JP3130688B2 - 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 an improved method for producing a crosslinked polymer molded product by simultaneously polymerizing and molding a metathesis polymerizable cyclic olefin in a mold in the presence of a metathesis polymerization catalyst. More specifically, the present invention relates to a method for preventing a dent or a lead-through appearing on a showside surface opposite to a place where bosses and ribs are present in a molded product to obtain an excellent molded product.

[0002]

It is known that cyclic olefins give ring-opened polymers with metathesis polymerization catalysts. Therefore,
A method has been proposed in which a liquid metathesis-polymerizable cyclic olefin, such as dicyclopentadiene (DCP), which is inexpensively obtained, is polymerized and molded in one step in a mold using a metathesis polymerization catalyst to obtain a polymer molded product. That is, the metathesis polymerization catalyst system comprises a catalyst component such as tungsten chloride and an activator component such as an alkyl aluminum halide.
A method has been proposed in which a crosslinked polymer molded product is obtained by reaction injection molding by collision mixing using two kinds of liquids consisting of these two components and a monomer, taking advantage of the fact that the two components are composed of two components (for example, Japanese Patent Application Laid-Open No. 58-1983). -12913).

According to such a method, a large molded product having good performance can be obtained using an inexpensive low-pressure molding die.
This is an industrially attractive method. In this way,
Inexpensive molds generally used include a metal spraying mold such as a nickel electroforming mold and a zinc-based alloy, a metal casting mold such as an aluminum and zinc-based alloy, and a resin mold.

However, among these, except for the resin mold, a molding defect called lead-through tends to appear in the crosslinked polymerized product, and depending on the width of the boss and the root of the rib with respect to the product thickness, a good surface can be obtained. There are few molded products.

However, it is difficult to stably produce a large number of molded products in the resin mold due to restrictions on the physical properties of the resin, and a metal mold is generally used.

In such a case, the molding defect is inevitably repaired by post-processing to obtain a product. However, in such a method, the characteristics of the reaction injection molding method having a short molding cycle are lost, and the productivity is extremely poor. Become something.

As a solution to these problems, a method has been proposed in which a polytetrafluoroethylene sheet is attached to a mold (Japanese Patent Application Laid-Open No. 63-112123), but there is a problem that the method cannot cope with a complicated mold surface. In addition, according to this method, a good surface is obtained by sliding the sheet in close contact with the surface of the molded article due to shrinkage of the molded article. However, in practice, the monomer liquid enters between the sheet and the mold, and a practical problem such that a clean molding surface is not always obtained occurs.

[0008]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a method for producing a crosslinked polymer molded article by simultaneously polymerizing and molding a metathesis polymerizable cyclic olefin in a mold in the presence of a metathesis polymerization catalyst. The purpose of the present invention is to prevent lead-through and obtain an excellent molded product.

[0009]

Means for Solving the Problems The present inventors have prepared a metathesis polymerizable cyclic olefin in the presence of a metathesis polymerization catalyst.
In a method of simultaneously performing polymerization and molding in a mold to obtain a crosslinked polymer molded article, as a result of detailed examination of heat transfer on the mold surface, a heat insulating layer is provided in advance on the cavity side of a durable metal mold. As a result, it has been found that a molded article having a good surface can be obtained, and the present invention has been accomplished.

That is, the present invention relates to a method for preparing a monomer solution comprising a metathesis polymerizable cyclic olefin containing a catalyst component of a metathesis polymerization catalyst (solution A) and a metathesis polymerizable cyclic olefin containing an activator component of a metathesis polymerization catalyst. In the method of mixing a monomer liquid (solution B) to be mixed, injecting into a mold and polymerizing to produce a crosslinked polymer molded article, it is preferable to use a cavity mold in which a surface in contact with the molded article is coated with a heat insulating material. This is a method for producing a crosslinked polymer molded product.

This heat insulating material is for releasing non-uniform heat generated by self-heating during polymerization to the outside of the system while controlling the heat on the mold surface, and is based on the idea of JP-A-63-11223. Are essentially different.

