JPH0872085A - Composite structural member and manufacturing method thereof - Google Patents

Abstract

(57) [Abstract] [Purpose] Small residual stress during resin molding, good dimensional accuracy, little warpage and deformation, capable of withstanding high loads, relatively lightweight, and impact resistant. (EN) Provided is a composite structural member which is excellent in and easy to manufacture. [Structure] The resin pipe 2 and a coating layer 6 that covers the outer periphery of the resin pipe 2 so as not to block the through hole 10 of the resin pipe 2.
And a metal pipe 4 which is removably inserted into the through hole 10 of the resin pipe 2, and the coating layer 6 is made of a polynorbornene resin obtained by a reaction injection molding method. The through hole 10 is formed on the outer periphery of the resin pipe 2 having the through hole 10.
To form a coating layer 6 by reaction injection molding using a norbornene-based resin so that the resin pipe 2 is not blocked.
The metal pipe 4 is passed through the through hole 10 and the metal pipe 4 is bonded to the through hole 10 of the resin pipe 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite structure of a synthetic resin and a metal and a method for producing the same, more specifically,
Small residual stress during resin molding, good dimensional accuracy,
TECHNICAL FIELD The present invention relates to a composite structural member with less warpage and deformation and a method for manufacturing the same.

[0002]

2. Description of the Related Art Synthetic resins excellent in various properties are being developed, but they are inferior to metallic materials in terms of mechanical strength and economy. Therefore, conventionally, metal is often used as a structural member in a field requiring mechanical strength.

For example, a structural member constituting a tank for storing a liquid, a caster for transferring a product, a support for supporting a product, a holding arm for holding a product, or a building, a building or a civil engineering structure. A metal material is used as a part of the structural member.

However, the metal material has the problems that it is heavy and easily rusts. Therefore, a composite structural member in which a resin and a metal are combined has been developed. The composite structural member is molded (insert molding) by previously inserting metal into a mold and performing injection molding.

[0005]

However, when a composite structural member composed of metal and resin is molded by insert molding, residual stress is generated inside the resin after molding due to the difference in thermal shrinkage between the metal and resin. This may cause internal distortion, which may cause deformation such as distortion or cracks in the molded product, which may make it impossible to obtain desired dimensional accuracy.

Further, the composite structural member obtained by insert molding has a problem that it is difficult to separate the resin and metal when recycling them and the workability for resource recycling is poor. The present invention has been made in view of such an actual situation, the residual stress at the time of resin molding is small, the dimensional accuracy is good, the warpage and the deformation are small, it is possible to withstand a high load, and it is relatively lightweight. It is an object of the present invention to provide a composite structural member which has excellent impact resistance and is easy to manufacture.

[0007]

In order to achieve the above object, the composite structural member according to the present invention is a coating for covering the outer periphery of the resin pipe so as not to block the resin pipe and the through hole of the resin pipe. A layer and a metal pipe removably inserted into the through hole of the resin pipe, and the coating layer is made of a polynorbornene resin obtained by a reaction injection molding method.

The method of manufacturing a composite structural member according to the present invention is
On the outer periphery of the resin pipe having a through hole, a step of forming a coating layer by reaction injection molding using a norbornene-based resin so as not to block the through hole, and after molding the coating layer, A step of inserting a metal pipe into the through hole and, if desired, adhering the metal pipe to the through hole of the resin pipe.

The overall shape of the composite structural member according to the present invention is
It can have any shape such as a rod shape, a flat plate shape, or a tank shape. In the present invention, the resin pipe may be a resin having a good fusion property with the norbornene-based resin, and is made of, for example, a polyolefin-based resin such as polyethylene or polypropylene, or a resin such as polystyrene or EVA. On the outer circumference of the resin pipe, for example, an annular convex portion, a spiral convex portion, or another convex portion or concave portion may be formed. By forming these convex portions or concave portions, the adhesion between the resin pipe and the coating layer is improved.

