JP3145539B2 - Method for producing crosslinked polymer molded article - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for producing a crosslinked polymer molded article of a cyclic olefin. More specifically, the present invention relates to a method for producing a crosslinked polymer molded article having a small amount of air bubbles and excellent physical properties.

Conventionally, a monomer solution comprising a metathesis polymerizable cyclic olefin containing a catalyst component of a metathesis polymerization catalyst system (also referred to as a metathesis catalyst system) and a monomer solution comprising a metathesis polymerizable cyclic olefin containing an activator component are used. Mixing (in this specification, this mixed
Nomer liquid is sometimes referred to as raw material mixture or mixture) ,
A method for producing a crosslinked polymer molded article by injecting it into a mold and polymerizing and crosslinking in the mold is known (for example, Japanese Patent Publication No.
-28451).

This reaction injection molding method can use easily available raw material monomers, has low viscosity of monomers and low injection molding pressure, has a fast polymerization / crosslinking reaction, has a short molding cycle, and has a large molded product. And the molded article have excellent advantages such as a good balance between rigidity and impact resistance.

In the above reaction injection molding method, the polymerization / crosslinking reaction is extremely fast due to high reactivity, and the reaction is usually completed within a mold within several minutes after the injection of the raw material mixture.
Often less than a minute. After the two monomer liquids are mixed because the reaction is fast, the raw material mixture is injected into a mold through a short pipe. This raw material mixture is mainly composed of a cyclic olefin monomer, and its viscosity is extremely low as compared with the case of injection molding of a usual resin.

[0005] The reaction injection molding method is characterized in that it is easy to obtain a large molded product due to the low viscosity of the raw material mixture to be injected and that an expensive heat-resistant mold is not required. It is a great advantage.

However, since the raw material mixture has a low viscosity, is injected into a mold at a high speed, and the polymerization reaction is extremely fast, bubbles are easily generated in the mold due to gas being introduced into the mold. May be taken in. In particular, it has been found that bubbles generated at the start of the injection of the raw material mixture or at the initial stage may remain as bubbles on the surface of the molded article.

[0007]

Therefore, the present inventors have conducted various studies on a method in which bubbles are not generated in a mold by rapid injection of a raw material mixture. In particular, research was conducted on a method of suppressing generation of bubbles in a mold and not adversely affecting the characteristics of a molded product by injecting a raw material mixture.

As a result, by adding a soluble polymer substance to the raw material mixture to increase the viscosity of the raw material mixture,
It has been found that the generation of air bubbles in the mold can be suppressed, and in particular, that the viscosity of the raw material mixture at 300 ° C. is not less than 300 cps is desirable for suppressing the generation of air bubbles.
In this specification, the unit of the viscosity of the raw material mixture "cps"
Means centipoise measured at 30 ° C. unless otherwise specified.

On the other hand, if the viscosity is too high, the energy required for preparing the raw material mixture becomes large, and the mixing may become insufficient. In addition, a large amount of energy is required for the supply. Therefore, from this point, it is desirable that the speed be 1800 cps or less.

In order to adjust the viscosity to 300 to 1800 cps by mixing and dissolving a high-molecular substance in the raw material mixture, a large amount of a high-molecular substance, usually 3 to 25% by weight, must be added to the raw material mixture. Must. However, it has been found that a molded article obtained from such a raw material mixture to which a large amount of a polymer substance has been added has rather adverse effects such as low heat resistance. In addition, when a large amount of a high-molecular substance is added, the reaction may be hindered by various additives contained in the high-molecular substance, and the high-molecular substance is often expensive, resulting in an increase in product cost. This also increases the energy required for injecting the raw material mixture.

Therefore, the inventor of the present invention increased the viscosity of the raw material mixture to be injected into the mold at the beginning of the injection at 300 to 1800 cp.
s, and thereafter, by injecting a low-viscosity raw material mixture, the presence of air bubbles on the surface of the obtained molded article is not recognized, and the decrease in heat resistance of the molded article is substantially allowed. Was found to be about. In addition, it was also found that even if a usual low-viscosity raw material mixture was injected from the middle, the generation of bubbles was small, and even if it was generated, the presence thereof was not a problem because it was confined inside the molded article.

