JPH09314609A - Production of reactive injection molded object having opening part and mold apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a reactive injection molded object having an opining part suppressed in the generation of burr at its opening part to the utmost, generating no voids, reduced in the area of a part requiring high dimensional accuracy and low in production cost and to provide a mold apparatus. SOLUTION: A seal groove 28 is formed to a part of a first or second mold 20 or 22 corresponding to the opening part 12 of a reactive injection molded object and a seal member 30 is fitted in the seal groove 28. The first and second molds 20, 22 are clamped and, in such a state that the gap between the first and second molds 20, 22 is sealed by the seal member 30, a reactive raw soln. is injected into the cavity 8 of a mold apparatus to perform reactive injection molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a reaction injection molded article having an opening and a mold device.

[0002]

2. Description of the Related Art Concrete molded products and metal molded products have disadvantages such as heavy weight and difficulty in cutting, and in recent years, molded products conventionally formed of metal or concrete have been made of synthetic resin. There are many attempts to mold.

In particular, a reaction injection molded article (RIM) of a norbornene-based monomer has been studied for use in various technical fields because of its excellent impact resistance and easy molding of a large molded article. . For example, in the case of molding a tank or a constituent member of a tank with a reaction injection molded product of a large norbornene-based monomer, a plurality of openings such as manholes are provided in the upper part for cleaning the inside of the tank. The opening portion such as a manhole formed in such a tank has a large opening area with an inner diameter of about 450 mm to 600 mm.

FIG. 2 shows an example of a conventional mold apparatus for producing a reaction injection molded article having an opening. As shown in FIG. 2, this mold device 2 includes a core mold 4 and a mold mold 6.
And a cavity 8 is formed therebetween by combining them. The cavity 8 has a shape corresponding to the shape of the molded body, and in order to form the opening 12 in the molded body, the core mold 4 is provided with the convex portion 10 corresponding to the shape of the opening 12. . The top surface of the convex portion 10 is configured to be in close contact with the inner peripheral surface of the mold die 6.

[0005]

However, the opening 12
It is difficult to make the top surface of the convex portion 10 of the core mold 4 and the inner peripheral surface of the cavity mold 6 uniformly contact each other when the opening area of the core mold 4 is large or when a plurality of openings 12 must be formed. Therefore, as shown in FIG. 3, a burr 14 that blocks up to about half of the opening 12 may be formed in the molded body. This burr had to be removed after molding, and the work was complicated.

Further, if there is a gap between the top surface of the convex portion 10 of the core mold 4 and the inner peripheral surface of the cavity mold 6, not only burrs are generated but also the reaction stock solution is injected into the cavity 8. However, there is a possibility that air may be entrained in the injected reaction solution, which may cause voids in the molded body.

In order to eliminate such inconvenience, it is necessary to strictly control the dimensional accuracy of the inner peripheral surface of the cavity mold 6 and the dimensional accuracy of the top surface of the convex portion of the core mold 4. With the technology, it was difficult to prevent burrs from occurring in all openings. Further, since the area of the portion that requires high dimensional accuracy is large, the manufacturing cost of the mold may increase.

The present invention has been made in view of such circumstances, and suppresses the occurrence of burrs at the opening of the molded body as much as possible.
It is an object of the present invention to provide a method for producing a reaction injection-molded article having an opening, which does not cause voids in the molded article, has a small area required for high dimensional accuracy, and has a low manufacturing cost, and a die device. To aim.

[0009]

In order to achieve the above object, a method of manufacturing a reaction injection-molded article according to the present invention is characterized in that a reaction occurs in a cavity of a mold apparatus having a first mold and a second mold. A method for producing a reaction injection-molded article having an opening by injecting a stock solution and performing a reaction injection molding, comprising one of the first mold and the second mold corresponding to the opening of the reaction injection-molded article. A sealing groove is formed along the shape of the opening, a sealing member is attached to the sealing groove, and the first die and the second die are clamped, and the sealing member is the first die. A reaction injection molding is performed by injecting a reaction stock solution into a cavity of a mold device in a state where a gap between the mold and the second mold is sealed.

