JPH04368843A - Ultra-high-molecular-weight polyethylene composite tubular material and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide composite tubular material suitable for transporting liquid and powder and granular material combined with characteristics such as excellent wear resistance, self-lubricating properties, shock resistance, resistance to chemicals and non-tackiness, all of which are indigenous to ultra-high- molecular-weight polyethylene, and excellent elasticity, flexibility, durability and the like, all of which are indigenous to rubber. CONSTITUTION:The ultra-high-molecular-weight polyethylene composite tubular material concerned is produced by bonding the ultra-high-molecular-weight polyethylene, of which inner tube 1 having the wall thickness of 0.01-5mm and the outer diameter of 2mm or more is made, and the rubber, of which outer tube 2 is made so as to fit onto the inner tube through vulcanization.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to an ultra-high molecular weight polyethylene composite pipe material and a method for producing the same, and in particular to ultra-high molecular weight polyethylene's excellent wear resistance, self-lubricating property, impact resistance, chemical resistance, and non-stick properties. The present invention relates to an ultra-high molecular weight polyethylene composite pipe material that has the properties of rubber, such as excellent elasticity, flexibility, and durability, and a method for obtaining the composite pipe material through a simple process.

0002

[Prior art] Ultra-high molecular weight polyethylene has wear resistance,
It has excellent self-lubricating properties, chemical resistance, and low-temperature properties, such as low-temperature impact resistance, and is being considered for use in various applications by taking advantage of these excellent properties. Therefore, a method of manufacturing a composite material has been proposed that utilizes the excellent properties of this ultra-high molecular weight polyethylene. For example, JP-A-61-27
Publication No. 3934 discloses that a core material made of ultra-high molecular weight polyolefin is processed at a temperature near its melting point and solidified in a thinner diameter state, and the core material is made of another material and has an inner diameter smaller than the outer diameter of the core material before processing. A method is disclosed in which the core material is inserted into a small hollow body, and the core material is heated to a temperature higher than its melting point to enlarge its diameter, thereby being press-bonded to the inner wall of the hollow body. Also, in Japanese Patent Application Laid-open No. 62-99133,
In this method, a method is disclosed in which an ultra-high molecular weight polyolefin and a hollow body made of another material are bonded by interposing an adhesive between them.

0003

[Problems to be Solved by the Invention] However, the composite materials obtained by the methods described in JP-A-61-273934 and JP-A-62-99133 are hollow bodies made of thermoplastic resin such as polyamide or polyester. or a composite material whose outer coating is made of thermosetting resin such as phenolic resin, metal such as copper, inorganic material such as glass, or organic material such as wood, but the elasticity and The problem was that flexibility was extremely poor. Furthermore, since the composite material obtained by the method described in JP-A No. 62-99133 is a composite material in which the hollow body and the core material are bonded with an adhesive, applying the adhesive to the core material, Alternatively, the number of molding steps such as lamination increases, and the molding process becomes complicated. Furthermore, there were other problems such as an increase in costs.

Therefore, the object of the present invention is to combine the excellent abrasion resistance, self-lubrication, impact resistance, chemical resistance, and non-adhesiveness of ultra-high molecular weight polyethylene with the excellent elasticity, flexibility, and durability of rubber. To provide an ultra-high molecular weight polyethylene composite pipe material which has properties such as elasticity, and in which an outer pipe material and an inner pipe material are firmly bonded, and a method for economically obtaining the composite pipe material through a simple process. It is in.

[0005]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a wall thickness of 0.01 to 5 mm made of ultra-high molecular weight polyethylene having an intrinsic viscosity [η] of 5.0 dl/g or more.
, has an inner tube with an outer diameter of 2 mm or more, and an outer tube made of rubber fitted on the outside of the inner tube, and the ultra-high molecular weight polyethylene of the inner tube and the rubber of the outer tube are vulcanized and bonded. The present invention provides an ultra-high molecular weight polyethylene composite pipe material characterized by:

[0006] Furthermore, the present invention provides a first method for producing this ultra-high molecular weight polyethylene composite pipe material, in which the inner part of the outer pipe material made of unvulcanized rubber has an intrinsic viscosity [η] of 5.0 dl/g.
It is made of ultra-high molecular weight polyethylene with a temperature of 1
After inserting an expandable inner tube material that expands by 0% or more, while expanding the inner tube material made of ultra-high molecular weight polyethylene by heating it to a temperature near the melting point of the ultra-high molecular weight polyethylene or higher,
The present invention provides a method for manufacturing an ultra-high molecular weight polyethylene composite pipe material, which includes a step of vulcanizing and bonding ultra-high molecular weight polyethylene of the inner pipe material and unvulcanized rubber of the outer pipe material.

