JPH10635A - Manufacture of norbornene resin molded item - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacture capable of allowing polymerization reaction liquid to readily permeate in the corner to corner of the mold and also polymerization to uniformly advance to both the central part and superficial part when the polymerization has started, and capable of obtaining a norbornene resin molded item having a good mechanical strength as well as physical properties and being uniform over the entire part of the molded item. SOLUTION: Poured into the mold is block polymerization reaction liquid having a viscosity of 3-100cps at 25 deg.C and being so late in its reaction start that the time of viscosity reaching 1,000cps is 3min or longer as the polymerization reaction is started at 25 deg.C, and then the mold is heated to 50 deg.C or higher to perform block polymerization immediately after the completion of pouring.

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 norbornene-based resin molded article, and more particularly, to a reinforced norbornene-based resin molded article having high uniformity, excellent mechanical strength and less polymerization unevenness throughout the molded article. The present invention relates to a method for manufacturing a product.

[0002]

2. Description of the Related Art It is well known that a norbornene monomer such as dicyclopentadiene or methyltetracyclododecene is obtained by reaction injection molding (RIM), that is, a ring-opening bulk polymerization in a mold to obtain a molded product. is there. At that time, it is also known to incorporate a filler, glass fiber, or other reinforcing material. For example, JP-A-59-51911 discloses that
A bulk polymerization method of a norbornene-based monomer by a RIM method using a metathesis catalyst system is described, and it is disclosed that in this polymerization, long glass fibers are blended as a reinforcing material. However, when a polymerization reaction solution containing a norbornene-based monomer as a main component is injected after filling the fiber reinforcing material into the mold, the polymerization proceeds before the reaction solution does not sufficiently penetrate all the way into the mold. There is a tendency to start.
In particular, when the reinforcing material is highly filled, the tendency is remarkably exhibited, and the mechanical strength and other physical properties are not uniform over the entire molded product, and only an insufficient molded product can be obtained. Particularly, in the production of a molded article having a complicated shape or having a thin or elongated end portion or an annular portion, the polymerization reaction solution is not affected by the above-described polymerization regardless of whether or not the fiber reinforcing material is filled. The problem that the polymerization proceeds before the permeation in the mold does not sufficiently penetrate appears remarkably.

In general, a polymerization reaction solution comprising a monomer mixture must not undergo a reaction before it is injected into a mold, but it is desired that polymerization be started immediately after the reaction solution is injected into the mold. I have. For this reason, a mold is preliminarily heated before injection of a reaction solution. However,
When the long fiber reinforcing material is filled at a high level, the reaction liquid to be injected starts to polymerize before permeating into every corner of the mold, thereby increasing the viscosity. Therefore, sufficient penetration into the mold becomes more difficult. Further, in the RIM method, in the center of the mold, particularly in the long fiber reinforcing material, when the polymerization is started, the temperature rises due to the reaction heat, and the polymerization easily proceeds. In some cases, heat is easily radiated by conduction of the mold, the temperature of the reaction solution is hardly increased, and the reaction solution may not be sufficiently cured.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to allow a polymerization reaction solution to easily penetrate into every corner of a mold, and
After the initiation of the polymerization, the polymerization proceeds uniformly in both the central part and the surface part, so that the mechanical strength and other physical properties are uniform over the entire molded article, and a production method capable of obtaining a good norbornene resin molded article. Is to provide. The present inventors have used the polymerization reaction liquid having a low viscosity and a slow rise of the polymerization reaction, and without heating the mold, heating the mold after injecting the reaction liquid to achieve the above object. They have found that this can be achieved, and have completed the present invention.

