JPH1148352A - Method for repairing reactive injection molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out the rapid and flawless repair on-site of a part intended for repair such as a void formed on the surface of a protecting sleeve by embedding a polythiol curable epoxy resin additive into the part intended for repair such as the void formed on the surface of a reactive injection molding. SOLUTION: A polythiol curable epoxy resin additive is embedded into e.g. a void 60 or an unfilled part 62, when either of these parts 60, 62 is generated on the surface of a protecting sleeve 50 comprising a reactive injection molding of norbornene monomer. This adhesive is of a two-pack curable type, so that during a repair work, a chief agent and a curing agent are beforehand milled separately, on, for example, the surface of a polypropylene plate material and the respectively required amounts of the chief agent and the curing agent are mixed at a stage in which a part intended for repair is detected on the surface of the reactive injection molding to fill the part intended for repair with this mixture. The chief agent of the additive is composed of an epoxy oligomer with two or more epoxy groups in a molecule and the curing agent is of the polythiol type.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for repairing a reaction injection molded article, and more particularly, to a repair target portion such as a void or an unfilled portion formed on the surface of a protective sleeve made of a reaction injection molded article. To a method for repairing a reaction injection molded article that can be quickly and satisfactorily repaired even on site.

[0002]

2. Description of the Related Art Reaction injection molding (hereinafter also referred to as RIM).
In the method, two or more reaction stock solutions are mixed in a mixing chamber, fed into a cavity of a mold apparatus, and injection-molded while reacting in the mold apparatus. This RIM method is
It is suitably used for molding a polymer (molded article) from a norbornene-based monomer.

[0003] RIM molded articles are considered to be used in various technical fields because of their excellent impact resistance, low molding pressure and easy molding.

[0004]

For example, it has been proposed to join a synthetic resin-coated pipe by welding or the like, and to form a protective sleeve made of a reaction injection molded body around the joint. By covering the joint portion of the pipe with the protective sleeve, it is possible to prevent water or the like from entering the joint portion (welded portion) of the pipe, and it is possible to enhance the corrosion resistance of the joint portion.

However, on the outer periphery of the joint of the pipe,
It is difficult to form a protective sleeve made of a reaction injection molded body well in the field, and various methods such as devising a mold used for reaction injection molding and using a special material as a mold sealing material are used. A device has been proposed. However, voids and unfilled portions may still occur on the surface of the protective sleeve made of the reaction injection molded article.

The pipe having the protective sleeve attached thereto may be propelled in soil such as rubble or sand, and tapered portions are provided at both ends of the protective sleeve to reduce resistance during propulsion. However, it is difficult to completely fill the portion corresponding to the tapered portion with the reaction solution during RIM molding, and an unfilled portion often occurs in the tapered portion. In addition, the reaction injection molding mold is provided with a vent port, but bubbles of the reaction solution are likely to remain on the surface of the molded article located between the vent port and the vent port. Voids often occur.

[0007] If the pipe is constructed while leaving voids and unfilled portions generated when the protective sleeve is formed as it is, the corrosion protection function of the protective sleeve is reduced, and the pipe joint may be rusted. is there. In order to prevent such an inconvenience, it has been proposed that when a void or an unfilled portion occurs on the surface of the protective sleeve, the portion is filled with an adhesive and repaired.

[0008] However, the types of adhesives that can be favorably adhered to a reaction injection molded article of a norbornene-based monomer in particular are limited, and ordinary adhesives peel off from the surface of the reaction injection molded article, for example, when a pipe is propelled. There was a fear.

Therefore, it is conceivable to use an epoxy resin-based adhesive which is considered to be capable of adhering well to a reaction injection molded article of a norbornene-based monomer. The curing time of the epoxy-based adhesive is as long as about one day or more, which is not suitable for on-site construction. In addition, this type of adhesive has a soft surface after curing and is easily damaged when the pipe is propelled and installed, or after the pipe is installed, and there has been a demand for an improved repair effect.

The present invention has been made in view of such circumstances, and for example, a repair target portion such as a void or an unfilled portion formed on the surface of a protective sleeve made of a reaction injection molded article is provided.
An object of the present invention is to provide a method for repairing a reaction injection molded article that can be quickly and satisfactorily repaired even on site.

[0011]

Means for Solving the Problems In order to achieve the above-mentioned object, the present inventors have made intensive studies and as a result, by using a specific adhesive, particularly for a reaction injection molded article of a norbornene-based monomer. Finding a repair method for reaction injection molded products that can quickly repair voids and unfilled parts formed on the surface, and after repair, the repaired part does not peel off and the repaired part is less likely to be damaged Thus, the present invention has been completed.

