JPH08142151A - Laminated tube - Google Patents

Abstract

PURPOSE: To enhance the peel strength between inner and outer layer tubes by forming an inner layer tube composed of a polyvinyidene fluoride resin and an outer layer tube composed of a polyurethane resin or a polyurethane elastomer by co-extrusion molding to integrally laminate both tubes. CONSTITUTION: The inner layer tube 1 composed of a polyvinylidene fluoride and the outer layer tube 2 composed of a polyurethane resin or a polyurethane elastomer are formed by co-extrusion molding to be integrally laminated. That is, the polyvinylidene fluoride resin is extruded through the common head die of a first extrusion molding machine at molding temp. of 220-250 deg.C to form the inner layer tube with an inner diameter of 6mm and a wall thickness of 0.3mm and, at the same time, for example, the polyurethane resin is extruded through the common head die of a second extrusion molding machine at molding temp. of 190-210 deg.C to form the outer layer tube 2 with a wall thickness of 1.7mm to be thermally fused to the inner layer tube.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated tube having an inner layer made of polyvinylidene fluoride (PVdF) resin.

[0002]

2. Description of the Related Art Conventionally, a single-layer tube made of a fluororesin has a chemical resistance,
Since it has excellent properties such as non-adhesiveness, gas barrier property, non-elution property, and food hygiene, it is used for various purposes such as beverages, but since it is expensive, the amount used is reduced. Has been proposed as an inner layer tube, and various outer layer tubes made of other various synthetic resins are integrally laminated on the outer peripheral surface thereof by the means described below. In general, since a fluororesin has poor adhesiveness with other resins, before laminating it with another thermoplastic resin, the surface of the fluororesin is previously subjected to surface treatment such as corona discharge treatment or sodium etching treatment. After that, an outer layer tube is laminated on the outer peripheral surface and integrally bound, or, as another means, after applying an adhesive layer to the outer peripheral surface, the outer layer tube is laminated and integrally bound. It has been taken. However, the need for such a surface treatment step and an adhesive layer coating step complicates the manufacturing work and requires equipment accordingly, resulting in an increase in the manufacturing cost. On the other hand, a laminated tube in which an outer layer tube made of a thermoplastic resin is laminated on the outer peripheral surface of an inner layer tube made of polyvinylidene fluoride (PVdF) by coextrusion molding without the need for such an intermediate step (actually, is proposed. Kaisho 61-1667
30 publication). However, all of the thermoplastic resins listed on page 5 of the specification do not have strong adhesion with the inner layer tube by coextrusion molding, and suffer from the drawback of delamination and are strong. Adhesion requires the interposition of an adhesive layer.
The beverage tube described in Japanese Utility Model Publication No. 62-163680 is also manufactured by extruding an outer layer tube made of EVA resin on a PVdF inner layer tube, but the outer layer tube can be peeled by hand. The smaller the peel strength, the more unsuitable for practical use. Therefore, it is desired to develop a laminated tube having a polyvinylidene fluoride (PVdF) resin as the innermost layer, which has a large peel strength by coextrusion molding and is suitable for practical use. Further, in this case, it is advantageous in handling that it has a great flexibility.

[0003]

The present invention solves the above-mentioned conventional problems and provides a laminated tube satisfying the above-mentioned demands. The innermost layer is made of polyvinylidene fluoride (PVdF) resin by coextrusion molding. Forming a tube,
An outer layer tube is integrally laminated with a polyurethane resin or a polyurethane-based elastomer on the outer peripheral surface.

[0004]

The present invention relates to the polyvinylidene fluoride (PVd
When a polyurethane resin or a polyurethane-based elastomer is laminated as an outer layer tube on the innermost layer tube made of F) by coextrusion molding, intermediate steps such as surface treatment of the inner layer tube and coating of an adhesive layer are required as in the conventional case. Therefore, a laminated tube having extremely high delamination strength can be obtained easily and at low cost.

Further, the present invention provides, in the laminated tube of the present invention, a flexible and flexible flexible laminated tube, in which the inner layer tube has an inner diameter in the range of 1 to 100 mm and a thickness thereof. Thickness a is 0.01-2
The thickness of the outer layer tube is in the range of 1 mm to 20 mm.