Furthermore, the present invention provides a second method for producing the ultra-high molecular weight polyethylene composite pipe material, which has a limiting viscosity [η
] After inserting a core material made of a heat-resistant resin having a predetermined outer diameter into the inside of a shrinkable inner tube material made of ultra-high molecular weight polyethylene with a diameter of 5.0 dl/g or more and shrinking by 5% or more at 140°C, A step of shrinking the inner tube material made of ultra-high molecular weight polyethylene by heating to bring the inner tube material into close contact with the core material and fitting the inner tube outside the core material; A process of coating the outside with unvulcanized rubber and then heating at the vulcanization temperature of the rubber to vulcanize and bond the rubber and ultra-high molecular weight polyethylene to form an outer tube, and a process of extracting the core material from the inner tube. The present invention also provides a method for producing an ultra-high molecular weight polyethylene composite pipe material having the following.

[0008] Hereinafter, the ultra-high molecular weight polyethylene composite pipe material (hereinafter referred to as "composite pipe material") of the present invention and its manufacturing method will be explained in detail.

The composite tube material of the present invention has an inner tube 1 and an outer tube 2 fitted on the outside of the inner tube 1, as schematically shown in FIG.

The inner tube 1 is made of ultra-high molecular weight polyethylene and has a wall thickness of 0.01 to 5 mm, preferably 0.01 to 3 mm.
belongs to. In order to obtain a flexible composite pipe material, the thickness is usually about 0.01 to 3 mm, preferably 0.01 to 3 mm.
A thin ultra-high molecular weight polyethylene pipe with a wall thickness of about 2 mm, a cylindrical film of ultra-high molecular weight polyethylene, or the like may be used as the inner tube. Further, in order to obtain a composite pipe material having rigidity, an ultra-high molecular weight polyethylene pipe or the like having a wall thickness of approximately 0.1 to 5 mm, preferably approximately 3 to 5 mm may be used as the inner pipe.

Further, the outer tube 2 is made of rubber, and the outer tube 2 and the inner tube 1 are made by bonding the ultra-high molecular weight polyethylene constituting the inner tube and the rubber constituting the outer tube by vulcanization. ing. The wall thickness of this outer tube 2 is usually 0.5 to 70 mm.
It is about mm, preferably about 1 to 50 mm.

The ultra-high molecular weight polyethylene that is the material for the inner pipe of this composite pipe material has ethylene as its main component. Examples include copolymers with other monomers. Examples of monomers copolymerizable with ethylene include α-olefins having 3 or more carbon atoms.

Examples of the α-olefin having 3 or more carbon atoms include propylene, 1-butene, isobutene, and 1-butene.
-Pentene, 2-methyl-1-butene, 3-methyl-1
-butene, 1-hexene, 3-methyl-1-pentene,
4-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1
-hexadecene, 1-octadecene, 1-icosene, etc.

[0014] This ultra-high molecular weight polyethylene, when molding the inner tube material, does not cause the molten material of this ultra-high molecular weight polyethylene to twist due to co-rotation with the inner die, which will be described later, or cause thickness unevenness due to the deflection of the inner die, and the wall thickness can be increased. In order to obtain a uniform inner tube material, the material has an intrinsic viscosity [η] of 5.0 dl/g or more, preferably an intrinsic viscosity [η] of 8 to 30 dl/g.
l/g.

[0015] This ultra-high molecular weight polyethylene may be blended with various stabilizers as required. Examples of the stabilizer include tetrakis[methylene (3,5-di-t
-butyl-4-hydroxy)hydrocinnamate]methane, heat stabilizers such as distearylthiodipropionate, or bis(2,2',6,6'-tetramethyl-
4-piperidine) sebacate, 2(2-hydroxy-t
-butyl-5-methylphenyl)-5-chlorobenzotriazole and other weathering stabilizers. Furthermore, an inorganic or organic dry color may be added as a coloring agent.