If the thickness of the heat insulating material is too small, it does not function as a heat insulating material, and if it is too thick, heat dissipation takes time, and molding recycling is deteriorated. Accordingly, the thickness is suitably from 10 μm to 500 μm, and preferably from 20 to 500 μm. Even better results can be expected if the thickness of the heat insulating material is not only uniform over the entire cavity surface, but also the thickness of the portion corresponding to the ribs and bosses is increased.

The organic resin which can be used as a heat insulating material is preferably one which does not inhibit metathesis polymerization and resists the heat generated by the metathesis polymerization, but is preferably a thermosetting resin selected from tetrafluoroethylene, epoxy, polyester and phenolic resins. Organic resin is preferred, and the thermal conductivity is 3.0 × 1
^{0 -4 calS -1 cm -2 (Kcm} -1) -1 or more, preferably ^{3.0 × 10 -4 calS -1 cm -2} (Kcm -1) -1 from 6.0 × 10 ^-4 calS ^{- 1} cm ^-1 (Kcm ^-1 ) ^-1 and a heat resistant temperature of 220 ° C. or higher, preferably 220 to 260
° C.

As polytetrafluoroethylene, polytetrafluoroethylene (PTFE), polytetrafluoroethylene-hexafluoropropylene copolymer, polytetrafluoroethylene-ethylene copolymer, polychlorotrifluoroethylene-ethylene copolymer, A fluorine-containing polymer such as polyvinylidene fluoride, polyvinyl fluoride, m- (5-perfluoroisopropylphenylene) bis (perfluoroisopropylidene-glycidyl ether-based epoxy resin, or a blend of the fluorine compound and a polyamideimide resin; A blend of the above-mentioned fluorine compound phenol resin and phenol resin is used, and the trade name is L-4111BKM [Tokyo Silicone] or Spray CFC BU-73 [Norton].
And so on.

The epoxy resin is a resin containing bisphenol A type as a main component, and specific product names include High Resin L-2360 and PLAST CENTENT WR-71.

Examples of the polyesters include phthalic unsaturated polyesters, isophthalic unsaturated polyesters, vinyl ester unsaturated polyesters, and polyurethane polyesters.
tal [US CHEMICAL PLASTIC].

Novolak resins, resole resins, and methylol-containing phenol resins are phenol-based resins, and specific trade names are Bellpearl S-890 or S-89.
5 [Kanebo] and the like.

The coating of the mold can be performed by spray coating, brushing, etc., and then curing the resin. There are cases where the composition is heated and cured immediately after application, and cases where the composition is heated and cured after being left at room temperature for a certain period of time.

Various additives can be further incorporated into the organic resin in order to improve or maintain its properties.
Such additives include fillers, pigments, antioxidants, light stabilizers, flame retardants, polymer improvers, and the like.

Further, a heat-resistant primer may be applied between the mold and the organic resin layer in order to increase the adhesive strength with the mold.

The coating is not limited to the cavity type,
There is no problem if it is performed on the core type.

In the present invention, the molding can be carried out by a reaction injection molding method (RIM) in which the monomer liquid is mixed by a mixing head, then injected into a mold, and polymerization and molding are performed simultaneously. In addition, depending on the monomer liquid to be used, mixing can be performed by a stirrer or a static mixer, and injection and molding can be performed with a longer time than the RIM method, that is, a so-called casting method.

The temperature of the mold at the time of molding is generally used by raising the temperature in order to smoothly carry out the curing reaction. In the case of curing in the present invention, the mold temperature is generally in the range of 50 to 110 ° C., and particularly in the range of 90 ° C. ± 10 ° C. as the showside. Blowing nitrogen into the mold in advance is effective in improving the surface properties of the molded product.

The metathesis polymerizable cyclic olefin used in the present invention has one metathesis polymerizable cycloalkene group.
Those containing up to two are used. Preferably, it is a compound having at least one norbornene skeleton in the molecule.

