JPH0569514A - Composite formed body, and manufacture and usage thereof - Google Patents

Abstract

PURPOSE:To obtain composite formed body suitable for highly safe connecting member or the like by a method wherein both heat generating body made of electrically- conductive particle-containing thermoplastic polymer and base made of thermosetting polynorbornene-based resin, which has shape retention at the melting point of the thermoplastic polymer, are integrally formed. CONSTITUTION:The composite formed body concerned is produced by integrally forming both heat generating body 72 and base 71 together. The heat generating body 72 is made of electrically-conductive particle-containing thermoplastic polymer and power source 75 is connected to ring electrodes 73. On the other hand, the base 71 is made of thermosetting polynorbornene-based resin, which has shape retention at the melting point of the thermoplastic polymer. Further, on the surface opposite to the laminate interface between the heat generating body 72 and the base 71, fusion layer 74 made of thermoplastic polymer is formed integrally or in tight contact with the heat generating body. Furthermore, at the manufacturing of the composite formed body concerned, in the interior of a mold, in which the heat generating body 72 or the composite body of the body 72 and the fusion layer 74 is housed, reaction stock liquid containing norbornene-based monomer and metathetical catalyst is fed and hardened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite molded article having a heating element, and more specifically, to a composite molded article suitable for joining, sealing, reinforcing, etc. of a thermoplastic polymer molded article, and a method for producing the same. Regarding usage.

[0002]

2. Description of the Related Art As a joint or sealing material (sealing material) for an olefin polymer pipe typified by polyethylene,
It is a well-known technique to use an olefin polymer and a fusible material, for example, the same or the same kind of polymer, and to bond or seal by heat fusion. Then, conventionally, an electrofusion joint made of a polymer molded product in which a heating wire wound in a spiral shape is embedded is known, and the joint and the joint portion of the pipe are fused by energizing the heating wire. (Japanese Patent Laid-Open No. 1-206026
issue).

However, this electrofusion joint is expensive because the manufacturing process is complicated, and a large amount of embedded heating wire (often made of metal such as nichrome wire) is not necessary at the time of heat fusion. However, after that, in the long term, it is a corrosive substance, it is a material that does not easily adhere to polyolefin, and it is different from polymer and has high rigidity, so if it is used as it is embedded, It is not preferable from the viewpoint of long-term stability (for example, causing fluid leakage from the inside) of the joint adapted to various usage conditions.

On the other hand, it is known that a thermosetting polynorbornene-based resin and an olefin-based resin such as polyethylene or polypropylene have extremely good adhesiveness, and a composite molded body in which both are integrated can be obtained (special feature: Kaihei 1-31
6262). However, this publication does not disclose a composite molded body with an olefin resin containing conductive particles.

Further, on the surface of the shape memory resin molded body,
A method is known in which a synthetic resin containing conductive particles, for example, a polyurethane resin or a polyacrylic resin is coated and used as a heating source (Japanese Patent Laid-Open No. Hei 2-239930).
No.), the manufacturing method is a method of immersing or applying a molded body in a conductive resin liquid, and the process is complicated and a thick heating element layer cannot be formed. In addition, the practical resistance value is as large as 1 to 100 kΩ per unit of the molded body, which is unsuitable as an alternative means of the electrofusion method.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a composite molded body which is easy to manufacture and has a high safety and which is suitable as a joining member, a sealing member, a reinforcing member or the like. Further, an object of the present invention is to provide a composite molded article which, when used as a joining member or the like, can be fused by energization in a short time and has a high efficiency of construction work. Further, it is an object of the present invention to provide a composite molded body in which the fusion bonding layer can be selected according to the material of the members to be joined such as the thermoplastic polymer pipe.

The inventors of the present invention have conducted extensive studies to overcome the above-mentioned problems of the prior art, and as a result, a heating element made of a thermoplastic polymer containing conductive particles and a thermosetting polynorbornene resin. It has been found that the above-mentioned object can be achieved by a composite molded body formed by integrally molding a substrate constituted by.

This composite molded body is easily obtained by a reaction injection molding method (RIM method) in which a reaction stock solution containing a norbornene-based monomer and a metathesis catalyst is cured in a mold in the presence of a preformed heating element. be able to. Also,
On the surface of the heating element, a fusion bonding layer made of a thermoplastic polymer is integrally or intimately molded, and by adjusting the material of the fusion bonding layer to the material of the joined member made of the same thermoplastic polymer, a strong fusion is obtained. You can wear it. In addition, the fusion with the members to be joined is performed simply by covering the joined portion of the members to be joined with the heating element or the fusion layer of the composite molded body and energizing the heating element. The composite molded article of the present invention can have various shapes and can be used in a wide range of fields such as a sealing member and a reinforcing member in addition to a joining member. The present invention has been completed based on these findings.