That is, in the method for repairing a reaction injection molded article according to the present invention, a reaction injection obtained by mixing two or more reaction stock solutions, feeding the mixture into a mold cavity, and performing reaction injection molding in the mold. A repair target portion such as a void or an unfilled portion formed on the surface of the molded body is embedded with a polythiol-curable epoxy resin-based adhesive.

In the present invention, the polythiol-curable epoxy resin-based adhesive is a two-part curable adhesive, which comprises a main agent comprising an epoxy oligomer having two or more epoxy groups in a molecule and a polythiol-type curing agent. An adhesive that cures by mixing liquids.

The epoxy oligomer is not particularly limited, and bisphenol A type and polyglycidyl ether are the most common. From the viewpoint of quick curing, resorcinol / diglycidyl ether, tetraglycidylphenol, Preferred are bisphenol S / diglycidyl ether, aromatic carboxylic acid diglycidylesterol resorcinol / diglycidyl ether, bisphenol F methyl epichloro, cresol novolak, phenol novolak, and glycidylamine. The average molecular weight of the epoxy oligomer used in the present invention is preferably about 300 to 3000. Further, the epoxy equivalent is preferably about 100 to 400 g / eq. Further, the softening point is preferably about 5 to 100 ° C.

A solvent may be used to make the main ingredient liquid. Examples of the solvent include, but are not particularly limited to, ketones, for example, methyl ethyl ketone, methyl isobutyl ketone, diacetone alcohol, cyclohexanenone, other methyl glycol, methyl glycidyl acetate, ethylene glycol, cellosolve, short oil ester, xylene, toluene and the like. .

In the present invention, a polythiol-based (polymercaptan-based) curing agent is used as the curing agent, and specifically, PET (pentaerythritol tetrateoglycolate) manufactured by Nippon Kayaku and Dainippon Ink. Mercox MP-2290 (trade name), DPM-3-800LC (trade name) of Diamond Shamrock Co., Ltd., Tiocoll LP-3 (trade name: SH, polysulfide) of Toray Thiokol Co., Ltd., trade name of Yuka Shell Co. Epomate QX-
11. Showa Denko's TMTT (trimethylolpropane trithioglycolate), Showa Denko's PETT
(Pentaerythritol tetrathioglycolate), DPEHT (dipentaerythritol hexathioglycolate) manufactured by Showa Denko KK, and the like.

The viscosity of the base material and the curing agent (cps / 25 °)
C) is preferably in the range of about tens of thousands to hundreds of thousands. Further, it is preferable that the main agent and the curing agent are a combination of those having similar viscosities. The curing speed can be arbitrarily changed depending on the type and amount of the tertiary amine.

In the present invention, the reaction stock solution used in the reaction injection molding is not particularly limited, but includes urethane-based, urea-based, nylon-based, epoxy-based, unsaturated polyester-based, phenol-based and norbornene-based solutions. In particular, a norbornene system is preferable. As general molding conditions, the temperature of the reaction solution is 20 to 80 ° C., and the viscosity of the reaction solution is, for example, 5 cps to 30 at 30 ° C.
00 cps, preferably about 100 cps to 1000 cps.

In such molding, a reinforcing material (molded body) can be manufactured by placing a reinforcing material in a mold in advance and supplying a reaction liquid therein to polymerize. As the reinforcing material, for example, glass fiber, aramid fiber, carbon fiber, ultra high molecular weight polyethylene fiber,
Examples include metal fibers, polypropylene fibers, aluminum-coated glass fibers, cotton, acrylic fibers, boron fibers, silicon carbide fibers, and alumina fibers. These reinforcing materials can be used in various shapes, such as those obtained by forming a long fiber or chopped strand into a mat, woven into a cloth, or remaining in a chopped shape. It is preferable that the surface of these reinforcing materials is treated with a coupling agent such as a silane coupling material in order to improve the adhesion to the resin. The amount to be used is not particularly limited, but is usually 10% by weight or more, preferably 20 to 60% by weight of the total weight of the molded article.

Also, various additives such as an antioxidant, a filler, a pigment, a colorant, a foaming agent, a flame retardant, a sliding agent, an elastomer, a dicyclopentadiene-based thermopolymerized resin and a hydrogenated product thereof are blended. Thereby, the properties of the obtained polymer can be modified.

