JPH09254180A - Reactive injection molded object of norbornene type monomer having flange - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep the mating surface of a flange smooth by forming a protruding part protruding in the direction opposite to the mating surface of the flange to the leading end part of the flange. SOLUTION: In this reactive injection molded object 2 of a norbornene type monomer having a flange, the possibility of the damage of the part of the flange 6 is reduced even if external force acts on the part of the flange 6 and the mating surface of the flange 6 is made smooth. Since the mating surface of the flange 6 becomes smooth by providing a protruding part 8 to the leading end part of the flange 6, when the mating surface of the flange 6 is brought into contact with other member 10 to bond the molded object 2 to the other member 10, the hermetical sealability of the part of the flange 6 is also kept well.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reaction injection molded body of norbornene type monomer having a flange.

[0002]

2. Description of the Related Art When a plurality of members are assembled to form a structure or when one member is attached to another member,
Sometimes a member is provided with a flange and the flange is attached to another member with a bolt / nut or an adhesive.

A technique using a flange is generally used as a means for detachably attaching members made of a metal molded body. However, since the metal molded body has drawbacks such as being heavy and being difficult to cut, in recent years, attempts have been actively made to mold the molded body, which has been conventionally molded with metal, with synthetic resin. .

In particular, a reaction injection molded product of a norbornene-based monomer has excellent impact resistance, and since a large molded product can be easily molded, it is considered to be used in various technical fields.

[0005]

However, when the flange is provided on the reaction injection molded product of the norbornene-based monomer, there are the following problems. For example, when a reaction injection molded body of a norbornene-based monomer having a flange is transferred, the molded body may be pulled up by using the flange portion. At that time, depending on the weight of the molded body,
There was a risk that the flange would crack.

Further, when the flange is formed integrally with the molded body, a corrugated shape appears on the mating surface of the flange along the longitudinal direction of the flange, the mating surface is not smooth, and the flange is formed on another member. In some cases, good adhesion cannot be achieved. In this case, there is a possibility that satisfactory sealing performance may not be obtained in applications where sealing performance is required at the flange portion.

The present invention has been made in view of such circumstances, and even if an external force acts on the flange portion, the flange portion is less likely to be damaged, and the flange mating surface can be made smooth. An object of the present invention is to provide a reaction injection molded product of a norbornene-based monomer having

[0008]

In order to achieve the above object, a reaction injection-molded product of a norbornene-based monomer having a flange according to the present invention (hereinafter, also referred to as RIM) is formed by aligning the flange with the tip of the flange. It is characterized in that a convex portion protruding in a direction opposite to the surface is formed.

In order to improve the strength of the flange, it is common in the field of metal moldings to form triangular plate-shaped reinforcing ribs at the base end of the flange at predetermined intervals. If this technique is directly applied to RIM, voids may be generated in the ribs or flanges, which may cause the ribs to break.

In the RIM, the present inventors form a convex portion projecting in a direction opposite to the mating surface of the flange at the tip end portion of the flange in RIM without providing a rib at the base end portion of the flange. The strength of the part is sufficiently improved,
Moreover, it has been newly found that a wavy shape can be prevented from appearing on the mating surface of the flange, and the present invention has been completed based on this finding.

From the viewpoint of preventing shrinkage during molding, the thickness of the flange is preferably approximately the same as the thickness of the molded body on which the flange is formed, and is preferably 2 mm or more, more preferably 2.5 mm or more. Is 3 mm or more. If it is too thin, the flange may not have sufficient strength. The upper limit of the thickness of the flange is preferably 30.
mm or less, more preferably 20 mm or less, particularly preferably 1
5 mm or less. If it is too thick, it becomes difficult to manufacture a molded product having a flange.