[0016] Furthermore, the rubber constituting the outer tube may be natural rubber,
Alternatively, it may be made of synthetic rubber, and is not particularly limited. Examples of this synthetic rubber include styrene-butadiene rubber, butadiene rubber, isoprene rubber, and ethylene-butadiene rubber.
Examples include various conventionally known rubbers such as diene rubber such as α-olefin-diene copolymer, olefin rubber such as butyl rubber, ethylene-α-olefin rubber, and acrylic rubber, silicone rubber, and urethane rubber.

[0017] The first method for manufacturing the composite pipe material of the present invention is to insert an expansible inner pipe material made of ultra-high molecular weight polyethylene into an outer pipe material made of unvulcanized rubber, and then It has a step of vulcanizing and bonding the ultra-high molecular weight polyethylene of the inner tube material and the unvulcanized rubber of the outer tube material while expanding the inner tube material made of the ultra-high molecular weight polyethylene by heating to a temperature near the melting point of the molecular weight polyethylene or higher. There are several methods.

In this first method, first, as shown in FIG. 2, the inside of the outer tube material 3 made of unvulcanized rubber containing a vulcanizing agent is made of ultra-high molecular weight polyethylene, and the inner diameter of the outer tube material 3 is An expandable inner tube 4 having an outer diameter smaller than that is inserted.

Next, the inner tube material 4 made of the expandable ultra-high molecular weight polyethylene is expanded by heating to increase its outer diameter, and the outer peripheral surface of the inner tube material 4 and the inner peripheral surface of the outer tube material 3 are brought into close contact. . At this time, the heating temperature is a temperature near the melting point of ultra-high molecular weight polyethylene or higher, usually a temperature of (melting point of ultra-high molecular weight polyethylene -15°C) to (melting point +120°C),
Preferably, the temperature is from (melting point -10°C) to (melting point +100°C).

By this heating, the unvulcanized rubber of the outer tube material 3 is vulcanized by the vulcanizing agent contained therein, and is vulcanized and bonded to the ultra-high molecular weight polyethylene, thereby forming the composite material of the present invention shown in FIG. Piping materials can be manufactured.

The vulcanizing agent contained in the unvulcanized rubber that is the raw material for the outer tube material is not particularly limited, and may be a vulcanizing agent used for vulcanizing this type of rubber. Examples include conventionally known organic peroxides such as di-t-butyl peroxide and dicumyl peroxide, and sulfur. Also,
This unvulcanized rubber may contain conventionally known inorganic fillers such as carbon black, calcium carbonate, clay, or vulcanization accelerators, anti-aging agents, reinforcing agents, softeners, vulcanization aids, etc. good.

[0022] The heating method is not particularly limited, and for example,
Examples include heating with hot water, heating with an oven, and heating with far infrared rays.

Further, the inner tube material 4 made of expandable ultra-high molecular polyethylene has, for example, an intrinsic viscosity [η] of 5.0 dl.
/g or more of ultra-high molecular weight polyethylene is supplied to a screw extruder, melted and kneaded, and an inner die is arranged inside that is connected to the screw of the screw extruder and rotates with the rotation of the screw of the screw extruder. The melt of ultra-high molecular weight polyethylene is continuously extruded from a die having an L/D ratio of at least 10 to form a cylindrical rough molded product, and then the cylindrical rough molded product is transferred to a drawing machine or The winding machine adjusts the outer diameter to 0.00 mm of the inner diameter of the outer die.
1 of the extrusion speed of ultra-high molecular weight polyethylene in a screw extruder while reducing the diameter to 9 to 0.1 times.
．． It can be produced by a method in which the ultra-high molecular weight polyethylene is taken at a take-up speed of 1 times or more, and the ultra-high molecular weight polyethylene starts cooling and solidifying in a cooling device.

Furthermore, as a second method for manufacturing the composite pipe material of the present invention, a core material made of a heat-resistant resin having a predetermined outer diameter is inserted inside a shrinkable inner pipe material made of ultra-high molecular weight polyethylene. After that, heating is performed to shrink the inner tube material made of ultra-high molecular weight polyethylene so that the inner tube material is brought into close contact with the core material, and the inner tube is fitted on the outside of the core material. A process of coating the outside of the inner tube with unvulcanized rubber and then heating it at the vulcanization temperature of the rubber to vulcanize and bond the rubber and ultra-high molecular weight polyethylene to form an outer tube, and removing the core material from the inner tube. The method includes a step of extracting the.

