JP2001205660A - Method for manufacturing reaction injection-molded article, and mold apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a reaction injection-molded article hard to generate stickiness on its bonding surface at the time of molding of the molded article having a bonding surface to be bonded to other member. SOLUTION: In a method for manufacturing a reaction injection-molded article having a bonding surface to be bonded to other member by injecting a reactive raw solution in the cavity of a mold apparatus having at least first and second molds to perform reaction injection molding, the bonding surface forming mold surface, which comes into contact with the bonding surface of a molded article to be molded, and molded article main body forming mold surface, which comes into contact with the principal part other than the bonding surface of the molded article, formed to at least either one of the first and second molds are separately regulated in temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a reaction injection molded article and a mold apparatus, and more particularly, to a method for producing a septic tank having a flange portion.
The present invention relates to a method for manufacturing a reaction injection molded product having a joining surface to be joined to another member and a mold apparatus.

[0002]

2. Description of the Related Art In recent years, a method for producing a reaction injection molded product by injecting a reaction stock solution containing a metathesis polymerization catalyst and a norbornene-based monomer into a cavity of a mold and curing the solution in the mold has been widely used. I have. In such reaction injection molding, usually, a core mold (convex mold) and a mold (concave mold) formed so as to form a cavity (cavity) corresponding to the shape of a molded article to be molded. ) Is used.

In this type of mold, a heat medium pipe is embedded in each of a core mold and a mold, and the mold temperature during molding of the core mold and the mold can be adjusted to a predetermined temperature. Things are known.

There is also known a method in which a core mold and a mold are formed with a temperature difference by using such a mold (for example, see Japanese Patent Application Laid-Open No. 2-167333). By molding the core mold and the mold with a difference in temperature, it is possible to make one surface of the molded product a beautiful surface appearance.

[0005]

However, when a conventional mold is used to form, for example, an upper tank body and a lower tank body which are members of a septic tank, the upper tank body and the lower tank body are formed on the upper tank body and the lower tank body, respectively. In some cases, stickiness originating from the unreacted monomer may occur on the joining surface of the flange portion to be formed. If stickiness occurs on the joint surface of the flange portion, poor adhesion of the flange portion is likely to occur when assembling the septic tank, and water leakage easily occurs from the flange surface after installation of the septic tank.

In Japanese Patent Application Laid-Open No. 9-323334, at least one of a core mold and a mold mold is provided with a plurality of molds in order to make the mold temperature uniform within the same mold (for example, within the core mold). A mold apparatus is disclosed which is divided into zones, and in which a plurality of heat medium flow paths for controlling temperature are formed in each of the plurality of zones.

However, even when the above-mentioned septic tank, for example, a lower tank body is manufactured using such a mold apparatus, the same problem occurs because the mold temperature in the same mold is made uniform. .

An object of the present invention is to provide a method and a mold apparatus for producing a reaction injection molded product in which a molded product having a joint surface to be joined to another member is less likely to be sticky on the joint surface. That is.

[0009]

In order to achieve the above object, a method for producing a reaction injection molded product according to the present invention is provided in a cavity of a mold apparatus having at least a first mold and a second mold. In a method of performing a reaction injection molding by injecting a reaction stock solution and producing a reaction injection molded product having a joint surface to be joined with another member, the reaction mold is formed in at least one of the first mold and the second mold. In addition, the temperature of the joint surface forming mold surface that is in contact with the joining surface of the molded product to be molded and the temperature of the molded product body forming mold surface that is in contact with the main part other than the joining surface of the molded product are separately controlled. Features.

Preferably, the temperature of the mold surface on which the bonding surface is formed is adjusted to a temperature higher than that of the mold surface on which the molded article body is formed. This is particularly effective when a reaction solution containing a norbornene-based monomer is used.

The method for controlling the temperature of the mold surface for forming the bonding surface and the mold surface for forming the molded article main body is not particularly limited. For example, a method of heating with a heater, a heating medium ( For example, a method of circulating water or oil) may be mentioned, and among them, from the viewpoint that stable temperature control is easily obtained, a method of circulating a heat medium in a pipe buried inside a mold is used. Is preferred.

