JPH0792170B2 - Corrugated pipe fitting - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a joint for watertightly joining the ends of a corrugated pipe having spiral irregularities formed on its peripheral surface.

TECHNICAL BACKGROUND OF THE INVENTION AND PROBLEMS OF THE INVENTION Since the corrugated pipe has spiral irregularities on its peripheral surface and is rich in elasticity, it is mainly used for drainage when constructing golf courses, residential land, parks, etc. It is used as a pipe and is buried underground. In order to use this corrugated pipe as a drainage pipe or the like, it is necessary to join the ends of each corrugated pipe in a watertight manner. A corrugated pipe joint is used as a member for watertightly joining the ends of each corrugated pipe.

The corrugated pipe joint has a cylindrical shape, a semi-cylindrical shape, or a three-part cylindrical shape.The outer peripheral surfaces of both ends of the corrugated pipe that are butted are tightened with packing to make the corrugated pipe ends watertight. Join them.

As a conventional corrugated pipe joint, one in which a metal plate such as an iron plate is formed into a cylindrical shape, a semi-cylindrical shape, or a three-section cylindrical shape is known. However, such a corrugated pipe joint formed of a metal plate has problems such as rust and the like, and has a disadvantage that it is complicated to handle because it is relatively heavy.

Therefore, recently, a corrugated pipe joint made of synthetic resin has been proposed. However, corrugated pipe joints made of synthetic resin do not have sufficient tensile strength and bending rigidity to withstand the intended use, so corrugated pipe joints made of glass fiber reinforced plastic (FRP) are used. It is used a lot. FRP corrugated pipe joints are molded by the hand lay-up method.

The FRP corrugated pipe joint formed by the hand lay-up method as described above has an advantage that it has tensile strength and bending rigidity to withstand the intended use. However, such an FRP corrugated pipe joint has the following disadvantages.

First of all, the FRP corrugated pipe joint has high bending rigidity but lacks flexibility, and depending on the finished size, a gap is created between the outer ends of the joints of the corrugated pipe. There was a risk that the outer circumference of the end could not be tightened as a whole and the watertightness would be partially reduced. In addition, since the flexibility is insufficient, it is not possible to elastically deform the FRP corrugated pipe joint into, for example, the corrugated pipe during product inventory or during transportation, and the volume for stock or transportation It was inconvenient because it took up a lot of space. Further, there is a problem that it is easily broken when it receives an impact during work.

Secondly, in such a corrugated pipe joint made of FRP, since glass fibers are mixed, the specific gravity is increased, and it is still heavy and inconvenient to handle. Further, since the glass fibers are mixed in this way, the end portions of the glass fibers are exposed from the surface of the corrugated pipe joint,
There is a risk of injuring the hands of workers, and there is a problem in terms of work safety.

Thirdly, such a corrugated pipe fitting made of FRP is molded by the hand lay-up method performed manually,
There is a risk that defective products may occur depending on the degree of skill of the operator, and it is not suitable for mass production.

The object of the present invention is to solve such inconveniences all at once, and it is possible to join the joining ends of the corrugated pipe to each other in a good watertight state, and moreover, the specific gravity is light and the handling is easy. At the same time, it is an object of the present invention to provide a corrugated pipe joint which is excellent in work safety and shock resistance, does not take up a lot of space during stocking or transportation, and is easy to manufacture and can be mass-produced.

SUMMARY OF THE INVENTION In order to achieve such an object, the present invention is directed to the outer circumference of both end portions of these corrugated pipes in a state where the end portions of the corrugated pipes having spiral irregularities formed on the circumferential surface are butted against each other. In a corrugated pipe joint that tightens and joins both ends of a corrugated pipe, a reaction stock solution containing a norbornene-based monomer having three or more ring bodies is subjected to ring-opening polymerization in a mold to cover the outer periphery of both ends of the corrugated pipe. Part, a protrusion that is formed in the body portion and that engages with a recess formed in the outer peripheral surface of the corrugated pipe, and flange portions that are formed at both circumferential ends of the body portion are integrally molded. Is characterized by.