In this second method, first, FIG.
As shown in A), the core material 5 is inserted into the shrinkable inner tube material 6 made of ultra-high molecular weight polyethylene.

The core material 5 is made of a heat-resistant resin, and examples of the heat-resistant resin include those having a melting point of 150° C. or higher, such as polypropylene, poly4-methyl-1-pentene, Examples include polyamide and polyester rubber. Further, it is preferable to use a core material 5 having a predetermined outer diameter so that a composite pipe material having a desired inner diameter can be obtained.

Next, the inner tube material 6 made of shrinkable ultra-high molecular weight polyethylene is contracted by heating, and as shown in FIG. 3(B), the inner tube material 6 is brought into close contact with the core material 5 and fitted.

[0028] The heating temperature is usually 100 to 200°C;
The temperature is preferably 130 to 160°C, and the heating method is not particularly limited, and examples thereof include methods such as heating with hot water, heating with an oven, and heating with far infrared rays.

The inner tube material 6 made of shrinkable ultra-high molecular weight polyethylene has, for example, an intrinsic viscosity [η] of 5.0 d.
Ultra-high molecular weight polyethylene of 1/g or more is supplied to a screw extruder, melted and kneaded, and an inner die connected to the screw of the screw extruder and rotated with the rotation of the screw of the screw extruder is disposed inside. The melt of ultra-high molecular weight polyethylene is continuously extruded from a die having an L/D ratio of at least 10 to form a cylindrical rough molded product, and then the cylindrical rough molded product is The tapered core connected to the die expands the inner diameter of the maximum diameter part to 1.05 to 4 times the outer diameter of the inner die, while increasing the extrusion speed of ultra-high molecular weight polyethylene in the screw extruder by 5 times. It can be produced by a method in which the ultra-high molecular weight polyethylene is taken at a take-up speed of twice that or less, and the ultra-high molecular weight polyethylene starts cooling and solidifying in the tapered portion of the tapered core.

After the inner tube material 6 is fitted onto the core material 5 as described above, the outside of the inner tube material 6 is coated with unvulcanized rubber 7, and then heated. By vulcanizing the unvulcanized rubber 7 and vulcanizing and adhering the unvulcanized rubber and ultra-high molecular weight polyethylene, it is possible to obtain a composite pipe material in which an outer pipe is fitted into an inner pipe. Covering with unvulcanized rubber can be performed by extrusion molding or other methods. When coating by extrusion molding, the temperature of extrusion molding is usually below the melting point of ultra-high molecular weight polyethylene (136°C), preferably in the range of 70 to 110°C. For extrusion molding, an extrusion molding machine such as a twin-screw extruder or a single-screw extruder may be used, for example.

[0031] The unvulcanized rubber used may be the same as exemplified for the first method.

The vulcanization temperature is usually 140 to 200°C, preferably 150°C, although it depends on the material of the core material.
~170°C.

Next, by removing the core material, the composite pipe material of the present invention shown in FIG. 1 can be obtained. When removing this core material, for example, 3 to 30 kg is placed at the interface between the core material and the inner tube.
This can be done by injecting pressurized water at a pressure of about /cm2 to slightly expand the composite pipe material and pulling out the core material.

[0034] In this second method, by appropriately selecting the outer diameter of the core material, a composite pipe material having a desired inner diameter can be manufactured, and the dimensional accuracy of the inner diameter can also be made good. There is an advantage that it can be done.

[0035]

[Examples] The present invention will be explained in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples in any way unless the gist of the invention is exceeded.

(Example 1) Specifications of each part are as follows: Screw outer diameter
30mmφ Screw effective length (L/D) 22 Flight pitch
18mm constant screw compression ratio
Screw extruder, pipe die length is 1.8
750mm Outer die inner diameter at die exit 20mmφ Die effective length (L/D)
37.5 Inner die outer diameter
The apparatus consisted of a die having a diameter of 16 mm, a cooling water tank having a length of 1.5 m, a take-up machine having two pairs of rubber rolls, and a winding machine.