The reaction solution supplied into the cavity is not particularly limited, and includes, for example, urethane, urea, polyamide, epoxy, unsaturated polyester, phenol, norbornene and the like. And norbornene are particularly preferred. The temperature of the reaction solution before it is fed into the cavity of the mold apparatus is preferably 1
0 to 80 ° C., and the viscosity of the reaction stock solution is, for example, 30 ° C.
In general, 5 to 3000 cps, preferably 100
It is about 1000 cps. These reaction stock solutions include:
Not only the monomer but also a catalyst and an activator may be contained.

The norbornene-based reaction stock solution usually contains a metathesis catalyst and an activator in addition to the norbornene-based monomer.

The norbornene-based monomer may be any monomer having a norbornene ring, and specific examples thereof include bicyclics such as norbornene and norbornadiene, dicyclopentadiene (cyclopentadiene dimer), dihydrodicyclopentadiene and the like. Of tricyclic, tetracyclic such as tetracyclododecene, pentacyclic such as cyclopentadiene trimer, heptacyclic such as cyclopentadiene tetramer, and methyl and ethyl of these bicyclic to heptacyclic Alkyl, such as propyl and butyl; alkenyl, such as vinyl; alkylidene, such as ethylidene; and aryl, such as phenyl, tolyl and naphthyl, and the like, furthermore, ester groups, ether groups, and cyano groups of these bicyclic to heptacyclic compounds. Substituents having a polar group such as a group or a halogen atom are exemplified. Among them, tricyclic or higher polycyclic norbornene-based monomers are preferable because they are easily available and excellent in reactivity, and more preferably tricyclic, tetracyclic or pentacyclic norbornene-based monomers. These norbornene-based monomers can be used alone or in combination of two or more.

It should be noted that within a range not to impair the object of the present invention,
Monocyclic cycloolefins such as cyclobutene, cyclopentene, cyclopentadiene, cyclooctene and cyclododecene, which can be ring-opening copolymerized with norbornene monomers, can also be used as comonomers.

The metathesis catalyst is not particularly limited as long as it is capable of ring-opening polymerization of a norbornene monomer by the RIM method, and may be a known one. For example, 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, tridodecyl ammonium molybdate, or tri (tridecyl) ammonium molybdate. However, an organic ammonium molybdate is preferred. As a metathesis catalyst, a known ruthenium carbene complex (WO97 / 061)
85, JP-T-10-508891 and JP-A-11-108
No. 329553) can also be applied.

The amount of the metathesis catalyst to be used is generally 0.01 mmol or more, preferably 0.1 mmol or more, and 50 mmol or less, preferably 20 mmol or less, per 1 mol of the monomers used in the whole reaction solution. If the amount of the metathesis catalyst used is too small, the polymerization activity is too low and the reaction takes a long time, so the production efficiency is poor.If the amount is too large, the reaction is too vigorous and the resin hardens before being sufficiently filled in the mold. Or the catalyst is likely to precipitate, making it difficult to store homogeneously.

The metathesis catalyst is usually used by dissolving it in a monomer. However, as long as the properties of a molded article obtained by the RIM method are not essentially impaired, the catalyst is suspended and dissolved in a small amount of a solvent, and then dissolved in a monomer. May be used to make precipitation difficult or to increase solubility.

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 JP-A-47-47, for example, alkylaluminum halides such as ethylaluminum dichloride and diethylaluminum chloride, organoaluminum compounds such as alkoxyalkylaluminum halides, and organotins. And the like. When a ruthenium carbene complex is used as a metathesis catalyst, an activator may or may not be used.

The amount of the activator used is not particularly limited.
Usually, 0.1 mol or more, preferably 1 mol or more, and 1 mol per 1 mol of the metathesis catalyst used in the whole reaction solution.
It is at most 00 mol, preferably at most 10 mol. If the activator is not used or the amount of the activator is too small, the polymerization activity is too low and the reaction takes a long time, resulting in poor production efficiency. Conversely, if the amount is too large, the reaction may be too vigorous and may be cured before the mold is sufficiently filled.