Specific examples thereof include dicyclopentadiene, tricyclopentadiene, cyclopentadiene, methylcyclopentadiene codimer, 5-ethylidene norbornene, norbornene, norbornadiene,
-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-1,4,4
a, 5,6,7,8,8a-octahydronaphthalene,
6-ethylidene-1,4,5,8-dimethano-1,4
4a, 5,7,8,8a-heptahydronaphthalene,
1,4,5,8-dimethano-1,4,4a, 5,8,8
Examples thereof include a-hexahydronaphthalene 1, ethylenebis (5-norbornene) and the like, and mixtures thereof can also be used. Particularly, didiclopentadiene or a mixture containing 50 mol% or more thereof is suitably used.

If necessary, a metathesis polymerizable cyclic olefin having a polar group containing a different element such as oxygen or nitrogen can be used for the copolymerization. Such a copolymerizable monomer also preferably has a norbornene structural unit, and as a polar group, an ester group, an ether group, a cyano group, 5-methoxycarbonylnorbornene,
5- (2-ethylhexyloxy) carbonyl-5-methylnorbornene, 5-phenyloxymethylnorbornene, 5-cyanonorbornene, 6-cyano-1,4
5,8-Dimethano-1,4,4a, 5,6,7,8,8
Examples thereof include a-octahydronaphthalene, N-butylnadic imide, and 5-chloronorbornene.

The molding in the present invention comprises a monomer solution (solution A) comprising a metathesis polymerizable cyclic olefin containing a metathesis polymerization catalyst component and a metathesis polymerizable cyclic olefin containing a metathesis polymerization catalyst activator component. This is a method of mixing a monomer solution (solution B) consisting of the above and injecting it into a mold, but a method of dividing the solution into three or more is also possible.

As the catalyst component in the metathesis polymerization catalyst system in such molding, salts such as halides of metals such as tungsten, rhenium, tantalum and molybdenum are used, and tungsten compounds are particularly preferable. As such a tungsten compound, tungsten hexachloride, tungsten oxyhalide, and the like are more preferable, and more specifically, tungsten hexachloride,
Tungsten oxychloride and the like are preferred. Also,
Organic ammonium tungstate can also 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, such a tungsten compound is suspended in an inert solvent such as benzene, toluene, chlorobenzene or the like in advance, and a small amount of an alcohol compound and
Alternatively, it is preferable to use it after solubilization by adding a phenolic compound.

As described above, in order to prevent undesired polymerization, about 1 to 1 mole of the tungsten compound is used.
It is preferred to add 5 moles of a Lewis base or chelating agent. Examples of such additives include acetylacetone, alkyl acetoacetates, tetrahydrofuran, benzonitrile and the like. 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. Thus, the monomer solution containing the catalyst component (solution A) has substantially sufficient stability.

On the other hand, the activator component in the metathesis polymerization catalyst system is an organometallic compound centered on an alkylated metal of Group I to Group III of the periodic table, especially a tetraalkyltin, an alkylaluminum compound, an alkylaluminum halide compound. And specifically, diethyl aluminum chloride, ethyl aluminum dichloride, and trioctyl aluminum. Dioctyl aluminum iodide, tetrabutyl tin, and the like can be given. The other solution (corresponding to solution B) is formed by dissolving the organometallic compound as the activator component in the monomer.

In the present invention, a crosslinked polymer molded product can be basically obtained by mixing the solution A and the solution B. However, if the above composition is maintained, the polymerization reaction starts very quickly. Therefore, the curing may occur while not sufficiently flowing into the mold, which often causes a problem, and as described above, it is preferable to use an activity modifier.

As such a regulator, Lewis bases are generally used, and among others, ethers, esters,
Nitriles and the like are used. Specific examples include ethyl benzoate, butyl ether, diglyme and the like. Such regulators are generally used in addition to the solution side of the component of the activator of the organometallic compound. When a monomer having a Lewis base is used in the same manner 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 about 1,000 to 15,000 to 1, preferably on a molar basis,
In the case where alkyl aluminums are used as the activator component, the ratio of the aluminum compound to the raw material monomer is about 1 on a molar basis.
00: 1 to 2000: 1, preferably about 200: 1 to 5
A neighborhood of 00: 1 is used. 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 practical use of the crosslinked polymer molded product obtained by the present invention, various additives can be further blended in order to improve or maintain its properties. Such additives include fillers, pigments, antioxidants, light stabilizers,
There are flame retardants, polymer improvers and the like. Such an additive cannot be added after the crosslinked polymer of the present invention has been formed, and therefore must be added to the above-mentioned raw material solution beforehand.