In this case, a third layer tube made of a soft synthetic resin is integrally laminated on the outer peripheral surface of the above-mentioned two-layer flexible laminated tube by coextrusion molding with or without a tubular reinforcing member. However, the wall thickness of the third layer was 0.5 by replacing a part of the wall thickness of the outer layer tube.
In the range of ˜19.5 mm, a flexible laminated tube with increased pressure resistance can be obtained.

[0007]

Next, embodiments of the present invention will be described. The laminated tube of the present invention is manufactured by using a known desired coextrusion molding machine. That is, using the first extruder, the polyvinylidene fluoride (PVdF) resin is heated and melted, and 220 to
At a molding temperature in the range of 250 ° C., an inner layer tube made of PVdF resin having an inner diameter of, for example, 6 mm and a wall thickness of 0.3 mm is extruded through a common head die, and at the same time, a second extruder is used to form polyurethane (PU). When the resin is heated and melted and the outer layer tube made of PU having a wall thickness of 1.7 mm is extruded through the common head die at a molding temperature in the range of 190 to 210 ° C., the outer peripheral surface of the inner layer tube is continuously formed. Heat fusion bonding to, and binding together to form an inner diameter of 6 mm and an outer diameter of 1
A 0 mm laminated tube of the invention is obtained. Hereinafter, this is referred to as a product 1. As the vinylidene fluoride (PVdF) resin, "Forafuron 1000H" manufactured by Showa Denko KK
"D" was used as the PU resin, "Pandex T1185" manufactured by Dainippon Ink and Chemicals, Inc.

Instead of the above polyurethane (PU), a polyurethane elastomer can be used. For example, polyurethane / vinyl chloride (PU / PVC) copolymer resin, blended product of polyurethane (PU) and soft vinyl chloride (PVC), and the like. When PU / PVC copolymer resin is used with the same coextrusion molding machine described above, extrusion molding is performed at a molding temperature of 170 to 190 ° C, and a blended product of PU and PVC is extrusion molded at 170 to 200 ° C. Then, each laminated tube of the present invention was manufactured. Hereinafter, these will be referred to as Example 2 and Example 3, respectively. As the PU / PVC copolymer resin, "Aron Elastomer NP NPRA5000" manufactured by Toa Gosei Chemical Industry Co., Ltd. was used. Also, P
As the blended product of U and soft vinyl chloride, a 1: 1 blend of "Pandex T1190" manufactured by Dainippon Ink and Chemicals, Inc. and "Binica JISA70" manufactured by Mitsubishi Kasei Vinyl Co., Ltd. was used.

FIG. 1 is a perspective view in which a part of a two-layer type laminated tube A of an embodiment of the present invention having the above-mentioned embodiment 1, 2, 3 is cut away, and 1 is PVdF resin. The inner layer tube 2 made of is an outer layer made of polyurethane (PU) or polyurethane-based elastomer (PUE) that is heat-sealed and integrally laminated on the outer peripheral surface of the inner layer tube 1. The peel strength is extremely large, as will be made clear below, and a two-layer type laminated tube in which polyurethane or a synthetic resin other than polyurethane-based elastomer is laminated by extrusion molding on the outer peripheral cotton of the inner layer tube made of PVdF resin is easy. The disadvantage of delamination can be eliminated.

For comparison, using the above coextrusion machine,
The above PVdF resin is used as the inner layer tube molding material, and PVC, EVA, and low-density polyethylene LD-PE are each used as the outer layer tube molding material, at respective preferable molding temperatures, that is, PVC is 150 to 170 ° C. E
VA is 140 to 160 ° C, LD-PE is 150 to 170
Each two-layer laminated tube was manufactured by extrusion molding at 0 ° C. Each of the following will be referred to as Comparative product 1, Comparative product 2, Comparative product 3
Called. As the PVC resin, "Binica JISA 70" manufactured by Mitsubishi Kasei Vinyl Co., Ltd. was used. As the EVA resin raw material, "Evaflex P2505" manufactured by Mitsui DuPont Polychemical Co., Ltd. was used. As the LD-PE raw material, "Mirason 16P" manufactured by Mitsui Petrochemical Co., Ltd. was used. For comparison, a PVdF resin, which is the same material as above, is used to extrude a tube having the same inner diameter and wall thickness as above, and then subjected to surface treatment by corona discharge. A polyurethane (PU) resin made of the same material as the above was melted by extrusion molding to produce a laminated tube. Hereinafter, this is referred to as comparative product 4.

