JP2005315362A - Tube for fluid piping - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tube for fluid piping which has a chemical resistance to an internal fluid and an external environment and which has flexibility and a wear resistance. <P>SOLUTION: A fluororesin having adhesion is made into an inner layer side, a nylon resin in which nylon 11 and nylon 12 are blended, is made into an outer layer side, and they are coextrusion molded. Although the nylon 11 has the adhesion and excellent flexibility, the property deteriorated in a wear resistance is found in the nylon 11. Although the nylon 12 has a high surface hardness and excellent wear resistance, the property deteriorated in the adhesion is found. But, since the tube for this fluid piping is constituted as described above, the tube has the chemical resistance to the internal fluid with the fluororesin having the adhesion of the inner layer side, the adhesion with the fluororesin by the nylon resin in which the nylon 11 of the outer layer side is blended with the nylon 12, and excellent flexibility and wear resistance. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fluid piping tube that has chemical resistance to internal fluid and external environment and is flexible and excellent in wear resistance.

  Conventionally, there are pipes in which a plurality of bundles are attached in a movable arm of an industrial robot. Among these pipes, there is a chemical-resistant tube for fluid piping that supplies fluid to the inside and is used for painting and other applications.

  PTFE (fluororesin) is excellent in chemical resistance and has some flexibility as a material for the fluid piping tube, but it wears in a relatively short time when sliding with a tube of a different material in the movable arm. . ETFE (fluororesin) is excellent in chemical resistance and fracture strength (rupture resistance), but inferior in flexibility. The fluid piping tube needs to bend to a certain extent in the movable arm, and is required to be flexible.

By the way, a laminated tube having a chemical resistance in the inner layer has been proposed in which polyurethane resin is thermally welded as an outer layer tube to the outer peripheral surface of the inner layer tube made of PVdF resin by coextrusion molding for use in food and drink applications. However, there is a problem that the chemical resistance, wear resistance and flexibility of the outer layer cannot be achieved at the same time.
JP-A-8-142151

  Therefore, the present invention intends to provide a fluid piping tube which has chemical resistance against internal fluid and external environment, and also has flexibility and wear resistance.

  In order to solve the above problems, the present invention takes the following technical means.

 (1) The fluid piping tube of the present invention is characterized by being co-extruded with an adhesive fluororesin as the inner layer side and a nylon resin blended with nylon 11 and nylon 12 as the outer layer side.

  Nylon 11 was found to have adhesiveness and excellent flexibility but poor wear resistance. Nylon 12 was found to have high surface hardness and excellent wear resistance but poor adhesion. However, since the fluid piping tube has the above-described configuration, the outer layer side nylon 11 and the nylon 12 are blended with chemical resistance against the inner fluid by the fluororesin having adhesiveness on the inner layer side. Nylon resin has adhesiveness with fluororesin and has excellent flexibility and wear resistance.

  Here, the nylon resin (nylon 11, nylon 12) may or may not contain a plasticizer. In addition, stabilizers such as antioxidants and weathering agents, impact modifiers, conductive agents, polymers other than nylons 11 and 12, aliphatic and aromatic nylons, copolymer nylons thereof, elastomers having amide groups, etc. May be included as a modifier.

  As the adhesive fluororesin, ETFE resin, FEP resin, PFA resin, or the like can be used. Further, the adhesive fluororesin includes a carboxyl group, a carboxylic anhydride residue, an epoxy group, a hydroxyl group, an isocyanate group, an ester group, an amide group, an aldehyde group, an amino group, a hydrolyzable silyl group, a cyano group, It can be set as the polymer into which the 1 type, or 2 or more types of the functional group of a carbon-carbon double bond, a sulfonic acid group, and an ether group was introduce | transduced.

(2) The nylon resin may be a blend of nylon 11 and nylon 12 in a ratio of about 3: 7 to 7: 3.

  Nylon 11 and nylon 12 can be blended, for example, at a ratio of about 1: 1. When the blend ratio is set to about 3: 7 to 7: 3, the adhesiveness between the fluororesin and the nylon resin, and nylon The wear resistance of the resin can be made highly compatible.