[0009]

Thus, according to the present invention, a heating element (A) composed of a thermoplastic polymer containing conductive particles, and a heat retaining shape at the melting point of the thermoplastic polymer. There is provided a composite molded body, which is formed by integrally molding a base (B) made of a curable polynorbornene-based resin. A fusion-bonding layer (C) made of a thermoplastic polymer may be formed integrally or in close contact with the surface of the heating element (A) opposite to the laminated interface with the substrate (B).

Further, according to the present invention, the heating element (A) or the composite of the heating element (A) and the fusion layer (C) is disposed in the mold, and the void is formed in the mold. By supplying and curing a reaction stock solution containing a norbornene-based monomer and a metathesis catalyst, the heating element (A) or the heating element (A) having the fusion layer (C) and the substrate (B) are integrally molded. A method for producing a composite molded body is provided. Furthermore, according to the present invention, using the composite molded body, a predetermined portion (D) of the molded body formed of a thermoplastic polymer is covered with a heating element (A) or a fusion bonding layer (C), and then the heating element. (A)
There is provided a method for using the composite molded body, which is obtained by energizing the heating element (A) or the fusion bonding layer (C) and fusing the predetermined portion (D) with electricity.

(Substrate and Reaction Stock Solution) In the composite molded article of the present invention, the polymer serving as the substrate is a thermosetting polynorbornene resin. Molded articles made of polynorbornene-based resin react with each other to quickly produce a polymer. 2
A reaction injection molding (RIM) method or RTM in which one or more low-viscosity raw materials are mixed and then supplied into a mold and cured in the mold.
It can be manufactured by a method, casting, or the like. For example, as a reaction solution, a reaction solution containing an activator and a norbornene-based monomer and a reaction solution containing a metathesis catalyst and a norbornene-based monomer are used, and both solutions are mixed and supplied into a mold to perform bulk ring-opening polymerization. A polynorbornene-based resin molded product is obtained. Molding of polynorbornene-based resin by the RIM method has a significantly lower injection pressure than injection molding of ordinary thermoplastic resin, so an inexpensive and lightweight mold can be used.
Since the raw material has good fluidity in the mold, it is preferable for producing a large-sized molded product or a molded product having a complicated shape.

The polynorbornene-based resin used as the base material in the present invention may be any one as long as it has a norbornene ring, but it is particularly preferable that it is produced using a polycyclic norbornene-based monomer having three or more rings. preferable. When it is a tricyclic compound or more, a polymer having a high glass transition temperature or a high heat distortion temperature can be obtained and the heat resistance required as a composite material can be satisfied. Further, in the present invention, in order to make the resulting polymer thermosetting, at least 10% by weight, preferably 30% by weight or more of the total monomers is used as the crosslinking monomer.

The norbornene-based monomer includes a bicyclic compound such as 2-norbornene and norbornadiene, a tricyclic compound such as dicyclopentadiene and dihydrodicyclopentadiene, a tetracyclic compound such as tetracyclododecene, and a pentacyclic compound such as tricyclopentadiene. Cyclic compounds, heptacyclic compounds such as tetracyclopentadiene, their alkyl-substituted compounds (eg, methyl, ethyl, propyl, butyl-substituted compounds), alkenyl-substituted compounds (eg, vinyl-substituted compounds), alkylidene-substituted compounds (eg, Examples thereof include ethylidene substitution products), aryl substitution products (eg, phenyl, tolyl, naphthyl substitution products, etc.), and substitution products having ester groups, ether groups, cyano groups, and polar groups such as halogen atoms. Among them, tricyclic or pentacyclic compounds are favored from the viewpoint of availability, reactivity, heat resistance and the like.

The crosslinkable monomer has two reactive double bonds.
It is a polycyclic norbornene-based monomer having at least one, and specific examples thereof include dicyclopentadiene, tricyclopentadiene, and tetracyclopentadiene.
Therefore, when the norbornene-based monomer and the crosslinkable monomer are the same, it is not necessary to use another crosslinkable monomer. These norbornene-based monomers may be used alone or in combination of two or more.

One of the above norbornene-based monomers is used.
A monocyclic cycloolefin such as cyclobutene, cyclopentene, cyclopentadiene, cyclooctene, or cyclododecene, which can undergo ring-opening polymerization with one or more species, can be used in combination within a range not impairing the object of the present invention.