[0037] Intrinsic viscosity [η]: 15 dl/
g, supplying ultra-high molecular weight polyethylene with a melting point of 136°C,
Melted and kneaded in a screw extruder, taken off by a take-off machine at a take-off speed 4 times the extrusion speed in the screw extruder, and has 100% expandability at 125°C, outer diameter 1
An expandable inner tube material having a diameter of 0 mm and a wall thickness of 1 mm was molded.

Next, the following formulation: Natural rubber
10
0 parts by weight Carbon black (furnace carbon) 40 parts by weight Softener (naphthenic process oil)
4 parts by weight Vulcanizing agent (sulfur)

2.5 parts by weight Vulcanization accelerator (N-cyclohexyl-2-benzothiazylsulfenamide)


0.5 parts by weight Vulcanization accelerator (zinc white)

5 parts by weight Vulcanization accelerator (stearic acid)
2
The weight part of the rubber compound was molded to obtain an outer tube material made of unvulcanized rubber with an inner diameter of 14 mmφ and a wall thickness of 2 mm, and an expandable inner tube material was inserted into this outer tube material to form the shape shown in FIG. 2. The expandable inner tube material was expanded by heating at 150°C for 1 hour in an oven, and the outer tube was made of vulcanized natural rubber, the inner tube was made of ultra-high molecular weight polyethylene, and the inner tube and outer tube were vulcanized and bonded. A composite pipe material was obtained.

The obtained composite tube material has an outer tube made of vulcanized rubber, an outer tube and an inner tube that are firmly bonded, and has the excellent wear resistance, self-lubricity, and chemical resistance of ultra-high molecular weight polyethylene. In addition to being non-adhesive, it also had the excellent properties of rubber, such as elasticity, flexibility, and durability.

(Comparative Example 1) Intrinsic viscosity [η]: 3.0 dl
An attempt was made to mold an expandable inner tube material in the same manner as in Example 1, except that ultra-high molecular weight polyethylene with a weight of Therefore, it was not possible to mold the inner tube material.

(Comparative Example 2) Molding was carried out in the same manner as in Example 1 except that the withdrawal speed was 1.096 times the extrusion speed of the screw extruder. An expandable inner tube material having an outer diameter of 19.2 mmφ and a wall thickness of 1.9 mm was obtained.

Next, the following formulation: Natural rubber
10
0 parts by weight Carbon black (furnace carbon) 40 parts by weight Softener (naphthenic process oil)
4 parts by weight Vulcanizing agent (sulfur)

2.5 parts by weight Vulcanization accelerator (N-cyclohexyl-2-benzothiazylsulfenamide)


0.5 parts by weight Vulcanization accelerator (zinc white)

5 parts by weight Vulcanization accelerator (stearic acid)
2
The weight part of the rubber compound was molded to an inner diameter of 20.2 mmφ,
An outer tube material made of unvulcanized rubber with a wall thickness of 1.5 mm was obtained, an expandable inner tube material was inserted into this outer tube material, the shape shown in Fig. 2 was obtained, and the composite tube material was heated in an oven at 150°C for 1 hour. However, a composite tube material in which the outer tube material and the inner tube material were sufficiently bonded could not be obtained.

(Example 2) Specifications of each part are as follows: Screw outer diameter
30mmφ Screw effective length (L/D) 22 Flight pitch
18mm constant screw compression ratio
Screw extruder, pipe die length is 1.8
750mm Outer die inner diameter at die exit 20mmφ Die effective length (L/D)
37.5 Inner die outer diameter
The die is 15mmφ, and is connected to the tip of the inner die, expands at an angle of 8 degrees to the shaft, has a maximum outer diameter of 30mmφ, and has a length of 80m.
Tapered part that is m, outer diameter 30mmφ, length 90mm
It consists of a cylindrical part, a tapered core whose surface is coated with fluororesin, and a cooling water tank,
The apparatus consisted of a take-up machine having four pairs of rubber rolls and a winding machine.