A mold apparatus according to the present invention comprises a first mold and a second mold.
A mold apparatus for producing a reaction injection molded product having a mold and having an opening, the part of the first mold or the second mold corresponding to the opening of the reaction injection molded product. A seal groove is formed along the shape of the opening, and the seal groove is formed with the first mold and the second mold with the first mold and the second mold clamped. It is characterized in that a seal member for sealing a gap between the die and the mold is attached.

In the present invention, the shape of the opening is not particularly limited, but considering that the opening is covered with a lid, it is preferably circular in order to prevent the lid from falling inside. In the present invention, as the seal member, for example, O
It is preferable to use a sealing member such as a ring, and the material thereof is not particularly limited, but is basically composed of an elastic elastomer or foam. Elastomers are particularly preferred, as compared to foams, the material has less settling due to repeated use. Depending on the application of the sealing material, heat resistance capable of withstanding the heat of the mold and reaction heat and resistance to the reaction stock solution are required.

Specifically, the seal member is made of styrene-butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), nitrile butadiene rubber (NB).
R), diene rubber such as chloroprene rubber (CR),
Butyl rubber (IIR), ethylene-propylene-diene terpolymer rubber (EPDM), acrylic rubber, chlorosulfonated polyethylene rubber, olefin rubber such as fluororubber, silicone rubber, urethane rubber, polysulfide rubber, or foams thereof, Alternatively, it is made of urethane or nylon foam. Among them, the seal member is an elastomer, and particularly preferably NBR, IR, E
It is composed of PDM, fluororubber, etc.

In the present invention, the dimensional shape of the seal groove is determined according to the size of the seal member, and the seal member is crushed in the state where the first mold and the second mold are clamped. Determined to exert sealing properties. A mold matching convex portion is formed on the outer peripheral side of the first mold or the second mold in which the seal groove is formed, and the top surface of the mold matching convex portion is not formed with the seal groove. It is adapted to come into pressure contact with the inner peripheral surface of the second mold or the first mold. Since the inner peripheral surface of the first mold or the second mold in which the seal groove is formed does not need to be pressed against the inner peripheral surface of the second mold or the first mold in which the seal groove is not formed. A flat surface with rough dimensional accuracy is sufficient.

In the method for producing a reaction injection-molded body using the mold apparatus according to the present invention, an opening is formed in a part of the first mold or the second mold corresponding to the opening of the reaction injection-molded body. A seal groove is formed along the shape, and a seal member is attached to the seal groove. Therefore, when the reaction stock solution is injected into the cavity, the gap between the molds is sealed by the seal member, the reaction stock solution does not wrap around the inner peripheral side of the opening, and the burr generated at the opening of the molded body is minimized. be able to. Therefore, the work of deburring after molding can be facilitated.

Further, since the reaction stock solution does not wrap around to the inner peripheral side of the opening due to the action of the seal member, it is possible to prevent air from being entrained in the reaction stock solution, and as a result, voids are less likely to occur in the molded body. Further, since the reaction stock solution does not wrap around to the inner peripheral side of the opening due to the action of the seal member, the seal groove is formed on the inner peripheral flat surface of the first mold or the second mold in which the seal groove is formed. It is not necessary to press-contact the inner peripheral surface of the second mold or the first mold which is not formed, and a flat surface with rough dimensional accuracy may be used. The portion where high dimensional accuracy is required is only the top surface of the mold matching convex portion formed on the outer peripheral side of the first mold or the second mold in which the seal groove is formed. Therefore, according to the present invention, it is possible to minimize the portion requiring high dimensional accuracy and reduce the manufacturing cost of the mold device.

In the present invention, the reaction stock solution used in the reaction injection molding is not particularly limited, but examples thereof include urethane type, urea type, nylon type, epoxy type, unsaturated polyester type, phenol type and norbornene type. As a general molding condition, the reaction stock solution temperature is 20 to 8
At 0 ° C., the viscosity of the reaction stock solution is, for example, 5 cps to 3000 cps, preferably 100 cps at 30 ° C.
It is about 1000 cps.