Any catalyst may be used as long as it is a metathesis catalyst system known as a catalyst for ring-opening polymerization of norbornene type monomers, and specific examples thereof include halides such as tungsten, molybdenum and tantalum, oxyhalides and oxides. , A metathesis catalyst such as an organic ammonium salt, and specific examples of the activator (cocatalyst) include an alkylaluminum halide, an alkoxyalkylaluminum halide, an aryloxyalkylaluminum halide, and an organic tin compound.

The metathesis catalyst is usually used in an amount of about 0.01 to 50 mmol, based on 1 mol of the norbornene-based monomer.
It is preferably used in the range of 0.1 to 10 mmol.
The activator has a molar ratio of 0.
It is used in the range of 1 to 200, preferably 2 to 10. Both the metathesis catalyst and the activator are preferably used by dissolving them in the monomer, but they may be used by suspending or dissolving them in a small amount of solvent as long as the properties of the product are not substantially impaired.

In a preferred method for producing a polynorbornene-based resin, the norbornene-based monomer is divided into two liquids and placed in another container, a metathesis catalyst is added to one of them, and an activator is added to the other, and two stable reactions are carried out. Prepare the liquid. The two kinds of reaction liquids are mixed and then poured into a mold or a mold having a predetermined shape (both are collectively referred to as a mold), where ring-opening polymerization is performed in bulk.

The mold temperature is usually 30 ° C. or higher, preferably 40 to 200 ° C., particularly preferably 50 to 130 ° C. The components used in the polymerization reaction are preferably stored and manipulated under an atmosphere of an inert gas such as nitrogen gas.
The material of the mold may be any of metal, resin, wood, plaster and the like.

An additive such as an antioxidant, a filler, a reinforcing material, a foaming agent, a pigment, a coloring agent or an elastomer can be added to the polynorbornene resin. These additives are usually dissolved or dispersed in the reaction stock solution and blended.

When the base material is a foam, a foaming agent is added to the reaction solution, which is poured into a mold. Preferred blowing agents are usually liquid, low boiling organic compounds that volatilize easily,
For example, pentane, hydrocarbons such as hexane, methylene chloride, trichlorofluoromethane, halogenated hydrocarbons such as dichlorodifluoromethane, etc., thermally expandable microcapsules containing these low-boiling organic compounds,
Alternatively, an inert gas such as nitrogen or argon can be used.

(Heating Element) Thermoplastic Polymer The thermoplastic polymer used as the matrix polymer of the heating element in the present invention can be integrally molded with the thermosetting polynorbornene-based resin of the base material, and when it is blended with conductive particles. Any material that can be molded into a predetermined shape may be used.

Examples of such a thermoplastic polymer include high density polyethylene (PE), medium density PE, low density PE, ultra high molecular weight PE, ethylene-propylene copolymer, ethylene-butene-1 copolymer, Polypropylene (PP), polybutene-1, polypentene-1, poly4
-Methylpentene-1, ethylene-propylene rubber (E
PR), ethylene-propylene-diene terpolymer (EPDM), ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, ethylene-vinyl chloride copolymer and other olefin-based monomers as main components Olefin-based polymer; polyvinyl halide (PVC) and other halogenated polymers; polystyrene and other aromatic vinyl-based polymers; chlorinated products of these polymers;
And mixtures thereof.

Specific examples of the mixture include, for example, a mixture of high density PE and low density PE, a mixture of medium density PE and low density PE, a mixture of high density PE and ethylene-α-olefin copolymer, low density PE. And a mixture of ethylene-α-olefin copolymer and the like.

Further, various block copolymers composed of an aromatic vinyl compound typified by styrene and a conjugated diene such as isoprene and butadiene, specifically, S-
I type, S-B type, S-I-S type, S-B-S type, S-I
-S-IS type block copolymers, hydrides thereof, hydrocarbon-based thermoplastic elastomers such as mixtures thereof; polybutadiene, polyisoprene, styrene-
Unvulcanized rubber such as butadiene copolymer, chloroprene rubber and butyl rubber; and the like. These hydrocarbon-based thermoplastic elastomers and unvulcanized rubbers can be used as a mixture with the above-mentioned olefin-based polymer in an arbitrary ratio. Among these polymers, an olefin-based polymer is preferable, and a polyolefin composed of only an olefin-based monomer is particularly preferable, from the viewpoints of adhesion to a base material, integral moldability, and fusion property to a member to be joined.