The width of the flange (the length from the front end to the base end of the flange) is 15 mm or more, preferably 20 mm or more, more preferably 25 mm or more. If this width is too short, it may be difficult to bond and the bonding strength may be insufficient. The upper limit of the flange width is preferably 300 mm or less,
More preferably 250 mm or less, particularly preferably 200 mm
It is as follows. If this width is too long, it is difficult to manufacture,
It may get in the way. When the wall surface of the molded body on which the flange is formed is a curved surface, the length from the intersection of the tangent line of the inner wall surface and the mating surface of the flange to the tip of the flange is the width of the flange.

The height of the molded body to which the flange is attached (the height from the mating surface of the flange) is preferably 10
mm or more, more preferably 20 mm or more, particularly preferably 4
It is 0 mm or more. If this height is too low, the purpose of the flange will not be achieved and the entire inner surface of the molded body will be bonded. The upper limit of the height of this molded body is preferably 3 m or less,
It is more preferably 2 m or less, and particularly preferably 1 m or less. If this height is too high, filling becomes difficult depending on the position of the injection port during injection molding, and it becomes difficult to manufacture a molded body.

The height of the convex portion formed at the tip of the flange (the height from the upper surface of the flange) is 2 mm or more, preferably 2.5 mm or more, more preferably 3 mm or more. If the height of this convex portion is too low, the effect is small. The upper limit of the height of this convex portion is preferably 30 mm or less, more preferably 20 mm or less, and particularly preferably 15 mm or less. If the height of the convex portion is too high, filling becomes difficult depending on the position of the injection port, and molding of the flange having the convex portion becomes difficult.

The width of the convex portion formed at the tip of the flange (the length from the point where the convex portion starts to rise from the upper surface of the flange to the tip of the flange) is 1 mm or more, preferably 1.5 mm or more, more preferably Is 2 mm or more. If this width is too short, the effect of providing the convex portion is small. The upper limit of the width of this convex portion is preferably 50 mm or less, more preferably 20 mm or less, and particularly preferably 10 mm or less. If the width of the convex portion is too long, manufacturing becomes difficult, and the effect as the convex portion may not be obtained.

In the present invention, the projection is preferably formed continuously at the tip of the flange along the longitudinal direction of the flange, but it may be formed intermittently. In the reaction injection molded product of the norbornene-based monomer having the flange according to the present invention, it is preferable that the corners of the molded product have an appropriate radius of curvature. For example, the corner preferably has a radius of curvature of 0.5 mm or more, more preferably 1 mm or more, and particularly preferably 2 mm or more. That is, the inner surface of the mold for molding this molded body preferably has a radius of 0.5.
It is desirable that the sphere having a size of mm, more preferably 1 mm, and particularly preferably 2 mm is rolled so that there is no portion that does not come into contact with the sphere. This is because if there is such a portion where the balls do not come into contact with each other, it is difficult to fill the molding material and a void may be generated in the molded body.

In the reaction injection molded body of norbornene-based monomer having a flange according to the present invention, even if an external force acts on the flange portion, there is little possibility of damaging the portion,
Moreover, the mating surface of the flange can be made smooth. Therefore, even if an external force acts on the flange during the transportation of the molded body, the flange is not damaged. Further, since the mating surface of the flange becomes smooth, when the mating surface of the flange is brought into contact with another member and the molded body is joined to the other member, the sealing property of the flange portion is also well maintained. .

Therefore, the reaction injection-molded product of the norbornene-based monomer having the flange according to the present invention is not particularly limited, but it can be suitably used as a component of a water tank or a septic tank.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a reaction injection-molded product of a norbornene-based monomer according to the present invention will be described in detail based on an embodiment shown in the drawings. First Embodiment FIG. 1 is a sectional view of a reaction injection molded product of a norbornene-based monomer having a flange according to an embodiment of the present invention, FIG. 2 is a sectional view of a main part of the molded product shown in FIG. 1, and FIG. It is a bottom view of the molded object shown in FIG.

As shown in FIGS. 1 and 2, a reaction injection molded body 2 of norbornene-based monomer according to the present embodiment has a container-shaped molded body 4 and a flange formed around the opening of the molded body 4. 6 and. In FIG. 1, reference numeral 10
Is another plate-shaped member 10 to which the mating surface 6a (see FIG. 2) of the flange 6 is joined.

