JP3216964U - Laminated tube - Google Patents

Abstract

To provide a laminated resin tube having high pressure resistance, flexible flexibility, and excellent flame retardancy. In a laminated resin tube 1 comprising at least two layers of an inner layer tube 2 and an outer layer tube 3, the inner layer tube 2 is made of polyurethane resin, and the outer layer tube 3 is made of polyamide resin or nylon resin; To do. The inner tube 2 has a thickness of 0.15 mm to 3.0 mm, and the outer tube 3 has a thickness of 0.1 mm to 1.5 mm. Further, a non-halogen flame retardant is added to the resin material of the outer tube 3. [Selection] Figure 1

Description

  The present invention relates to a resin tube. More specifically, the present invention relates to a laminated resin tube characterized by having both high pressure resistance, ease of bending, and flame retardancy.

  Conventionally, resin tubes made from resins having various characteristics have been put to practical use. For example, when a high pressure resistance is required, a resin tube with a high pressure resistance is realized as a design for selecting a high-hardness resin having a high breaking stress in order to withstand a high circumferential stress applied to the resin tube. Resin tubes with high pressure resistance are convenient for transporting gases and liquids, and are used in large quantities in almost every industry, not only in the food and medical fields, but also as piping parts that introduce high-pressure air into air cylinders. is there.

  However, when a resin tube is manufactured from a high-hardness resin, the property (flexible flexibility) of how small the resin tube can be bent is impaired. Resin tubes that are inferior in flexibility are difficult to install in a space-saving manner because the curvature cannot be increased, and it is fatal to transport gas and liquid, which is the main use of resin tubes, if you try to bend them forcibly Cause buckling (being bent so that the internal space of the resin tube is closed). Since it is a great advantage of the resin tube that it can be bent relatively freely and can be carried out in a space-saving manner, the lack of flexible flexibility greatly impairs the convenience of the resin tube. Therefore, there has been a demand for a resin tube that achieves a high pressure resistance and also has a good flexibility.

  As an invention that can solve the above-mentioned problems, there can be mentioned a laminated resin tube according to Japanese Patent No. 5542268 according to the applicant's own invention. The resin tube according to this patent invention is a laminated resin tube composed of two layers of an inner layer and an outer layer, wherein the inner layer is made of polyurethane resin having a thickness of 1.0 mm to 3.0 mm, and the outer layer is made of thickness 0.01 mm to 1. The main feature is that it is made of a 5 mm polyamide resin. In this way, by making a laminated resin tube in which the thickness and material of each layer are appropriately selected, both high pressure resistance and good flexible flexibility are achieved.

  In addition, since the main use of the resin tube is transportation of gas and liquid, it is often used for transportation of air and flammable liquid. Therefore, how hard the resin tube itself does not burn (flame retardancy) is of great concern, but it is often difficult to impart flame retardancy to resin materials with high breaking stress that can produce resin tubes that can withstand high pressures. There are cases. For example, a polyamide resin is an excellent material having a high breaking stress, but it is difficult to impart sufficient flame retardance particularly with a non-halogen flame retardant. However, in order to reduce the influence on the environment at the time of disposal, a resin tube that does not contain a halogen element is socially demanded.

  Regarding this problem, the patented invention proposes a solution. Specifically, if the resin constituting the inner layer and the outer layer of the laminated tube is selected as described above, the flame retardant added to the resin constituting each of these layers is sufficient as a non-halogen flame retardant. Has been obtained.

As described above, the laminated tube according to Japanese Patent No. 5542268 has excellent characteristics, but there are various specifications required for the laminated tube depending on the application and the use environment. In some cases, it is not easy to satisfy the above requirements. For example, when a flame retardant is not added to the inner layer tube that is in contact with the gas / liquid conveyed by the laminated tube and it is desired to be constituted by a substantially pure resin material, the configuration of the laminated tube is not appropriate. In addition, properties such as strength often deteriorate due to the addition of a flame retardant, and in this respect as well, there is a demand for a laminated tube that achieves the flame retardancy required without adding a flame retardant to the inner layer.
Patent Publication No. 5542268

  Therefore, the problem to be solved by the present invention is to provide a laminated resin tube that achieves sufficient flame retardancy without adding a flame retardant to the constituent material of the inner layer tube, and has both high pressure resistance and flexible flexibility. Is to provide.