[0005]

Thus, according to the present invention, there is provided a method for producing a norbornene-based resin molded article by bulk-polymerizing a norbornene-based monomer in a mold, comprising: (1) (a) It has a viscosity of 3 to 100 cps at 25 ° C., and (b) when the polymerization reaction is started at 25 ° C., the time required for the viscosity to reach 1,000 cps is 3
A method for producing a norbornene-based resin molded product, comprising: injecting a polymerization reaction liquid having a slow rise in reaction for at least one minute into a mold, and (2) immediately heating the mold to 50 ° C. or more after completion of the injection. Is provided.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The norbornene-based monomer used in the present invention is not particularly limited as long as it has a norbornene ring. It is preferable to use a polycyclic norbornene monomer. Specific examples of the norbornene-based monomer include bicyclics such as norbornene and norbornadiene; tricyclics such as dicyclopentadiene and dihydrodicyclopentadiene; tetracyclics such as tetracyclododecene; and cyclopentadiene trimers. Pentacyclic ring; heptacyclic ring such as cyclopentadiene tetramer; substituted by alkyl such as methyl, ethyl, propyl and butyl; alkenyl such as vinyl; alkylidene such as ethylidene; aryl such as phenyl, tolyl and naphthyl. And a group containing an element other than carbon and hydrogen, such as an ester group, an ether group, a cyano group, and a halogen atom, and a substituent having a so-called polar group. These monomers are used alone or in combination of two or more.
Tricyclic, tetracyclic, and pentacyclic monomers are preferred from the viewpoint of easy availability, excellent reactivity, and excellent heat resistance of the obtained resin molded product.

The norbornene-based resin molded product is preferably of a thermosetting type. For this purpose, a crosslinkable monomer of 10% by weight or more, preferably 30% by weight or more of the monomer used is used. Good. The crosslinkable monomer is a polycyclic norbornene monomer having two or more reactive double bonds, and specific examples thereof include dicyclopentadiene, cyclopentadiene trimer, and cyclopentadiene tetramer. Is done. Incidentally, cyclobutene capable of ring-opening copolymerization with a norbornene monomer within a range not to impair the object of the present invention,
Monocyclic cycloolefins such as cyclopentene, cyclopentadiene, cyclooctene and cyclododecene may be used as comonomers.

(Metathesis Catalyst) In the method for producing a norbornene-based resin molded article of the present invention, the catalyst used for polymerizing the norbornene-based monomer is a metathesis catalyst. The metathesis catalyst is not particularly limited as long as it is capable of ring-opening polymerization of a norbornene-based monomer by bulk polymerization, and may be a known one. For example, halides such as tungsten, molybdenum, and tantalum, oxyhalides, oxides, organic ammonium salts, and the like can be given.

The amount of the metathesis catalyst used is usually at least 0.01 mmol, preferably at least 0.1 mmol and at most 50 mmol, preferably at most 20 mmol, based on 1 mol of the monomer used in the whole polymerization reaction solution. It is as follows. If the amount of the metathesis catalyst used is too small, the polymerization activity is too low and the reaction takes a long time, so the production efficiency is poor.If the amount is too large, the reaction is too vigorous and the resin hardens before being sufficiently filled in the mold. Or the catalyst is likely to precipitate, making it difficult to store homogeneously. The metathesis catalyst is usually used by dissolving it in a monomer.However, as long as the properties of the bulk polymerized resin molded product are not substantially impaired, the catalyst is suspended and dissolved in a small amount of a solvent, and then simply dissolved. By mixing with the monomer, it is possible to make precipitation difficult or to increase the solubility.

(Activator and activity regulator) In the production of norbornene-based resin molded articles, bulk polymerization is usually carried out using an activator, also called a metathesis cocatalyst, together with a metathesis catalyst. The activator is not particularly limited as long as it can activate a metathesis catalyst capable of ring-opening polymerization of a norbornene-based monomer by bulk polymerization, and may be a known one. For example,
Examples thereof include alkyl aluminum, alkyl aluminum halide, alkoxyalkyl aluminum halide, aryloxyalkyl aluminum halide, and organotin compounds.

The amount of the activator used is not particularly limited,
If the amount is too large, the reaction of the polymerization reaction solution starts up quickly,
The object of the present invention cannot be achieved. The amount used is usually based on 1 mol of the metathesis catalyst used in the entire reaction solution.
It is 0.1 mol or more, preferably 1 mol or more, and 100 mol or less, preferably 10 mol or less. However, if the activator is not used, or the amount used is too small, the polymerization activity is too low and the reaction takes a long time, resulting in poor production efficiency. The activator is usually used by dissolving it in a monomer, but as long as it does not substantially impair the properties of the molded article by bulk polymerization, the activator is suspended or dissolved in a small amount of a solvent, and then mixed with the monomer. Mixing may be used to make precipitation difficult or to increase solubility.