Further, these thermoplastic polymers include fillers such as titanium oxide, calcium carbonate, aluminum hydroxide and talc, colorants such as various pigments and dyes, antioxidants, anti-combustion agents, ultraviolet absorbers, Anti-fog agent, antistatic agent, petroleum resin, etc.
It can be colored and the weather resistance can be improved.

Conductive Particles As the conductive particles to be contained in the thermoplastic polymer, for example, carbon black, graphite powder, metal particles (copper,
Powders of iron, nickel, etc.), mixtures thereof, and the like.

The amount of the conductive particles to be blended may be appropriately selected within the range where uniform heat generation of the heating element is generated by energization.
Normally, the volume resistivity of the heating element at 25 ° C is 5 x 10 ²
It is selected to be Ω · cm or less, preferably 1 × 10 ² Ω · cm or less, and the lower the volume resistivity, the easier the heat generation. For example, among carbon blacks, Ketjen Bla has excellent conductivity.
In the case of ck), it is usually 5 to 5 with respect to the thermoplastic resin.
The content is 35% by weight, preferably 10 to 30% by weight.

Heating Element The heating element first comprises a thermoplastic polymer and conductive particles.
Sheets, ribbons or pellets are melted and kneaded with a Banbury mixer, plastomill, mixing roll, pressure kneader, etc., and then extruded, injection-molded, blow-molded, rotational-molded, compression-molded, etc. Mold into the desired shape.

The heating element used in the present invention preferably has a volume resistivity at 25 ° C. of 5 × 10 ² Ω · cm or less. If the volume resistivity is excessively large, non-uniform heat generation occurs due to energization, which causes defective fusion.

(Fusion Layer) The heating element may be molded integrally or in close contact with the fusion layer composed of a thermoplastic polymer. The polymer constituting the fusion layer needs to be capable of being fused with the heating element, and is generally appropriately selected from the thermoplastic polymers constituting the heating element. Since the heating element and the fusion layer are fused by the heat generated during use,
It is not always necessary to integrate them in advance. When the heating element and the fusion bonding layer are integrated, for example, a conventional lamination method such as heat fusion or coextrusion can be adopted. In the case of joining or sealing, the material of the fusion layer is the same as or similar to that of the thermoplastic polymer molded body to be fused, so that strong fusion can be achieved.

Further, since the heating element contains a large amount of filler, it is difficult to process it into a complicated shape, and there are cases in which the elbow, cheese, etc. cannot be molded. In such a case, for example, an elbow (fusion layer) made of a thermoplastic polymer by blow molding
Can be solved by arranging a heating element between the base and the fusion layer at a location requiring heating, and integrally or closely attaching them.

Furthermore, when transferring high-purity water or high-purity chemicals, if the heating element comes into direct contact with the liquid, the liquid may be contaminated or the heating element may swell depending on the material used. There are things you can't do. For example, in gasoline containers and pipes, ultra-high molecular weight polyethylene is exclusively used because ordinary polyethylene easily swells. Therefore, it is effective to use ultra-high molecular weight polyethylene as the fusing layer in order to prevent the swelling of the portion in contact with gasoline.

By providing the fusion layer formed of the polymer containing no impurities or the polymer having resistance to the liquid to be contacted as described above, the material difference between the material of the joined member such as the pipe and the material of the heating element is provided. Can be supplemented.

(Composite Molded Product) In the composite molded product, a heating element or a composite of a heating element and a fusion layer is arranged in a mold, and a norbornene-based monomer and a metathesis catalyst are placed in a void in the mold. It is possible to manufacture by a method of integrally molding a heating element or a heating element having a fusion layer and a substrate made of a thermosetting polynorbornene-based resin by supplying and curing a reaction stock solution containing the same.

When the composite molded body is, for example, a tubular composite molded body such as a pipe joint, a preformed tubular heating element is used as a core, and this is surrounded by a mold, and the inner surface of the mold and the heating element are surrounded. By supplying a reaction stock solution containing a norbornene-based monomer and a metathesis catalyst to the void formed by the outer peripheral surface of the polymer and performing bulk ring-opening polymerization, a composite molded body in which a heating element and a substrate are integrated is obtained. You can In addition, when the composite molded body has a plate shape or the like, the heating element is placed in the mold,
The reaction stock solution may be supplied to the remaining voids to perform bulk ring-opening polymerization. When the heating element has a fusion layer, it is placed in the mold so that the heating element portion and the reaction stock solution come into contact with each other.