Further, a spiral recess, a recess parallel to the axis of the pipe, etc. may be formed on the inner circumference of the resin pipe. By forming these recesses, even if there is substantially no gap between the inner circumference of the resin pipe and the outer circumference of the metal pipe, the elasticity of the resin pipe can be used to facilitate the insertion of the metal pipe or to seal the tip. When the stopped metal pipe is inserted, it serves as an escape passage for air in the resin pipe, which facilitates insertion.

Examples of the metal constituting the metal pipe include iron and carbon steel, manganese steel, chrome steel, chrome / molybdenum steel, nickel-chromium steel, stainless steel, cast iron and other iron and alloys thereof, copper, brass, white copper, Examples thereof include copper and copper alloys such as bronze, aluminum, nickel, lead, titanium and their alloys, and plated steel sheets such as aluminum, zinc and tin. Iron and iron alloys are preferred because they are versatile and most easily available.

In the present invention, the coating layer is composed of a polynorbornene resin obtained by a reaction injection molding method.
In particular, a ring-opening polymer of a norbornene-based monomer modified with an elastomer is preferable. Examples of the elastomer include polybutadiene, styrene-butadiene copolymer (SBR), styrene-butadiene-
Examples thereof include styrene block copolymer (SBS), polyisoprene, styrene-isoprene-styrene block copolymer (SIS), ethylene-propylene-diene terpolymer (EPT) and the like.

The blending ratio of the elastomer is 1 to 20 parts by weight, preferably 2 to 15 parts by weight, based on 100 parts by weight of the norbornene-based monomer. When the blending ratio of the elastomer is low, the flexibility decreases. On the other hand, if the blending ratio of the elastomer is too large, the glass transition temperature and the strength decrease, which is not preferable.

The monomer used in the present invention is a cycloolefin having a norbornene ring such as dicyclopentadiene, dihydrodicyclopentadiene, tetracyclododecene and tricyclopentadiene. The metathesis catalyst used in the present invention may be a metathesis catalyst known as a catalyst for bulk polymerization of norbornene-based monomers such as organic molybdate ammonium salts such as tungsten hexachloride, tridodecyl ammonium molybdate, and tri (tridecyl) ammonium molybdate. There is no particular limitation, but organic molybdic acid ammonium salt is particularly preferable.

Examples of activators (cocatalysts) include alkylaluminum halides such as ethylaluminum dichloride and diethylaluminum chloride, alkoxyalkylaluminum halides thereof, and organic tin compounds. As a pre-preparation for reaction injection molding, a reaction injection molding material containing a norbornene-based monomer, a metathesis catalyst, and an activator as a main material is a liquid containing a norbornene-based monomer and a metathesis catalyst, and the norbornene-based monomer and an activator described above. Separate the two stable liquids into a separate container.

At the time of reaction injection molding, the two liquids are mixed, and then the mixed liquid is injected into a cavity of a mold in which a resin pipe is inserted, and bulk polymerization is performed in the cavity to form a coating layer. obtain. This reaction injection molding is also insert molding because the resin pipe is inserted into the mold in advance. In order to prevent the reaction injection mixed solution from entering the through hole of the resin pipe, it is desirable to attach a removable plug to the opening of at least one end of the resin pipe. It is preferable to attach a removable plug or a non-removable plug to the other end opening of the resin pipe. The removable plug is used because the plug is removed after the molding and the metal pipe is inserted from there.

The metal mold used for the reaction injection molding does not necessarily have to be an expensive metal mold having high rigidity, and it is not limited to a metal metal mold, and a resin metal mold or a simple mold can be used. This is because the reaction injection molding of the norbornene-based resin can be performed at a relatively low temperature and low pressure by using a low-viscosity reaction liquid. The mold is sealed with an inert gas, and the components used for the polymerization reaction are stored under an atmosphere of an inert gas such as nitrogen gas,
And it is preferable to operate.

The mold temperature is preferably 10 to 150.
C., more preferably 30 to 120.degree. C., still more preferably 50 to 100.degree. Mold pressure is usually 0.1 to 1
It is in the range of 00 Kg / cm ² . The polymerization time may be appropriately selected, but usually 30 seconds to 2 after the completion of the injection of the reaction solution.
It is 0 minutes, preferably 5 minutes or less.