The above-mentioned working products 1, 2, manufactured in this manner
JIS K 6 for 3 and comparative products 1, 2, 3, 4
A peeling test was performed according to 301. The results were as shown in Table 1 below.

[0012]

[Table 1]

As is apparent from Table 1 above, when the outer layer tube made of polyurethane or polyurethane elastomer is coextruded on the outer peripheral surface of the inner layer tube made of PVdF resin, as shown in Examples 1, 2 and 3. A laminated tube having extremely high peel strength can be obtained. On the other hand, the outer layer tube is made of PVC,
When molded with a resin composed of EVA and LD-PE, there is almost no peel strength as shown in Comparative Products 1, 2, and 3. It was confirmed that with this peel strength, it was easily peeled off by hand and could not be put to practical use at all. In addition, when the inner layer tube made of PVdF is subjected to a surface treatment and then polyurethane is extruded and laminated on the outer peripheral surface thereof, as shown in Comparative product 4,
The peeling strength is 2.5 Kgf / 25 mm, and although the strength is slightly increased, when joining a plurality of these through a joint, when inserting the nipple of the joint into the tube, The inner layer tube was peeled off from the outer layer tube and was not suitable for practical use. As a result of many tests, it was found that a peel strength of at least 3.0 Kgf / 25 mm is necessary in order to prevent peeling when joining with a joint. As described above, when the wall thickness of the single-layer tube made of PVdF resin is thinned and the above-mentioned polyurethane resin outer layer tube is laminated by co-extrusion molding by that amount, it is inexpensive and extremely high in peel resistance. A laminated tube is obtained.

In the laminated tube of the present invention, since the inner layer tube is made of PVdF resin, it has various well-known properties such as chemical resistance, non-elution property and gas barrier property, and the outer layer tube is As it is made of polyurethane resin, it has excellent properties such as toughness, water resistance, aging resistance, chemical resistance, abrasion resistance, and electrical insulation. Its extremely large peel resistance and extended service life In addition, the product is easy to manufacture and inexpensive. In addition, since both transparent laminated tubes can be manufactured, if necessary, it can be used for the purpose of observing the state of fluid flowing inside, which is advantageous. Of course, if necessary, a pigment may be mixed into the colored laminated tube. The laminated tube of the present invention is
It is used for various conventional applications. Drinking water,
Conventionally known for household use, such as transfer of various beverages, pure water, ultrapure water, alcohol and other chemicals, compressed air, exhaust gas, fuel gas, transfer of various gases such as inert gas such as argon Used as various tubes (hoses) for chemical testing and industry.

The laminated tube of the present invention may be made of a hard one, but a flexible laminated tube having a flexibility convenient for carrying in a spirally wound state or bending as desired for piping work is provided. Is convenient and preferred. In view of this point, the inner diameter and wall thickness of the PVdF resin inner layer tube and the wall thickness of the outer layer tube made of the above polyurethane resin are variously changed, and various laminated tubes are produced and subjected to a bending test. The inner diameter suitable for various uses, that is, the inner diameter of the inner layer tube is 1 to
The thickness of the inner tube is in the range of 100 mm and is 0.01 to
If the outer tube has a thickness of 2 mm and the thickness of the outer tube is in the range of 1 to 20 mm, the coextrusion laminated tube is a flexible flexible tube that can be wound in a spiral shape for transportation, or can be bent as needed for piping work. It was found that In this case, when the inner diameter of the inner layer is 1 mm, the wall thickness is as thin as 0.01 mm, and when the inner diameter is 100 mm, the wall thickness is as thick as 2 mm. Generally, when the inner diameter increases, It is preferred and common to manufacture such that its wall thickness is increased accordingly.