As the antioxidant, there are various antioxidants for plastics / rubbers such as phenol type, phosphorus type and amine type. Fillers include inorganic fillers such as milled glass, carbon black, talc, calcium carbonate, aluminum hydroxide, mica, potassium titanate, calcium sulfate, and the like. Examples of the elastomer include natural rubber, polybutadiene, polyisoprene, styrene-butadiene copolymer (SBR), styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), and ethylene- Examples include propylene-diene terpolymer (EPDM), ethylene vinyl acetate copolymer (EVA) and hydrides thereof.

The additive is usually mixed in advance with one or both of the reaction solutions. The polymerization time may be appropriately selected, and is usually from 20 seconds to 20 seconds after the completion of the injection of the reaction solution.
Minutes.

In the present invention, the temperature of the mold during the reaction injection molding is preferably from 10 to 150 ° C., more preferably from 20 to 120 ° C., and further preferably from 30 to 10 ° C.
It is controlled at 0 ° C. Before injecting the unreacted reaction solution into the mold, warm air is circulated inside the mold, and at least the inside of the cavity of the mold is heated to a predetermined temperature. The reaction stock solution may be poured into the cavity to perform the reaction injection molding. In particular, it is preferable that after the insert member integrated with the reaction injection molded body is arranged inside the cavity of the mold apparatus, warm air is circulated inside the cavity of the mold apparatus. After arranging a reinforcing material integrated with the reaction injection molded body inside the cavity of the mold, it is also preferable to flow warm air into the cavity of the mold apparatus. By preheating these insert members or reinforcing materials, the adhesion between them and the molded body is improved.

Although the hot air is inexpensive when the air is heated to a predetermined temperature, it may be a hot air that is heated with an inert gas such as nitrogen gas. The temperature of the hot air flowing through the cavity of the mold is not particularly limited, but is preferably 30 to 1
The temperature is 20 ° C, more preferably 40 to 80 ° C. If the temperature is too low, a reaction injection molded article of good quality cannot be obtained, and if it is too high, it is uneconomical. The hot air that has flowed through the cavity of the mold device may be discharged into the atmosphere from the vent port of the mold device. May be circulated into the cavity.

The material of the mold used in the present invention is as follows.
The material is not particularly limited, and is not limited to metals such as stainless steel, aluminum, and nickel electroformed, but may be a synthetic resin or other materials. Reaction injection molding can be performed at a relatively low pressure, and it is not always necessary to use a highly rigid mold.

When the mold is made of a synthetic resin, the synthetic resin is not particularly limited, and may be polyethylene (LDP).
E, MDPE, HDPE, ultra-high molecular weight PE), polystyrene, polypropylene, polyvinyl chloride, urethane, epoxy, phenol, polyester and the like.

[0027]

For example, the ends of a synthetic resin-coated pipe may be welded to each other on site, and a protective sleeve made of a reaction injection molded article may be formed on the outer periphery of the joint. However, it is difficult to form a good reaction injection molded body on the outer periphery of the pipe, and voids and unfilled portions may be generated on the surface. In addition, even in a reaction injection molded article used for other purposes, voids or unfilled portions may occur on the surface depending on molding conditions and the like. Disposing of such a reaction injection molded article is a waste of material and is against the demand for resource saving.

Therefore, in the present invention, a polythiol-curable epoxy resin-based adhesive is embedded in a portion to be repaired such as a void or an unfilled portion formed on the surface of such a reaction injection molded article. Since this adhesive is a two-part curing type, at the time of repair, for example, the main agent and the curing agent were separately kneaded on the surface of a polypropylene plate material, and a repair target portion was found on the surface of the reaction injection molded body. At the stage, these are mixed in a necessary amount and filled in the repair target portion.

If the adhesive according to the present invention is used, after mixing the main agent and the curing agent, at 20 ° C., about 2 minutes to 30 minutes
Hardens in about a minute. Therefore, the repair is completed in a short time, and in the case of repairing the protective sleeve of the pipe, the protective sleeve can be promptly propelled and constructed together with the pipe, so that the construction work can be shortened.

In addition, the repaired portion with the adhesive according to the present invention has particularly good adhesion to the reaction injection molded article of norbornene-based monomer and does not peel off during or after construction. Further, the cured surface of the adhesive, which is the repaired portion, is sufficiently hard as compared with a polyamide-curable epoxy-based adhesive or the like, and does not cause scratches or the like during or after construction.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments shown in the drawings.