The activator is used by dissolving it in a monomer.
As long as the properties of the molded article by the RIM method are not essentially impaired, the substance is suspended in a small amount of a solvent and then mixed with a monomer to make it difficult to precipitate or to increase the solubility. Good.

The above-mentioned undiluted reaction solution may contain, if desired,
Various additives such as a reinforcing material, an antioxidant, a filler, an elastomer, a pigment, a coloring agent, a foaming agent, a flame retardant, a sliding agent, a dicyclopentadiene-based thermopolymerized resin and a hydrogenated product thereof can be compounded. it can. Thereby, the characteristics of the obtained molded article can be modified. Usually, it is preferable that such an additive is previously mixed with one or both of the reaction stock solutions.

As preparations for the reaction injection molding, a molding material mainly composed of a norbornene monomer, a metathesis catalyst and an activator is mixed with a B liquid comprising a norbornene monomer and a metathesis catalyst, It is preferable to divide the liquid into two stable liquids, the liquid and the liquid A, and put them in separate tanks.

At the time of reaction injection molding, these two liquids are mixed in a mixing head, and then this mixed liquid is
It is poured into a cavity of a mold and is subjected to bulk polymerization to obtain a molded product.

At the time of reaction injection molding, the inside of the mold is preferably sealed with an inert gas, and the components used for the polymerization reaction are preferably stored and operated under an atmosphere of an inert gas such as nitrogen gas. Mold clamping pressure is usually 0-100kgf
/ Cm ² . The polymerization time may be appropriately selected, but is usually 30 seconds to 20 minutes after the completion of the supply of the reaction solution,
Preferably it is 5 minutes or less.

The molded article obtained by the reaction injection molding is not particularly limited, and examples thereof include a tank of a water tank or a septic tank, a bathtub pan, a waterproof pan, and an automobile bumper. Preferably, a flange portion is formed. (For example, an upper tank portion or a lower tank portion, or an intermediate tank portion interposed between the upper tank portion and the lower tank portion).

A mold apparatus according to the present invention is a mold apparatus for producing a reaction injection molded article having a joint surface to be joined with another member, and comprises a first mold and a second mold. At least one of the first mold and the second mold has a joining surface forming mold surface in contact with a joining surface of a molded product to be molded, and a main portion excluding the joining surface of the molded product. And a molded product body forming mold surface that is in contact with the mold, and the joining surface forming mold surface and the molded product body forming mold surface are each provided with a temperature adjusting means capable of independently controlling the temperature. Features.

The material of the mold is not particularly limited. For example, the material is not limited to metals such as cast iron, iron, stainless steel, aluminum and nickel electroformed, and 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 high-rigidity mold. Therefore, the production of the mold is relatively easy.

[0029]

In the method for producing a reaction injection molded article using the mold apparatus according to the present invention, the joining surface of the molded article to be molded, which is formed on at least one of the first mold and the second mold. For example, a joining surface forming mold surface that is in contact with a lower tank body that constitutes a tank body of a septic tank, and a main portion excluding a joining surface of the molded product (for example, a lower tank body that constitutes a tank body of a septic tank) The temperature of the mold body forming die surface that is in contact with the inner wall surface of the mold is separately controlled. For this reason, it is easy to set the mold temperature of the joint surface forming mold surface to be high independently of the mold temperature of the molded product body forming mold surface. It is possible to effectively prevent stickiness derived from unreacted monomers from being generated on the bonding surface of (1). As a result, even when bonded to other members via the bonded portion of the reaction injection molded product manufactured by the method of the present invention,
The possibility of poor adhesion at the joint is low. That is, according to the method for producing a reaction injection molded product according to the present invention,
It is possible to obtain a reaction injection-molded article having an improved bonding property on the joining surface.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for producing a reaction injection molded article 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 schematic sectional view showing a tank body of a septic tank which is an embodiment of a reaction injection molded product according to the present invention, FIG. 2 is a schematic sectional view showing an embodiment of a mold apparatus according to the present invention, 3 is a sectional view taken along the line III-III of FIG. 2, and FIG. 4 is a schematic view of a core mold in the mold apparatus of FIG.

