JPH06182799A - Manufacture of norbornene resin molded form and reaction stock solution thereof - Google Patents

Abstract

PURPOSE:To provide a method for manufacturing a molded form in which generation of void is prevented or largely reduced and reaction stock solution in a lumplike polymerization using the solution containing norbornene monomer and metathetical catalyst series. CONSTITUTION:A method for manufacturing norbornene resin molded form has the steps of supplying reaction stock solution containing metathetical catalyst and norbornene monomer to a mold and conducting bulk polymerization and comprises the steps of adding silicone anti-foaming agent to the solution and molding it. Norbornene resin reaction stock solution is formed by mixing silicone anti-foaming agent with any of multi-solution type reaction stock solutions for reaction injection molding containing reaction stock solution which contains norbornene monomer and metathetical catalyst and reaction stock solution which contains norbornene monomer and activator.

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 resin molded article by bulk polymerization of a norbornene-based monomer in the presence of a metathesis catalyst system, and a reaction stock solution used therefor.
More specifically, the present invention relates to a method for producing a norbornene-based resin molded article having a small surface bubble and a beautiful surface, which is carried out by adding a foam-suppressing antifoaming agent to the reaction stock solution, and the reaction stock solution used therefor.

[0002]

2. Description of the Related Art In recent years, a reaction molding method (RIM, LIM, RTM, etc.) for producing a molded product by performing a bulk polymerization reaction in a mold using a low-viscosity reaction stock solution containing a norbornene-based monomer and a metathesis catalyst system. Is being developed. The norbornene-based resin molded product obtained by these methods is excellent in heat resistance, dimensional stability, water absorption resistance, and the like, and is characterized by being lightweight.

In such reaction molding, generally, after a reaction liquid (A liquid) containing a monomer and a metathesis catalyst and a reaction liquid (B liquid) containing a monomer and an activator are mixed in a mixing section such as a mixing head, The mixed solution is injected into the mold and reacted.

However, in this molding method, since a low-viscosity reaction stock solution is often injected into the mold at a relatively high speed, when mixing the solutions A and B with a mixer or when the reaction solution is a narrow gate. There is a problem that a large number of voids (air bubbles and voids) are generated inside and on the surface of the molded product when the flow is disturbed by being discharged from a portion into a wide space of the mold cavity.

Therefore, in order to prevent the generation of voids, the activity and viscosity of the reaction stock solution have been adjusted.
The result is not always satisfactory.

Particularly, a thick-walled molded product (for example, a product having a thickness of 5 mm or more) or a molded product having an uneven thickness portion (an uneven thickness portion is a portion where the thickness of the molded product changes rapidly, , Where the thickness of the uneven thickness portion changes by 1.5 times or more than other portions), or when a molded product is produced using a mold having a nest or a core, Even if the viscosity of the reaction stock solution is adjusted, it is difficult to prevent the generation of voids.

Therefore, studies have been made to prevent the generation of voids by devising a molding method. As a specific example, a reaction liquid containing a norbornene-based monomer and a metathesis catalyst system is heated at a temperature higher than the mold (form) temperature. Inject into the mold with
After that, a method has been proposed in which a thick molded product having substantially no pores is obtained by pressurizing the inside of the mold with an inert gas (JP-A-2-239915).

However, in this method, the pressure is applied after injecting the reaction liquid into the mold, and therefore a good molded product cannot be obtained unless the reaction liquid is pressed at the right timing immediately before the reaction liquid is cured. That is, if the pressing time is too early, it is not possible to apply a uniform pressure, and the molded product is subject to a sudden pressure, so that the molded product is easily deformed. There is a problem that the void generation preventing effect cannot be obtained. Therefore, in this method, it is necessary to precisely control the pressurizing time, but in the case of a thick-walled molded product or an uneven-walled molded product having a complicated shape, it is extremely difficult to uniformly start the reaction, It is difficult to obtain a good molded product by applying this method.

[0009]

DISCLOSURE OF THE INVENTION An object of the present invention is to produce a molded article by bulk polymerization using a reaction liquid containing a norbornene-based monomer and a metathesis catalyst system. It is intended to provide a production method for producing a compound and a reaction stock solution used therein.

As a result of intensive studies aimed at achieving such an object, the present inventors have found that it is effective to add a specific defoaming agent to a monomer stock solution, and have completed the present invention.