FIG. 1 is a schematic sectional view of a mold apparatus used in a reaction injection molding method according to one embodiment of the present invention, and FIG. 2 shows an example of a protective sleeve obtained by using the mold apparatus shown in FIG. It is an outline sectional view.

As shown in FIG. 1, a mold apparatus 2 according to the present embodiment is an apparatus for molding a protective sleeve made of a reaction injection molded body around the joint of pipes 30, 30. It has a first mold 4 and a second mold 6 that can be divided. These dies 4 and 6 may be made of an aluminum casting, but are made of a synthetic resin in the present embodiment.

The first mold 4 has a semi-cylindrical first mold body 8 in which a cavity 40 (see FIG. 1) is formed by being combined with the second mold 6. At both ends of the first mold body 8, semi-cylindrical pipe holding parts 12, 1 are provided.
2 is integrally molded. The pipe holding parts 12, 12
The pipe 3 is formed smaller than the inner diameter of the first mold body 8.
It comes into close contact with the outer periphery of 0, 30. A taper portion 11 is formed integrally with a portion connecting the main body 8 and the pipe holding portion 12.

The second mold 6 has a semi-cylindrical second mold body 10 in which a cavity 40 is formed by being combined with the first mold 4. This second mold body 10
Are formed integrally with each other at both ends thereof. The pipe holding parts 14 and 14 are formed to be smaller than the inner diameter of the second mold body 10 and the pipes 30 and 3
It is designed to be in close contact with the outer periphery of 0. A tapered portion 13 is formed integrally with a portion connecting the main body 10 and the pipe holding portion 14.

A flange (not shown) is formed around each of the first mold 4 and the second mold 6.
The mating surfaces of the flanges are the split surfaces of the mold device, and the mold device 2 shown in FIG. 1 is assembled by abutting these surfaces.

In this embodiment, when the mold apparatus 2 is assembled, the mold body 10 of the second mold 6 located below
An injection port 26 is formed at the bottom of the injection hose 25.
The reaction stock solution is filled into the cavity 40 through the hole. Also, the first device located above the mold device 2
Two vent holes 20 are provided at the top of the mold 4 along the axial direction.
a and 20b are formed in communication with the cavity 40.

The first mold 4 and the second mold 6 are formed by vacuum molding, compression molding, injection molding and the like, respectively.
The synthetic resin constituting the molds 4 and 6 is not particularly limited, and examples include polyethylene (LDPE, MDPE, HDPE, ultrahigh molecular weight PE), polystyrene, polypropylene, polyvinyl chloride, urethane, epoxy, and phenol. .

It is preferable that the mold apparatus 2 configured as described above is heated to a predetermined temperature before or during the reaction injection molding, but in the present embodiment, the cavity of the mold apparatus before the reaction injection molding is used. Heating is performed by flowing warm air through the inside or by attaching a planar heater to the outer surface of the mold apparatus. As the planar heater, a silicon rubber heater is preferable.

Next, the reaction injection molding method according to this embodiment will be described. As shown in FIG. 1, in the present embodiment, first, the piping pipes 30, 30 are welded at the connection portions 36. The pipes 30, 30 have a metal pipe 32 made of, for example, a steel pipe, and the outer periphery thereof is covered with a resin layer 34 such as a polyethylene resin. Resin layer 34 for ease
Has been removed.

In the present embodiment, after connecting the connecting portions of the metal pipes 32 by welding, the outer periphery of the connecting portions 36 is covered with a heat-shrinkable tube 38 made of cross-linked polyethylene or the like.
Shrink by heating. Both ends of the tube 38 extend to the outer periphery of the end of the resin layer 34, and the connecting portion 3
6 completely covers the outer periphery of the metal pipes 32, 32 exposed in the vicinity. Even with this heat shrink tube 38 alone,
Although it is possible to prevent the metal pipes 32, 32 from being exposed, scratches and the like are likely to occur during use. Therefore, in this embodiment, a protective sleeve made of a reaction injection molded body is covered so as to cover the tube 38. Molding.

The protective sleeve is formed at the site where the pipes 30, 30 are connected by the following reaction injection molding method. As shown in FIG.
8 mounts the mold apparatus 2 on the outer periphery of the connection portion of the pipes 30 after the mounting. In the mold apparatus 2 of the present embodiment, the first mold 4 and the second mold 6 made of synthetic resin can be divided on the split surface, so that transport and storage are easy and light weight. In addition, it can be easily attached to the outer periphery of the joint between the pipes 30 at the site.