In the present embodiment, the thickness t of the flange 6 is
From the viewpoint of preventing shrinkage during molding, ₁ is preferably about the same as the thickness t ₂ of the molded body 4 on which the flange 6 is formed, 2 mm or more, preferably 2.5 mm or more,
More preferably, it is 3 mm or more. If it is too thin, the flange 6 may not have sufficient strength. Also,
The upper limit of the thickness of the flange 6 is preferably 30 mm or less, more preferably 20 mm or less, and particularly preferably 15 mm or less. If it is too thick, it becomes difficult to manufacture the molded body 2 having the flange 6.

The width w _{2 of the} flange 6 (the length from the front end to the base end of the flange 6) is 15 mm or more, preferably 20 mm.
More preferably, it is 25 mm or more. If this width is too short, it may be difficult to bond it to the other member 10 and the bonding strength may be insufficient. The upper limit of the width w ₂ of the flange 6 is preferably 300 mm or less, more preferably 25 mm.
It is 0 mm or less, particularly preferably 200 mm or less. If this width w ₂ is too long, it is difficult to manufacture and there is a risk that it will be an obstacle. In the present embodiment, as shown in FIG.
Since the connecting portion between the molded body 4 and the flange 6 is a curved surface, the tangent to the inner wall surface of the molded body 4 and the mating surface 6a of the flange 6
The length from the intersection 12 to the tip of the flange 6 is defined as the flange width w ₂ .

As shown in FIG. 1, the height h ₂ (height from the mating surface 6a of the flange 6) of the molded body 4 to which the flange 6 is attached is preferably 10 mm or more, more preferably 20 mm or more, and particularly It is preferably 40 mm or more.
If this height is too low, the purpose of the flange 6 cannot be achieved,
The entire inner surface of the molded body 4 is bonded to the other member 10 shown in FIG. The upper limit of the height of the molded body 4 is preferably 3 m or less, more preferably 2 m or less,
It is particularly preferably 1 m or less. If this height h ₂ is too high, filling becomes difficult depending on the position of the injection port at the time of injection molding, and manufacturing of the molded body 2 becomes difficult.

In this embodiment, the convex portion 8 is formed at the tip of the flange 6 so as to project in the direction opposite to the mating surface 6a of the flange 6. The height h ₁ of this convex portion 8 (the height from the upper surface of the flange 6) is 2 mm or more, preferably 2.5 mm or more, and more preferably 3 mm or more. If the height of the convex portion 8 is too low, the effect is small. The upper limit of the height of the convex portion 8 is preferably 30 mm or less, more preferably 20 mm or less, and particularly preferably 15 mm or less. If the height of the convex portion 8 is too high, filling becomes difficult depending on the position of the injection port, and molding of the flange 6 having the convex portion 8 becomes difficult.

The width w ₁ of the protrusion 8 formed at the tip of the flange 6 (the length from the point where the protrusion 8 starts to rise from the upper surface of the flange 6 to the tip of the flange 8) is 1 mm or more, preferably It is 1.5 mm or more, more preferably 2 mm or more. If this width is too short, the effect of providing the convex portion 8 is small. The upper limit of the width of the convex portion 8 is preferably 50 mm or less, more preferably 20 mm or less, and particularly preferably 10 mm or less.
If the width of the convex portion 8 is too long, manufacturing becomes difficult, and the effect as the convex portion 8 may not be obtained.

In this embodiment, the convex portion 8 is formed continuously at the tip of the flange 6 along the longitudinal direction (circumferential direction) of the flange 6. In the present embodiment, the corners of the molded body 2 have an appropriate radius of curvature. For example, the corner of the joint between the molded body 4 and the flange has a radius of curvature r. The radius of curvature r is preferably 0.5 mm or more, more preferably 1 mm or more, and particularly preferably 2 mm or more.