[0012]

DISCLOSURE OF THE INVENTION The present invention has been achieved based on the above-mentioned findings, and comprises a monomer liquid A (solution A) comprising a metathesis polymerizable cyclic olefin containing a catalyst component of a metathesis polymerization catalyst system. A monomer solution B (solution B) comprising a metathesis-polymerizable cyclic olefin containing an activator component of a metathesis polymerization catalyst system is mixed, and the mixed solution is injected into a mold to perform polymerization and crosslinking reaction in the mold. In the method for producing a crosslinked polymer molded article at least, when the volume of the mixed solution to be injected into the mold is 100 V by volume, (1) an arbitrary amount of 1 V to 50 V from the start of injection. The mixed liquid [I] adjusted to a viscosity of 300 to 1800 cps is injected into the mold until the mixed liquid is injected, and (2) the mixed liquid is injected at the start of the injection until the injection is completed. The viscosity of the liquid More 200c.p.s low, and 10
A method for producing a crosslinked polymer molded article, which comprises injecting a mixed liquid [II] adjusted to a viscosity of about 500 cps into a mold.

As described above, according to the method of the present invention, a certain percentage of the total amount of the raw material mixture to be injected into the mold is increased by adding a polymer substance to increase the viscosity. Thereafter, a raw material mixture containing no polymer substance or adjusted to a low viscosity with a small content is injected. Thus, in the method of the present invention, the generation of bubbles in the mold at the beginning of the injection of the raw material mixture is suppressed,
A molded article with few bubbles can be obtained.

[0014] In addition, despite the fact that a relatively large amount of a high-molecular substance was added to the raw material mixture at the beginning of the injection, the compounding ratio of the high-molecular substance in the molded article as a whole was high. Since it is kept low, problems of physical properties such as a decrease in heat resistance are sufficiently acceptable.

Conventionally, when a crosslinked polymer molded article of a cyclic olefin is obtained using a metathesis polymerization catalyst system, a method of adding a high-molecular substance (high-molecular-weight improving agent) to a raw material mixture is known (Japanese Patent Publication (Kokoku) Heisei). 4-9812). The method described in this publication aims to increase the impact resistance of a molded product by adding a polymer substance, particularly an elastomer, by 5 to 10 times as compared with the case where no polymer substance is added.

According to another study by the present inventors, in order to improve the impact resistance of a crosslinked cyclic olefin polymer molded article,
The addition of polymeric modifiers, especially elastomers, is generally a few percent
(Weight) may be sufficient, and even if it is added more, the impact strength does not always improve as the amount of addition increases, and if it exceeds about 10% (weight), the heat resistance tends to decrease.

When a polymer modifier is added to improve the impact resistance, the raw material mixture may not reach the viscosity of the raw material mixture [1] at the beginning of the injection in the method of the present invention.
On the other hand, the viscosity (300 to
1800c. p. when molded using the raw material mixture having a s) from the start to the completion of the injection, the higher the content of the polymer material, lowering of heat resistance of the molded article, high cost, due to the additives in the polymer material Obstructions such as adverse effects and an increase in injection pressure are often inevitable .