According to such a corrugated pipe joint according to the present invention, since the corrugated pipe joint is formed by molding a norbornene-based monomer having three or more ring bodies by a reaction injection molding method, a reinforcing material such as glass fiber is used. Therefore, the corrugated pipe joint has tensile strength, bending rigidity, and impact resistance that can withstand the intended use without being mixed. Moreover, in the corrugated pipe joint according to the present invention in which no glass fiber or the like is mixed, the flexibility is improved as compared with the conventional product, and when used, the end pipe outer peripheral surface of the corrugated pipe is closely adhered and sealed. As a result, the corrugated pipe joint can be elastically deformed and put into the corrugated pipe during stock or transportation, and the stock volume or the transport volume can be reduced. Further, since the structure does not include a reinforcing material such as glass fiber, the corrugated pipe joint has a low specific gravity and is easy to handle, and the glass fiber or the like is not exposed on the surface to hurt an operator's hand. Moreover, since the projections formed on the body forming the corrugated pipe joint according to the present invention engage with the recesses formed on the outer peripheral surface of each corrugated pipe, the corrugated pipes are mutually It does not easily come off, and the engagement of the projection and the recess can reliably prevent the leakage of the fluid that leaks from the corrugated pipe joint end gap and flows out along the spiral recess. it can.

Furthermore, since the corrugated pipe joint according to the present invention is molded by the reaction injection molding method, it is easy to manufacture and mass production is possible.

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the present invention will be specifically described with reference to the drawings.

FIG. 1 is a perspective view showing a usage state of a corrugated pipe joint according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line II-II shown in FIG.

As shown in FIG. 1, a corrugated pipe joint 10 according to the present invention includes corrugated pipes 12, 14 each having spiral irregularities formed on the circumferential surface thereof, and the corrugated pipes 12 and 14 are abutted against each other at their ends. It is used when the outer peripheries of both end portions of the corrugated pipes 12 and 14 are clamped from the outside and the both end portions of the corrugated pipes 12 and 14 are liquid-tightly joined. The corrugated pipes 12 and 14 are used as drain pipes, for example, when constructing a golf course, a residential land, a park, etc., and usually have an outer diameter of 500 to 1000 mm. These corrugated pipes 12 and 14 are usually molded from plastic such as polyethylene or polypropylene.

The corrugated pipe joint 10 according to the present invention has a body portion 18 that covers the outer circumference of the corrugated pipes 12 and 14 around the butt ends 16. In this embodiment,
The body portion 18 has a semi-cylindrical shape, but is not limited to this,
It may have a cylindrical shape or a three-divided cylindrical shape.

Flange portions 20 are integrally formed at both ends in the circumferential direction of the body portion 18. Plural bolt through holes 22 are formed in the flange portion 20. This flange portion 20 is abutted with another flange portion 20, a bolt is inserted into the bolt through hole 22, and the body portion 18 is brought into close contact with the outer peripheries of the corrugated pipes 12 and 14 by tightening this bolt.

Reinforcing ribs 21 are provided at the joint between the flange portion 20 and the body portion 18.
Are integrally formed. In the present invention, since the corrugated pipe joint having sufficient tensile strength or bending strength is obtained by reaction injection molding a norbornene-based monomer having three or more ring members as described below, the reinforcing rib 21 is necessary. Can be of minimal size. As a result, the suppleness of the body portion 18 is improved, and the corrugated pipes 12 and 14 are easily adhered to each other to improve workability at the time of tightening and easily deformed. It is convenient because it can be inserted. Incidentally, in the conventional FRP corrugated pipe joint, it is necessary to provide a reinforcing rib along the outer circumference of the body portion 18, and from this point also, the flexibility of the body portion 18 is insufficient.