The molded body 2 of this embodiment is composed of a polynorbornene resin obtained by a reaction injection molding method (RIM). In particular, those composed of a ring-opened polymer of a norbornene-based monomer modified with an elastomer are preferable. As the elastomer, for example, polybutadiene,
Styrene-butadiene copolymer (SBR), styrene-
Examples thereof include butadiene-styrene block copolymer (SBS), polyisoprene, styrene-isoprene-styrene block copolymer (SIS), ethylene-propylene-diene terpolymer (EPT) and the like.

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

The monomer is a cycloolefin having a norbornene ring such as dicyclopentadiene, dihydrodicyclopentadiene, tetracyclododecene and tricyclopentadiene. The metathesis catalyst is not particularly limited as long as it is a known metathesis catalyst for bulk polymerization of norbornene-based monomers such as organic hexamolybdate ammonium salts such as tungsten hexachloride, tridodecyl ammonium molybdate, and tri (tridecyl) ammonium molybdate. However, ammonium ammonium molybdate is particularly preferable.

Examples of the activator (cocatalyst) include alkylaluminum halides such as ethylaluminum dichloride and diethylaluminum chloride, alkoxyalkylaluminum halides thereof, and organic tin compounds. As a preparation for reaction injection molding, a reaction injection molding material containing a norbornene-based monomer, a metathesis catalyst, and an activator as a main component is a liquid comprising a norbornene-based monomer and a metathesis catalyst, and the norbornene-based monomer and the activator are used. Separately into two stable liquids and separate liquids. At the time of reaction injection molding, the two liquids are mixed, and then the mixed liquid is injected into the cavity of the mold, and bulk polymerization is performed in the cavity to obtain the molded body 2.

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

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

Since the molded body 2 according to the present invention is made of a polynorbornene resin obtained by the reaction injection molding method, the internal ribs can be easily molded integrally, and a relatively large molded body 2 can be molded easily. can do. Further, the polynorbornene-based resin can have a sufficient pressure resistance required for the molded body 2 by utilizing the material characteristic that the specific rigidity is low but the specific strength is high.

In the reaction injection-molded body 2 of norbornene-based monomer having the flange according to the present embodiment, even if an external force acts on the portion of the flange 6, the portion is less likely to be damaged, and the mating surface of the flange 6 is 6a can be smoothed. Therefore, even if an external force acts on the flange 6 when the molded body 2 is conveyed, the flange 6 is not damaged.

Further, since the mating surface 6a of the flange 6 is made smooth by providing the convex portion 8 at the tip of the flange 6, the mating surface 6a of the flange 6 is brought into contact with another member 10 to form the molded body 2 The sealability of the portion of the flange 6 is also favorably maintained when the is joined to the other member 10. In addition,
As shown in FIG. 5, when the convex portion is not provided at the tip end portion of the flange 6 ′, the rigidity is lowered and the flange 6 ′ has a wavy shape along the longitudinal direction, which is not preferable because the mating surface is uneven. .

Second Embodiment In this embodiment, as shown in FIG. 4, the shape is different from that of the molded body 2 shown in FIGS. 1 and 2, but the flanges 26a to 26e are similar to the molded bodies shown in FIGS. The casing of the septic tank is assembled by using the molded bodies 20a to 20e each having a convex portion (not shown) formed at the tip end thereof. Each molded body 20a-
20e is molded by reaction injection molding of norbornene-based monomer in the same manner as in the first embodiment. If necessary, ribs 30 may be added to these molded bodies 20a to 20e.
Etc. may be formed.

Flange 26a of each molded body 20a-20e
~ 26e are contacted with the mating surfaces of adjacent flanges,
The flanges are tightened with bolts and nuts. An adhesive may be attached to the mating surface of the flange. Further, an O-ring groove may be formed on the mating surface of either one of the flanges, and an O-ring may be attached thereto to further improve the airtightness.

