistant, but it goes without saying that a material that satisfies these requirements must be selected.

  Suitable materials for the oxygen barrier layer (intermediate layer) include ethylene-vinyl alcohol copolymer (EVOH), polyamide (MXD6) and the like (Claim 2). Needless to say, the position where the oxygen barrier layer is buried is preferably a position that is not affected by the biting of the claw of the pipe slip-off preventing member. Usually, the material forming the inner and outer layers, the length and size of the claw of the pipe slip-off preventing member Depending on the pressure applied to the pipe removal preventing member, the pipe thickness is about 10 to 20% when viewed from the side where the nail bites. Therefore, the oxygen barrier layer is preferably formed at a site of 20% or more, and preferably the oxygen barrier layer is formed at a site 40 to 70% thicker than the side where the nail bites.

  As the inner layer and the outer layer, a resin and a rubber material are selected. Examples of the resin material include polybutene, cross-linked polyethylene, vinyl chloride, and polyamide (Claim 3). Examples of the rubber material include butyl rubber, brominated butyl rubber, ethylene / propylene copolymer (EPDM), nitrile / butadiene rubber (NBR), hydrogenated NBR, chloroprene rubber (CR), acrylic rubber, and CSM. . The selected material for the inner and outer layers may be the same material or different materials. When a rubber material is used, a fiber reinforcing layer (for example, PET, PEN, polyester, polyamide, etc.) may be further used.

  In particular, when the pipe of the present invention is used as a water supply / hot water supply pipe, the inner and outer layers are composed of a resin such as polybutene, cross-linked polyethylene, vinyl chloride, and polyethylene (Claim 3), and ethylene is used as an intermediate oxygen barrier layer. -A resin pipe obtained by three-layer coextrusion molding (Claim 4) using vinyl alcohol copolymer (EVOH), polyamide (MXD6) or the like (Claim 2) is suitable.

  In order to further exhibit the features of the present invention, it is of course preferable to use a joint system in which a device is also devised on the pipe joint side. For example, conventionally, a non-oxygen-free O-ring such as NBR or EPDM is used. In addition to this, the provision of an oxygen-impermeable O-ring such as butyl rubber has a great effect.

  As a first system (Claim 5), a joint base formed with two stepped portions, a water stop O-ring and a pipe slip-off preventing member are incorporated in the large-diameter stepped portion, and a cap for preventing these slipping is provided. A pipe joint mounted on a joint base, comprising an oxygen-impermeable O-ring in parallel with the water-stopping O-ring 4, and a pipe having an oxygen barrier layer according to claim 1 to a pipe having a small diameter of the joint base. It is a pipe joint system characterized by being inserted into a stepped portion.

  As a second system (Claim 6), a joint base provided with an inner cylinder inserted into the inner periphery of the pipe, a pipe removal prevention member that covers the inner cylinder, and a cap that prevents the pipe removal prevention member from coming off. 5. A pipe joint mounted on a joint base, wherein the inner cylinder is provided with a water-stop O-ring and an oxygen-impermeable O-ring in parallel, and the pipe having the oxygen barrier layer according to claim 1 is inserted into the inner cylinder. It is a pipe joint system characterized by that.

  The present invention will be further described below with reference to examples. FIG. 2 is a cross-sectional view of the resin pipe 10 provided with the oxygen barrier layer of the present invention. In the figure, 11 is a polybutene resin layer forming an inner layer, and 12 is a polybutene resin layer forming an outer layer. An EVOH resin layer is sandwiched between the inner and outer polybutene layers as an oxygen barrier layer 13 at approximately 50% (intermediate) position, and the thickness thereof is about 0.5 mm. These three layers are coextruded at the same time.

  The resin pipe 10 shown in FIG. 2 is inserted and attached to a so-called one-push joint using the pipe removal preventing member 2 shown in FIG. A support sleeve 20 was inserted into the insertion end of the resin pipe 10. The water stop ring 1 exhibited the water stop function completely when the water stop ring 1 contacted the outer surface of the resin pipe 10.

  On the other hand, the resin pipe 10 was disconnected, but the claw 4 of the pipe disconnection preventing member 2 bited into the surface, and the disconnection was prevented. At this time, the claw 4 will bite into the outer layer 12 of the resin pipe 10, but it does not reach the intermediate layer 13 having an oxygen barrier effect, and repeated attachment and detachment of both. There was no influence by the contact of the water stop ring 1, the oxygen barrier layer (intermediate layer) 13 was intact, and the barrier effect was perfect.

  1 includes a structure in which the water stop ring 1 is in contact with the inner surface of the pipe 10, but the oxygen barrier layer 13 is also protected by the inner layer 11, so that the barrier effect is also achieved. It goes without saying that it is perfect.

  FIG. 3 is a diagram showing a first of the pipe joint system. In this example, two step portions 32 and 33 are formed on the joint base 31. The large-diameter step 32 includes a water-stopping O-ring 34, an oxygen-impermeable O-ring 37, and a pipe removal preventing member 35, and a cap 36 that prevents these removals. The pipe 10 shown in FIG. 2 is inserted into the cap 36, and the water-stopping O-ring 34 and the oxygen-impermeable O-ring 37 come into contact with the outer surface of the pipe 10 to prevent water leakage and oxygen from entering. The claw 35a of the pipe dropout prevention member 35 bites into the surface and prevents the dropout. In this case, it is preferable to arrange a water-stopping O-ring 34 on the inner side and an oxygen-impermeable O-ring 37 on the outer side.