 (3) Further, the fluororesin having adhesiveness may be further co-extruded by disposing a fluororesin layer that is not modified on the inner layer side and is inferior in adhesiveness.

  Adhesive fluororesin has been modified, but with this construction, it is possible to impart higher chemical resistance because it is a layer of unmodified fluororesin that comes into contact with the internal fluid. it can. Moreover, although the layer of the fluororesin which is not modified | denatured is inferior to adhesiveness, the fluororesin which has adhesiveness is the same resin, compatibility, and mutual adhesiveness is sufficient.

(4) The fluororesin may be ETFE resin. In this way, the ETFE resin has an advantage that it is easy to co-extrusion molding because the molding temperature is close to that of nylon 11 or nylon 12.

  The adhesive ETFE resin includes a carboxyl group, a carboxylic acid anhydride residue, an epoxy group, a hydroxyl group, an isocyanate group, an ester group, an amide group, an aldehyde group, an amino group, a hydrolyzable silyl group, a cyano group, a carbon- It can be set as the polymer into which the 1 type (s) or 2 or more types of the functional group of a carbon double bond, a sulfonic acid group, and an ether group were introduce | transduced.

 (5) The ratio of the thickness of the ETFE resin layer to the thickness of the tube may be set to about 1 to 80%. If set in this manner, the fluid piping tube has sufficient chemical resistance and chemical permeation resistance.

 (6) The ratio of the thickness of the ETFE resin layer to the thickness of the tube may be set to about 5 to 30%. In this way, it has sufficient chemical resistance and chemical permeation resistance as a tube for fluid piping, and in addition to ETFE resin, there is a tendency to be inferior in flexibility. In addition to being flexible, the tube as a whole has sufficient wear resistance.

  The present invention is configured as described above and has the following effects.

  The inner layer side adhesive fluororesin has chemical resistance to the internal fluid, the outer layer side nylon 11 and nylon 12 blended with the fluororesin has adhesiveness, and flexibility. Since it has excellent wear resistance, it is possible to provide a tube for fluid piping that has chemical resistance to the internal fluid and the external environment, and also has flexibility and wear resistance.

Embodiments of the present invention will be described below.
(Embodiment 1)
The fluid piping tube of this embodiment has an adhesive ETFE resin (manufactured by Asahi Glass Co., Ltd., Fluon LM-ETFE AH-2000) as the inner layer side, and plasticized nylon 11 (manufactured by ATOFINA, Rilsan BESN O P40TL). And nylon 12 containing plasticizer (Ube Kosan Co., Ltd., Uvesta 3035JU) blended at a ratio of 1: 1 is co-extruded with the outer layer side.

  That is, an adhesive fluororesin (modified ETFE) is used as an inner layer, and a nylon resin blended with nylon 11 and nylon 12 is used as an outer layer. The adhesive ETFE resin is modified so as to improve the adhesiveness more than usual.

  The tube diameters to be co-extruded were three types: outer diameter × inner diameter φ4.0 × 2.5 mm, φ6.0 × 4.0 mm, and φ8.0 × 6.0 mm. Further, the ratio of the thickness of the ETFE resin layer to the total thickness of the tube is about 5 to 30% (0.2 mm thickness at φ4.0 × 2.5 mm, 0.2 mm thickness at φ6.0 × 4.0 mm) , Φ8.0 × 6.0 mm, 0.2 mm thickness).

  The ratio of the thickness of the layer of the ETFE resin can be implemented as about 1 to 80% with respect to the total thickness of the tube, but when set as described above, the ETFE resin is inherently inferior in flexibility, From the ratio to the total wall thickness, the tube as a whole becomes flexible and the tube as a whole has excellent wear resistance.

  Next, the usage state of the fluid piping tube of this embodiment will be described.