[0011]

Thus, according to the present invention, firstly, in a method for producing a norbornene-based resin molded article by bulk polymerization of a norbornene-based monomer in the presence of a metathesis catalyst system, a foam-suppressing product is used. Provided is a method for producing a norbornene-based resin molded article, which is characterized by incorporating a defoaming agent. Further, as a second invention, at least one of a reaction stock solution for reaction injection molding composed of a reaction stock solution containing a norbornene-based monomer and a metathesis catalyst, and a reaction stock solution containing a norbornene-based monomer and an activator. On the other hand, there is provided a reaction stock solution for reaction molding, which is characterized by being mixed with an antifoaming agent.

The present invention will be described in detail below. (Reaction stock solution) In the present invention, a catalyst and an activator are divided into two streams, and a reaction stock solution is prepared by adding a monomer to at least one, preferably both, and a foam-suppressing antifoaming agent is added to at least one of them. To do. Further, the present invention is not limited to the method using two types of reaction stock solutions. As will be readily appreciated by those skilled in the art, various modifications are possible, such as, for example, putting the monomer and the desired additive in the third container and using it as the third stream.

(Norbornene-based Monomer) The norbornene-based monomer used in the present invention may be any one having a norbornene ring. However, when a polycyclic norbornene-based monomer having a tricyclic or higher ring is used, it has a high heat distortion temperature. A coalescence is obtained. Further, in order to make the resulting ring-opening polymer a thermosetting type, at least 10% by weight, preferably 30% by weight or more of the total monomers may be used as the crosslinkable monomer.

Specific examples of the norbornene-based monomer include bicyclic compounds such as norbornene and norbornadiene, tricyclic compounds such as dicyclopentadiene and dihydrodicyclopentadiene, tetracyclic compounds such as tetracyclododecene, tricyclopentadiene and the like. Pentacycles, heptacycles such as tetracyclopentadiene, and their alkyl-substituted products (for example, methyl,
Ethyl, propyl, butyl substitution, etc.), alkenyl substitution (eg, vinyl substitution), alkylidene substitution (eg, ethylidene substitution, etc.), aryl substitution (eg, phenyl, tolyl, naphthyl substitution, etc.),
Examples thereof include substituents having a polar group such as an ester group, an ether group, a cyano group, and a halogen atom. These monomers may be used alone or in combination. Among them, tricyclic or pentacyclic compounds are favored from the viewpoint of availability, reactivity, heat resistance and the like.

The crosslinkable monomer has two reactive double bonds.
It is a polycyclic norbornene-based monomer having two or more thereof, and specific examples thereof include dicyclopentadiene, tricyclopentadiene, tetracyclopentadiene and the like.
When the norbornene-based monomer and the crosslinkable monomer are the same, it is not necessary to use any other crosslinkable monomer.

It should be noted that monocyclic cycloolefins such as cyclobutene, cyclopentene, cyclopentadiene, cyclooctene, and cyclododecene, which are capable of ring-opening polymerization with one or more of the above norbornene-based monomers, are used together within a range not impairing the object of the present invention. be able to.

(Catalyst system) In the present invention, a metathesis catalyst system comprising a known metathesis catalyst and an activator can be used as a catalyst for ring-opening polymerization of norbornene monomers. Specific examples of the metathesis catalyst used in the liquid A include halides such as tungsten, molybdenum and tantalum, oxyhalides, oxides, organic ammonium salts and the like. Specific examples of the activator (cocatalyst) used in the liquid B include alkylaluminum, alkylaluminum halide, alkoxyalkylaluminum halide, aryloxyalkylaluminum halide,
Examples include organic tin compounds.

The metathesis catalyst is usually used in an amount of about 0.01 to 50 mmol, based on 1 mol of the norbornene-based monomer.
It is preferably used in the range of 0.1 to 20 mmol.
The activator is preferably 1 relative to the metathesis catalyst component.
It is used in the range of 10 to 10 (molar ratio). Both the metathesis catalyst and the activator are preferably used by dissolving them in the monomer, but they may be used by suspending or dissolving them in a small amount of solvent as long as the properties of the product are not substantially impaired.

(Bulk Polymerization) In the present invention, at least the two types of reaction stock solutions are mixed and then poured into a mold having a predetermined shape, where ring-opening polymerization by bulk is carried out.