The flanges 26a to 26e according to this embodiment.
Injection molded product 20a of norbornene-based monomer having
.About.20e, even if an external force acts on the flanges 26a to 26e, the flanges 26a to 26e are less likely to be damaged, and the mating surfaces of the flanges 26a to 26e can be made smooth. Therefore, even if an external force acts on the flanges 26a to 26e during the transportation of the molded bodies 20a to 20e,
The flanges 26a to 26e are not damaged.

Further, since the mating surfaces of the flanges 26a to 26e are made smooth by providing the same protrusions as in the case of the first embodiment on the tip end portions of the flanges 26a to 26e, the flanges 26a to 26e are formed. When assembling the casing of the septic tank by joining the mating surfaces of the above, the sealing property of the flanges 26a to 26e is also maintained well.

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 reaction injection-molded body of the norbornene-based monomer having the flange according to the present invention can be used not only for the purpose of the septic tank but also for the water tank and other applications.

[0041]

EXAMPLES The present invention will be described below based on more specific examples, but the present invention is not limited to these examples. Example 1 A reaction injection molded body 2 of norbornene-based monomer having a flange shown in FIGS. 1 to 3 was molded.

In reaction injection molding, 85% dicyclopentadiene (DCP) and 15% asymmetrical cyclopentadiene trimer were used, and styrene-isoprene-
Styrene block copolymer (Kraton 1170, manufactured by Shell Co.) was dissolved in 5% and phenolic antioxidant Irganox 1010 (manufactured by Ciba Geigy Co., Ltd.) was dissolved in 2%. Diethyl aluminum chloride (DEAC) was added to the monomer so that the concentration was 40 mmol, n-propanol was 44 mmol, and silicon tetrachloride was 20 mmol (A).
liquid). 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 by a gear pump so that the volume ratio was 1: 1 and then the mold temperature was 70 ° C. in the mold. And the injection pressure was 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.

Then, the molded body was taken out from the mold to obtain a molded body 2 shown in FIGS. Width s of the inner surface of the molded body 2
Is 1550 mm, the vertical width v is 3350 mm, the height h ₂ of the molded body ₂ is 855 mm, the thickness t ₂ of the molded body 4 is 7 mm, and the thickness t ₁ of the flange 6 is 7 mm. Yes, the width W ₂ of the flange is 60 mm, and the height h of the convex portion 8 is
₁ was 6 mm, and the width w ₁ of the convex portion 8 was 8 mm.

No wavy shape was observed on the mating surface 6a of the flange 6. In addition, wires were attached to four locations around the flange of the molded body of this example and the entire molded body 2 was caught, but no damage occurred at the flange portion.
In addition, in this embodiment, the portion of the flange 6 is shown in FIG.
The geometrical moment of inertia I of only the portion of the flange 6 was calculated and approximated to the shape shown in FIG. The second moment of area I can be obtained by the following approximate expression.

[0046]

## EQU1 ## I = [w ₂ × e ₂ ³ − (w ₂ −w ₁ ) × h ₃ ³
+ W ₁ × e ₁ ³ ] / 3, where e ₂ = [(w ₂ −w ₁ ) × t ₁ ² + w ₁ × (h
₁ + t ₂ ) ² ] / 2 × [(w ₂ −w ₁ ) × t ₁ + w ₁ ×
(H ₁ + t ₂ )], e ₁ = h ₂ −e ₂ , and h
₃ = - is the _{[w 2 × t 1 -w 1} × h 1] / 2 × w 2.

In the present embodiment, this second moment of area I
Was about 2770 mm ⁴ , and it was confirmed that the bending rigidity E × I was high, the rigidity of the flange was high, and the flange was difficult to deform. Note that E is the Young's modulus of the material forming the flange. In addition, the flanges 6 of the two molded bodies 2
When the two components were bonded together using a two-component urethane adhesive (Mighty Grip, manufactured by Japan Synthetic Rubber Co., Ltd.), the bonding strength was about 600 kg.