Before attaching the mold apparatus 2 to the outer periphery of the joint between the pipes 30, 30, the pipe holding section 1 of the mold apparatus 2
It is preferable to apply a sealant or the like for maintaining liquid tightness to the inner peripheral surfaces of the second and the second. By applying the sealant to the inner peripheral surfaces of the pipe holding portions 12 and 14, the gap between the inner peripheral surfaces of the pipe holding portions 12 and 14 and the outer peripheral surfaces of the pipes 30 and 30 is sealed well. In addition, it is preferable to apply the sealing agent also to the split surfaces of the dies 4 and 6.

The first mold 4 and the second mold 6 are clamped by tightening the flanges having the split surfaces with each other with fasteners such as bolts and nuts. In the present embodiment, the mold clamping pressure of the mold apparatus 2 is 0.5 to 15 kg /
cm ² .

After the mold device 2 composed of the first mold and the second mold 6 is mounted on the outer periphery of the connecting portion of the pipes 30, 30, the mold device 2 is heated by a flat heater or the like. When the mold apparatus 2 reaches a predetermined temperature, the reaction stock solution is filled into the cavity 40 of the mold apparatus 2 through the injection hose 25 and the injection port 26 by the mixer. The mixer mixes and discharges the reaction liquid A in one tank and the reaction liquid B in the other tank. The reaction liquid A and the reaction liquid B are mixed in the mixer, and the mixed liquid is mixed. , Hose 25
Then, the cavity 40 is filled through the injection port 26.

The reaction injection molding performed in the present embodiment is a reaction injection molding using a norbornene-based monomer. The monomer used is a norbornene such as dicyclopentadiene, dihydrodicyclopentadiene, tetracyclododecene, tricyclopentadiene or the like. It is a cycloolefin having a ring.

The metathesis catalyst that can be used in reaction injection molding using a norbornene-based monomer is
There is no particular limitation as long as it is a metathesis catalyst known as a catalyst for bulk polymerization of norbornene-based monomers such as organic ammonium molybdate such as tungsten hexachloride, or tridodecyl ammonium molybdate, or tri (tridecyl) ammonium molybdate, Organic ammonium molybdate is preferred.

As the activator (cocatalyst), JP-A-58-1983
127728, JP-A-4-226124,
JP-A-58-129003, JP-A-4-1452
There is no particular limitation as long as it is a known activator as disclosed in Japanese Patent No. 47, for example, alkyl aluminum halides such as ethyl aluminum dichloride and diethyl aluminum chloride, organic aluminum compounds such as alkoxyalkyl aluminum halides, and organic tin. And the like.

As preparations for the reaction injection molding, a reaction injection molding material mainly composed of a norbornene-based monomer, a metathesis catalyst and an activator was used to prepare a liquid B composed of a norbornene-based monomer and a metathesis catalyst, and the aforementioned norbornene-based monomer. Divided into two stable liquids, A liquid and activator,
Keep each in a separate tank.

In order to start the reaction injection molding, the mixer is controlled to mix the liquid A and the liquid B from the tank, and the mixed liquid is filled into the cavity 40 as a reaction liquid. The reaction stock solution filled in the cavity 40 is filled with the cavity 40
All over the interior.

At the stage when the reaction injection molding in the cavity 40 is completed and the molded body to be the protective sleeve is solidified, the first
If the mold 4 and the second mold 6 are divided by a split surface and opened,
As shown in FIG. 2, a protective sleeve 50 made of a reaction injection molded article of a norbornene-based monomer is obtained. Tapered portions 52, 52 are formed at both ends in the axial direction of the protective sleeve 50. In the reaction injection molding, the tapered portions 52, 52 are formed.
It is difficult to form a good shape of the unfilled portion 62.
May occur. In addition, bubbles in the reaction solution are likely to remain in a portion located between the vent ports 20a and 20b of the mold 4 shown in FIG. 1, and voids 60 are formed on the surface of the molded body as shown in FIG. There is.

In the present embodiment, the surface of the protective sleeve 50 made of a reaction injection molded article of a norbornene-based monomer is
When voids 60, unfilled portions 62, and the like occur, a polythiol-curable epoxy resin-based adhesive is embedded in those portions 60 and 62. Since this adhesive is a two-part curing type, at the time of repair, for example, the main agent and the curing agent were separately kneaded on the surface of a polypropylene plate material, and a repair target portion was found on the surface of the reaction injection molded body. At the stage, these are mixed in a necessary amount and filled in the repair target portion.