Hereinafter, the method of the present invention will be described more specifically. In the method of the present invention, as the metathesis polymerizable cyclic olefin for forming the crosslinked polymer, one containing one or two metathesis polymerizable cycloalkene groups in the molecule is used. Preferably, it is a compound having at least one norbornene skeleton in the molecule. Specific examples of these include dicyclopentadiene, tricyclopentadiene, cyclopentadiene-methylcyclopentadiene co-dimer, 5-ethylidene norbornene, norbornene, norbornadiene, 5-cyclohexenylnorbornene, 1,4,5,8-dimetano. -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- One,
4,4a, 5,6,7,8,8a-octahydronaphthalene,
6-ethylidene-1,4,5,8-dimetano-1,4,4a,
5,6,7,8,8a-Heptahydronaphthalene, 1,4,
5,8-Dimethano-1,4,4a, 5,6,7,8,8a-hexahydronaphthalene, ethylenebis (5-norbornene), and the like, and a mixture thereof can also be used. In particular, dicyclopentadiene or a mixture containing 50 mol% or more, preferably 70 mol% or more thereof is suitably used. Further, if necessary, a metathesis polymerizable cyclic olefin having a polar group containing a different element such as oxygen or nitrogen can be used as a copolymer monomer. Such a copolymer monomer preferably has a norbornene structural unit, and the polar group is preferably an ester group, an ether group, a cyano group, an N-substituted imide group, a halogen group, or the like. Specific examples of such a copolymerized monomer include 5-methoxycarbonylnorbornene,
(2-ethylhexyloxy) carbonyl-5-methylnorbornene, 5-phenyloxymethylnorbornene,
-Cyanonorbornene, 6-cyano-1,4,5,8-dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene, N-butylnadecimide, 5-chloronorbornene, etc. Can be mentioned.

The monomer solution A (solution A) in the present invention contains a catalyst component of a metathesis polymerization catalyst system. As such a catalyst component, salts such as halides of metals such as tungsten, rhenium, tantalum and molybdenum are used, and a tungsten compound is particularly preferable. As such a tungsten compound, tungsten hexahalide, tungsten oxyhalide and the like are preferable, and more specifically, tungsten hexachloride, tungsten oxychloride and the like are preferable. Further, an organic ammonium tungstate or the like can be used. It has been found that such a tungsten compound immediately starts cationic polymerization when added directly to a monomer, which is not preferable. Therefore, it is preferable that the tungsten compound is used by suspending it in an inert solvent such as benzene, toluene, chlorobenzene or the like in advance and solubilizing by adding a small amount of an alcohol compound and / or a phenol compound. Further, as described above, it is preferable to add about 1 to 5 mol of a Lewis base or a chelating agent to 1 mol of the tungsten compound in order to prevent undesired polymerization. Examples of such additives include acetylacetone, alkyl acetoacetates, tetrahydrofuran, and benzonitrile. When a polar monomer is used, as described above, the polar monomer itself may be a Lewis base, and in some cases, the compound may have its action without adding any of the above compounds. As described above, the monomer liquid A containing the catalyst component (solution A) has substantially sufficient stability.

On the other hand, the monomer solution B (solution B) of the present invention contains an activator component of a metathesis polymerization catalyst system. The activator component is preferably an organometallic compound centered on an alkylated metal of Group I to Group III of the periodic table, particularly a tetraalkyltin, alkylaluminum compound, or alkylaluminum halide compound. Examples thereof include diethyl aluminum, ethyl aluminum dichloride, trioctyl aluminum, dioctyl aluminum iodide, and tetrabutyl tin. A monomer liquid B (solution B) is formed by dissolving the organometallic compound as an activating component in a monomer.

Basically, a cross-linked polymer molded article can be obtained by mixing the solution A and the solution B and injecting the mixture into a mold. Since it is started, curing may occur while not sufficiently flowing into the molding die, and often causes a problem. Therefore, it is preferable to use an activity regulator.
As such a regulator, Lewis bases are generally used, and above all, ethers, esters, nitriles and the like are used. Specific examples include ethyl benzoate, butyl ether, diglyme and the like.
Such a regulator is generally used by being added to the solution (solution B) of the component of the activator of the organometallic compound. When a monomer having a Lewis base is used as described above, it can also serve as a regulator.

The amount of the metathesis polymerization catalyst system used is, for example, when a tungsten compound is used as a catalyst component, the ratio of the tungsten compound to the raw material monomer is as follows:
It is about 1,000 to 1 to 1,5000 to 1, preferably about 2,000 to 1, on a molar basis. When an alkyl aluminum is used as the activating component, the aluminum compound based on the starting monomer is used. The ratio is used on a molar basis of about 100: 1 to 5,000: 1, preferably around 200: 1 to 500: 1. Further, as described above, the masking agent and the adjusting agent can be appropriately adjusted and used according to the amount of the catalyst system to be used by experiments.