In the present invention, generally, an activity regulator is used in combination with the above-mentioned active agent. The reaction rate, the time from the mixing of the reaction solution to the start of the reaction, the reaction activity, and the like can be changed by using the activity modifier together. In the present invention, particularly, the polymerization reaction is started at 25 ° C. The time required for the viscosity to reach 1,000 cps
This is an effective means for preparing a polymerization reaction solution in which the reaction rises slowly for more than one minute.

As the activity regulator, a compound having an action of reducing a metathesis catalyst is used, and examples thereof include alcohols and halo alcohols. Specific examples of alcohols include n-propanol, n-butanol, n-hexanol, 2-butanol, isobutyl alcohol, isopropyl alcohol, t-butyl alcohol, and the like. Specific examples of halo alcohols include 1, 3-Dichloro-2-propanol, 2-chloroethanol, 1-chlorobutanol and the like. The amount of the activity modifier added is 1.0 or more, preferably 1.1 or more, and 1.5 or less, preferably 1.4 or less in terms of the molar ratio of the activity modifier / activator. If the amount of the activity modifier is too small, the reaction is too fast, and the undiluted reaction solution is less likely to flow between the fibers or into a narrow portion. Conversely, if the amount is too large, the reaction is too slow even when heated, resulting in poor molding efficiency.

(Optional components) If desired, antioxidants, fillers, pigments, colorants, foaming agents, sliding agents, flame retardants,
Various additives such as a combustible agent, an elastomer, a dicyclopentadiene-based thermopolymerized resin, and a hydrogenated product thereof can be blended in the molding stock solution, thereby improving the properties of the obtained RIM product. As antioxidants, various antioxidants for plastics and rubbers such as phenols, phosphorus and amines are used, and as fillers, inorganic fillers such as glass, carbon black, talc, calcium carbonate and mica are used. Agent is used.

Further, an elastomer may be added to the reaction solution for the purpose of adjusting the viscosity of the reaction solution. Examples of the elastomer used include natural rubber, polybutadiene, polyisoprene, styrene-butadiene copolymer, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene copolymer, and ethylene-propylene-diene copolymer. Diene-based elastomers, ethylene-vinyl acetate copolymers, and hydrides thereof. The amount of the elastomer added is 2
The viscosity is appropriately selected so that the viscosity at 5 ° C. falls within the range described below.

(Polymerization reaction solution) The reaction solution used for producing norbornene-based resin molded products includes norbornene-based monomers, metathesis catalysts, activators such as alkylaluminum halides, activity regulators such as alcohols, and optional components. Prepared by dividing into two or more liquids. These reaction stock solutions do not undergo bulk polymerization with only one solution, but when all the solutions are mixed, each component has a predetermined ratio,
The norbornene-based monomer undergoes bulk polymerization. For example, a reaction stock solution composed of a norbornene-based monomer, a metathesis catalyst and an optional component and a reaction stock solution composed of a norbornene-based monomer, an activator, an activity regulator and an optional component do not polymerize as they are. If the total amount of each component contained in the two liquids is the amount of each component used in the present invention, each of these two liquids is a reaction stock solution used in the present invention, and when both are mixed, bulk polymerization is disclosed.

For good workability, bulk polymerization is usually carried out using two reaction stock solutions, but three or more reaction stock solutions may be used. In order to allow other components to be sufficiently diffused into the norbornene-based monomer after mixing of the reaction stock solution, all the reaction stock solutions usually contain a norbornene-based monomer, and the other components are composed of a norbornene-based monomer. It is preferable that the reaction solution is dissolved or dispersed in the monomer, but there may be a reaction stock solution containing no norbornene-based monomer.
In addition, since the bulk polymerization starts when the norbornene-based monomer, the metathesis catalyst, and the activator are contained in one reaction stock solution, the metathesis catalyst and the activator are not usually contained in one reaction stock solution. . The reaction stock solution is usually preferably prepared, stored, and transferred under an atmosphere of an inert gas such as nitrogen gas for the purpose of preventing deactivation of the metathesis catalyst and the like.