  FIG. 4 is a diagram showing a second of the pipe joint system. A joint base 31 having an inner cylinder 38 inserted into the inner periphery of the pipe 10 shown in FIG. 2 and an outer cylinder 38a covering the inner cylinder 38 are formed, and a pipe removal prevention member 35 is disposed at the tip of the outer cylinder 38a. A pipe joint is provided with a cap 36 that prevents the pipe slip-off preventing member 35 from coming off the joint base 31, and is provided with a water-stopping O-ring 34 and an oxygen-impermeable O-ring 37 in parallel on an inner cylinder 38. . In the figure, reference numeral 35b denotes a ring for releasing the pipe drop-out preventing member 35 from biting into the pipe 10, and the biting is released by pushing the pipe from the outside toward the inside. The outer cylinder 38a may be formed separately from the joint base 31 (31a, 31b).

  In this example, two circumferential grooves 39a and 39b are formed on the surface of the inner cylinder 38, and a water-stopping O-ring 34 and an oxygen-impermeable O-ring 37 are separately fitted therein. In the second system, it is preferable to fit the water-stopping O-ring 34 in the inner circumferential groove 39a and the oxygen-impermeable O-ring 37 in the outer circumferential groove 39b.

  In the pipe joint shown here, the pipe is mounted with one push, the O-ring is divided into two functions, and two O-rings made of optimum materials are used respectively. It is possible to prevent the transmission of the light. Thereby, it can be used as a one-push joint oxygen impervious joint, and the workability is dramatically improved.

  In the pipe and pipe joint system of the present invention, since the oxygen barrier layer is arranged between the inner and outer layers of the pipe due to the above configuration, the barrier effect can be reduced by connecting to a joint using a pipe removal prevention member. In addition, even when the pipe is caulked and connected to another member, the oxygen barrier layer remains intact. On the other hand, even in the pipe joint system, the sealing property is increased by adopting an oxygen-impermeable O-ring.

  Here, EVOH and MXD6 exemplified as examples of the oxygen barrier layer are resins having a high barrier property against leakage of internal fluid, and therefore can be used for environmental purposes that are problematic in various places. For example, the present invention can also be applied to a refrigerant pipe such as a cooler. When the hot water is filled in the pipe, it is also effective that the oxygen barrier layer closer to the hot water side is less affected by the deterioration of the characteristics due to the humidity of the hot water.

FIG. 1 is a diagram showing an application example of a conventional pipe and a pipe drop prevention member. FIG. 2 is a partially cut side view showing the (resin) pipe of the present invention. FIG. 3 is a view showing a first pipe joint system. FIG. 4 is a view showing a second pipe joint system.

Explanation of symbols

1 ... water stop ring,
2. Pipe removal prevention member,
3. Socket,
4. Claw of pipe removal prevention member,
5. Pipes
5a ... oxygen barrier layer on the pipe surface,
10. The resin pipe of the present invention,
11 ... Inner layer,
12 ... outer layer,
13. Intermediate layer (oxygen barrier layer)
31 ... Joint base,
32, 33 ... steps,
34. Still water O-ring,
35. Pipe removal prevention member,
35a: nails,
36 ... cap,
37 ... oxygen-impermeable O-ring,
38 ... inner cylinder,
39a, 39b ... circumferential grooves.

Claims (6)

  A pipe provided with an oxygen barrier layer, characterized by comprising an inner layer and an outer layer, and an intermediate layer having an oxygen barrier property sandwiched therebetween.   The pipe provided with the oxygen barrier layer according to claim 1, wherein the intermediate layer is selected from ethylene-vinyl alcohol copolymer (EVOH) and polyamide (MXD6).   The pipe provided with the oxygen barrier layer according to claim 1 or 2, wherein the inner and outer layers are selected from polybutene, crosslinked polyethylene, vinyl chloride, and polyamide.   The pipe provided with the oxygen barrier layer according to any one of claims 1 to 3, wherein the inner and outer layers and the intermediate layer are formed by three-layer coextrusion molding.   A joint base in which two stepped portions are formed, and a water stop O-ring and a pipe dropout prevention member are built in a stepped portion of a large diameter, and a cap that prevents these slippages is mounted on the joint base, 5. A pipe joint system comprising an oxygen-impermeable O-ring in parallel with the water-stop O-ring, and a pipe having an oxygen barrier layer according to claim 1 inserted into a small-diameter step portion of a joint base. .   A pipe joint in which a joint base having an inner cylinder inserted into the inner periphery of a pipe, a pipe removal prevention member that covers the inner cylinder, and a cap that prevents the pipe removal prevention member from coming off are attached to the joint base 1. 5. A pipe joint system comprising a water-stopping O-ring and an oxygen-impermeable O-ring arranged in parallel in the inner cylinder, and a pipe provided with the oxygen barrier layer according to claim 1 inserted into the inner cylinder.

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