After the molding, the plugs attached to one end or both ends of the resin pipe are removed, and the metal pipe is inserted into the through hole of the resin pipe through the opening. Metal pipe
If necessary, it is bonded inside the through hole of the resin pipe. As the adhesive used, urethane adhesive, epoxy adhesive, unsaturated polyester adhesive, etc. are preferably used.

As another aspect of the method for manufacturing a composite structural member according to the present invention, a metal pipe is inserted into a resin pipe in advance, the metal pipe is placed in a mold, and reaction injection molding is performed on the outer periphery of the resin pipe. It is also possible to form a coating layer of polynorbornene resin.

[0021]

In the composite structural member according to the present invention, an external force such as a load applied to the structural member can be received by the metal pipe, so that the composite structural member has sufficient mechanical strength to withstand the intended use. Further, the coating layer formed on the outer periphery of the resin pipe is composed of a polynorbornene resin obtained by a reaction injection molding method, and the polynorbornene resin has sufficient mechanical strength and impact resistance. Therefore, cracks or cracks do not occur against external force such as load.

By using the resin pipe, when the coating layer is formed by reaction injection molding of polynorbornene resin, the coating layer is well fused to the resin pipe. Also,
Since the heat shrinkage of the resin pipe and the polynorbornene-based resin obtained by reaction molding are almost equal, the residual stress generated in the reaction injection molded resin as a result of reaction injection molding to form the coating layer on the outer periphery of the resin pipe. Is extremely small,
It is possible to effectively prevent deformation such as distortion and cracking of the molded product. Also, the dimensional accuracy of the molded product is improved.

Further, when the composite structural member is discarded, the respective resources can be easily recycled by forcibly extracting the metal pipe from the resin pipe. That is, the composite structural member according to the present invention is easy to disassemble, and has excellent workability and economy in the resource recycling process.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The composite structural member according to the present invention will be described in detail below with reference to the embodiments shown in the drawings. 1 is a cross-sectional view of an essential part showing a manufacturing process of a composite structural member according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of an essential part showing a next manufacturing process of the composite structural member shown in FIG. 1, and FIG. 2 is a cross-sectional view of an essential part showing the next manufacturing process of the composite structural member shown in FIG. 2, FIG. 4 is a cross-sectional view of an essential part of the composite structural member according to another embodiment of the present invention, and FIG. 5 is still another embodiment of the present invention. 6 is a cross-sectional view of an essential part of the composite structural member according to FIG.
Is a side view of a resin pipe used in a composite structural member according to still another embodiment of the present invention, and FIG. 7 is a perspective view of a main part of a tank using the composite structural member according to an embodiment of the present invention.

First, the embodiment shown in FIGS. 1 to 3 will be described. As shown in FIG. 3, the composite structural member 1 according to the first embodiment of the present invention has a rod shape as a whole, and the metal pipe 4 is bonded inside the through hole 10 of the resin pipe 2,
A coating layer 6 is integrally formed on the outer circumference of the resin pipe 2. The resin pipe 2 is made of polyolefin resin. The cross-sectional shape of the resin pipe 2 is not particularly limited,
It can have any cross-sectional shape, such as rectangular cross-section or ring-shaped cross-section. The length and wall thickness of the resin pipe 2 can be freely designed according to the application for which the structural member 1 is used.

The metal pipe 4 inserted into the through hole 10 of the resin pipe 2 is made of a metal such as an iron alloy, and has an outer diameter slightly smaller than the inner diameter of the resin pipe 2 and the resin pipe 2
It has a shorter length. The thickness of this metal pipe 4 is
The structural member 1 can be freely designed according to the use and the like. The cross-sectional shape of this metal pipe is not particularly limited, but is a shape that matches the inner peripheral shape of the resin pipe.