Particularly in the present invention, the corrugated pipe 1 is provided on the inner peripheral surface of the body portion 18.
The protrusion 24 that engages with the recess formed on the outer peripheral surface of the body 2, 14
It is formed integrally with 18. In the embodiment shown in FIG. 1, a total of four protrusions 24 are formed so that there are two rows in the axial direction of the body and two rows in the circumferential direction. The protrusion 24 engages with the recess of the corrugated pipes 12 and 14 to prevent the ends of the corrugated pipes 12 and 14 from being easily disengaged from each other. When the fluid flows out, it prevents the fluid from leaking along the spiral recess. Such a protrusion
The shape or the number of the 24 is not particularly limited, but the larger the number of the protrusions 24 is, the more the watertightness is improved and the mutual connection of the corrugated pipes is strengthened. However, from the viewpoint of economy, etc., as shown in FIG.
Is preferred. As shown in FIG. 2, a packing 26 is interposed between the inner circumference of the body portion 18 and the outer circumferences of the corrugated tubes 12, 14. As the material of the packing 26, a rubber material such as chloroprene rubber, nitrile rubber, natural rubber or the like is generally used, and a foamed body of these rubber materials is particularly preferable. In order to interpose such a packing 26 between the inner circumference of the body portion 18 and the outer circumferences of the corrugated pipes 12 and 14, after packing the packing 26 around the corrugated pipes 12 and 14, the packing 26 The corrugated pipe fitting 10 may be attached to.

(Norbornene-based monomer) The body portion 18 and the flange portion 2 in such a corrugated pipe joint 10
The 0 and the protrusions 24 are integrally molded by a so-called reaction injection molding method in which the reaction stock solution is injected into the mold and reacted in the mold. In the present invention, this reaction stock solution contains a norbornene-based monomer having three or more ring bodies. By having three or more rings, the tensile strength and bending rigidity required for the corrugated pipe joint can be satisfied.

Examples of the norbornene-based monomer having a tricycle or more include tricycles such as dicyclopentadiene and dihydrodicyclopentadiene, tetracycles such as tetracyclododecene, pentacycles such as tricyclopentadiene, and tetracyclopentadiene. Examples include heptacycles and the like. Of course, these alkyl substitution products may be sufficient.

These norbornene-based monomers may be used alone or in combination of two or more. From the viewpoint of economy, it is preferable that the content of zinc pentapentene is 50% or more.

The tricyclic or higher norbornene-based monomer can also be obtained by heat-treating dicyclopentadiene. (Japanese Patent Application No. 62-65669). The heat treatment conditions include dicyclopentadiene in an inert gas atmosphere of 120 to 250
Examples include a method of heating at a temperature of 0.5 ° C. for 0.5 to 20 hours. By this heat treatment, a monomer mixture containing pentacyclopentadecadiene and unreacted dicyclopentadiene is obtained.

In addition, a bicyclic norbornene-based monomer such as 2-norbornene or 5-methyl-2-norbornene capable of ring-opening polymerization with one or more of the above tricyclic or higher norbornene-based monomers, or cyclobutene, cyclopentene, cyclopentadiene, Monocyclic cycloolefins such as cyclooctene and cyclododecene can be used as long as the object of the present invention is not impaired.

(Metathesis Catalyst System) It is preferable to add a catalyst and an activator to the reaction liquid to be subjected to reaction injection molding. This catalyst may be any metathesis catalyst system known as a catalyst for bulk polymerization of norbornene-based monomers (for example, JP-A-58-127728 and JP-A-58-12).
9013, 59-51911, 60-79035, 60-186511
No. 61-126115, etc.), but there is no particular limitation.

As the metathesis catalyst, tungsten, molybdenum,
Examples thereof include halides such as tantalum, oxyhalides, oxides, organic ammonium salts, and the like. Suitable examples are tungsten hexachloride, tungsten oxytetrachloride, tungsten oxide, tridodecyl ammonium tungstate, methyl tricapryl ammonium. Tungsten compounds such as tungstate, tri (tridecyl) ammonium tungstate, trioctylammonium tungstate: molybdenum pentachloride, molybdenum oxytrichloride, tridodecylammonium molybdate, methyltricaprylammonium molybdate, tri (tridecyl) ammonium molybdate. Molybdenum compounds such as trioctyl ammonium molybdate: tantalum compounds such as tantalum pentachloride. Among them, it is preferable to use a catalyst that is soluble in the norbornene-based monomer used in the reaction, and organic ammonium salts are preferred from the viewpoint. When the catalyst is a halide, the catalyst can be solubilized by pretreatment with an alcohol compound or a phenol compound. If necessary, Lewis base such as benzonitrile or tetrahydrofuran, acetylacetone,
A chelating agent such as alkyl acetoacetate can be used in combination, which can prevent premature polymerization.