[0044] Intrinsic viscosity [η]: 15 dl/
g. Ultra-high molecular weight polyethylene with a melting point of 136°C is supplied, melted and kneaded in a screw extruder, and a tapered core is used to make the inner diameter of the maximum diameter part 1.
While expanding the diameter to 5 times, it is taken by a take-off machine at a take-off speed of 1.91 times the extrusion speed of the screw extruder, and the inner diameter is 30 mmφ, which shrinks by 30% at 140 ° C.
A shrinkable inner tube material with a wall thickness of 0.5 mm was molded.

In this shrinkable inner tube material, heat-resistant poly-4-methylpentene-1 resin (Mitsui Petrochemical Industries Co., Ltd.
A core material made by Co., Ltd., TPX) with an outer diameter of 22 mmφ was inserted, and the shape shown in FIG. A composite tube as shown in FIG. 3(B) was obtained, in which an inner tube made of ultra-high molecular weight polyethylene was fitted with a core material made of poly-4-methylpentene-1.

[0046] On the outside of the obtained composite tube, the following compounding recipe:
natural rubber
100 parts by weight carbon black (furnace carbon)
40 parts by weight Softener (naphthenic process oil)
4 parts by weight Vulcanizing agent (sulfur)

2.5 parts by weight Vulcanization accelerator (N-cyclohexyl-2-benzothiazylsulfenamide)

0.
5 parts by weight Vulcanization accelerator (zinc white)
5
Part by weight Vulcanization accelerator (stearic acid)
2 parts by weight of the rubber compound was extruded using a single-screw extruder to coat it to a thickness of 3 mm, and a core material made of poly-4-methylpentene-1 and an inner tube made of ultra-high molecular weight polyethylene were unvulcanized. A molded product was obtained by covering it with an outer tube material made of a natural rubber compound, and this molded product was heated in an oven at 150° C. for 1 hour.

After that, a pressure of 5 kg is applied between the core material and the inner tube.
/cm2 of water was press-injected and the core material was extracted to obtain a composite pipe material consisting of an outer pipe made of vulcanized natural rubber and an inner pipe made of ultra-high molecular weight polyethylene.

The obtained composite tube material has an outer tube made of vulcanized natural rubber, an outer tube and an inner tube that are firmly adhered, and has the excellent wear resistance, self-lubrication, and chemical resistance of ultra-high molecular weight polyethylene. In addition to being flexible and non-adhesive, it also had the excellent properties of rubber, such as elasticity, flexibility, and durability.

(Comparative Example 3) Intrinsic viscosity [η]: 3.0 dl
An attempt was made to mold a shrinkable inner tube material in the same manner as in Example 2, except that ultra-high molecular weight polyethylene with a weight of However, the molten ultra-high molecular weight polyethylene twisted in conjunction with the inner die, making it impossible to form the inner tube material.

(Comparative Example 4) The diameter was expanded at an angle of 0.5 degrees with respect to the shaft connected to the tip of the inner die, and a tapered part with a maximum outer diameter of 20.9 mmφ and a length of 25 mm was formed.
The inner diameter of the maximum expanded diameter part was the same as the outer diameter of the inner die in the same manner as in Example 2, except that a tapered core consisting of a cylindrical part with a diameter of 0.9 mm and a length of 50 mm and whose surface was coated with fluorine was used. While expanding the diameter to 1.045 times that of the screw extruder, it was taken at a take-up speed that was 1.04 times the extrusion speed of the screw extruder, and the inner diameter was 20.9 mmφ and the wall thickness was 1.8.
A shrinkable inner tube material having a shrinkage rate of 5% or less at 140° C. was molded.

In this shrinkable inner tube material, heat-resistant poly-4-methylpentene-1 resin (Mitsui Petrochemical Industries Co., Ltd.
A core material with an outer diameter of 19.9 mm φ made by Co., Ltd., TPX) was inserted, and the shape shown in Fig. 3 (A) was formed. This was heated in an oven at 150 ° C. for 1 hour to prevent the shrinkable inner tube material from shrinking. However, a composite tube was obtained in which the inner tube material did not completely adhere to the core material.

Next, Example 2 was applied to the outside of the obtained composite tube.
In the same manner as above, a molded product having an outer tube material coated with an unvulcanized natural rubber compound to a thickness of 3 mm was obtained, and this molded product was heated in an oven to 150°C to cure the outer tube and inner tube. I tried sulfur bonding. However, because the inner tube material and the core material are not completely in contact with each other and there is a gap between the inner tube material and the core material, the inner tube material has a partially twisted double structure, and the outer tube material and the inner tube material It was not firmly bonded over the entire surface. Furthermore, when the inner surface of the inner tube was observed after removing the core material, it was found that the inner surface had poor smoothness.