Further, of the two molded bodies 2, one is used as an upper tank and the other is used as a lower tank, and their flanges 6 are separated from each other by 2
Bond with liquid urethane adhesive (Mighty Grip, made by Japan Synthetic Rubber Co., Ltd.), fix with bolts and nuts at 120 mm intervals, make a hole in the center of the upper tank and fill it with water for 2 weeks. When left to stand, no water leak was observed. Further, when the bolts and nuts were fixed at 180 mm intervals, no water leak was observed.

Comparative Example 1 A reaction injection molded body of norbornene-type monomer having a flange was molded in the same manner as in Example 1 except that no convex portion was formed at the tip of the flange. The corrugated shape as shown in FIG. 5 was observed on the mating surface of the flange of the molded body according to this comparative example.

When wires were attached to the surroundings of the flange of the molded body according to this comparative example and the entire molded body was caught, the flange was chipped. In this comparative example, the portion of the flange 6 was approximated to the shape as shown in FIG. 6 (B), and the moment of inertia I of area of only the portion of the flange 6 was calculated. The second moment of area I can be obtained by the following approximate expression.

[0051]

## EQU2 ## I = (w ₂ × t ₁ ³ ) / 12 In this comparative example, the second moment of area I is about 1710 mm.
^{It was 4 and} it was confirmed that the bending rigidity E × I was lower than that of Example 1.

Further, when the flanges 6 of the two molded bodies 2 according to this comparative example were bonded to each other using a two-component urethane adhesive (Mighty Grip, manufactured by Japan Synthetic Rubber Co., Ltd.),
The adhesive strength was about 400 kg. In addition, one of the two molded bodies 2 according to the comparative example is used as an upper tank and the other is used as a lower tank, and the flanges 6 of the two molded bodies are treated with a two-component urethane adhesive (Mighty Grip, manufactured by Japan Synthetic Rubber Co., Ltd.). It was adhered by using it, further fixed with a bolt and a nut at 120 mm intervals, a hole was made in the center of the upper tank, water was fully filled and left for 2 weeks, but no water leakage was observed. However, when fixed with bolts and nuts at 180 mm intervals, some water leakage was observed on the 5th day.

[0053]

As described above, according to the reaction injection-molded product of norbornene-based monomer having the flange according to the present invention, even if an external force acts on the flange portion, there is less possibility of damaging the portion. Moreover, the mating surface of the flange can be made smooth. Therefore, even if an external force acts on the flange during the transportation of the molded body, the flange is not damaged. Further, since the mating surface of the flange becomes smooth, when the mating surface of the flange is brought into contact with another member and the molded body is joined to the other member, the sealing property of the flange portion is also well maintained. . In particular, when a molded product is joined to another member by bringing the flange mating surface into contact with another member by using a bolt and a nut together with an adhesive, the present invention compares them with a molded product having a conventional flange. As a result, sufficient sealing performance can be obtained even if the intervals between the bolts are wide.

Therefore, the reaction injection-molded product of the norbornene-based monomer having the flange according to the present invention is not particularly limited, but it can be suitably used as a component of a water tank or a septic tank.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a reaction injection molded body of norbornene-based monomer having a flange according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of the molded body shown in FIG.

FIG. 3 is a bottom view of the molded body shown in FIG.

FIG. 4 is a perspective view of a reaction injection molded body of norbornene-based monomer having a flange according to an embodiment of the body of the present invention.

FIG. 5 is a side view of a main part of a flange according to a comparative example.

6 (A) and 6 (B) are cross-sectional views showing a model for obtaining a second moment of area used in Examples and Comparative Examples.

[Explanation of symbols]

 2, 20a to 20e ... Molded body 4 ... Molded body main body 6, 26a to 26e ... Flange 8 ... Convex portion

Claims (1)

[Claims] 1. A reaction injection molded body of norbornene-based monomer having a flange, characterized in that a convex portion protruding in a direction opposite to a mating surface of the flange is formed at a tip end portion of the flange. Reaction injection molded product of norbornene-based monomer.