In the present embodiment, the main component of the adhesive is an epoxy oligomer having two or more epoxy groups in the molecule, and the curing agent is a polythiol type curing agent.

The epoxy oligomer is not particularly limited, and bisphenol A type and polyglycidyl ether are the most common, but from the viewpoint of quick curing, resorcinol / diglycidyl ether, tetraglycidylphenol, Preferred are bisphenol S / diglycidyl ether, aromatic carboxylic acid diglycidylesterol resorcinol / diglycidyl ether, bisphenol F methyl epichloro, cresol novolak, phenol novolak, and glycidylamine. The average molecular weight of the epoxy oligomer used in the present invention is preferably about 300 to 3000. Further, the epoxy equivalent is preferably about 100 to 400 g / eq. Further, the softening point is preferably about 5 to 100 ° C.

In order to make the main ingredient liquid, a solvent may be used in some cases. Although it does not specifically limit as a solvent, ketones, for example, methyl ethyl ketone, methyl isobutyl ketone, diacetone alcohol, cyclohexane non, other methyl glycol, methyl glycidyl acetate,
Examples include ethylene glycol, cellosolve, short oily esters, xylene, and toluene.

In the present invention, a polythiol-based (polymercaptan-based) curing agent is used as the curing agent. Specifically, PET (pentaerythritol tetrathioglycolate) (trade name) manufactured by Nippon Kayaku, Dainippon Ink Mercox MP-2290 (trade name), DPM-3-800LC (trade name) of Diamond Shamrock Co., Ltd., Tiocoll LP-3 (trade name: SH, polysulfide) of Toray Thiokol Co., Ltd., trade name of Yuka Shell Co. Epomate QX-
11. Showa Denko's TMTT (trimethylolpropane trithioglycolate), Showa Denko's PETT
(Pentaerythritol tetrathioglycolate), DPEHT (dipentaerythritol hexathioglycolate) manufactured by Showa Denko KK, and the like.

The viscosities of the base material and the curing agent (cps / 25 °)
C) is preferably in the range of about tens of thousands to hundreds of thousands. Further, it is preferable that the main agent and the curing agent are a combination of those having similar viscosities.

If the adhesive according to the present embodiment is used, after mixing the main agent and the curing agent, at 20 ° C., it takes about 2 minutes to
It cures in about 30 minutes. Therefore, the repair can be completed in a short time, and the protection sleeve 50 can be promptly propelled and constructed together with the pipe 30, so that the construction work can be shortened.

Moreover, the portion repaired by the adhesive according to the present embodiment has good adhesion to the norbornene-based monomer reaction injection molded body constituting the protective sleeve 50 and does not peel off during or after construction. Further, the cured surface of the adhesive, which is the repaired portion, is sufficiently hard as compared with a polyamide-curable epoxy-based adhesive or the like, and does not cause scratches or the like during or after construction.

In particular, since this protective sleeve 50 is made of a reaction injection molded article of a norbornene-based monomer, it has excellent impact resistance and does not crack or scratch even when disposed in the soil. Few.

Since the mold device 2 used in the reaction injection molding method of the present embodiment is a mold device made of a synthetic resin, it is lightweight, easy to handle even on site, and has good workability. Are better. Moreover, since the mold device 2 is molded from synthetic resin and is lightweight, it is convenient for transporting and storing the mold device 2 and further improves workability at the site.

It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified within the scope of the present invention. For example, the specific structure of the mold device is not particularly limited, and can be variously modified. In the above-described embodiment, voids and unfilled portions formed on the surface of the protective sleeve 50 made of a reaction injection molded article of a norbornene-based monomer were repaired. It can be suitably used when repairing a repair target portion such as a void or an unfilled portion formed on the surface of the body.

[0063]

EXAMPLES Hereinafter, the present invention will be described based on more detailed examples, but the present invention is not limited to these examples.

Example 1 Resin molds 4 and 6 each made of an aluminum mold and shown in FIG. 1 were prepared. An injection port 26 having an inner diameter of 19 mm is formed in the lower mold 6, and the injection port 26 is formed in the upper mold 4.
Vent ports 20a and 20b having the same inner diameter as those of the above were integrally molded.

Further, as the pipe 30 shown in FIG. 1, a steel metal pipe 32 covered with a resin layer 34 made of polyethylene resin was prepared. The outer diameter of the metal pipe 32 is 21
6.3 mm, the resin layer 34 is removed and the metal pipe 3
The axial length of the connection part where the surface of No. 2 was exposed was 450 mm.