Examples of the activator (cocatalyst) include alkylaluminum halides, alkoxyalkylaluminum halides, aryloxyalkylaluminum halides, organic tin compounds, and the like. Suitable examples are ethylaluminum dichloride, diethylaluminum monochloride, ethylaluminum. Sesquichloride, diethyl aluminum iodide, ethyl aluminum diiodide, propyl aluminum dichloride, propyl aluminum diiodide, isobutyl aluminum dichloride, ethyl aluminum dibromide, methyl aluminum sesqui chloride, methyl aluminum sesquibromide, tetrabutyl tin, alkyl aluminum halide and Preliminary reaction products with alcohol, etc.

Among these activators, alkoxyalkylaluminum halides and aryloxyalkylaluminum halides have an appropriate pot life at room temperature even when the catalyst components are mixed, and thus are advantageous in operation (for example,
JP-A-59-51911). In the case of alkylaluminum halide, there is a problem that polymerization will start immediately when a catalyst is mixed, but in that case, an activator and a regulator such as ethers, esters, ketones, nitriles and alcohols are used together. By doing so, the initiation of polymerization can be delayed (for example, JP-A-58-129013 and 61-120814).
issue). If these regulators are not used, it is necessary to give consideration to the equipment and operation so that even those with a short pot life can be used. However, in the case of a catalyst system having a short pot life, it is difficult to efficiently remove the heat of reaction because the reaction proceeds rapidly, so the pot life at 25 ° C is 5 minutes or more, preferably 10 minutes or more, and more preferably Is
It is better to use the one for 30 minutes or more.

In addition to a catalyst and an activator, halogenated hydrocarbons such as chloroform, carbon tetrachloride, hexachlorocyclopentadiene and the like may be used in combination (for example, JP-A-60-790).
No. 35). Further, a halide such as tin tetrachloride, silicon tetrachloride, magnesium chloride or germanium chloride may be used in combination.

The metathesis catalyst is usually used in an amount of about 0.01 to 50 mmol, preferably 0.1 to 10 mmol based on 1 mol of the norbornene-based monomer. The activator (cocatalyst) is usually used in the range of 0.1 to 200 (molar ratio), preferably 2 to 10 (molar ratio) with respect to the catalyst component.

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.

(Polymerization conditions) In the present invention, a corrugated pipe joint is formed by a polymerization method in which a norbornene-based monomer is introduced into a mold having a predetermined shape and bulk polymerization is performed in the presence of a metathesis catalyst system in the mold. It suffices if it is substantially bulk polymerization, and a small amount of an inert solvent may be present.

In a preferred method for producing a corrugated pipe joint, the norbornene-based monomer is divided into two liquids and placed in another container, a metathesis catalyst is added to one, and an activator is added to the other to prepare two types of stable reaction solutions. To do. The two types of reaction solutions are mixed and then poured into a mold having a predetermined shape, where ring-opening polymerization is started in the form of a block to obtain a corrugated pipe joint.

In the present invention, a collision mixing device conventionally known as a RIM molding device can be used for mixing two kinds of reaction solutions. In this case, the containers containing the two types of reaction solutions serve as separate flow sources. Two kinds of flow RI
The mixing head of the M machine mixes instantaneously, then it is poured into a hot mold, whereupon it is bulk polymerized to obtain the corrugated pipe fitting according to the invention.

Thus, although an impingement mixing device can be used, a feature of the invention is that it is not limited to such mixing means. If the pot life at room temperature is longer than 1 hour, after mixing the two reaction solutions in a mixer, inject or inject the preheated mold once or several times. (For example, JP-A-59-51911)
No.). In the case of this system, the device can be downsized as compared with the collision mixing device, which is economical,
It also has the advantage that it can be operated at low pressure.