In the present invention, reaction injection (RI
M) A collision mixing device known as a molding device can be used for mixing the respective reaction stock solutions. In this case, the vessels containing the respective reaction stock solutions serve as separate flow sources. The respective reaction stock solutions are mixed instantaneously by the mixing head of the RIM machine and then poured into a molding die, where they are immediately bulk polymerized to obtain a molded article.

In addition to the impingement mixer, a low pressure injector such as a dynamic mixer or a static mixer can be used. When the pot life at room temperature is as long as 1 hour, it may be injected or injected into the preheated mold several times after the completion of mixing of the reaction stock solutions in the mixer, or continuously. May be injected. In the case of this method, the device can be downsized as compared with the impingement mixing device, and in addition to having the advantage that it can be operated at low pressure, when the filling amount of the filler such as glass fiber is large, By slowing down the speed,
It becomes possible to uniformly impregnate the system with the reaction solution.

The reaction solution is usually stored and operated in an atmosphere of an inert gas such as nitrogen gas in order to prevent deactivation of the metathesis catalyst system.

(Foam suppressive defoaming agent) Generally, the defoaming agent is classified into a defoaming defoaming agent and a defoaming defoaming agent. In the present invention, among these, the defoaming defoaming agent is included. Foams are optionally used. The foam-suppressing antifoaming agent is an antifoaming agent having a function of suppressing foaming, and specific examples thereof include silicone-based defoaming agents such as trifluoropropylmethyl silicone, perfluorooctylmethyl silicone, and methyl hydrogen silicone, Dimethyl silicone, phenylmethyl silicone,
The ends and side chains of these silicones are methylstyrene groups,
Examples thereof include those modified with long-chain alkyl groups, polyether groups, carbinol groups, amino groups, epoxy groups, carboxyl groups, higher fatty acid groups, and the like.

These antifoaming agents are oil type, modified oil type,
Although it is commercially available in the form of solution type, emulsion type, powder type, etc., in the present invention, oil type, modified oil type, and solution type have good solubility in monomers, particularly oil type,
The solution type is preferably used because it has little polymerization inhibition and is easy to handle.

FL1 is a specific example of a preferred commercial product.
00 (Shin-Etsu Chemical Co., Ltd. oil type fluorosilicone), F
S1265 (manufactured by Toray Dow Corning Silicone,
Organic solvent type fluorosilicone), FQF501 (Oil type fluorosilicone manufactured by Toshiba Silicone Co., Ltd.), KF-9
6 (Shin-Etsu Chemical, oil type dimethyl silicone), SH
-200 (Toray Dow Corning Silicone, oil type dimethyl silicone), TSF-451 (Toshiba silicone, oil type dimethyl silicone), FS-2
00 (Dow Corning, oil type dimethyl silicone), KS-602 (Shin-Etsu Chemical, solution type dimethyl silicone), SD-5591 (Toray Dow Corning Silicone, solution type dimethyl silicone), YSA-
02 (made by Toshiba Silicone, solution type dimethyl silicone), XD-2899 (made by Dow Corning, solution type dimethyl silicone), etc. are illustrated. Of these, fluorosilicone-based defoaming agents are particularly preferably used because they have little polymerization inhibition and have a high defoaming effect even with an extremely small amount added.

Further, in the present invention, any defoaming agent having a foam suppressing property may be used even if it is generally classified as a defoaming defoaming agent.

The amount to be added is determined in consideration of the defoaming effect of the defoaming agent and the polymerization inhibitory property, but it is usually 5% by weight or less, preferably about 3 to 500 ppm in the reaction stock solutions on both sides of the liquids A and B. Compound. Moreover, it is desirable to add as little as possible. A larger amount may be added as long as it does not cause polymerization inhibition, but it is not preferable from the economical viewpoint.

The antifoaming agent used in the present invention is usually preferably added to both solutions and used from the viewpoint of exhibiting the antifoaming effect. When a defoaming agent having a relatively strong polymerization inhibitory property is used, it is preferable to mix it as the liquid A side or the third liquid, but as compared with the case where it is added to both liquids, the defoaming agent is mixed during the mixing of both liquids. Since it is difficult to disperse uniformly, the defoaming effect decreases.

The order of addition of the defoaming agent in the liquid A or the liquid B is not particularly limited, but since the addition amount is minute, it is necessary to sufficiently stir before use.