In this embodiment, as an example of a molded article to be formed by reaction injection molding, the upper tank body 4 and the lower tank body 6 of the purification tank 2 shown in FIG. 1 are illustrated. 4 and the lower tank 6 will be described, and then a mold apparatus and a manufacturing method for manufacturing the lower tank 6 will be described.

[0033] As shown in the tank body Figure 1 septic tank, the upper tank body according to the present embodiment (the upper tank portion) 4 and the lower tank body (the lower tank portion) 6 are both wash water flush toilet, a kitchen Treatment septic tank 2 for purifying domestic wastewater discharged from ordinary households such as domestic wastewater and bath water
After mounting components (not shown) such as a partition plate and a filter bed inside, the two flange portions 4 are formed.
a and 6a are assembled.

The flange portions 4a and 6a are usually fastened and fixed by bolts and nuts. At this time, preferably, the flange joining surface (corresponding to the joining surface of the present invention) 4 is used.
An adhesive such as a polyurethane-based, epoxy-based, or polyacrylate-based adhesive is applied to 2a and 62a, and then is fixed by tightening. At the time of tightening, a packing made of, for example, butyl rubber, acrylonitrile-butadiene rubber, urethane elastomer, silicone rubber or the like may be interposed.

The upper tank body 4 and the lower tank body 6 include:
Inner wall surfaces 44, 64 and outer wall surfaces 46, 66 are formed, respectively. In FIG. 1, reference numeral "8" denotes a manhole cover attaching portion.

In order to manufacture the lower tank body 6 which is a member of the purification tank 2 as described above, for example, a mold apparatus 20 shown in FIG. 2 is used.

Mold apparatus As shown in FIG. 2, the mold apparatus 20 according to this embodiment
Has a core mold (first mold) 24 and a mold mold (second mold) 26 that can be divided in the mold opening direction X along the division surface 22. The dividing surface 22
The cavity 28 is formed inside by clamping the mold. In the present embodiment, the core mold 24
The mold 26 is made of, for example, synthetic resin or metal.

As shown in FIGS. 2 and 3, the core mold 24 according to the present embodiment has a joining surface forming mold surface which is in contact with the flange joining surface 62a (see FIG. 1) of the lower tank body 6 to be molded. 242a and a molded product main body forming mold surface 242b that is in contact with the inner wall surface 64 (see FIG. 1) except for the flange joining surface 62a of the lower tank body 6 to be molded.
The mold 26 has a molded product body forming mold surface 262b (see FIG. 2) in contact with an outer wall surface 66 (see FIG. 1) of the lower tank body 6 to be molded.

As shown in FIGS. 2 and 4, in the present embodiment, the core first mold portion 24a having the joint surface forming mold surface 242a and the molded product main body forming mold surface 24
The temperature control heat medium flow paths 30a, 3a, each of which is independently temperature-controllable, are connected to the core second mold portion 24b having the core 2b.
0b is formed, and a joining surface forming mold surface 242a and a molded article main body forming mold surface 242b are introduced by introducing a heat medium (for example, hot water) whose temperature is controlled by a temperature controller (not shown). Can be controlled separately. In addition, although illustration is omitted,
In the mold 26, a heat medium passage for temperature control similar to the above is formed.

The heat medium passages 30a and 30b for temperature control are formed directly in the core mold 24 by forming gaps in the core first mold portion 24a and the core second mold portion 24b, respectively. Alternatively, it may be formed by embedding a pipe or the like. Heat medium flow path 30 for temperature control
Preferably, a and 30b are provided as close to the cavity 28 as possible. The joining surface forming mold surface 242a in contact with the cavity 28 and the molded product main body forming mold surface 2
This is for facilitating the temperature control of 42b.