(1) In order to solve the above problems, in the present invention, in the laminated resin tube comprising at least two layers of the inner layer tube and the outer layer tube, the inner layer tube is made of polyurethane resin having a thickness of 0.15 mm to 3.0 mm. The outer layer tube is made of a polyamide resin having a thickness of 0.1 mm to 1.5 mm, the inner layer tube does not contain a flame retardant, and the outer layer tube contains a non-halogen flame retardant, It is a laminated resin tube.

  In a laminated resin tube composed of two layers, an inner layer tube and an outer layer tube, a combination in which the inner layer tube is a resin having excellent flexibility and flexibility and the outer layer tube is a resin having a high breaking stress performance has been generally adopted. However, as the present inventors have clarified in the description of Japanese Patent Publication No. 5542268, this combination method has a surprisingly superior characteristic. It has been found that a resin tube can be obtained.

  In other words, when a laminated resin tube is formed by laminating a resin with excellent flexibility and a resin having high performance at break stress, the resin layer with excellent flexibility and flexibility is usually thick and performance at high break stress. The resin layer having a thickness should be designed to be thin. This is because if the resin layer having a high breaking stress performance is too thick, the laminated resin tube becomes hard as a whole and the flexible flexibility is lost. At this time, if the inner tube is made of a resin layer having a high breaking stress, the inner tube is likely to buckle when the laminated resin tube is bent strongly. This is because the outer layer tube is made of a resin having excellent flexibility and flexibility, and thus it cannot be expected to support the tough inner layer tube reliably.

  On the other hand, when the outer layer tube is made of a resin having a high breaking stress, even if the laminated resin tube is strongly bent, the inner layer tube is excellent in flexibility and flexibility, so that it does not easily buckle. Further, even if the outer layer tube is about to buckle, in order for the buckling to occur, the inner layer tube covered with a strong outer layer tube must be crushed, so this does not occur easily.

  In the present invention, a polyurethane resin is selected as the resin having excellent flexibility and flexibility constituting the inner layer tube, and a polyamide resin is selected as the resin having a high breaking stress property constituting the outer layer tube. By setting the thickness of the outer tube to 15 mm to 3.0 mm and 0.1 mm to 1.5 mm, a laminated resin tube having high pressure resistance and excellent flexibility and flexibility was realized.

  Since the outer tube is exposed to friction and the like, if it is too thin, the pressure resistance and the like will be insufficient.On the other hand, it is composed of a polyamide resin having a high breaking stress. It will be damaged. As a guideline, it is preferable that the thickness of the outer layer tube is not more than one half of the thickness of the inner layer tube. This is because, by making the outer layer tube thinner than the inner layer tube in this way, a laminated resin tube excellent in flexible flexibility can be obtained as already described.

  Specifically, the thickness of the outer layer tube can be 0.1 mm to 1.5 mm, and the thickness of the inner layer tube can be 0.2 mm to 3.0 mm. If it does in this way, the laminated resin tube suitable for various gas and liquid conveyance can be obtained. That is, it is particularly convenient because it is possible to provide a laminated tube having a high demand, such as a diameter of about 80 mm or less, a pressure resistance of about 0.6 MPa or less, and a minimum bending radius of about 20 mm. By the way, in the present invention, the thickness of the inner layer tube and the thickness of the outer layer tube are also related to flame retardancy, and by setting these as described above, in addition to pressure resistance performance and flexible flexibility, flame retardancy is also achieved. You can be satisfied. The flame retardancy will be explained later.

  By the way, since both the polyurethane resin constituting the inner layer tube and the polyamide resin constituting the outer layer tube are thermoplastic resins, there is no need to perform a special adhesion treatment between the inner layer tube and the outer layer tube, and the laminated resin is obtained by coextrusion molding. Tubes can be manufactured. The high productivity of coextrusion molding has a great effect on reducing the production cost of resin tubes. Further, co-extrusion molding using a thermoplastic resin can also obtain strong adhesion between the layers, so that a higher quality laminated resin tube can be obtained.