Further, the present invention is not limited to the case of using two kinds of reaction solutions. As those skilled in the art can easily understand,
For example, various modifications are possible such as putting the reaction solution and the additive in the third container and using it as the third flow.

The mold temperature is 50 ° C or higher, preferably 60 to 200 ° C, particularly preferably 90 to 130 ° C.

Mold pressure is usually in the range of 0.1 to 100 Kg / cm ² .

The polymerization time may be appropriately selected, but is usually shorter than about 20 minutes, preferably 5 minutes or less, but may be longer than that.

The polymerization reaction components must be stored and operated under an atmosphere of an inert gas such as nitrogen gas. The molding die may or may not be sealed with an inert gas.

(Arbitrary component) The corrugated pipe of the present invention is prepared by blending various additives such as a filler, a pigment, a colorant, an antioxidant, a polymer modifier such as an elastomer or a dicyclopentadiene-based thermopolymer resin. The properties of the joint can be modified.

The additives are mixed in advance with either one or both of the reaction solutions, or placed in the cavity of the mold.

Fillers include inorganic fillers such as glass, carbon black, talc, calcium carbonate and mica.

As antioxidants, there are various antioxidants for plastics and rubber such as phenol-based, phosphorus-based, amine-based and the like. These antioxidants may be used alone or in combination. The blending ratio is 0.5% by weight or more, preferably 1 to 3% by weight based on the norbornene-based polymer.

Polymer modifiers include elastomers and thermopolymerized DCP resins. For example, blending an elastomer can increase the impact strength of the polymer, and blending a thermopolymerized DCP resin can further improve the flexural modulus. The polymer modifier is usually added to the reaction solution and dissolved before use.

As the elastomer, natural rubber, polybutadiene, polyisoprene, styrene-butadiene copolymer (SB
R), styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), ethylene-propylene-dienter-
Polymer (EPDM), ethylene vinyl acetate copolymer (EV
A) and their hydrides.

If the reaction solution containing the monomer has a low viscosity by adding an elastomer or DCP-based thermopolymer resin,
The viscosity of the reaction solution can be adjusted to an appropriate value. Further, since these polymer modifiers lower the freezing point of the monomer reaction solution, the monomer reaction solution does not solidify even when a monomer having a high freezing point is used, and the operability in reaction injection molding is improved. On the contrary, when the viscosity of the monomer reaction solution is too low, it is possible to adjust the viscosity to an appropriate level by adding the dicyclopentadiene resin, so that the operability is similarly modified.

The compounding ratio of these polymer modifiers can be appropriately determined, but in the case of an elastomer, it is usually 0.5% with respect to 100 parts by weight of the monomer.
~ 20 parts by weight, preferably 1-15 parts by weight, thermal polymerization DC
In the case of P resin, it is 0.5 to 150 parts by weight, preferably 20 to 50 parts by weight.

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. Parts and% are based on weight unless otherwise specified.

Example 1 A styrene-isoprene block copolymer (Quintac 3420, manufactured by Zeon Corporation) was dissolved in dicyclopentadiene (DCP) to obtain a monomer solution having a rubber content of 3%. This solution was divided into two parts, and to one side, diethylaluminum chloride (DEAC) was added to DCP at a concentration of 41 mmol and n-propyl alcohol at a concentration of 49.2 mmol to prepare a solution A.

On the other hand, tri (dodecyl) ammonium molybdate was added to DCP so as to have a concentration of 21 mmol, and this was designated as solution B.

Both reaction solutions were mixed at a ratio of 1: 1 using a collision mixing device into a mold heated to 90 ° C and having a space volume for molding the corrugated pipe joint 10 shown in Fig. 1, and then injected. Injection was performed at a pressure of 40 kg / cm ² . The injection time was about 7 seconds. Thirty seconds after the completion of injection, the reaction rapidly started with heat generation. Then, the reaction was performed in the mold for a total of 3 minutes. These series of operations were carried out under a nitrogen gas atmosphere.