In such molding, a reinforcing material is placed in advance in a mold, and a reinforced polymer (molded product) can be manufactured by supplying a reaction solution into the reinforcing material and polymerizing it. As the reinforcing material, for example, glass fiber, aramid fiber, carbon fiber, ultra high molecular weight polyethylene fiber,
Examples thereof include metal fibers, polypropylene fibers, aluminum coated glass fibers, cotton, acrylic fibers, boron fibers, silicon carbide fibers, alumina fibers and the like. Also, whiskers such as potassium titanate and calcium sulfate can be used. Further, these reinforcing agents can be used in various shapes such as those obtained by matting long fiber-shaped or chopped strand-shaped materials, cloth-woven materials, and chopped materials.
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 blending amount is not particularly limited, but is usually 10% by weight or more, preferably 20 to 60% by weight.
It is.

Further, 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 type thermopolymer 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. Filled with milled glass,
There are inorganic fillers such as carbon black, talc, calcium carbonate, aluminum hydroxide and mica. As the elastomer, natural rubber, polybutadiene, polyisoprene, styrene-butadiene copolymer (SBR), styrene-butadiene-styrene block copolymer (SB
S), styrene-isoprene-styrene block copolymer (SIS), ethylene-propylene-diene terpolymer (EPDM), ethylene vinyl acetate copolymer (EV)
A) and their hydrides.

The additive is usually mixed in advance with one or both of the reaction solutions. The mold used for the reaction injection molding does not necessarily need to be a rigid and expensive mold, and is not limited to a metal mold, but may be a resin mold or a simple mold. This is because reaction injection molding can be performed at a relatively low temperature and a low pressure by using a low viscosity reaction liquid.
The components used in the polymerization reaction are preferably stored and manipulated under an inert gas atmosphere such as nitrogen gas. Also,
Before injecting the reaction solution into the cavity of the mold, it is preferable to replace the inside of the cavity with an inert gas such as nitrogen gas.

The mold temperature is preferably from 10 to 150
C., more preferably 30 to 120.degree. C., still more preferably 50 to 100.degree. Mold pressure is usually 0.1-1
It is in the range of 00 kg / cm ² . The polymerization time may be appropriately selected, but usually 20 seconds to 2 after the completion of injection of the reaction solution.
0 minutes, preferably 5 minutes or less, more preferably 20 to
40 seconds.

The specific use of the molded article obtained by the reaction injection molding method according to the present invention is not particularly limited, and it is a tank body of a water tank or a septic tank. Particularly, when a large tank body of a septic tank in which a plurality of openings are formed is to be molded by reaction injection molding, the mold apparatus according to the present invention and the method for manufacturing a reaction injection molded body using the same are effective. .

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method of manufacturing a reaction injection molded article having an opening and a mold apparatus according to the present invention will be described in detail based on an embodiment shown in the drawings. FIG. 1 is a cross-sectional view of essential parts of a mold device according to an embodiment of the present invention.

As shown in FIG. 1, the mold apparatus according to this embodiment has a first mold 20 and a second mold 22. By matching the split surfaces of the molds 20 and 22, a cavity 8 is formed inside the mold device. In this embodiment,
The first mold 20 is a concave mold (cavity mold), and the second mold 22 is a convex mold (core mold). The shape of the cavity 8 corresponds to the shape of the obtained molded body, and in the present embodiment,
It is a tank body shape of a septic tank having a plurality of openings 12. The overall shape of the tank body (the overall shape of the cavity 8) is the same as the shape of the cavity 8 shown in FIG.

In the present embodiment, the ring-shaped mold matching projections 26 are formed in the second portions at the portions corresponding to the openings 12 of the molded body.
It is formed on each of the molds 22, and a seal groove 28 is formed on the inner peripheral side thereof. Convex part 26 for mold matching
The radial width b of is not particularly limited, but is preferably 5
It is about 15 mm. If the width b is too narrow, it becomes difficult to form the seal groove 28 on the inner peripheral side thereof, and if the width b is too wide, there is no point in forming the seal groove 28.

On the inner peripheral side of the seal groove 28, a flat surface 32 lower than the mold matching convex portion 26 is formed. First mold 2
0 and the second mold 22 are clamped, the top surface of the mold-matching convex portion 26 needs to be pressed against the inner peripheral surface of the cavity of the second mold 20. It is formed. On the other hand, the flat surface 3 located on the inner circumference of the seal groove 28
No. 2 does not need to be pressed against the inner peripheral surface of the cavity of the second mold 20, so that the dimensional accuracy is rougher than that of the top surface of the mold-matching convex portion 26.

