JPS63222824A - Method for reaction injection molding - Google Patents

Abstract

PURPOSE:To prevent physical properties of an obtained crosslinked polymer molded product from lowering by a method wherein the catalyst component is used in excess within a specified amount over the amount, which develops the fastest polymerization rate. CONSTITUTION:In the reaction injection molding, which obtains a crosslinked polymer molded product by rapidly mixing the combination of reactive solutions, which consists of reactive solution of metathetical polymeric monomer containing catalyst component of metathetical polymerization catalyst type and reactive solution of metathetical polymeric monomer containing activating component of metathetical polymerization catalyst type, through collision mixing and casting the resultant mixture in a mold, the ratio of the catalyst component to the activating component is used in excess than the ratio of catalyst component to the activating component, which develops the fastest polymerization rate, by 50mol.% or less of the catalyst component. As the metathetical polymeric monomer, raw material mainly consisting of dicyclopentadiene is especially preferably used. As the catalyst component of metathetical polymerization catalyst type a tungsten compound is especially preferable. As the activating component of metathetical polymerization catalyst type, tetraalkyltin, aluminum alkyl compound and aluminum alkyl halide compound are preferable.

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to an improved method for obtaining molded articles by reaction injection molding of metathesis polymerizable monomers in the presence of a metathesis polymerization catalyst system. More specifically, using a combination of a reactive solution of a metathesis polymerizable monomer containing a catalyst component of a metathesis polymerization catalyst system and a reactive solution of a metathesis polymerizable monomer containing an active agent component of a metathesis polymerization catalyst system, The present invention relates to a method for improving the properties of a molded product by adding a catalyst and an activator to a specific ratio different from the reactivity point of view.

b. Prior Art It is known that cyclic olefins can be subjected to metathesis polymerization catalyst systems to give ring-opened polymers. Therefore, a method has been proposed in which polymerization and molding are performed in one step in a mold using an inexpensive liquid metathesis-polymerizable cyclic olefin metathesis polymerization catalyst such as dicyclopentadiene (DCP) to obtain a polymer molded product. . That is, taking advantage of the fact that the metathesis polymerization catalyst system consists of two components, a catalyst component such as tungsten chloride and an activator component such as alkyl aluminum, collision is performed using two types of liquids consisting of each of the two components and a monomer. A method of obtaining a cured molded product by a reaction injection molding method using mixing has been proposed (for example, Japanese Patent Application Laid-Open No. 12901/1983)
3 @Refer to the official bulletin).

According to this method, large molded products with good performance can be produced using inexpensive low-pressure molds (7), so it can be said that it is a very attractive method from an industrial perspective, but when applied to actual molding, several improvements are required. It has become clear that there are some points.

As mentioned above, regarding the combination and combination of the catalyst component and the activator component of the metathesis polymerization catalyst system, there is a point at which the polymerizability is highest at a certain ratio. For such evaluation of polymerization, polymerization is started by rapid mixing at a constant temperature such as 30°C, and the temperature inside the reaction system is raised until the temperature is constant, for example 10°C.
This can be done by measuring the time it takes for the temperature to reach 0°C.

In general, the polymerizability is affected more by changes in the mixing ratio of the main catalyst component and the activator component than by changes in their absolute concentrations, and from the viewpoint of catalyst usage efficiency, the ratio with the highest polymerizability is selected. It had been.

However, it has been found that when these two types of reactive solutions are stored for a long period of time or exposed to high temperatures, their polymerization activity decreases even if they are stored in an inert atmosphere. However, even in that case, the value of the highest polymerizability ratio will not deviate significantly, but as mentioned above, it may take longer to reach a certain temperature after mixing due to heat generation due to reaction. . It has been found that in such a state, the amount of residual monomer in the crosslinked polymer molding increases and the secondary transition point decreases, which is a very undesirable phenomenon.

Therefore, the inventor of the present invention has arrived at the present invention as a result of intensive research in order to find a method for easily obtaining a good molded product even from a liquid in such a state.

Structure of the C0 Invention: As mentioned above, the inventor of the present invention variously changed the mixing ratio of both reaction solutions starting from the highest ratio of polymerizability, and mixed and reacted both reaction solutions. In the region where the activator component is in excess even though the activator component is decreased, the amount of residual monomer increases and the secondary transition point also decreases, whereas in the region where the catalyst component is in excess, the residual monomer 7 is also small. It has also been found that the decrease in the secondary transition point is also reduced, making it possible to prevent deterioration in the physical properties of the resulting crosslinked polymer molded product.