[0053]

[Effects of the Invention] The ultra-high molecular weight polyethylene composite pipe material of the present invention has excellent low-temperature properties such as wear resistance, self-lubricating property, chemical resistance, and low-temperature impact resistance due to the ultra-high molecular weight polyethylene constituting the inner pipe. Therefore, it is suitable as a transport hose for liquids and powders. It is particularly suitable as a refrigerant transport hose. Moreover, the first and second manufacturing methods of the ultra-high molecular weight polyethylene composite pipe material of the present invention make it possible to manufacture the ultra-high molecular weight polyethylene composite pipe material into a composite pipe material having an inner diameter of a desired wall thickness by a simple method. can. In addition, the inner tube made of ultra-high molecular weight polyethylene can have a wide range of wall thickness from 0.01 to 5 mm, so if flexibility is required for the composite tube material, it is possible to use one of these inner tubes. By making the tube thin and using a thick-walled inner tube for composite tube materials that require rigidity, it is possible to manufacture tube materials that meet the respective requirements. Moreover, according to the second method of the present invention, it is possible to obtain a composite pipe material having a smooth inner surface and a uniform inner diameter. Moreover, by appropriately selecting the outer diameter of the core material, a composite tube material having a desired inner diameter can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view illustrating the structure of the ultra-high molecular weight polyethylene composite pipe material of the present invention.

FIG. 2 is a schematic cross-sectional view illustrating the first embodiment of the method for producing an ultra-high molecular weight polyethylene composite pipe material of the present invention.

FIG. 3 is a schematic cross-sectional view illustrating a second embodiment of the method for producing an ultra-high molecular weight polyethylene composite pipe material of the present invention.

[Explanation of symbols]

1 Inner pipe 2 Outer tube 3 Outer pipe material 4 Inner pipe material 5 Core material 6 Shrinkable inner tube material 7 Unvulcanized rubber

Claims (3)

[Claims] Claim 1: A wall thickness of 0.01 to 5 m made of ultra-high molecular weight polyethylene with an intrinsic viscosity [η] of 5.0 dl/g or more.
m, has an inner tube with an outer diameter of 2 mm or more, and an outer tube made of rubber fitted on the outside of the inner tube, and the ultra-high molecular weight polyethylene of the inner tube and the rubber of the outer tube are vulcanized and bonded. Ultra-high molecular weight polyethylene composite pipe material. 2. The method for producing an ultra-high molecular weight polyethylene composite tube material according to claim 1, wherein the outer tube material made of unvulcanized rubber contains an ultra-high molecular weight material having an intrinsic viscosity [η] of 5.0 dl/g or more. After inserting an expandable inner tube material made of polyethylene that expands by 10% or more at 125 ° C., while expanding the inner tube material made of ultra-high molecular weight polyethylene by heating it to a temperature near or above the melting point of the ultra-high molecular weight polyethylene, A method for manufacturing an ultra-high molecular weight polyethylene composite pipe material, which includes the step of vulcanizing and adhering ultra-high molecular weight polyethylene as an inner pipe material and unvulcanized rubber as an outer pipe material. 3. A method for producing the ultra-high molecular weight polyethylene composite pipe material according to claim 1, wherein the intrinsic viscosity [η] is 5.0 d.
Made of ultra-high molecular weight polyethylene of 1/g or more, 140
A core material made of heat-resistant resin having a predetermined outer diameter is inserted into a shrinkable inner tube material that shrinks by 5% or more at °C, and then heated to shrink the inner tube material made of ultra-high molecular weight polyethylene to create an inner tube material. A step of fitting the inner tube to the outside of the core material by bringing the inner tube into close contact with the core material, and coating the outside of the inner tube fitted to the core material with unvulcanized rubber, and then heating the inner tube at the vulcanization temperature of the rubber. A method for producing an ultra-high molecular weight polyethylene composite pipe material, comprising the steps of: heating and vulcanizing and bonding rubber and ultra-high molecular weight polyethylene to form an outer tube; and extracting a core material from the inner tube.