The shape of the composite molded article of the present invention is not particularly limited and includes, for example, pipe joints, board joining members, sealing members,
It can be appropriately determined according to the purpose of use of the reinforcing member and the like. The composite molded article of the present invention covers a predetermined portion of a molded article formed of a thermoplastic polymer with a heating element or a fusion layer and energizes the heating element to melt the heating element or the fusion layer and the predetermined portion. Depending on the method of attachment, it can be used as a joint member, a sealing member, a reinforcing member, or the like.

For example, a joint portion of two pipes made of an olefin polymer is inserted into a hollow portion of a tubular composite molded body provided with an exothermic body or a fusion layer on the inner peripheral surface, and then the exothermic body is formed. When the heating element or the fusing layer is heated and fused by applying electricity, a joined pipe is obtained. In this case, if the heating element or the polymer of the fusing layer is formed of the same olefin-based polymer, when the heating element is energized, the outer peripheral surface of the pipe also partially melts, and since it is the same material, it becomes firm. Fuse together. Even if the heating element and the fusing layer are not integrated, they will be integrated when electricity is applied.

As a means for energizing, a heating element may be provided with an energizing electrode so that it can be connected to a power source. The electrode material is preferably an electrically conductive paint, an electrically conductive paste, or an electrically conductive metal typified by copper, which has a lower heat resistance than the electric resistance of the heating element. If the contact resistance between the electrode and the heating element is high, local heat is generated. Therefore, in order to reduce this, it is preferable to widen the contact area by using a number of thin copper wires.

The current-carrying electrodes may be arranged so that the current flows evenly through the heating element at the location where the temperature should be raised. For example, in the case of a tubular composite molded body (pipe), whether two linear electrodes are arranged at equal intervals parallel to the pipe on the outer peripheral portion (interface with the base) of the heating element to conduct electricity (Fig. 1). Alternatively, depending on the diameter of the pipe and the resistance of the heating element, multiple electrodes are arranged at equal intervals, and current is applied from the bipolar terminals. Further, if the length of the heating element of the tubular composite molded body is made longer than that of the substrate and the end portion of the heating element is formed to protrude, a ring-shaped electrode can be arranged at the end portion of the heating element (FIG. 3). .. In this method, the electrodes can be easily arranged, so that the energizing electrodes can be attached and detached at the construction site. When the diameter of the pipe is large, and in the case of a complicated shape such as an elbow or cheese, a plurality of ring-shaped electrodes may be arranged at equal intervals at locations where the temperature of the heating element should be raised, and current may be supplied from the bipolar terminals ( (Fig. 7). The thermosetting polynorbornene-based resin of the substrate is required to be able to retain its shape without melting when the heating element and the fusion layer are melted.

[0041]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the following examples, parts and% are based on weight unless otherwise specified.

[Example 1] Low-density polyethylene (melt index 0.3, density 0.92, melting point 110 ° C)
Conductive carbon black (Ketjen Black E
25% of C) was mixed in a Banbury mixer, and a sheet was formed with a receiving roll, and then pelletized.

The pellets were extruded with an outer diameter of 36
mm, inner diameter 33 mm, extruded into a pipe shape, length 60 m
A heating element was prepared by cutting into m. 1 on the surface of this heating element
Resistance measuring device at intervals of cm (SOAR COPORATORI
ON-made ME-530 type) terminals were crimped to measure the resistance value, which was taken as the volume resistivity. The result is 53Ω
It was cm.

As shown in FIG. 1, a copper-made electrode terminal 3 is joined to both ends of the heating element 2 as a core for RIM molding, and an aluminum cylindrical mold having an inner diameter of 41 mm and an outer diameter of 80 mm is provided around the core. It was fixed via the upper and lower lids and sealed. An injection port for injecting the reaction stock solution was provided in the upper lid in the space between the cylinder and the core. The entire cylinder assembled at 60 ℃
The mixture was heated to, nitrogen gas was made to flow from the injection port, the gap between the core and the cylinder was replaced with nitrogen gas, and then the reaction stock solution was injected.

The reaction stock solution used had the following composition. That is, as the norbornene-based monomer, 75% of dicyclopentadiene (DCP) and 25% of cyclopentadiene trimer (a mixture of about 20% of symmetric type and about 80% of asymmetric type) were used, and styrene-isoprene-styrene block was used. 5% of a copolymer (Kreighton 1170, manufactured by Shell Co.) and 2% of a phenolic antioxidant Irganox 1010 (manufactured by Ciba Geigy Co., Ltd.) were dissolved and placed in two containers, one of which was used as a monomer. Diethyl aluminum chloride (DEAC) at a concentration of 40 mmol,
n-Propanol was added at a concentration of 44 mmol and silicon tetrachloride was added at a concentration of 20 mmol. On the other hand, tri (tridecyl) ammonium molybdate was added to the monomer so as to have a concentration of 10 mmol. Both reaction solutions were conveyed to a power mixer by a gear pump so that the volume ratio was 1: 1 and injected into the void portion in the mold through the injection port.