On the outer periphery of the connecting portion, a mold apparatus 2 composed of molds 4 and 6 having an inner diameter of 265 mm and a length of 600 mm obtained by the blow molding was arranged. Prior to the arrangement of the mold 2, a surface treatment (rust removal) of Swedish Industrial Standard (SIS) St-3 is applied to the surface of the connection portion 36 with a disk sander, and the resin layers 34 and 3 near the connection portion 36 are provided.
The surface of No. 4 was roughened with sandpaper of about No. 80. Further, the periphery of the connection portion 36 by welding is covered with a heat-shrinkable tube 38 made of cross-linked polyethylene manufactured by Furukawa Electric Co., Ltd.
2 was brought into close contact with the outer peripheral surface.

After arranging the mold apparatus 2 on the outer periphery of the connecting portion of the pipes 30, 30, a hot air of 60 ° C. is sent from the injection port 26 before the reaction solution is injected into the cavity from the injection port 26.
Warm air was discharged from the vents 20a and 20b. As the hot air generator, a TKS hot air generator “TKS-15” manufactured by Takeko Seisakusho Co., Ltd. was used.

After confirming that the internal temperature of the mold 2 reached 50 ° C., the blowing of the warm air was stopped, and the unreacted solution was injected from the injection port 26 to perform the reaction injection molding.

The preparation of the reaction resin stock solution was performed as follows. That is, a mixed monomer consisting of 85% by weight of dicyclopentadiene (DCP) and 15% by weight of tricyclopentadiene was used, and a styrene-isoprene-styrene block copolymer (Clayton 1170, Shell 510 parts by weight and Irganox 1010, a phenolic antioxidant
(Made by Ciba-Geigy) and 2 parts by weight thereof were put into two containers, and one of them was mixed with 40 mmol of diethylaluminum chloride (DEAC), 44 mmol of n-propanol, and tetrachloride with respect to the mixed monomer. Silicon was added to a concentration of 20 mmol (Solution A).
On the other hand, tri (tridecyl) ammonium molybdate was added to the mixed monomer at a concentration of 10 mmol (solution B).

The liquid A and the liquid B are sent to the mixer by a gear pump so as to have a volume ratio of 1: 1. Next, the injection pressure of 2.0 kg / g is injected into the cavity 40 from the injection port 26 of the mold apparatus 2. Injected below cm ² .

The temperature inside the cavity of the mold apparatus 2 is 11
After 0 seconds, the maximum temperature was reached. Ten minutes after the injection of the stock solution, the mold was opened to obtain a protective sleeve (reaction injection molded body) 50 shown in FIG.

When such reaction injection molding was repeated five times, two of the reaction injection moldings were performed, and the void 60 and the unfilled portion 62 were formed on the surface of the protective sleeve 50 made of the obtained reaction injection molded body. Sometimes occurred.

In this embodiment, in such a case,
The void 60 and the unfilled portion 62 were filled with "Quick Mender" (trade name) manufactured by Konishi Bond, which is a polythiol-curable epoxy resin-based adhesive. The main component of this epoxy resin-based adhesive is mainly composed of polyglycidyl ether, and its viscosity is 170,000 to 230,000 cps.
(25 ° C.), and the curing agent has a polythiol-based component as a main component and a tertiary amine added thereto.
000-330,000 cps (25 ° C.).
At the time of repair, the main agent and the hardener are separately kneaded on a polypropylene plate in advance, and when the repair target portion is found, the main agent and the hardener are mixed 100 to 10 times.
The mixture was mixed at a weight ratio of 0, and filled in the portion to be repaired.

The time required for the repaired portion composed of the adhesive layer to harden was 13 minutes at 20 ° C. The hardness of the surface of the adhesive layer after curing was measured by JIS K7202 and found to be Rockwell hardness R-112.

Further, the pipe with the protective sleeve thus repaired was propelled and constructed in muddy water, returned to the original state for inspection again, and the repaired portion of the protective sleeve was observed. No peeling or scratches were observed.

Example 2 A protective sleeve was prepared in the same manner as in Example 1 except that the part to be repaired was filled with "Quick Set" (trade name) manufactured by Konishi Bond, which is a polythiol-curable epoxy resin adhesive. 50 repairs were made.

The main component of the epoxy resin-based adhesive is a polyglycidyl ether-based component having a viscosity of 30%.
000 to 70000 cps (25 ° C.), the curing agent was a polythiol-based main component, and the type and amount of the tertiary amine were changed as compared with Example 1. The viscosity was 30,000 to 70,000 cps. It was 60,000 cps (25 ° C.).