A heat insulating layer (not shown) may be provided at the boundary between the first core portion 24a and the second core portion 24b. The type of the heat insulating layer is not particularly limited, and may include only a cut for heat insulation without using a heat insulating material,
Although an air layer may be used, it is preferable to use a heat insulating material filled in the cut. As insulation, for example,
Johnman packing (compressed asbestos sheet), glass laminate, ceramic board, heat insulating paper, etc.
From the viewpoint of increasing the heat insulating effect, Johnman packing is preferable. The thickness of the heat insulating layer is usually 0.5 to 15 mm, preferably 1 to 5 mm. The cut of the heat insulating layer is usually 5 to 30 mm, preferably 10 to
15 mm. When the heat insulating layer is provided close to the cavity 28, the heat insulating effect becomes higher. However, if the heat insulating layer is too close to the cavity 28, the mold loses its strength, so there is a limit.

In the present embodiment, the mold mold 26 is not divided, and the temperature is not separately adjustable. However, the present invention is not limited to this. It can be changed as needed.

The lower tank body 6 of the septic tank 2 shown in FIG.
It is manufactured as follows using the mold apparatus 20 having the above-described configuration.

The method for producing a lower tank body 6 First, as shown in FIG. 2, the cavity mold and core mold 24 2
In combination with 6, a cavity 28 is formed between the core mold 24 and the mold mold 26. At this time, the heat medium controlled to a predetermined temperature is supplied to each of the temperature control heat medium passages 30a and 30b formed in the core first mold portion 24a and the core second mold portion 24b of the core mold 24. Is introduced.

In the present embodiment, the temperature T1 of the joining surface forming mold surface 242a is set to be higher than the temperature T2 of the molded article main body forming mold surface 242b by introducing the heat medium (T1> T2). . By setting T1> T2, stickiness derived from the unreacted monomer is effectively prevented from being generated on the flange joining surface 62a (see FIG. 1) of the lower tank body 6 to be molded.

In the present embodiment, T1-T2 is usually 5 to 5.
100 ° C., preferably 10-80 ° C., more preferably 1
0 to 50 ° C, T1 is preferably 40 to 100 ° C, more preferably 60 to 90 ° C, and T2 is preferably 5 to 60 ° C.
° C, more preferably 30 to 50 ° C.

In this embodiment, the temperature T3 of the mold body forming mold surface 262b in contact with the outer wall surface 66 (see FIG. 1) of the lower tank body 6 to be molded in the mold 26.
Is controlled in the same manner as described above. In the present embodiment, T
3 is preferably 40 to 100 ° C., more preferably 60 to 100 ° C.
９０90 ° C. In the present embodiment, the relationship between T1, T2, and T3 is T1> T3 ≧ T2.

After controlling the temperature of each mold in this manner, a reaction solution is supplied into the cavity 28 to perform reaction injection molding (R).
IM). In the present embodiment, a reaction stock solution containing a norbornene-based monomer, a metathesis catalyst and an activator, and preferably further containing an elastomer is used. And
The bulk polymerization proceeds in the cavity 28 and is cured to obtain the lower tank 6 (see FIG. 1).

Specifically, dicyclopentadiene (DC
P) 85% by weight, 15% by weight of an asymmetric cyclopentadiene trimer, 5% by weight of a styrene-isoprene-styrene block copolymer (Clayton 1170, manufactured by Shell), and a phenolic antioxidant 2% by weight of Irganox 1010 (manufactured by Ciba Specialty Chemicals) was dissolved in two containers,
On the other hand, diethyl aluminum chloride (DEAC) is added to the monomer in a concentration of 40 mmol, n-propanol in a concentration of 44 mmol, and silicon tetrachloride in a concentration of 20 mmol (Solution A). On the other hand, tri (tridecyl) ammonium molybdate is added to the monomer in an amount of 10%.
It is added so as to have a millimolar concentration (solution B). The solution A and the solution B thus prepared are respectively sent to a power mixer by a gear pump so as to have a volume ratio of 1: 1. Then, an injection pressure of 2 kgf is injected into the cavity 28.
/ Cm ² or less. The reaction is performed in the mold for 2 to 4 minutes, and these series of operations are performed under a nitrogen atmosphere. Thereafter, the core mold 24 and the mold cavity 26 are opened and the molded product is taken out to obtain a lower tank body 6 having a flange portion 6a having a flange joining surface 62a (FIG. 1).
Reference) can be obtained.