The easiest method is to use the solution A
And either or both of the solution B and the solution B in advance, but in this case, the catalyst does not react with the highly reactive catalyst component and activator component in the solution to a certain extent in practical use. And must not inhibit polymerization. In the case where the polymerization is not substantially inhibited even if the reaction cannot be avoided, the third liquid is prepared by mixing with the monomer, and the third liquid can be mixed and used immediately before the polymerization. A method is also conceivable in which the polymerization catalyst or the activator is used as the third liquid, and the above-mentioned additive is added to the solution A or the solution B containing no third liquid. Furthermore, in the case of a solid filler, both components are mixed, and immediately before the start of the polymerization reaction or while the polymerization is being performed, a shape that can sufficiently fill the voids is included in the mold.
It is also possible to fill.

[0036] Reinforcing agents or fillers as additives are effective in improving the flexural modulus. Such materials include glass fiber, mica, carbon black, wollastonite and the like. Those surface-treated with a silane coupler or the like can also be suitably used.

It is preferable that an antioxidant is added to the crosslinked polymer molded product obtained by the present invention, and therefore, a phenol or amine antioxidant is added to the solution in advance. desirable. Specific examples of these antioxidants include 2,6-t-butyl-P-cresol, N, N'-diphenyl-P-phenylenediamine,
Tetrakis [methylene (3,5-di-t-butyl-4-)
Hydroxycinnamate)] methane and the like.

Further, the crosslinked polymer molded product obtained according to the present invention can be added when another polymer is in a monomer solution state. As such a polymer additive, the addition of an elastomer is effective in increasing the impact resistance of the molded product and in adjusting the viscosity of the solution. Elastomers used for this purpose include a wide range of elastomers such as styrene-butadiene-styrene triblock rubber, styrene-isoprene-styrene triblock rubber, polybutadiene, polyisoprene, butyl rubber, ethylene propylene-diene polymer and nitrile rubber. Can be done.

In the molding according to the present invention, once the polymerization reaction is started in the mold, the temperature of the monomer rapidly rises due to the heat of reaction, and the polymerization reaction is completed in a short time.

[0040]

According to the present invention, an excellent molded article without lead-through can be obtained. Further, according to the present invention, since the mold surface is coated, almost no stain on the mold surface occurs at the time of molding, the operation of cleaning the stain is eliminated, and the molding cycle is improved. Furthermore, according to the present invention, not only the improvement of the lead-through but also the molding failure due to a defect on the mold surface such as a pinhole on the mold surface can be suppressed.

Therefore, the polymer molded product obtained by the present invention has very few defects on its surface, is of high quality, is excellent in cosmetics, has little thermal distortion, and is hardly subject to thermal deformation. It can be used for a wide range of applications, mainly large-sized molded products, such as members of various transport equipment including automobiles and motorcycles, and housings of electric and electronic equipment.

[0042]

The present invention will be described below with reference to examples. It should be noted that the examples are for explanation, and the present invention is not limited to them.

[0043]

Example 1 and Comparative Example 1 (Mold) A mold having a sectional shape shown in FIG. 1 was used.
The dimensions of the mold cavity are 500mm wide, 700mm long,
The depth is 200 mm.