FIG. 2 is a perspective view showing another embodiment of the present invention with a part of a laminated tube having three layers cut away. The laminated tube was prepared by the co-extrusion molding machine in the same manner as in Example 1 except that the inner layer tube 1 made of PVdF resin having an inner diameter of 9 mm and a wall thickness of 0.3 mm and a wall thickness of 1.7 m on the outer peripheral surface thereof.
After co-extrusion molding with the outer layer tube 2 made of polyurethane resin of m, a reinforcing member 3 is applied to the outer peripheral surface thereof. That is,
Synthetic fiber threads such as polyester fiber thread and nylon fiber thread, metal wire such as stainless wire, etc.
The reinforcing member 3 is formed by winding and braiding 00 denier polyester fiber and then meshing it into a tubular shape. Then, through an extruder, the polyurethane material such as polyurethane or polyurethane elastomer of the same material as the outer layer tube The pressure-resistant flexible laminate of the present invention having an outer diameter of 15 mm and formed of three layers by coating and forming an outermost tube 4 having a thickness of 1.0 mm, which is made of a resin, a different soft vinyl chloride resin, or another soft synthetic resin. Tube A was manufactured. still,
By extruding the third layer made of the desired resin with the surface of the outer layer tube 2 made of the polyurethane resin slightly heated to give an adhesive property, the three layers having increased peel resistance of both layers are formed. A flexible laminated tube A is obtained. In this case, if a polyurethane resin or polyurethane elastomer is used as the molding material for the outermost tube,
It is most suitable because it is extremely strongly bonded to the outer peripheral surface of the third layer tube 2. The reinforcing member 3 is not always necessary. Further, the outer layer tube 2 and the outermost layer tube 4 are
When the mutual binding properties are weak, they may be bound via an adhesive layer.

This three-layer flexible laminated tube A
In order to obtain the above, the thickness of the outermost layer is obtained by forming a part of the outer layer 2 with the thickness of the third layer in the range of 0.5 to 19.5 mm.

As the soft synthetic resin forming the third layer tube, in addition to the above, as the soft synthetic resin material of the third layer tube, in addition to the above-mentioned polyurethane and polyurethane elastomer, EVA, EEA, Styrene-based elastomers, olefin-based elastomers, polyamide-based elastomers, PVC, vinyl chloride-based elastomers, polyester-based elastomers and the like can be mentioned, and these are appropriately selected and used.

[0019]

As described above, according to the present invention, PVd
In manufacturing a laminated tube using the F resin as the inner layer tube, the polyurethane resin was heat-welded as the outer layer tube to the outer peripheral surface of the inner layer tube made of the PVdF resin by coextrusion molding. An extremely strong, stable and robust laminated tube can be obtained.
Further, a laminated tube composed of the inner layer tube made of the PVdF and an outer layer tube made of the polyurethane resin or polyurethane-based elastomer has an inner diameter of the inner layer tube of 1 to 100 mm, a wall thickness of 0.01 to 2 mm, and the outer layer tube. When the wall thickness is 1 to 20 mm, it is possible to obtain a flexible laminated tube having excellent flexibility and applicable to various flexible uses. In addition, when laminating a third layer tube made of a soft thermoplastic synthetic resin on the outer peripheral surface of the above-mentioned two-layer type laminated tube, a part of the wall thickness is set within the range of the wall thickness of the outer layer tube. Replace, 0.5
When the thickness is in the range of ˜19.5 mm, a flexible laminated tube having improved pressure resistance and yet maintaining flexibility and flexibility can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing a laminated tube according to an embodiment of the present invention with a part thereof cut away.

FIG. 2 is a perspective view showing a laminated tube according to another embodiment of the present invention with a part thereof cut away.

[Explanation of symbols]

1 Inner layer tube made of PVdF resin 2 Outer layer made of polyurethane resin or polyurethane elastomer 3 Reinforcing member 4 Third layer soft thermoplastic synthetic resin tube

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Claims (3)

[Claims] 1. An inner layer tube is formed from polyvinylidene fluoride (PVdF) resin by coextrusion molding, and
A laminated tube, wherein an outer layer tube is integrally laminated on the outer peripheral surface of a polyurethane resin or a polyurethane elastomer. 2. The inner diameter of the inner layer tube is 1 to 100 mm
The thickness a is in the range of 0.01 to 2 mm, and the wall thickness b of the outer tube is in the range of 1 to 20 mm.
The laminated tube described. 3. A third layer tube made of a soft synthetic resin is integrally laminated on the outer peripheral surface of the laminated tube according to claim 2 by extrusion molding, with or without a tubular reinforcing member interposed therebetween. The thickness of the three layers is a laminated tube in which the thickness of the outer layer tube is partly replaced with 0.5 to 19.5 mm.