Blind plates 8 and 8 are joined to both ends of the metal pipe 4. This joining is performed by welding, for example. The metal pipe 4 to which the blind plates 8 and 8 are joined is inserted into the through hole 10 of the resin pipe 2 after the coating layer 6 is formed on the outer periphery of the resin pipe 2. At the time of insertion, it is preferable to apply an adhesive on the outer periphery of the metal pipe 4 or the through hole 10 of the resin pipe 2. Then, the one end opening of the resin pipe 4 is covered with the stopper 12. Resin pipe 4
A plug 14 is preliminarily attached to the opening at the other end of the plug so that the resin forming the coating layer does not flow into the through hole 10 when the coating layer 6 is molded.

The coating layer 6 is composed of a polynorbornene resin obtained by a reaction injection molding method. At the time of reaction injection molding, a plurality of resin pipes 2 shown in FIG. 1 having stoppers 14 and 16 attached to the openings at both ends are arranged in the mold as needed, and then the reaction stock solution is injected. Perform so-called insert molding. The reaction injection molding is performed so that the coating layer 6 obtained by the reaction injection molding covers the outer periphery of the resin pipe 2 and does not enter the through hole 10.

The layer thickness of the coating layer 6 can be freely designed according to the intended use of the structural member 1. Also,
The cross-sectional shape of the coating layer 6 is not particularly limited, and can be freely changed to a circle, an ellipse, a square, a rectangle, a polygon, or another shape. The polynorbornene-based resin forming the coating layer 6 is composed of a ring-opening polymer of an elastomer-modified norbornene-based monomer having three or more ring members, and the heat deformation temperature of the polymer is 100 ° C. or more at the time of breaking. Elongation is 10-1
It is preferably 00%.

After molding the coating layer 6 by reaction injection molding, as shown in FIG. 2, the plug 16 attached to the opening at one end of the resin pipe 2 is removed, and blind plates 8 and 8 are provided at both ends from the opening. The metal pipe 4 joined to is inserted into the through hole 10. At that time, it is preferable to apply an adhesive to the outer periphery of the metal pipe 4 or the through hole 10 of the resin pipe 2.

Then, as shown in FIG. 3, the resin pipe 2
After the metal pipe 4 has completely entered the through hole 10, the lid 12 is capped and the composite structural member 1 according to this embodiment is completed. According to the composite structural member 1 according to the present embodiment, an external force such as a load applied to the structural member 1 can be received by the metal pipe 4, so that the composite structural member 1 has sufficient mechanical strength to withstand the intended use. Further, the coating layer 6 formed on the outer periphery of the resin pipe 2
Is composed of a polynorbornene-based resin obtained by a reaction injection molding method, and this polynorbornene-based resin is
Since it has sufficient mechanical strength and impact resistance, it will not crack or crack due to an external force such as a load. Further, by combining the metal pipe 4 and the polynorbornene resin coating layer 6, the mechanical strength is improved as compared with the metal pipe alone.

Further, by using as the resin pipe 2 a resin pipe having a good fusion-bonding property with the polynorbornene resin, the coating layer 6 can be formed by reaction injection molding of the polynorbornene resin. 6 is well fused to both ends of the resin pipe 2. Further, since the resin pipe 2 and the polynorbornene-based resin obtained by the reaction molding have almost the same heat shrinkage, the reaction injection molding resin for forming the coating layer 6 on the outer periphery of the resin pipe 2 results in the reaction injection molding resin. The residual stress generated therein is extremely small, and it is possible to effectively prevent deformation such as strain and cracks in the molded product. Also, the dimensional accuracy of the molded product is improved.

Further, when the composite structural member 1 is discarded, each resource can be easily recycled by forcibly extracting the metal pipe 4 from the through hole 10 of the resin pipe 2. Next, a second embodiment of the present invention will be described.

As shown in FIG. 4, in the composite structural member 1a of this embodiment, unlike the embodiment shown in FIGS.
Both ends of the metal pipe 4a, to which a and 8a are joined, are configured to project from the resin pipe 2a and the coating layer 6a. The point that the metal pipe 4a is inserted into the through hole 10a of the resin pipe 2a after the coating layer 6a is formed on the outer periphery of the resin pipe 2a is the same as in the above embodiment. Other configurations are the same as those in the above-mentioned embodiment.