The surface of the cavity mold is made of nickel electroforming, and the surface of the core mold is made of aluminum. Spray CFC BU-73 (manufactured by Norton) with a thickness of 30 on the surface of the cavity mold
μm, leave at room temperature for half a day,
For 4 hours. (Monomer solution) A solution A of Teijin Hercules T02 containing dicyclopentadiene was mainly used as solution A. Further, a solution B of T02 manufactured by Teijin Hercules Co., Ltd. mainly containing dicyclopentadiene was used. (Molding) A mold heated to a cavity mold of 80 ° C. and a core mold of 50 ° C. was used. The molding was performed in the following procedure. After closing the mold, the solutions A and B were mixed by a mixing head, and the mixed solution was injected into the cavity. The injection time was 7.3 seconds, and 30 seconds after filling, the mold was opened and the molded product was taken out. (Measurement of lead-through) The lead-through appearing in the portion corresponding to the rib portion and the boss portion of the obtained molded product was measured by SURFCOM manufactured by Tokyo Seimitsu Co., Ltd. This device is a stylus type, and measures the unevenness of a cross section of a molded product by scanning a needle over the surface of the molded product.

The results are shown in Table 1. For comparison, the depth of the lead-through at the position indicated by 5 in FIG. 1 when molding was performed under the same conditions except that a mold without coating was used is shown as Comparative Example 1. In other examples and comparative examples, the lead-through was measured in the same manner as in Example 1.

[0046]

Example 2 and Comparative Example 2 In the cross-sectional shape shown in FIG. 2, the dimensions of the cavity of the mold were 300 mm in width, 500 mm in length, and 60 mm in depth. Was obtained under the same conditions as in Example 1 except that L-4111BKM (Tokyo Silicone) shown in Table 1 was used and the injection time was set to 2.3 seconds. 5 in FIG.
Table 1 shows the depth of the lead-through at the position indicated by.

Comparative Example 2 shows the depth of the lead-through when the coating was not performed.

[0048]

Example 3 and Comparative Example 3 In the cross-sectional shape shown in FIG. 3, the dimensions of the cavity of the mold were 350 mm in width, 600 mm in length, and 60 mm in depth. Was obtained under the same conditions as in Example 1 except that Spray Clon BU-73 (manufactured by Norton) shown in Table 1 was used and the injection time was set to 3.4 seconds. Table 1 shows the depth of the lead-through at the position indicated by 5 in FIG.

Comparative Example 3 shows the depth of the lead-through when the coating was not performed.

[0050]

Example 4 and Comparative Example 4 The same conditions as in Example 1 were used except that the shape shown in FIG. 1 was used, the mold material was the mold shown in Table 1, and the coating material was high resin L-2360 shown in Table 1. A molded product was obtained. Table 1 shows the depth of the lead-through at the position indicated by 5 in FIG.

Comparative Example 4 shows the depth of the lead-through when the coating was not performed.

[0052]

[Table 1]

As is clear from the above Examples and Comparative Examples, when a heat insulating material is coated, it is clear that the lead-through is extremely shallow and the effect of the present invention is great. The appearance of the molded product was flat and beautiful. In addition,
If the depth of the lead-through is 20 μm or less, the lead-through does not cause a problem in appearance quality for most uses.

[Brief description of the drawings]

FIG. 1 shows a sectional view of a mold used in an example.

FIG. 2 shows a sectional view of a mold used in an example.

FIG. 3 shows a sectional view of a mold used in the embodiment.

[Explanation of symbols]

 1 Cavity 2 Core type 3 Boss 4 Rib 5 Measurement position of lead-through

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI B29K 86:00 (56) References JP-A-2-184416 (JP, A) JP-A-3-114807 (JP, A) JP-A Sho 54 −142266 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 45/00-45/84 B29C 33/00-33/76

Claims (3)

(57) [Claims] 1. A monomer liquid comprising a metathesis-polymerizable cyclic olefin containing a catalyst component of a metathesis polymerization catalyst (solution A) and a monomer liquid comprising a metathesis-polymerizable cyclic olefin containing an activator component of a metathesis polymerization catalyst (Solution B) is mixed and injected into a mold having ribs and / or bosses, and polymerization is performed to produce a crosslinked polymer molded product. In this method, a cavity in contact with the molded product is coated with a heat insulating material. A method for producing a crosslinked polymer molded article, comprising using a mold. 2. The method according to claim 1, wherein the heat insulating material is an organic resin selected from polytetrafluoroethylene, epoxy, polyester and phenol. 3. The method according to claim 1, wherein the heat insulating material has a thickness of 10 to 500 μm.