The mechanism for suppressing the generation of voids by adding an antifoaming agent is not clear, but it is presumed to be due to the following mechanism. That is, when a molded product having an uneven thickness portion is molded, the flow of the reaction liquid in the mold is not only a uniform flow in the injection direction but also a flow in the thickness direction, so the flow is complicated and unclear. Become uniform,
As a result, the air in the mold is entrained at the confluence of the flows of a plurality of reaction liquids to form a void, or where the wall thickness of the molded product changes greatly, the pressure drop due to the volume change in the wall thickness part at the time of reaction liquid injection causes a pressure drop. It is considered that this occurs, causing gasses (nitrogen and oxygen) and low-boiling point components dissolved in the reaction solution to gasify, resulting in voids. Further, when a molded product is manufactured using a mold having a nest or a core, it is considered that the air in the gap between the nest or the core and the mold is caught when the reaction liquid flows. It is considered that the defoaming agent used in the present invention suppresses the generation of such bubbles in the mold, and as a result, suppresses the formation of voids.

(Arbitrary Ingredients) Further, if desired, the reaction stock solution may include an antioxidant, a filler, a pigment, a colorant, a foaming agent, a flame retardant, a sliding agent, an elastomer, a dicyclopentadiene-based heat-polymerized resin and the like. Various additives such as hydrogenated products can be added, and the properties of the resulting polymer can be modified.

An elastomer may be used for the purpose of adjusting the viscosity. Specific examples thereof include natural rubber, polybutadiene, polyisoprene, styrene-butadiene copolymer (SBR), styrene-butadiene-
Styrene block copolymer (SBS), styrene-isoprene-styrene copolymer (SIS), ethylene-propylene-diene terpolymer (EPDM), ethylene-
Examples thereof include vinyl acetate copolymer (EVA) and hydrides thereof. When these elastomers are added to the reaction liquid, not only impact resistance is given to the obtained polymer, but also the viscosity of the reaction liquid can be adjusted.

(Mold) Regarding the shape, material and size of the mold,
There is no particular limitation. Since a low-viscosity reaction liquid is used, not only a metal-made reaction liquid but also a synthetic liquid made of various materials such as various synthetic resins and low-melting point alloys can be used.

[0034]

EFFECTS OF THE INVENTION According to the present invention, a molded product having an excellent appearance can be molded without producing a void even in a molded product having a shape in which a void is likely to occur, such as a thick molded product or an uneven thickness molded product. It is possible.

[0035]

EXAMPLES The present invention will be described more specifically with reference to Examples and Comparative Examples below. In the following examples, parts and% are based on weight unless otherwise specified.

[Example 1] (Preparation of reaction solution) Dicyclopentadiene (DCP) and methyltetracyclododecene (MTD) containing 2% of a phenolic antioxidant (manufactured by Ciba-Geigy, trade name Irganox 259). Monomer mixture with (DCP / MT
D = 85/15) was placed in two containers, one for the monomer, diethylaluminum chloride (DEA
C) at a concentration of 33 mmol and n-propanol at 34.6.
A millimolar concentration and silicon tetrachloride were added so that the concentration would be 20 millimolar. On the other hand, tri (tridecyl) ammonium molybdate was added to the monomer so as to have a concentration of 4 mmol. The pot life of the reaction solution was 1 minute at 25 ° C. Fluorosilicone (FS1265-
300CS, manufactured by Toray Dow Corning Silicone)
10 ppm was added.

(Manufacturing Experiment of Molded Product) The mold is made of aluminum for both the cavity mold and the core mold, and the shape of the cavity (ie, the shape of the molded product) is 50 cm × 50 c.
In m, the average wall thickness was 7 mm and the weight was about 1.8 kg.

As the reaction solution, a mixture of both reaction solutions was used. That is, both reaction solutions were mixed at a ratio of 1: 1 using a gear pump and a power mixer, and were injected into the mold heated to 70 ° C. for the cavity mold and 50 ° C. for the core mold through the injection port. The bulk polymerization reaction time was about 20 seconds. After completion of the reaction, the molded product was taken out from the mold and the number of voids was examined.

The number of voids in the molded product was counted by the following method. <Number of voids> The number of holes having a diameter of 0.3 mm or more was counted by a method in which a molded product was watermarked on a 200 W light bulb and the number in a predetermined 5 cm x 5 cm square was counted. The results are shown in Table 1.

[0040]

[Table 1]

[Comparative Example 1] A reaction solution was prepared in the same manner as in Example 1 except that the defoaming agent was not used, and a molding experiment of a molded product was conducted in the same manner as in Example 1. It was The results are shown in Table 1.