The polymerization reaction was completed about 3 minutes after the injection. As shown in FIG. 1, the upper and lower lids of the cylindrical mold are removed, and the electrode terminal 3
As a result, a sleeve-shaped socket was obtained in which the heating element 2 having the above was used as the inner peripheral layer, and the base 1 made of the thermosetting polynorbornene resin was integrally molded around the inner peripheral layer. The outer peripheral layer and the inner peripheral layer of this socket were excellent in adhesiveness and could not be peeled off even if they were to be peeled off. The Tg of the polynorbornene-based resin of the outer peripheral layer was 170 ° C.

As shown in FIG. 2, two low density polyethylene pipes 4 (outer diameter 32.5 mm, wall thickness 4 mm, length 80 mm) of the same quality as the heating element were inserted from both ends of this socket to generate heat. When an AC voltage of 30 V is applied from the power source 5 to each of the two electrode terminals 3 on both ends of the body 2 for 2 minutes, the heating element 2 and the polyethylene on the surface of the pipe 4 are melt-bonded and a part of them flows out to the edge of the socket as a bead. It was

The pipe and socket thus joined were vertically cut into 6 equal parts to prepare a test sample, and the end of the sample was clamped to a clamp of a tensile tester to carry out a tensile test at a speed of 50 cm / min. In each sample, the pipe part was stretched and broken,
The socket portion was firmly bonded to each layer.

[Embodiment 2] As shown in FIG.
Mold both ends of 2 so that they protrude 5 mm from the base material 31,
A tubular composite molded body (socket) was produced in the same manner as in Example 1 except that a copper ring electrode 33 was joined to the protruding portion along the circumference to take out the terminal.

As in Example 1, the low density polyethylene pipe 4 was inserted from both ends of the socket, and 4 was inserted into this electrode.
When an alternating voltage of 0 V was applied for 2 minutes, the heating element 32 and the polyethylene on the surface of the pipe were melt-bonded (fused), and a part thereof flowed out as a bead from the edge of the socket. Then, the ring electrode was cut off with radio pliers. The jointed pipes were tested for joint strength in the same manner as in Example 1. However, in all cases, the pipe portion was stretched and broken, and the socket portion was strongly bonded to each layer.

Example 3 Instead of low-density polyethylene, polybutene (polybutene-1, P14 manufactured by Mitsui Yuka Co., Ltd.) was used.
04C; melt index 0.4, melting point 125 ° C.) was used to prepare a heating element (volume specific resistance 55 Ω · cm) in the same manner as in Example 1 and to similarly prepare a socket by reaction injection molding. .

From both ends of this socket, a polybutene pipe of the same quality as the heating element (outer diameter 32.5 mm, length 80 m)
m) Insert two of each, and apply an AC voltage of 5 to 30 V to the two electrode terminals at both ends of the heating element for 2 minutes, the heating element and the polybutene on the surface of the pipe are melted and adhered, and part of the socket Spilled as a bead on the edge of. The jointed pipes were tested for joint strength in the same manner as in Example 1. However, in all cases, the pipe portion was stretched and broken, and the socket portion was strongly bonded to each layer.

[Example 4] The pellets of the mixture of low-density polyethylene and conductive carbon black prepared in Example 1 were put into a mold for making a sheet having a thickness of 1 mm, and 180
It was compression-molded by a pressure press at ℃ to prepare a sheet-shaped heating element. This sheet is cut into a length of 10 cm and a width of 4 cm, and this is attached to a flat surface in a flat die (one of the split dies), then the other split die is overlapped, and nitrogen gas is flown into the void to remove the air inside. Replaced. After heating the mold to 60 ° C., the reaction stock solution used in Example 1 was injected into the void in the mold,
A composite molded body in which the heating element sheet 52 and the base body 51 made of polynorbornene-based resin as shown in (1) were integrally molded was prepared.

As shown in FIG. 6, a copper electrode 53 is joined to the protruding portion of the heating element 52, and then placed on the joining portion of two polyethylene plates 54 of the same quality as the heating element and having a thickness of 5 mm. When a load of light was applied and a voltage of 20 V was applied between the electrodes for 40 seconds, the heating element and the portion of the polyethylene plate in contact with the heating element were melt-bonded. When the fused plate-shaped composite molded body was peeled off, the polyethylene plate portion broke.