In the present embodiment, the flange joining surface 62a of the lower tank 6 to be formed, which is formed on the core mold 24,
And the inner wall surface 64 excluding the flange joining surface 62a of the lower tank body 6 to be formed.
By separately controlling the temperature of the molded article body forming mold portion 242b in contact with the mold, the joining surface forming mold portion 242a
Is easily set to be high independently of the temperature of the molded article main body forming mold portion 242b.
Stickiness derived from unreacted monomers can be effectively prevented from being generated on the flange joining surface 62a of the lower tank body 6. As a result, when assembling the septic tank 2, the lower tank 6
Is joined to the separately formed flange joint surface 42a of the upper tank body 4 via the flange joint 62a.
The flange joints 62a and 42a do not have poor adhesion to each other, and inconveniences such as leakage of water from the flange portion after installation of the septic tank are prevented.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments at all, and can be implemented in various modes without departing from the gist of the present invention. Of course.

In the above-described embodiment, the case where the lower tank body 6 of the septic tank 2 is manufactured has been described as an example. However, the case where the upper tank body 4 is manufactured can be similarly performed.

In the above embodiment, the core mold 24
Has a bonding surface forming mold surface 242a, but the mold 26 may have this depending on a molded product to be molded.

[0054]

As described above, according to the present invention, when a molded article having a joint surface to be joined to another member is molded, the reaction injection molded article which is less likely to have stickiness on the joint surface is formed. A manufacturing method and a mold apparatus can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a tank body of a septic tank which is one embodiment of a reaction injection molded product according to the present invention.

FIG. 2 is a schematic sectional view showing one embodiment of a mold apparatus according to the present invention.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a schematic view of a core mold in the mold apparatus of FIG.

[Explanation of symbols]

 2 ... Septic tank 4 ... Upper tank 6 ... Lower tank 4a, 6a ... Flange 42a, 62a ... Flange joining surface 44, 64 ... Inner wall 46, 66 ... Outer wall 8 ... Manhole cover attaching part 20 ... Molding device 22 ... Dividing surface 24 ... Core mold (first mold) 24a ... Core first mold portion 242a ... Joining surface forming mold surface 24b ... Core second mold portion 242b, 262b ... Molded product body forming mold surface 26 ... Cavity mold (second mold) 28 Cavities 30a, 30b ... Heat medium flow path for temperature control

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Claims (4)

[Claims] 1. A reaction injection is performed by injecting a reaction stock solution into a cavity of a mold apparatus having at least a first mold and a second mold to perform reaction injection molding, and having a joining surface joined to another member. In a method of manufacturing a molded product, a joining surface forming mold surface formed on at least one of the first mold and the second mold and in contact with a joining surface of a molded product to be molded, A method for producing a reaction injection molded product, wherein a temperature of a molded product main body forming mold surface which is in contact with a main portion excluding a joining surface is separately adjusted. 2. The method for producing a reaction injection molded product according to claim 1, wherein the temperature of the mold surface on which the bonding surface is formed is adjusted to a temperature higher than that of the mold surface on which the molded product body is formed. 3. The method for producing a reaction injection molded product according to claim 1, wherein the reaction injection molded product is a tank body of a septic tank having a flange portion. 4. A mold apparatus for producing a reaction injection molded article having a joint surface joined with another member, the mold apparatus having at least a first mold and a second mold, At least one of the mold and the second mold includes
A joining surface forming mold surface which is in contact with a joining surface of a molded product to be molded, and a molded product main body forming mold surface which is in contact with a main part except for a joining surface of the molded product; A mold apparatus in which a temperature adjusting means capable of independently adjusting the temperature is provided on each of a mold surface and a mold surface for forming a molded article body.