The resulting glass transition temperature of each molded article (Tg) of about 85 ° C., a tensile strength of 500 kg / cm ^2, the flexural modulus was 19,000kg / cm ^2. The ratio was 1.03.

Next, the results of experiments conducted to confirm the technical effects of the corrugated pipe joint thus obtained will be shown.

Watertightness test A polyethylene corrugated pipe having a diameter of about 1000 mm and a length of 4 m × 2 is attached with the joint according to the present invention, and a height of 20 at 1 m on both ends.
A 0 mm cargo bed was placed and the joint was in contact with the ground. It was filled with water and kept for 1 hour, and it was confirmed that there was no problem with the watertightness.

Impact resistance test A test in which the joint according to the present invention was attached to the corrugated pipe of 4 m × 2 was subjected to a drop test from a position of 3 m in height. As a result of repeating the test with respect to 10 pieces, no crack was generated. For comparison, a similar test was performed on a conventional unsaturated polyester joint made by hand layup.
Three of the pieces were destroyed.

Advantages in Transport When simultaneously transporting a corrugated pipe with a diameter of 1000 m / m and the joint, the joint of the present invention was easily elastically deformed and put into the corrugated pipe with a diameter of 1000 m / m.

Since the hydrated FRP has high rigidity, it did not enter the corrugated pipe and required a large transport volume.

Safety Since the joint of the present invention does not use glass fiber, the mounting work was easy. The surface was smooth with no glass fibers protruding, and the workers' hands were not damaged.

Effects of the Invention As described above, according to the corrugated pipe joint of the present invention, the corrugated pipe joint is formed by molding the norbornene-based monomer having three or more ring bodies by the reaction injection molding method. Therefore, the corrugated pipe joint has tensile strength, bending rigidity, and impact resistance capable of withstanding the intended use without the inclusion of a reinforcing material such as glass fiber. Moreover, in the corrugated pipe joint according to the present invention in which no glass fiber or the like is mixed, the flexibility is improved as compared with the conventional product, and when used, the end pipe outer peripheral surface of the corrugated pipe is closely adhered and sealed. And the corrugated pipe joint can be elastically deformed into the corrugated pipe at the time of inventory or transportation,
Stock volume or transportation volume can be reduced. Further, since the structure does not include a reinforcing material such as glass fiber, the corrugated pipe joint has a low specific gravity and is easy to handle, and the glass fiber or the like is not exposed on the surface to hurt an operator's hand. Moreover, since the projections formed on the body forming the corrugated pipe joint according to the present invention engage with the recesses formed on the outer peripheral surface of each corrugated pipe, the corrugated pipes are mutually It does not easily come off, and the engagement of the projection and the recess can reliably prevent the leakage of the fluid that leaks from the corrugated pipe joint end gap and flows out along the spiral recess. it can.

Furthermore, since the corrugated pipe joint according to the present invention is molded by the reaction injection molding method, it has excellent effects such as easy manufacture and mass production.

[Brief description of drawings]

FIG. 1 is a perspective view showing a usage state of a corrugated pipe joint according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line II-II shown in FIG. 10 …… Corrugated pipe joint, 12,14 …… Corrugated pipe 16 …… But end, 18 …… Body 20 …… Flange part, 24 …… Projection

Claims (1)

[Claims] 1. A corrugated tube having spiral corrugations formed on its peripheral surface, with the ends of the corrugated tube abutting each other, the outer ends of the corrugated tubes are clamped from the outside, and the both ends of the corrugated tube are joined. In the corrugated pipe joint, a ring-opening polymerization of a reaction stock solution containing a norbornene-based monomer having three or more ring bodies is performed in the mold, and a body portion covering both outer circumferences of both ends of the corrugated pipe is formed on the body portion. A corrugated pipe joint formed by integrally molding a protrusion that engages with a recess formed on the outer peripheral surface of the corrugated pipe, and flange portions that are formed at both circumferential ends of the body.