The present invention has been achieved based on such knowledge, and includes a reactive solution (solution A) of a metathesis polymerizable monomer containing at least a catalyst component of a metathesis polymerization catalyst system, and an activation method for at least a metathesis polymerization catalyst system. A reactive solution of a metathesis-polymerizable monomer containing an agent component (solution B)
) in a reaction injection molding method in which a combination of reactive solutions consisting of at least one of This is a reaction injection molding method characterized in that the catalyst component is used in excess of 50 mol % or less than the ratio that gives the fastest polymerization rate.

In method J3 of the present invention, the rate at which the catalyst component is used in excess depends on the degree of deterioration of the reaction solution; generally, the more the deterioration progresses, the greater the rate of excess required for recovery becomes, and saturation is reached at this rate. Generally, the optimum excess can be easily determined by test molding, but an excess of 5 mol % is desirable.

Specific examples of the metathesis-polymerizable monomer used in the reaction injection molding method of the present invention include dicyclopentadiene, tricyclopentadiene, and cyclopentadiene-methylcyclopentadiene copolymer.

5-Eylidennorbornene, norbornene, norbornadiene, 5-cyclohexenylnorbornene, 1,
4,5.8-dimethano-1,4,4a, 5.6.7.
8.8a-octahydronaphthalene, 1,4-methano-
1,4゜4a, 5.6.7.8.8a-octahydronaphthalene, 6-ethylidene-1,4,5,8-dimethano-1,4,4a, 5.7゜8.8a-hebuta Hydronaphthalene, 1,4,5.8-dimethano-1,4,4
Examples include one or more of a, 5,8.8a-hequinahydronaphthalene, ethylene bis(5-norbornene), and the like. In particular, raw materials mainly composed of dicyclopentadiene are preferably used.

Further, if necessary, a metathesis-polymerizable cyclic compound containing a different element such as oxygen or nitrogen can be used as a copolymerizable monomer.

Such a copolymerizable polymer preferably has a norbornene structural unit, and the polar group is an ester group,
Ether groups, cyano groups, N-substituted imide groups, halogens, and the like are preferred.

A specific example of such a copolymerizable polymer is 5-methoxycarbonylnorbornethylhexyloxy)carbonylbornene, 5-phenylokimethylnorbornene.

5-cyanonorbornene, 6-diatu 1.4, 5.8
-dimethano-1.4.4a,5,&,7,8.8a-octahydronaphthalene, N-butylnadic acid imide, 5-chloronorbornene, and the like.

As mentioned above, the metathesis polymerizable monomer is required to contain as few impurities as possible that would inactivate the metathesis polymerization catalyst system.

As mentioned above, the reaction injection molding method of the present invention uses two solutions, the solution containing the catalyst component of the metathesis vehicle combination catalyst system (solution A), and the solution containing the active agent component (B). After impact mixing, the mixture is press-fitted into a mold and polymerized.

Catalyst components in the metalesis polymerization catalyst system in such molding include tungsten and rhenium.

Salts such as halides such as tantalum and molybdenum are used, and tungsten compounds are particularly preferred. As such a tungsten compound, tungsten halide, tungsten oxyhalide, etc. are preferable, and more specifically, tungsten hexachloride, tungsten oxychloride, etc. are preferable. Furthermore, organic ammonium tungstate and the like can also be used. It is known that when such a tungsten compound is directly added to a monomer, cationic polymerization starts immediately, which is not preferable. Therefore, it is preferable to use such a tungsten compound by first suspending it in an inert solvent such as benzene, toluene, chlorobenzene, etc., and solubilizing it by adding a small amount of an alcoholic compound and/or a phenolic compound.

Generally speaking, in order to prevent undesirable polymerization as described above, it is preferable to add about 1 to 5 moles of a Lewis base or a chelating agent per mole of the tungsten compound. Darkening additives include acedelacetone and acetoacetic acid alkyl esters.

Examples include tetrahydrofuran and benzonitrile. When a polar monomer is used, as described above, it may itself be a Lewis base, and it may have the effect even without the addition of any of the above-mentioned compounds. Thus, the monomer solution containing the catalyst component (solution A
) has sufficient stability for practical use.

The active agent component in the metathesis polymerization catalyst system is an organometallic compound centered on a fully diluted alkylated compound of Groups 1 to 2 of the periodic table, especially tetraalkyltin, alkylaluminum compounds, and alkylaluminum halide compounds. Preferred examples include diethylaluminum chloride, ethylaluminum dichloride, trioctylaluminum, dioctylaluminum iotide, and detrabutyltin. The other solution (corresponding to solution B) is formed by dissolving the organometallic compound as the active ingredient in the raw material monomer.