  In the present invention, the resin material constituting the inner layer tube does not include a flame retardant, and the non-halogen flame retardant is added only to the resin material constituting the outer layer tube.

  As already explained, flame retardancy is often required for resin tubes. For laminated resin tubes, flame retardants are added to the resin materials that make up the inner and outer tube layers. The laminated resin tube is preferably used. However, on the other hand, it may be preferable not to add a flame retardant to the inner tube that contacts the gas or liquid to be conveyed, and it may allow deterioration of properties such as strength due to the addition of the flame retardant to the resin material. Sometimes you want to. On the other hand, the polyamide resin is a resin that has excellent breaking stress and molding stability but is relatively difficult to impart flame retardancy. Particularly, in the case of a non-halogen flame retardant, the vertical combustion test grade is 94V-1 or more. It is not easy to get flame retardant.

  However, according to the research of the inventor of the present invention, even if the flame resistance of the laminated resin tube is slightly lower than that of the outer layer tube, if the flame resistance of the inner layer tube is increased, the overall flame resistance of the inner layer tube is almost the same. It has been shown to show sex. And since the polyurethane resin which can obtain the flame retardance of 94V-0 by the vertical combustion test grade comparatively easily is used for the inner layer tube as mentioned above, the outer layer by the polyamide resin which added only the non-halogen flame retardant Despite having the tube, it is a laminated resin tube having a flame retardancy as high as 94V-0 as a whole in the vertical combustion test grade.

  In addition, in order to reduce the impact on the environment at the time of disposal, products made of resin that do not contain so-called halogen elements such as chlorine are required, and flame retardants must be non-halogenated. The present invention also realizes products that meet such social demands. Specifically, various additive-type flame retardants such as organic flame retardants containing malocyanurate flame retardants, inorganic flame retardants, and phosphorus flame retardants containing organic phosphate esters can be used. It is also possible to use a reactive flame retardant such as a hydrogen group-containing flame retardant or a carboxylic acid-containing flame retardant.

  By the way, since the polyamide resin has high crystallinity and high breaking stress, a high pressure-resistant laminated resin tube can be obtained by using this as a material for the outer tube. Moreover, since it is excellent in abrasion resistance, the effect that it becomes difficult to generate | occur | produce a damage | wound etc. on the exterior of a laminated resin tube is acquired.

  Furthermore, the polyamide resin has a feature of high dimensional stability at the time of molding, and is excellent in this point as a material for the outer layer tube of the laminated resin tube. In the first place, the main use of tubes is for transporting gases and liquids, and they are often used to connect tubes to each other or between tubes and devices using joints. Here, since a leak of gas or liquid is not allowed to occur at the joint between the tube and the joint, it is necessary to realize a reliable seal here. Since sealing is often performed on the outer periphery of the tube, high dimensional accuracy is required. Therefore, a high outer diameter dimensional accuracy can be realized by configuring the outer tube with a polyamide resin having high dimensional stability during molding.

(2) In order to solve the above problem, in the present invention, the thickness of the outer layer tube is 0.2 mm to 0.75 mm, and the laminated resin tube according to (1) is provided.

  The thickness of the outer tube is already 0.1 mm to 1.5 mm, so that the properties such as strength and flexible flexibility can be satisfied. Furthermore, the addition of a non-halogen flame retardant makes it an excellent flame retardant. It explains that it can also be realized. More preferably, the thickness of the outer layer tube is in the range of 0.2 mm to 0.75 mm. By doing in this way, it is because characteristics, such as intensity | strength suitable for more uses, and flexible flexibility are implement | achieved.

(3) In order to solve the above problem, in the present invention, the thickness of the inner tube is 0.3 mm to 1.5 mm, and the laminated resin according to either (1) or (2) It is a tube.

  It has already been explained that by setting the thickness of the inner tube to 0.15 mm to 3.0 mm, properties such as strength and flexible flexibility can be satisfied, and excellent flame retardancy can also be realized. More preferably, the thickness of the inner layer tube is in the range of 0.3 mm to 0.75 mm. By doing in this way, it is because characteristics, such as intensity | strength suitable for more uses, and flexible flexibility are implement | achieved.