The composite structural member 1a according to this embodiment is shown in FIG.
In addition to having the same effect as the embodiment shown in FIG. In this embodiment, since both ends of the metal pipe 4a are exposed, an external force such as a load can be directly applied to the exposed metal pipe, which may be advantageous in strength.

Next, a third embodiment of the present invention will be described. As shown in FIG. 5, the composite structural member 1b of the present embodiment.
Then, unlike the embodiment shown in FIGS. 1 to 3, the resin pipe 2b
The metal pipe 4b, to which the blind plates 8b, 8b are joined, is previously inserted into the through hole 10b, and the metal pipe 4b is mounted in the mold to perform the reaction injection molding for forming the coating layer 6b.

In this embodiment, at the time of reaction injection molding, the metal pipe 4b is placed in the mold, and a difference in thermal shrinkage between the metal pipe and the reaction injection molded product occurs. The resin pipe 2b is attached, and the metal pipe 4
The outer periphery of b is not in direct contact with the reaction injection molded product forming the coating layer 6b, so there is little risk of residual stress occurring in the molded product, and there is less risk of deformation or cracking of the molded product.

Other configurations and operations of this embodiment are the same as those of the above embodiment. Next, a fourth embodiment of the present invention will be described. In this embodiment, as shown in FIG. 6, the resin pipe 2c has spiral recesses 18 and projections 19 on the outer and inner circumferences.
Is formed, and the other structure is similar to that of the embodiment shown in FIGS. 1 to 3, 4 or 5.

In this embodiment, since the spiral concave portion 18 and the convex portion 19 are formed on the outer periphery of the resin pipe 2c, the adhesion with the coating layers 6, 6a and 6b is further improved. When inserting a metal pipe having a diameter substantially equal to the inner diameter of the resin pipe, the elasticity of the recess 18 allows the metal pipe to be easily inserted, and the inserted metal pipe is firmly fixed by the recess 18. In addition, when a metal pipe having a sealed tip is inserted, air easily flows out along the convex portion 19, and the insertion is easy. Further, even if there is some shrinkage, the elasticity of the resin pipe facilitates insertion of the metal pipe.

Next, a fourth embodiment of the present invention will be described. In the embodiment shown in FIG. 7, for example, when the rod-shaped composite structural member 1a of the embodiment shown in FIG. 4 is arranged at four positions in the circumferential direction and the coating layer 6a shown in FIG. The bottomed cylindrical tank portion 20 is integrally molded by reaction injection molding. A faucet 22 is attached to the bottom of the tank portion 20.

A lid member 24 is mounted on the upper portion of the tank portion 20. The lid member 24 is made of polynorbornene-based resin obtained by reaction injection molding performed in a process different from that of the tank unit 20. The lid member 24 has a filling cap 2
6 and an air bleeding cap 28 are attached.

Composite structural member 1a constituting the tank section 20
The metal pipe 4a protruding upward from the lid member 24 is also projected from the lid member 24. Bases 30 are attached to the lower ends of the metal pipes 4a protruding downward from the composite structural member 1a. Composite structural member 1 according to the present embodiment
The liquid container 32 having a can be stacked and stored by placing the base 30 of the other container 32 on the upper end of the metal pipe 4a. One container 32 is 1
In the case where 4 tons of liquid can be stored, a weight of more than 3 tons acts on the lowermost container 32 in the case of stacking 4 tons of liquid, but the container of this embodiment has sufficient strength. However, it is also possible to stack four layers.

Furthermore, since there is a gap between the bottom surface of the tank portion 20 and the installation surface of the liquid container 32, it is easy to move the liquid container 32 with a forklift. In addition,
The present invention is not limited to the embodiment described above,
Various modifications can be made within the scope of the present invention.