In the method of the present invention, a raw material mixture obtained by mixing the solution A and the solution B is basically injected into a mold to obtain a crosslinked polymer molded article. At that time, in the method of the present invention, when the total amount of the raw material mixture to be injected into the mold is 100 V by volume, the raw material mixture having an amount of 1 V to 50 V, preferably 5 V to 40 V is added to the polymer mixture by adding 300 to 300 V. 1800 cp
s, preferably from 500 to 1500 cps, and inject from the beginning of the injection. The raw material mixture [I] having this increased viscosity is introduced into a mold from the start of injection. After the completion of the injection of the raw material mixture [I], the injection of the raw material mixture [II] is subsequently performed. The raw material mixture [II] has a viscosity lower than that of the mixture [I] by 200 cps and has a viscosity of 10 to 500 cps, preferably 20 to 300 cps. The injection amount of the raw material mixture [II] is 99 V to 50 V, preferably 95 V to 60 V, when the total injection amount is 100 V in volume.

The raw material mixture immediately after mixing the solution A and the solution B, when no polymer substance is added, is usually about 1%.
It has a viscosity of 0 cps or less. A polymer substance is added to the raw material mixture [I] used at the beginning of the injection to adjust the viscosity.

As the polymer substance to be used, those which are soluble in cyclic olefins and do not inhibit or hardly inhibit the polymerization reaction are preferable. Particularly preferred are those having an effect on improving the physical properties of the molded article, particularly the impact strength. Preferred examples of such high molecular substances include olefin-based elastomers and diene-based elastomers. Specific examples include styrene-butadiene-styrene block rubber, styrene-isoprene-styrene block rubber, polybutadiene, polyisoprene, butyl rubber, and ethylene propylene. -A wide range of elastomers such as diene terpolymers, nitrile rubbers. Other polymer materials include resins such as polystyrene, styrene acrylonitrile copolymer, methacrylic resin, petroleum resin, vinylidene chloride, polyethylene, polypropylene, and copolymers of ethylene and propylene.

In carrying out the method of the present invention, a polymer substance may be added to one or both of the solution A and the solution B in advance, but it is preferable that the polymer be separately added to these solutions. The point is to prepare a cyclic olefin solution (solution C) containing a substance at a high concentration. First, solution A,
The solution B and the solution C are mixed by collision at an appropriate ratio with a mixing head to adjust the raw material mixture [I] to start injection, and the supply of the solution C to the mixing head is reduced or stopped at an appropriate time. Then, the raw material mixture [II] may be adjusted and the injection may be continued until the end.

In the practical use of the crosslinked polymer molded product according to the present invention, various additives can be blended in order to improve or maintain its properties. Such additives include fillers, pigments, oxidative spinning agents, light stabilizers and the like. Such an additive can be used as a viscosity modifier similarly to the above-mentioned polymer substance.

The easiest method is to use the solution A
And either or both of the solution B and the solution B in advance. In such a case, the reaction with the strongly reactive catalyst component or the activator component in the solution may be practically supported. And must not inhibit polymerization. If the reaction is inevitable but the polymerization does not substantially inhibit the coexistence,
It can be added to the solution C and mixed.

The filler is effective in improving the bending modulus. Such materials include fiberglass, mica,
Examples include carbon black and wollastonite. Those surface-treated with a silane coupler or the like can be suitably used.

It is desirable to add a phenol or amine antioxidant to the solution in advance. Specific examples of these antioxidants include 2,6-di-t-butyl-p-cresol, N, N'-diphenyl-p-phenylenediamine, tetrakis [methylene (3,5-di-t-
Butyl-4-hydroxycinnamate)] methane and the like.

[0031]

According to the present invention, the formation of air bubbles in the mold can be suppressed, and a crosslinked polymer molded article having a smooth surface free of air bubbles can be obtained. In addition, the molded article shows almost no decrease in heat resistance and maintains excellent properties.