  Nylon 11 was found to have adhesiveness and excellent flexibility but poor wear resistance. Nylon 12 was found to have high surface hardness and excellent wear resistance but poor adhesion. However, since this fluid piping tube has the above-described configuration, it has chemical resistance to the internal fluid by the ETFE resin having the adhesiveness on the inner layer side, and nylon 11 and nylon 12 on the outer layer side are blended. Nylon resin has adhesion to ETFE resin, and has excellent flexibility and wear resistance. It has chemical resistance to internal fluid and external environment, and also has flexibility and wear resistance. There is an advantage.

  In other words, this fluid piping tube has excellent chemical resistance to the internal fluid and the external environment, and also has excellent wear resistance. In addition, wear is less likely to occur, and maintenance can be reduced. Also, since it is flexible, small and easy to bend, the piping space can be reduced and the apparatus can be downsized.

(Embodiment 2)
The fluid piping tube of this embodiment has an adhesive ETFE resin (manufactured by Asahi Glass Co., Ltd., Fluon LM-ETFE AH-2000) as an inner layer side, and nylon 11 containing plasticizer (manufactured by ATOFINA, Rilsan BESN OP 40TL). ) And nylon 12 containing plasticizer (Ube Industries, Uvesta 3035 JU) blended at a ratio of 1: 1 is co-extruded with the outer layer side. Further, a layer of ETFE resin (made by Asahi Glass Co., Ltd., Fluoron LM-ETFE LM-720), which is not modified and inferior in adhesion, is disposed on the inner layer side of the adhesive ETFE resin and is co-extruded. ing.

  That is, an unmodified fluororesin (ETFE) is used as an inner layer, an adhesive fluororesin (modified ETFE) is used as an intermediate layer, and a nylon resin blended with nylon 11 and nylon 12 is used as an outer layer. . The adhesive ETFE resin is modified so as to improve the adhesiveness more than usual.

  The tube diameters to be co-extruded were three types: outer diameter × inner diameter φ4.0 × 2.5 mm, φ6.0 × 4.0 mm, and φ8.0 × 6.0 mm. Further, the ratio of the thickness of the ETFE resin layer (inner layer + intermediate layer) to the total thickness of the tube is about 5 to 30% (φ4.0 × 2.5 mm is 0.2 mm thick, φ6.0 × 4. The thickness was set to 0.2 mm for 0 mm and 0.2 mm for φ8.0 × 6.0 mm.

  The ratio of the thickness of the ETFE resin layer (inner layer + intermediate layer) can be about 1 to 80% of the total thickness of the tube, but if set as described above, the ETFE resin is inherently flexible. Although it is inferior, it becomes flexible as a whole tube from the ratio with respect to the total wall thickness, and it becomes excellent in the property of abrasion resistance as the whole tube.

  Next, the usage state of the fluid piping tube of this embodiment will be described.

  Nylon 11 was found to have adhesiveness and excellent flexibility but poor wear resistance. Nylon 12 was found to have high surface hardness and excellent wear resistance but poor adhesion. However, since this fluid piping tube has the above-described configuration, it has chemical resistance to the internal fluid by the ETFE resin having the adhesiveness on the inner layer side, and nylon 11 and nylon 12 on the outer layer side are blended. Nylon resin has adhesion to ETFE resin, and has excellent flexibility and wear resistance. It has chemical resistance to internal fluid and external environment, and also has flexibility and wear resistance. There is an advantage.

  In addition, the adhesive ETFE resin (intermediate layer) is modified, but when configured as in this embodiment, the ETFE resin layer (inner layer) that is not modified is in contact with the internal fluid. Therefore, higher chemical resistance can be imparted. In addition, the unmodified ETFE resin layer (inner layer) is inferior in adhesiveness, but the adhesive ETFE resin (intermediate layer) is the same resin and is compatible with each other and adhesiveness between them. Is enough.

  That is, this fluid piping tube is superior in chemical resistance to the internal fluid and the external environment, and also has excellent wear resistance, so the same or different types of tubes rub against each other in a narrow space (such as in a robot arm) during use. In addition, wear is less likely to occur, and maintenance can be reduced. Also, since it is flexible, small and easy to bend, the piping space can be reduced and the apparatus can be downsized.