The seal groove 28 is provided with O as a seal member.
The ring 30 is attached. As the shape of the O-ring, the cross-sectional shape is a circle, a rectangle, or a modified rectangle as shown in FIG. 4 (described later). The O-ring 30 is, for example, NBR,
It is composed of silicon rubber, IR, EPDM, fluororubber, and the like. The size of the O-ring 30 is determined according to the size of the opening 12 and the like, and the diameter of its cross section is 5 to 20 mm.
The degree is preferred. With respect to the dimensions and shape of the seal groove 28, the O-ring 30 is accommodated in the seal groove 28, and the O-ring 30 is placed in the seal groove 28 with the first die 20 and the second die 22 clamped. It is determined that the dies 20 and 22 are to be compressed and deformed with a predetermined crushing margin.

In this embodiment, the second mold 22 is made of cast aluminum. The first mold 20 is composed of an electroformed mold. The first die 20, which is an electroformed die,
The back of the metal plating layer is lined with a register. The metal plating layer is made of, for example, nickel or the like, and the resin condenser is made of concrete containing resin and aluminum powder. The first mold 20 and the second mold 22 are provided with heat medium passages (not shown). In the present embodiment, the temperature of both molds 20 and 22 is controlled by controlling the temperature with a heat medium. The temperatures of both molds do not necessarily have to be the same, for example, the first mold 2
It is also possible to set 0 to 70 ° C and set the second mold 22 to 45 ° C.

Next, a reaction injection molding method using the mold apparatus according to this embodiment will be described. First, the split surfaces of the molds 20 and 22 shown in FIG. 1 are aligned and the molds are clamped. The pressure during mold clamping is not particularly limited, but is 0.1 to 100K.
g / cm ² . At the time of mold closing, the reaction stock solution is not injected into the mold, and the temperature inside the mold is the temperature of each temperature-controlled mold itself, which is about 40 to 100 ° C.

Simultaneously with the mold clamping, in the present embodiment, the inside of the cavity is purged with nitrogen by a purging means (not shown). Due to this purging, the inside of the cavity 8
It is replaced with nitrogen gas, and the inside of the cavity 8 is 1 to 3k.
It is filled with nitrogen gas of about g / cm ² . By purging with nitrogen, moisture in the cavity can be driven out, preventing the deactivation of the reaction solution, improving the reactivity on the surface of the molded product, and preventing the inner peripheral surface of the mold from being stained. it can.
This nitrogen purging is performed until just before the injection of the reaction stock solution is started.

Next, a pump is used to supply a mixed solution serving as a reaction stock solution from the A liquid tank and the B liquid tank to the mix chamber, mix them in the chamber, and pass through the spool, runner, and film gate to the inside of the cavity 8. Inject the reaction stock solution into. In this embodiment, the reaction injection molding is reaction injection molding using a norbornene-based monomer. Monomers used in the present embodiment, dicyclopentadiene and dihydrodicyclopentadiene,
It is a cycloolefin having a norbornene ring such as tetracyclododecene and tricyclopentadiene.

A metathesis catalyst that can be used in reaction injection molding using a norbornene-based monomer is
The metathesis catalyst is not particularly limited as long as it is a known metathesis catalyst as a catalyst for bulk polymerization of norbornene-based monomers such as organic ammonium molybdate such as tungsten hexachloride, tridodecylammonium molybdate, and tri (tridecyl) ammonium molybdate. Organic ammonium salts are preferred.

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 A composed of a norbornene-based monomer and a metathesis catalyst, the norbornene-based monomer and an activator. It is divided into two stable liquids, liquid B and liquid B, each of which is placed in a separate tank.

As described above, at the time of reaction injection molding, the two liquids are mixed and then the mixed liquid is injected into the cavity 8 through the spool, runner and film gate. The time from the start of the injection to the end of the injection is determined depending on the size of the molded article and the like, but is 40 seconds in the present embodiment. In the present embodiment, the compounding activity of the compounding solution serving as the reaction stock solution is set to be 3 to 5 times 40 seconds.