[0032]

The method of the present invention will be specifically described below with reference to examples. Example 1 (1) Preparation of Catalyst Component Solution (A-1) 20 parts by weight of tungsten hexachloride was added to 70 parts by weight of dry toluene under a nitrogen stream, and then nonylphenol 2 was added.
A 0.5 M solution of tungsten-containing catalyst was prepared by adding a solution consisting of 16 parts by weight of toluene and 16 parts by weight of toluene, and the solution was purged with nitrogen gas overnight to produce a solution formed by the reaction of tungsten hexachloride with nonylphenol. Hydrogen chloride gas was removed, and 1 part by volume of acetylacetone was further added to 10 parts by volume of the solution to prepare a polymerization catalyst. Based on a monomer mixture consisting of 95 parts by weight of purified dicyclopentadiene and 5 parts by weight of purified ethylidene norbornene, 3.5 parts by weight of an ethylene-propylene-ethylidene norbornene polymerized rubber containing 70 mol% of ethylene, and 2 parts by weight of ethanolox 702 as an oxidation stabilizer Was added to the above solution, and the solution of tungustine in the solution was added.
The solution (A-1) containing the catalyst component was prepared by adding so as to be mol / l. The viscosity of this solution (A-1) is 3
It was 200 cp at 0 ° C.

(2) Preparation of Catalyst Component Solution (A-2) In the above (1), except that 4.5 parts by weight of an ethylene-propylene-ethylidene norbornene polymer rubber containing 70 mol% of ethylene was used in the above (1). In the same manner as in the above, a catalyst component solution (A-2) was prepared. This solution (A-2)
Was 500 cp at 30 ° C.

(3) Preparation of Activator Component Solution (B-1) A polymerization activator mixed solution prepared by mixing and adjusting the molar ratio of trioctyl aluminum 85, dioctyl aluminum iodide 15, and diglyme 100 to purified dicyclopentadiene A mixture consisting of 95 parts by weight, 5 parts by weight of purified ethylidene norbornene, and 3.5 parts by weight of an ethylene-propylene-ethylidene norbornene polymerized rubber containing 70 mol% of ethylene was mixed at a ratio of 0.03 mol / l of aluminum. A solution (B-1) containing an activator component was prepared. The viscosity of the solution (B-1) is 30 ° C.
Was 200 cp.

(4) Preparation of Activator Component Solution (B-2) In the above (3), except that 4.5 parts by weight of an ethylene-propylene-ethylidene norbornene polymer rubber containing 70 mol% of ethylene was used. An activator component solution (B-2) was prepared in the same manner as in 3). This solution (B-
The viscosity of 2) was 500 cps at 30 ° C.

(5) Preparation of Solution C A solution C comprising 95 parts by weight of purified dicyclopentadiene, 5 parts by weight of purified ethylidene norbornene, and 6.5 parts by weight of an ethylene-propylene-ethylidene norbornene polymer rubber containing 70 mol% of ethylene was prepared. did. Solution C had a viscosity of 2500 cps at 30 ° C.

(6) Production of Molded Articles Using the equipment as shown in FIG. 1, under a nitrogen atmosphere, the solutions A-1, B-1 and C were placed in the storage tanks 1, 2 and 3, respectively. The injection was performed under the conditions shown in FIG. In FIG. 1, 1 is a storage tank for solution A-1, 2 is a storage tank for solution B-1, and 3 is a storage tank for solution C. The respective solutions are circulated between the mixing head 7 and the storage tanks 1, 2, 3 by pipes 4, 4 ', 5, 5' and 6, 6 ', respectively.
When a signal for injection into the mold 8 is transmitted, the flow path in the mixing head 7 is changed, and the solution A, the solution B, and the solution C are changed.
Is injected into the space in the mixing head 7, and the mixing of the respective solutions is usually achieved by collision during the injection. At this time, the injection of the solution A-1, the solution B-1 and the solution C was simultaneously started, and the injection of the solution C was completed earlier than the injection of the solution A-1 and the solution B-1.