  As described above, according to the present invention, there can be obtained an effect that it is possible to provide a laminated resin tube having both high pressure resistance and flexible flexibility and having high flame retardancy even though it does not contain a halogen element.

It is explanatory drawing which showed the implementation method of the laminated resin tube which concerns on this invention. It is explanatory drawing which showed the state which connected the laminated resin tube which concerns on this invention to the joint.

  FIG. 1 shows an embodiment of a laminated resin tube according to the present invention. The laminated resin tube (1) is an explanatory diagram of a structure in which an inner tube (2) made of polyurethane resin and an outer tube (3) made of polyamide resin are laminated.

  The laminated resin tube (1) is a tube having an outer diameter of 6 mm and an inner diameter of 4 mm. As an example of this, the inner layer tube (2) has an inner diameter of 4 mm and a thickness of 0.6 mm, and an outer layer tube ( 3) has a thickness of 0.4 mm. With this configuration, a pressure resistance of 2.8 MPa and a minimum bending radius of 18 mm were obtained.

  Also, although the outer diameter is 8 mm, as another example, the inner layer tube (2) has an inner diameter of 5 mm and a thickness of 1.1 mm, and the outer layer tube (3) located outside thereof has a thickness of 0.4 mm. A tube was also prototyped. With this configuration, a pressure resistance of 3.0 MPa and a minimum bending radius of 20 mm were obtained.

  Thus, it was proved that the pressure resistance and the flexible flexibility can be adjusted very easily by adjusting the thicknesses of the inner layer tube (2) and the outer layer tube (3).

  The laminated resin tube (1) according to the present invention was manufactured by coextrusion molding. The polyurethane resin and the polyamide resin have good adhesion when co-extrusion molding is performed, and the peel strength at the interface between the inner layer tube (2) and the outer layer tube (3) is extremely high. Therefore, it is unlikely that the inner layer tube (2) and the outer layer tube (3) peel off under normal use conditions.

  Moreover, since the outer layer tube (3) is made of a polyamide resin having high molding shape stability, the outer shape accuracy of the laminated resin tube (1) is extremely high. For this reason, as shown in FIG. 2, when the laminated resin tube (1) is inserted into the joint (4), the outer peripheral seal portion (5) adheres to the outer periphery of the laminated resin tube (1) without any gap, and a reliable seal is obtained. can get. That is, since the outer shape of the laminated resin tube (1) is exactly circular and has almost no irregularities, there is no leakage of the gas / liquid transported when connected to the joint.

  Further, a non-halogen flame retardant is added to the material resin of the outer tube (3). The inner layer tube (2) made of polyurethane resin has a flame retardancy of 94V-0 in the vertical combustion test grade alone, but the outer layer tube (3) made of polyamide resin has vertical combustion in the case of a non-halogen flame retardant alone. Only the flame resistance of 94V-1 was ensured in the test grade. However, as a whole of the laminated resin tube (1) which is a combination of these, the vertical combustion test grade obtained a flame resistance of 94V-0 which is almost equal to the flame resistance of the inner layer tube (2). That is, although it does not contain a halogen element, a laminated resin tube having high flame retardancy can be realized.

  As described above, the present invention provides a laminated resin tube that has both high pressure resistance and flexible flexibility, and has high flame resistance even though it does not contain a halogen element. Is extremely expensive.

1 Laminated resin tube 2 Inner layer tube 3 Outer layer tube 4 Joint 5 Outer seal

Claims (3)

In a laminated resin tube consisting of at least two layers of an inner layer tube and an outer layer tube,
The inner tube is made of polyurethane resin having a thickness of 0.15 mm to 3.0 mm,
The outer tube is made of polyamide resin having a thickness of 0.1 mm to 1.5 mm,
The inner layer tube does not contain a flame retardant,
A laminated resin tube characterized in that the outer layer tube contains a non-halogen flame retardant. The laminated resin tube according to claim 1, wherein the outer layer tube has a thickness of 0.2 mm to 0.75 mm. The laminated resin tube according to claim 1, wherein the inner layer tube has a thickness of 0.3 mm to 1.5 mm.

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