For example, the cross section of the resin pipe and the metal pipe is not limited to a rectangle, but may be a circle, an ellipse, a polygon, or the like. The overall shape of the composite structural member is not limited to the linear rod shape, and various modes such as a flat plate shape, a pallet shape, a curved rod shape, a curved plate shape, a container shape, and a three-dimensional solid shape can be adopted. Moreover, the composite structural member according to the present invention may be used only for a part of a molded product.

[0045]

As described above, according to the present invention, an external force such as a load applied to a structural member can be received by a metal pipe, so that the metal pipe has sufficient mechanical strength to withstand the intended use. Further, the coating layer formed on the outer periphery of the metal pipe is composed of a polynorbornene-based resin obtained by a reaction injection molding method, and the polynorbornene-based resin has sufficient mechanical strength and impact resistance. Therefore, cracks or cracks do not occur against external force such as load. Furthermore, by combining the metal pipe and the polynorbornene-based resin coating layer, the mechanical strength is improved as compared with the metal pipe alone. Furthermore, since the polynorbornene-based resin that constitutes the coating layer has a specific gravity of 1.1 or less, which is lighter than ordinary plastics, the weight of the entire structural member can be reduced.

By using a polyolefin resin pipe as the resin pipe, when the coating layer is formed by reaction injection molding of polynorbornene resin, the coating layer is well fused to the resin pipe. Also, with a resin pipe,
Since the heat shrinkage rate of the polynorbornene-based resin obtained by the reaction molding is almost equal, as a result of the reaction injection molding for forming the coating layer on the outer periphery of the resin pipe, the residual stress generated in the reaction injection molded resin is extremely small, It is possible to effectively prevent deformation such as distortion and cracking of the molded product. Also, the dimensional accuracy of the molded product is improved.

Further, when the composite structural member is discarded, the respective resources can be easily recycled by forcibly extracting the metal pipe from the resin pipe. That is, the composite structural member according to the present invention is easy to disassemble, and has excellent workability and economy in the resource recycling process.

The composite structural member according to the present invention includes a part of a liquid container, a pallet for transferring a manufactured product, a caster for transferring a product, a support stand for supporting a product, a holding arm for holding a product, etc. Can be suitably used as a structural member constituting the above, or a structural member that is a part of a building, a building, or a civil engineering structure.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing a manufacturing process of a composite structural member according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of essential parts showing the next manufacturing process of the composite structural member shown in FIG.

FIG. 3 is a cross-sectional view of an essential part showing the next manufacturing process of the composite structural member shown in FIG.

FIG. 4 is a cross-sectional view of essential parts of a composite structural member according to another embodiment of the present invention.

FIG. 5 is a cross-sectional view of essential parts of a composite structural member according to still another embodiment of the present invention.

FIG. 6 is a side view of a resin pipe used for a composite structural member according to still another embodiment of the present invention.

FIG. 7 is a perspective view of a main part of a tank using a composite structural member according to an embodiment of the present invention.

[Explanation of symbols]

 1, 1a, 1b ... Composite structural member 2, 2a-2c ... Resin pipe 4, 4a, 4b ... Metal pipe 6, 6a, 6b ... Covering layer 8, 8a, 8c ... Blind plate 10, 10a, 10b ... Through hole 12 , 14, 16 ... Plug 18 ... Spiral convex portion 20 ... Tank portion 22 ... Faucet 24 ... Lid member 26 ... Injection cap 28 ... Air bleeding cap 30 ... Base 32 ... Liquid container

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Claims (2)

[Claims] 1. A resin pipe, a coating layer covering the outer periphery of the resin pipe so as not to block the through hole of the resin pipe, and a metal pipe removably inserted into the through hole of the resin pipe. A composite structural member having the coating layer made of a polynorbornene-based resin obtained by a reaction injection molding method. 2. A step of forming a coating layer on the outer circumference of a resin pipe having a through hole by reaction injection molding using a norbornene-based resin so as not to block the through hole, and after molding the coating layer. A step of inserting a metal pipe into the through hole of the resin pipe and adhering the metal pipe to the through hole of the resin pipe, if desired.