The solution A-1 was injected at a rate of 350 g / second, the solution B-1 was injected at a rate of 350 g / second, and the solution C was injected at the rate shown in Table 1. The term "elastomer concentration" in the table when the total injection volume was 100 V (volume), soluble from the start of injection
The viscosity of the mixture (% by weight) of the mixture while the injection of the liquid C is continued , and the viscosity refers to the viscosity of the mixture (c.
p. s). Die 8 is 550mm × 550mm × 4
An iron mold having a plate-shaped space of mm was used, and an injection component exceeding the amount filling the space overflowed into a container (liquid pool) provided at the exit of the mold. The mold temperature was previously 90 ° C. on one side and 60 ° C. on the other side.
One minute after the end of the injection, the mold was opened to obtain a molded product. FIG.
FIG. 2 is a cross-sectional view of the mold, in which 9 is a liquid inlet, 11 is a liquid pool, and 12 is a vent. At the start of the liquid injection, the injected liquid flows as indicated by the arrow, but falls downward when entering the mold, causing a disturbance in the flow, resulting in the generation of bubbles as shown in the enlarged view of FIG. May be. The “bubble state” in Table 1 is a result of observing the state of the bubble generated in this way from a molded product.

The results obtained are summarized in Table 1.

[0040]

[Table 1]

Example 2 An iron mold having a plate-shaped space of 550 mm × 550 mm × 10 mm was used for the solution A-2.
g / sec, solution B-2 was injected at a rate of 400 g / sec, solution C was injected at a rate shown in Table 2, and the injection time of each solution shown in Table 2 was changed to (6) of Example 1. ) A molded product was obtained in the same manner as in the production of the molded product. The results are summarized in Table 2.

[0042]

[Table 2]

[0043]

[Brief description of the drawings]

FIG. 1 shows a schematic diagram of an apparatus for carrying out the method of the invention.

FIG. 2 shows a cross-sectional view and a partially enlarged view of a mold used in an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Storage tank 2 Storage tank 3 Storage tank 4 Piping 4 'Piping 5 Piping 5' Piping 6 Piping 6 'Piping 7 Mixing head 8 Mold 9 Liquid inlet 10 Bubble generator 11 Liquid pool 12 Vent

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takamasa Asano 2-1 Hinodemachi, Iwakuni-shi, Yamaguchi Prefecture Teijin Hercules Co., Ltd. Technical Center (56) References JP-A-3-223310 (JP, A) JP-A-3-164216 (JP, A) JP-A-3-115322 (JP, A) JP-A-2-239915 (JP, A) JP-A-1-221415 (JP, A) JP-A-63-241008 ( JP, A) JP-A-63-222824 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 45/00-45/84 C08G 61/06-61/08

Claims (5)

(57) [Claims] 1. A monomer liquid A (solution A) comprising a metathesis polymerizable cyclic olefin containing a catalyst component of a metathesis polymerization catalyst system and a monomer comprising a metathesis polymerizable cyclic olefin containing an activator component of a metathesis polymerization catalyst system Liquid B (solution B) is mixed, and the mixed solution is poured into a mold, and polymerized and cross-linked in the mold to produce a crosslinked polymer molded article. When the volume of the mixed solution was set to 100 V by volume, (1) the viscosity was adjusted to 300 to 1800 cps from the start of the injection to the injection of an arbitrary amount of the mixed solution of 1 V to 50 V. The mixture [I] is poured into a mold, and (2) after that, until the injection is completed, the viscosity of the mixture [I] to be injected at the start of the injection is lower than 200 cps and 10 to 5 times.
A method for producing a crosslinked polymer molded article, comprising: injecting a mixed solution [II] adjusted to a viscosity of 00 cps into a mold. 2. The viscosity of the mixed liquid [I] is from 500 to 1500.
2. The method according to claim 1, wherein the method is adjusted to cp. 3. The mixed solution [I] has a voltage of 5 V after the start of injection.
The method according to claim 1, wherein an amount of -40V is injected into the mold. 4. The mixed solution [II] is two times more than the mixed solution [I].
00cps or less viscosity and 20-300cps
2. The process according to claim 1, which has a viscosity of: 5. The method according to claim 1, wherein the mixture [I] contains an olefin-based elastomer and / or a diene-based elastomer.