After the completion of the injection, the polymerization reaction starts. After the completion of the reaction, the system is cooled, and about 120 to 150 seconds after the completion of the injection,
The mold is opened and the molded body having the opening 12 is taken out.
In the present embodiment, a part of the first mold 22 corresponding to the opening 12 of the reaction injection molded body is provided along the shape of the opening 12.
The convex portion 26 for mold matching and the seal groove 28 are formed,
An O-ring 30 is attached to the seal groove 28. Therefore, when injecting the reaction stock solution into the cavity 8, the mold 2
The gap between 0 and 22 is sealed by the O-ring 30,
The reaction stock solution does not enter the inner circumference side of the ring 30. As a result, burrs that may occur in the opening 12 of the molded body are
It is only between the top surface of the convex portion 26 for mold matching and the inner peripheral surface of the cavity of the first mold 20. Therefore, the size of the burr can be minimized, and the deburring work after molding is easy.

Further, since the reaction stock solution does not wrap around the inner circumference of the O ring 30 by the action of the O-ring 30, it is possible to prevent air from being entrained in the reaction stock solution, and as a result, voids are less likely to occur in the molded body. Become. Furthermore, O ring 3
Since the reaction stock solution does not flow into the inner peripheral side of the O-ring 30 by the action of 0, the flat surface 32 on the inner peripheral side of the seal groove 28 is formed.
Need not be in pressure contact with the inner peripheral surface of the first mold 20 in which the seal groove is not formed, and may be a flat surface with rough dimensional accuracy. The portion where high dimensional accuracy is required is only the top surface of the mold matching convex portion 26. Therefore, in the present embodiment, it is possible to minimize the portion that requires high dimensional accuracy, and reduce the manufacturing cost of the mold device.

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, in the above-described embodiment, the mold matching projection 26, the seal groove 28, and the flat surface 32 are formed on the second mold 22 that is a convex mold, but in the present invention, the mold matching projection 26 and the seal groove are formed. 28 and the flat surface 32 may be formed on the inner peripheral surface of the cavity of the first mold 20, which is a concave mold.

Further, as the seal member, an O having a circular cross section is used.
Not limited to a ring, as shown in FIG. 4, a rubber packing 30a having a circular hollow portion 40 and a pressure-contacting convex portion 42 formed along the longitudinal direction may be used. The packing 30a is particularly excellent in the sealing property of the split surface of the mold.

[0038]

EXAMPLES Next, the present invention will be explained based on more detailed examples, but the present invention is not limited to these examples. Example 1 An electroformed mold is prepared as the first mold 20, and the second mold 2
A mold made of an aluminum casting was prepared as No. 2. Second
In the mold 22, as shown in FIG.
A ring-shaped mold matching convex portion 26, a seal groove 28, and a flat surface 32 are formed in a portion corresponding to
An O-ring 30 was attached. Ring-shaped matching protrusion 2
The outer diameter of 6 was 580 mm, and its width b was 10 mm. The O-ring 30 is made of NBR and has a cross-sectional outer diameter of 1
A 0 mm one was used. The groove depth of the seal groove 30 was determined so that the crushing margin of the O-ring 30 was 1.0 mm.

The top surface of the convex portion 26 for mold matching projects 2.0 mm from the flat surface 32, and the dimensional accuracy of the top surface of the convex portion 26 is ± 0.1 mm. , ±
It was 0.5 mm. As shown in FIG. 2, the shape of the cavity was such that three openings 12 were formed in the longitudinal direction of the molded body.

The distance between the centers of the openings 12 is 950 mm.
Met. The longitudinal length of the molded body was 3364 mm. The height of the molded body was 833 mm. The width of the molded product was 1424 mm. This molded body is used as a septic tank for 10 persons. In the reaction injection molding, 85% of dicyclopentadiene (DCP) and 15% of asymmetrical cyclopentadiene trimer were used, and styrene-isoprene-styrene block copolymer (Kreton 11
70, manufactured by Shell Co., Ltd.) and 2% of phenolic antioxidant Irganox 1010 (manufactured by Ciba Geigy Co., Ltd.) are dissolved and placed in two containers, one of which is diethylaluminum chloride (monomer) for the monomer. DEAC)
Was added to have a concentration of 40 mmol, n-propanol was added to have a concentration of 44 mmol, and silicon tetrachloride was added to have a concentration of 20 mmol (solution A). On the other hand, tri (tridecyl) ammonium molybdate was added to the monomer at a concentration of 10 mmol (Solution B).