In this Komei, a crosslinked polymer molded product can basically be obtained by mixing the solution A and solution B, but if the above composition remains unchanged, the polymerization reaction will start very quickly, so the molded Hardening may occur before it has sufficiently flowed into the casting mold, which is often a problem, and as mentioned above, it is preferable to use an activity regulator for this purpose.

As such regulators, Lewis bases are generally used, among which ethers, esters, nitriles, etc. are used. Specific examples include ethyl benzoate, butyl ether, and diglyme. Such regulators are generally added to the solution of the organometallic compound activator component. When a monomer having a Lewis space group is used as in Zenju, it can serve as a regulator.

The amount of the metathesis polymerization catalyst system to be used is, for example, when a tungsten compound is used as a catalyst component, the ratio of the tungsten compound to the raw material intermediate is about 1 on a molar basis.
000:1 to 15000:1, preferably 2000:1
In addition, when an alkyl aluminum is used as the active ingredient, the ratio of the aluminum compound to the raw material intermediate is about 100:1 to about i on a molar basis.
ooo to 1, preferably about 200:1 to about 500:1
The vicinity of is used.

Furthermore, as described above, the masking agent and regulating agent can be appropriately adjusted and used depending on the period of use of the catalyst system through experiments.

In practical use, various additives may be added to the crosslinked polymer molded product produced by the reaction injection molding method of the present invention in order to improve or maintain its properties. Such additives include fillers, pigments, antioxidants, light stabilizers, flame retardants.

Examples include polymer modifiers. Such additives are the key to the invention! Since it is impossible to add it after the polymer is molded, it is necessary to add it to the above-mentioned raw material solution in advance when adding it.

The easiest method is to use the solution A and solution B.
One method is to add it in advance to either or both of the above, but in that case, it does not react with the highly reactive catalyst component or other active agent components in the liquid to an extent that would pose a practical problem. In addition, it must not inhibit polymerization. If the reaction cannot be avoided, but coexistence does not substantially inhibit polymerization, it can be mixed with the monomer to prepare a third liquid and mixed and used immediately before polymerization. . In addition, in the case of a solid filler, if the filler is in a shape that can sufficiently fill the voids immediately before or during polymerization when both components are mixed, the filler may be placed in the mold. It is also possible to fill it.

Reinforcements or fillers as additives are effective in improving the flexural modulus. Examples of such materials include glass fiber, mica, carbon black, and wollastonite. Those surface-treated with a so-called silanga puller can also be suitably used.

Further, it is preferable to add an antioxidant to the crosslinked polymer molded product obtained by the reaction injection molding method of the present invention, and therefore, it is preferable to add a phenol-based or amine-based antioxidant to the solution in advance. is desirable. Specific examples of these antioxidants include 2,6-t-butylene-P-cresol, N,No-diphenyl-P-phenylenediamine, and tetrakis[medylene (3,5-di-t-butyl-
Examples include 4-hydroxycinnamate)] methane.

Furthermore, other polymers can be added to the polymer molded product produced by the reaction injection molding method of the present invention in a monomer solution state. As such polymer additives, addition of an elastomer is effective in increasing the impact resistance of the molded product and adjusting the viscosity of the solution. Elastomers used for this purpose include a wide range of elastomers, including styrene-butadiene-styrene triblock rubber, styrene-isoprene-brene triblock rubber, polybutadiene, polyisoprene, butyl rubber, ethylene-propylene-diene terpolymer, and nitrile rubber. I can give you.

A reaction solution A and a reaction solution B, which are composed of each component as described above, are prepared. Generally, the concentrations of the main catalyst and activator in Solution A and Solution B are preferably adjusted so that the above-mentioned polymerizability peaks when equal volumes of the solutions are injected.

In this way, as long as the activity of the solution is good, a good crosslinked molded product can be obtained by reaction injection molding, but as mentioned above, if both solutions are left for a long time after preparation, the polymerizability of the reaction solution will decrease. may decrease. The storage period during which such deterioration becomes severe depends on the degree of sealing and temperature of storage.

It greatly depends on the purity of the raw materials used to prepare the liquid, the skill of the preparation method, etc., and there are various cases such as cases where it does not have sufficient polymerization activity immediately after preparation, and cases where it seems that it has been stored for several months or more. .