The time required for the adhesive embedded in the repair target to harden was 6 minutes at 20 ° C. The hardness of the surface of the adhesive layer after curing was measured in the same manner as in Example 1, and found to be Rockwell hardness R-113.

Further, the pipe with the protective sleeve thus repaired was propelled and constructed in muddy water, returned to the original state for inspection again, and the repaired portion of the protective sleeve was observed. No peeling or scratches were observed.

Example 3 A "Quick Set 30" manufactured by Konishi Bond Co., Ltd., which is a polythiol-curable epoxy resin-based adhesive, was used for the repair target.
The protective sleeve 50 was repaired in the same manner as in Example 1 except that (trade name) was filled.

The main component of the epoxy resin-based adhesive is a polyglycidyl ether-based resin having a viscosity of 20%.
000 to 40000 cps (25 ° C.), and the curing agent is a polythiol-based main component, in which the type and amount of the tertiary amine are changed as compared with Example 1, and the viscosity is 40000 to 40000 cps. It was 70000 cps (25 ° C.).

The time required for the adhesive embedded in the repair target to harden was 75 minutes at 20 ° C. The hardness of the surface of the adhesive layer after curing was measured in the same manner as in Example 1 and found to be Rockwell hardness R-111.

Further, the pipe with the protective sleeve thus repaired was propelled and constructed in muddy water, returned to the original state for inspection again, and the repaired portion of the protective sleeve was observed. No peeling or scratches were observed.

Comparative Example 1 A part to be repaired was "Y-7" manufactured by Tokyo Hamatite Co., Ltd., which is a polyurethane resin adhesive which is not an epoxy resin adhesive.
Repair of the protective sleeve 50 was performed in the same manner as in Example 1 except that “122-A / B” (trade name) was filled.

The time required for the adhesive embedded in the repair target to harden was at least 2 days at 20 ° C.
When the hardness of the surface of the adhesive layer after curing was measured in the same manner as in Example 1, it was Rockwell hardness R-92.

The pipe with the protective sleeve thus repaired was propelled and constructed in muddy water, returned to the original state for inspection again, and the repaired portion of the protective sleeve was observed. Peeling and missing were observed.

Comparative Example 2 The repair target portion was filled with "Hybon 3400 LI" (trade name) manufactured by Hitachi Chemical Co., Ltd., which was an epoxy resin-based adhesive but was produced by using an aliphatic polyamine as a curing agent. The protection sleeve 50 was repaired in the same manner as in the first embodiment.

The time required for the adhesive embedded in the portion to be repaired to be cured was at least one day at 20 ° C.
When the hardness of the surface of the adhesive layer after curing was measured in the same manner as in Example 1, it was Rockwell hardness R-107.

Further, the pipe with the protective sleeve thus repaired was propelled and constructed in muddy water, returned to the original state for inspection again, and the repaired portion of the protective sleeve was observed. Scratches were observed.

[0090]

As described above, according to the present invention, a void or the like is formed on the surface of a molded article, for example, when a protective sleeve made of a reaction injection molded article is molded on the outer periphery of a connection portion of a pipe. Even when an unfilled portion is likely to occur, the repair target portion such as a void or an unfilled portion can be quickly and satisfactorily repaired even on site.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a mold apparatus used in a reaction injection molding method according to one embodiment of the present invention.

FIG. 2 is a schematic sectional view showing an example of a protective sleeve obtained by using the mold device shown in FIG.

[Explanation of symbols]

 2 mold apparatus 4 1st mold 6 2nd mold 8 1st mold body 10 2nd mold body 12, 14 ... pipe holding part 20a, 20b ... vent port 26 ... inlet 30 ... Synthetic resin coated pipe 32 ... Metal pipe 34 ... Resin layer 36 ... Connection part 38 ... Heat shrinkable tube 40 ... Cavity 50 ... Protective sleeve 52 ... Tapered part 60 ... Void 62 ... Unfilled part

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hiroyuki Ohhama 88, Ono-cho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Japan Steel Pipe Works Co., Ltd.

Claims (1)

[Claims] 1. Voids or unfilled portions formed on the surface of a reaction injection molded body obtained by mixing two or more reaction stock solutions, feeding them into a mold cavity, and performing reaction injection molding in the mold. A method for repairing a reaction injection molded article, characterized by embedding a polythiol-curable epoxy resin-based adhesive in a repair target portion such as.