[Embodiment 5] An elbow joint of a polyethylene pipe for transferring a high-purity chemical liquid was prepared in the following manner.
Using a low-density polyethylene with the same quality as the pipe as the raw material, a fusion molding layer 74 (inner diameter 36 mm, outer diameter 39 mm) of the elbow shown in FIG. 7 is made by blow molding so that it is in contact with the outsides of the both edges A ring of a heating element of the same quality as in Example 1 (inner diameter 39 mm, thickness 1.0 mm, length 35 mm) 72
Insert the copper current-carrying electrodes 7 on both sides of each heating element.
3 were attached at equal intervals, the lead wires were taken out, and each positive and negative electrode was attached to serve as a terminal, which was used as a core. The outside was covered with a die of an aluminum elbow having an inner diameter of 45 mm, and lids were attached to both openings to fix the core.

In the same manner as in Example 1, the reaction stock solution was injected into the space between the mold and the core and polymerized to prepare an elbow composite molding as shown in FIG. The base 71 and the heating element 72 were integrated. Further, the interface between the base 71 and the fusion layer 74 was also integrated. However, at this stage, the heating element 72 and the fusion bonding layer 74 were not yet integrated. Pipes made of low-density polyethylene were inserted into both openings, and a current was applied from each electrode terminal at a voltage of 30 V for 3 minutes, whereby the elbow joint and the pipe were melt-bonded. At this time, the heating element 7
2 and the fusion layer 74, and the fusion layer 74 and the pipe were completely fused to each other. When the elbow was energized under the same conditions as above before the pipe was inserted, the heating element 72 and the fusion layer 74 were completely fused. This elbow joint can also be used as a joint.

Example 6 A gasoline resistant pipe made of ultra high molecular weight polyethylene pipe was prepared as follows. Ultrahigh molecular weight polyethylene (trade name Ace Polyeth HD C4502) manufactured by Showa Denko KK was extruded to an outer diameter of 25 mm, a thickness of 1 mm and a length of 40 mm to form a fusion layer.
On the outside, 50% of the above ultra high molecular weight polyethylene, low density polyethylene manufactured by Sumitomo Chemical Co., Ltd. (trade name Sumikasen F
101) A compound obtained by mixing 25% of conductive carbon black (Ketjen Black EC) with a 50% mixture was covered with an extruded sleeve having an inner diameter of 25 mm, a thickness of 1 mm and a length of 40 mm to form a core.

On the outside of this core, an aluminum mold for injecting and molding a reaction stock solution having a thickness of 2 mm was mounted so that both ends of the sleeve were protruded by 5 mm to mount an electrode, and the first embodiment was used. In the same manner as above, the reaction stock solution was injected into the space between the mold and the core and polymerized to prepare a tubular composite molded body as shown in FIG. Base 81 and heating element 8
2 was integrally molded.

From both openings of the obtained joint, the outer diameter 22.
The ultra-high molecular weight polyethylene pipe 86 having a thickness of 5 mm and a thickness of 3 mm was inserted so as to be in contact with the center of the joint. A removable copper ring electrode 83 is fitted to the heating element portion protruding from both ends of the joint, the terminal is taken out, and the power source 85
When a current was applied for 3 minutes with an alternating voltage of 30 V from 30 to 40 V, the surfaces of the fusion layer 84 and the pipe 86 were fused. After cooling, a tensile test was performed in the same manner as in Example 1 by dividing the joint portion into four vertically. As a result, it showed sufficient strength, the base body, the heating element, the fusion layer and the pipe were integrated, and the portion in contact with gasoline was composed of ultra-high molecular weight polyethylene.

Example 7 Low-density polyethylene (melt index 2.0, density 0.92) and ethylene-α-
An olefin copolymer (melt index 1.0, density 0.87) was mixed in a weight ratio of 8: 2, and conductive carbon black (Ketjen Black EC) was added to 30 parts.
%, Mixed with a Banbury mixer, made into a sheet by a receiving roll, and then made into pellets.

These pellets were extruded with an outer diameter of 41
mm, an inner diameter of 35 mm was extruded into a pipe-shaped exothermic body. By a reaction injection molding method similar to that of Example 1, a polynorbornene-based resin having a thickness of 3 mm was integrated around the outer periphery of the heating element to form a pipe having a two-layer structure. The obtained pipe was cut into a length of 50 mm, and as shown in FIG. 9, a collar ring 93 made of copper and having a width of 5 mm was press-fitted inside the openings at both ends of the pipe to press it to a heating element to form a current-carrying electrode. A terminal was attached to a part of both electrodes to form a joint.