[Comparative Example 2] In Example 1, instead of the silicone type defoaming agent, a surfactant type defoaming agent (Byk-051, Byk Chemie) known as a defoaming defoaming agent was used.
A reaction liquid was prepared in the same manner as in Example 1 except that the product was used), and a molding experiment of a molded product was performed in the same manner as in Example 1. The results are shown in Table 1.

As is clear from the results shown in Table 1, it is understood that the number of voids can be greatly reduced by bulk polymerization using a silicone antifoaming agent.

[Example 2] (Preparation of reaction solution) 3 parts of a phenolic antioxidant (manufactured by Ciba-Geigy, trade name Irganox 259) and SIS
2 parts of a monomer mixture (DCP / MTD = 85/15) of dicyclopentadiene (DCP) and methyl tetracyclododecene (MTD) containing 6.5 parts and 1.0 part of BR.
Diethylaluminum chloride (DEAC) was added to one container at a concentration of 40 mmol and 1,3-dichloro-2-propanol was added to the monomer at a concentration of 42 mmol, respectively. On the other hand, tri (tridecyl) ammonium molybdate was added to the monomer so as to have a concentration of 10 mmol. The pot life of the reaction solution was 1 minute at 25 ° C. Fluorosilicone (FL1
00-450CS, manufactured by Shin-Etsu Silicone Co., Ltd.) 100 ppm
Was added.

(Manufacturing Experiment of Molded Product) The mold is made of chrome-plated iron for both the cavity mold and the core mold, and the shape of the cavity (that is, the shape of the molded product) is 200.
mm × 200 mm, the average wall thickness was 3 mm.

As the reaction liquid, both of the above reaction liquids were mixed and used. That is, both reaction solutions were mixed at a ratio of 1: 1 using a gear pump and a power mixer, and were injected into the mold heated to 75 ° C. for the cavity mold and 45 ° C. for the core mold through the injection port. The bulk polymerization reaction time was about 20 seconds. After completion of the reaction, the molded product was taken out from the mold and the number of voids was examined.

[Comparative Example 3] A reaction liquid was prepared in the same manner as in Example 2 except that the defoaming agent was not used. It was The results are shown in Table 1.

[Comparative Example 4] In Example 2, instead of the silicone type defoaming agent, a surfactant type defoaming agent (Byk-0) was used.
51, manufactured by Byk Chemie) was used to prepare a reaction solution in the same manner as in Example 2, and a molding experiment of a molded product was performed in the same manner as in Example 2. The results are shown in Table 1.

As is clear from the results shown in Table 1, it is understood that the number of voids can be greatly reduced by bulk polymerization using a silicone antifoaming agent.

[Embodiment 3] An experiment was conducted in the same manner as in Embodiment 2 except that a part of the mold was provided with an uneven thickness portion where the thickness of the molded product of 3 mm changed to 10 mm. The number of voids in the thick part was measured. The results are shown in Table 1.

[Comparative Example 5] A molding experiment of a molded product was conducted in the same manner as in Example 3 except that the reaction solution used in Comparative Example 3 was used. The number of voids in the thick part was measured. The results are shown in Table 1.

[Comparative Example 6] A molding experiment of a molded product was conducted in the same manner as in Example 3 except that the reaction liquid used in Comparative Example 4 was used. The number of voids in the thick part was measured. The results are shown in Table 1.

As can be seen from Table 1, when a silicone-based defoaming agent is used, even in a molded article having an uneven thickness portion, when the defoaming agent does not generate voids or when a surfactant-based defoaming agent is used. Less than if you were there.

[0054]

According to the present invention, there is provided a method for producing a molded article in which the generation of voids is prevented or greatly reduced by a reaction molding method using a reaction liquid containing a norbornene-based monomer and a metathesis catalyst system. It

Claims (2)

[Claims] 1. A method for producing a norbornene resin molded product by bulk polymerization of a norbornene monomer in the presence of a metathesis catalyst system, which comprises blending a defoaming defoaming agent in the norbornene resin molded product. Manufacturing method. 2. A multi-component reaction stock solution for reaction injection molding, comprising a reaction stock solution containing a norbornene-based monomer and a metathesis catalyst, and a reaction stock solution containing a norbornene-based monomer and an activator, A reaction stock solution for reaction molding, comprising a foam-suppressing defoaming agent.