However, the degree of deterioration in polymerization activity can be measured by the test method described above, such as the length of time compared to a standard sample polymerized under the best conditions, and the properties of the molded product actually attempted. Accordingly, it can be similarly detected by an increase in the residual monomer 1 or a decrease in the secondary transition point compared to that from the standard sample. For such reactive solutions,
Depending on the degree, the catalyst component may be added in excess, the excess amount corresponding to the required degree of recovery may be selected, and molding may be performed at that ratio.

One way to make the catalyst component excessive is to add the catalyst component to the solution A side, but in practice it is best to adjust the injection amounts of both solution A and the hot solution in the injection machine. The method of injecting an excessive amount of solution A is easier to carry out, and it is also advantageous in terms of cost since the concentration of the catalyst component and activator component used as a whole does not need to be increased.

According to the present invention, even from a liquid with degraded polymerization activity, a molded product with good properties can be produced by 1q, making it possible to greatly improve the practicality of reaction injection molding using metathesis polymerization.

Unlike the case of polyurethane, molded products made by reaction injection molding using metathesis Φ combination are generally easy to release from the mold even from the side surface, which is an exact replica of the mold surface, and especially when released from the mold. Often no medication is required.

In addition, in the case of metathesis polymerization, the molded product has double bonds remaining, which forms an oxidized layer on the surface, so that it has good adhesion to commonly used paints such as epoxy and polyurethane.

Metalhesis polymer molded products obtained by such reaction injection molding methods can be used in a wide range of applications, including large molded products such as parts for various transportation equipment such as automobiles and motorcycles, and housings for electrical and electronic devices.

The present invention will be described in detail below with reference to Examples. Note that the examples are merely for explanation and are not limited thereto.

Examples 1-6. Comparative Examples 1 to 7 [Preparation of Catalyst Component Solutions] Triocdyl aluminum and dioctyl aluminum iodide were used in a molar ratio of 85:15 and mixed with purified dicyclopentadiene to give an aluminum content of 0.
Solution B of 0038 was prepared.

(In addition, the capacity part and the heavy part in the above are 1rIIi and 1
(J.

11 and 1K (assuming that they correspond) such a solution A,
Take about 10 rdl of the hot solution into a syringe that has been kept at a constant temperature and replaced with nitrogen, and from the syringe, both liquids are simultaneously pushed out at a constant rate into a glass flask equipped with a stirrer with a thermocouple attached, under rapid stirring. Mixed. 100 from the time the liquid is injected from the syringe
When we measured the time it took to reach ℃ and used it as a guideline for polymerization, we found that the minimum time for each case of 10 d,
It was confirmed that the polymerizability was maximized when equal volumes were mixed.

These solutions A and B were stored at a temperature of 30°C for a long time under closed conditions, and the solutions whose polymerization times increased by 25% and 35% according to the above measurement method were taken out, and both the original solution and Niigata 3mm thick using ironworks reaction injection molding machine
A plate-shaped sample was molded by changing the injection ratio of liquid A and liquid B, and the Tg and residual monomer amount were measured using the DMA method.

The residual amount of dicyclopentadiene is determined by immersing 1 g of sample in 100 d of toluene for a long time, and 1 g of dicyclopentadiene extracted.
This is the value determined by gas chromatography.

The above results are summarized in Table 1 together with comparative examples.

From the above results, it is clearly seen that the lower the polymerizability of the liquid, the greater the effect of using an excess of liquid A.

Examples 7-9. Comparative Examples 8 to 11 All were carried out in the same manner as Examples 1 to 6, except that a mixture of 95 mol% dicyclopentadiene and 5 mol% ethylidene norbornene was used instead of dicyclopentadiene alone, and the results were shown in Table 2 below. The result was 19.

From the results of the above evaluation, it is clear that the effect of using the A liquid side in excess of the optimum value in terms of polymerization time is clear.

Claims (1)

[Claims] A reactive solution (solution A) of a metathesis polymerizable monomer containing at least a catalyst component of a metathesis polymerization catalyst system;
A reactive solution of a metathesis polymerizable monomer containing at least an activator component for a metathesis polymerization catalyst system (solution B)
In a reaction injection molding method for obtaining a crosslinked polymer molded article by rapidly mixing a combination of reactive solutions consisting of at least one of the following by impingement mixing and pouring into a mold, the proportions of the catalyst component and the activator component used are: A reaction injection molding method characterized in that the catalyst component is used in excess of 50 mol % or less than the ratio that gives the fastest polymerization rate.