As shown in FIG. 10, pipes 94 made of medium density PE having an outer diameter of 34 mm and a thickness of 5 mm were inserted from both openings of the joint so as to be aligned at the center of the joint. From the terminal of the joint, a current is first supplied from the power source 95 with an alternating voltage of 30V for about 30 seconds, and then the voltage is reduced to 15V for about 2 seconds.
A current was applied for 00 seconds. The heating element in the inner layer of the joint and the polyethylene pipe inserted through both openings of the joint were fusion-bonded.

[0063]

According to the present invention, it is possible to provide a composite molded body suitable as a highly safe joining member, sealing member, reinforcing member, or the like. Further, the composite molded article of the present invention is easy to manufacture, and when it is used as a joining member or the like, it can be fused by energization for a short time, and the construction work efficiency is good.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a specific example of a composite molded article of the present invention, in which the left figure is a vertical cross-section and the right figure is a horizontal cross-section.

FIG. 2 is a cross-sectional view when the composite molded article of the present invention is used as a joining member for a thermoplastic resin pipe.

FIG. 3 is a cross-sectional view showing a specific example of the composite molded article of the present invention, in which the left figure is a longitudinal sectional view and the right figure is a lateral sectional view.

FIG. 4 is a cross-sectional view when the composite molded article of the present invention is used as a joining member for a thermoplastic resin pipe.

FIG. 5 is a cross-sectional view showing a specific example of the composite molded article of the present invention, in which the left figure is a cross-sectional view and the right figure is a front view.

FIG. 6 is a diagram in which the composite molded article of the present invention is fused to a polyethylene plate, the left diagram is a cross-sectional view, and the right diagram is a front view.

FIG. 7 is a cross-sectional view showing an elbow (composite molded body having a substrate, a heating element and a fusion layer) of the present invention.

FIG. 8 is a cross-sectional view showing an example of joining pipes made of ultra-high molecular weight polyethylene using the pipe joint of the present invention (composite molded product having a substrate, a heating element and a fusion layer).

FIG. 9 is a cross-sectional view showing a pipe joint (composite molded article having a base, a heating element and a fusion layer) of the present invention, the left figure is a cross section and the right figure is a front view.

FIG. 10 is a cross-sectional view showing an example of joining pipes made of medium-density polyethylene by using the pipe joint of the present invention (composite molded body having a base, a heating element and a fusion layer).

[Explanation of sign]

 1 Base 2 Heat generating element 3 Electrode terminal 4 Low-density polyethylene pipe 5 Power supply 31 Base 32 Heating element 33 Ring electrode 36 Power supply 51 Base 52 Heat generating element 53 Electrode 54 Polyethylene plate 56 Power supply 71 Base 72 Heat generating element 73 Ring electrode 74 Fusion layer 75 Power Supply 81 Base Material 82 Heating Element 83 Ring Electrode 84 Fusion Layer (Made of Ultra High Molecular Weight Polyethylene) 85 Power Supply 86 Ultra High Molecular Weight Polyethylene Pipe 91 Base Material 92 Heating Element 93 Collared Ring Electrode 94 Medium Density Polyethylene Pipe 95 Power Source

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B32B 27/20 Z 6122-4F // B29K 86:00 B29L 9:00 4F

Claims (4)

[Claims] 1. A heating element (A) composed of a thermoplastic polymer containing conductive particles, and a substrate (a thermosetting polynorbornene-based resin having shape retention at the melting point of the thermoplastic polymer (A). A composite molded body characterized by being integrally molded with B). 2. The surface of the composite molded article according to claim 1 opposite to the laminated interface between the heating element (A) and the substrate (B),
Furthermore, a composite molded body obtained by molding a fusion-bonding layer (C) composed of a thermoplastic polymer integrally with or in close contact with the heating element (A). 3. A heating element (A) or a composite of the heating element (A) and a fusion layer (C) is disposed in a mold, and a norbornene-based monomer and a metathesis catalyst are placed in a void in the mold. The heating element (A) is obtained by supplying a reaction stock solution containing
Alternatively, the heating element (A) having the fusion-bonding layer (C) and the base body (B) are integrally molded, and the method for producing a composite molded article according to claim 1 or 2. 4. The heating element (A) of the composite molded body according to claim 1 or the fusion layer () of the composite molded body according to claim 2 in a predetermined portion (D) of the molded body formed of a thermoplastic polymer. C)
3. The composite according to claim 1 or 2, characterized in that the heating element (A) is energized to fuse the heating element (A) or the fusion layer (C) with the predetermined portion (D). How to use the molded product.