The liquids A and B thus prepared were fed to a power mixer with a gear pump so that the volume ratio was 1: 1, and then the first liquid was fed into the cavity of the mold device. Mold 20 temperature 70 ° C, second mold 2
2 at a temperature of 45 ° C. and an injection pressure of 2.0 Kg / cm ² or less. The reaction was carried out for 3 minutes in the mold, and a series of these operations was performed in a nitrogen atmosphere.

Thereafter, the molded body is taken out of the mold and 3
A molded body having one opening 12 was obtained. The burr formed in each opening 12 has a maximum width corresponding to the width b of the mold-matching convex portion 26, and the removal work thereof was extremely easy. Further, almost no void was observed in the molded body.

COMPARATIVE EXAMPLE 1 A seal groove 2 was formed in the mold portion corresponding to the opening 12 of the molded body.
8 is not formed, the area corresponding to the opening 12 is ± 0.2 mm
The convex portion 26 for mold matching with the dimensional accuracy of
Reaction injection molding was performed in the same manner as in Example 1 except that 0 was not attached.

Burrs were formed in each opening of the molded body in about half the total area of the opening, and voids were observed in the molded body near the opening.

[0045]

As described above, according to the present invention, when the reaction stock solution is injected into the cavity, the gap between the molds is sealed by the sealing member, and the reaction stock solution wraps around the inner peripheral side of the opening. Therefore, the burr generated in the opening of the molded body can be minimized. Therefore, the work of deburring after molding can be facilitated.

Further, since the reaction stock solution does not wrap around the inner peripheral side of the opening due to the action of the seal member, the entrainment of air into the reaction stock solution can be prevented, and as a result, voids or the like are less likely to occur in the molded body. Further, since the reaction stock solution does not wrap around to the inner peripheral side of the opening due to the action of the seal member, the seal groove is formed on the inner peripheral flat surface of the first mold or the second mold in which the seal groove is formed. It is not necessary to press-contact the inner peripheral surface of the second mold or the first mold which is not formed, and a flat surface with rough dimensional accuracy may be used. The portion where high dimensional accuracy is required is only the top surface of the mold matching convex portion formed on the outer peripheral side of the first mold or the second mold in which the seal groove is formed. Therefore, according to the present invention, it is possible to minimize the portion requiring high dimensional accuracy and reduce the manufacturing cost of the mold device.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts of a mold device according to an embodiment of the present invention.

FIG. 2 is an overall configuration diagram of a mold device.

FIG. 3 is a plan view showing a burr of a molded body according to a conventional example.

FIG. 4 is a sectional view showing a sectional shape of a seal member.

[Explanation of symbols]

 8 ... Cavity 12 ... Opening 20 ... 1st metal mold 22 ... 2nd metal mold 26 ... Mold matching convex part 28 ... Seal groove 30 ... O-ring (sealing member) 30a ... Rubber packing (sealing member)

Claims (2)

[Claims] 1. A method for producing a reaction injection-molded article having an opening by injecting a reaction stock solution into a cavity of a mold apparatus having a first mold and a second mold and performing reaction injection molding. Then, a seal groove is formed along a shape of the opening in a part of the first mold or the second mold corresponding to the opening of the reaction injection molded body, and a seal member is attached to the seal groove. Then, the first die and the second die are clamped, and the seal member is attached to the first die and the second die.
A method for producing a reaction injection-molded article having an opening, which comprises injecting a reaction stock solution into a cavity of a mold apparatus and performing reaction injection molding in a state where a gap between the mold and the die is sealed. 2. A mold apparatus for producing a reaction injection molded product having a first mold and a second mold and having an opening, wherein the mold device corresponds to the opening of the reaction injection molded product. A seal groove is formed in a part of the first mold or the second mold along the shape of the opening, and the first mold and the second mold are clamped in the seal groove. A mold device in which a seal member that seals a gap between the first mold and the second mold is mounted in the opened state.