  Next, the configuration of the present invention will be described more specifically.

  The following tests were performed using the sample of the fluid piping tube of the first embodiment (Example), the sample of the ETFE single-layer tube (Comparative Example 1), and the sample of the PTFE single-layer tube (Comparative Example 2). . The size of each material tube was set to φ6.0 × 4.0 mm.

[1] Abrasion resistance test The upper end of each sample tube was fixed to the upper support (not shown) of the rotating disk of the abrasion resistance test apparatus shown in FIG. 1, and a weight of 500 g was suspended at the lower end. Eleven rotating wear tubes (same or different materials as the material tubes) are fixed at equal intervals around the circumference of the rotating disk. The outer surface of the sample tube was brought into contact with the rotated rotating wear tube, and after rotating a predetermined number of times, the amount of wear of the sample tube was measured.

  In FIG. 2, the graph of the relationship of the amount of wear with the same kind material is shown. FIG. 3 shows a graph of the relationship between the amount of wear with a different material (nylon 12 single-layer tube).

  As shown in the graphs of FIG. 2 and FIG. 3, in the examples, between the same kind of materials and different kinds of materials, the amount of wear is less than that of Comparative Example 1 (ETFE single layer tube) below Comparative Example 2 (PTFE single layer tube). It was the amount of wear and was the most excellent in wear resistance.

[2] Bending strength test (flexibility)
Each sample tube T was attached to the bending strength test apparatus shown in FIG. 4, and each tube was deformed from both sides to measure the reaction force. The room temperature was 21 to 23 ° C., and the length of the sample tube T was 178 mm. The results are shown in the graph of the relationship between the bending radius and the bending force in FIG.

  As shown in this graph, the practical example was the most excellent bending force that was equal to or less than that of Comparative Example 2 (PTFE single-layer tube), which was more flexible than Comparative Example 1 (ETFE single-layer tube). . That is, the example tube is flexible and has a smaller bend radius.

[3] Breaking pressure test Internal pressure was applied to each sample tube, the maximum pressure (MPa) due to breaking was measured, and an average value of n = 5 was taken. The test conditions were normal temperature (23 ° C.) and the pressure increase rate was 0.12 MPa / sec.

  As a result, the average value of Comparative Example 1 (ETFE single-layer tube) was 8.2 MPa, and the average value of Comparative Example 2 (PTFE single-layer tube) was 6.2 MPa, while the average value of Examples was 5. 7 MPa. That is, the breaking pressure of the example had almost the same performance as Comparative Example 2 (PTFE single-layer tube).

  Since it has chemical resistance against internal fluid and external environment, and also has flexibility and wear resistance, it can be widely applied to the use of other fluid piping tubes for robots.

The figure explaining the structure of an abrasion-resistance test apparatus. The graph which shows the relationship of the amount of wear with the same kind material. The graph which shows the relationship of the amount of wear with a different kind of material. The figure explaining the structure of a bending strength test apparatus. The graph which shows the relationship between a bending radius and bending force.

Claims (6)

A fluid piping tube which is co-extruded with an adhesive fluororesin on the inner layer side and a nylon resin blended with nylon 11 and nylon 12 on the outer layer side. The fluid piping tube according to claim 1, wherein the nylon resin is a blend of nylon 11 and nylon 12 in a ratio of about 3: 7 to 7: 3. The fluid piping tube according to claim 1 or 2, wherein a fluororesin layer which is not modified on the inner layer side of the fluororesin having adhesiveness and is inferior in adhesiveness is disposed and coextruded. The fluid piping tube according to any one of claims 1 to 3, wherein the fluororesin is an ETFE resin. The tube for fluid piping according to claim 4, wherein the ratio of the thickness of the ETFE resin layer to the thickness of the tube is set to about 1 to 80%. The tube for fluid piping according to claim 4, wherein the ratio of the thickness of the ETFE resin layer to the thickness of the tube is set to about 5 to 30%.

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