The viscosity of the polymerization reaction solution used in the present invention is 25 ° C.
Is not less than 3 cps, preferably not less than 5 cps, and not more than 100 cps, preferably not more than 50 cps.
If the viscosity is too high, it is difficult to sufficiently penetrate into the mold filled with the long fiber reinforcing material. When the polymerization reaction is started at 25 ° C., the viscosity of the polymerization reaction liquid is 1,000
The time to reach cps needs to be 3 minutes or more, preferably in the range of 5 to 60 minutes. Viscosity is 1,
If the time required to reach 000 cps is excessively short, the penetration of the polymerization reaction solution when a large amount of long fiber reinforcing material is used is not preferable, which is not preferable.

(Long Fiber Reinforcement) In the formation of the norbornene resin molded article of the present invention, it is not essential to use a reinforcement, but the effect of the present invention is remarkable when a reinforcement, particularly a long fiber reinforcement, is used. Appears in As the long fiber reinforcement, those having good mechanical strength and heat resistance are used, and specific examples thereof include glass fiber, carbon fiber, silicon carbide fiber, inorganic long fiber such as steel fiber and amorphous metal fiber, and Organic long fibers such as aramid fibers and ultra-high molecular weight polyethylene are included. The form of the long fiber is not particularly limited, and may be any of a woven fabric, a knit, a continuous strand mat, and a filament winding. However, a continuous glass strand mat is most preferable because the polymerization reaction liquid easily permeates and has high strength.

The continuous strand mat is
It is fluffy as a whole, and when filling in a mold, it is compressed and filled. When the mold is closed, the continuous strand mat becomes almost uniform in the mold,
The molded article has a uniform mechanical strength. In addition, when the insert is fixed in the mold and the bulk polymerization is performed, the continuous strand mat is almost uniformly filled even between the surface of the insert and the inner surface of the mold. A resin molded product having mechanical strength can be easily obtained.

The filling amount of the long fiber reinforcing material is generally 20% by weight or more, preferably 25% by weight or more, more preferably 30% by weight and 50% by weight or less, preferably 45% by weight or less of the resin weight. It is more preferably at most 40% by weight. If the filling amount is small, the ratio of enhancement of the mechanical strength is small. If the filling amount is too large, uneven filling may occur without uniform filling or polymerization inhibition may occur. In addition, the resin weight referred to here is the weight of the long fiber reinforced resin excluding the insert from the resin molded product when there is an insert or the like.

(Bulk Polymerization) In the production of a norbornene-based resin molded product, a polymerization reaction liquid obtained by mixing a reaction stock solution is cured. Generally, if necessary, a mold is pre-filled with a long-fiber reinforcing material, and then two or more undiluted reaction solutions are instantaneously mixed using a mixing head or the like, and the mixed polymerization reaction is immediately performed. A method is used in which the liquid is poured into a mold, heated to initiate bulk polymerization, and then cured. The mold used here is not limited to a metal mold, and may be a glass mold, a wooden mold, or a resin mold. In the bulk polymerization step, in order to avoid a problem such as deactivation of the catalyst, it is preferable to make the inside of the mold an inert atmosphere by purging an inert gas such as a nitrogen gas.

In the present invention, after pouring the reaction solution for polymerization into a mold, it is immediately heated to 50 ° C. or higher to start bulk polymerization. In the present invention, using a bulk polymerization reaction solution having a slow rise in reaction, that is, a bulk polymerization reaction solution in which the time required for the viscosity to reach 1,000 cps when the polymerization reaction is started at 25 ° C. is 3 minutes or more is used. Heat the mold as soon as possible after the completion of the injection of the reaction liquid in order to easily penetrate the polymerization reaction solution throughout the mold, and then proceed with polymerization uniformly in both the center and the surface after the start of polymerization. This is very important. If the heating temperature is too low, the composition does not cure sufficiently or takes a long time to cure. On the other hand, when the heating temperature is too high, not only the energy loss is large but also the reaction runs away and carbonization may occur. Generally, the heating temperature is preferably from 50 to 100C, and from 70 to 9C.
0 ° C. is particularly preferred.

(Norbornene-based resin molded article) The norbornene-based resin molded article obtained by the method of the present invention has good mechanical strength because it is molded by uniform polymerization without polymerization unevenness. In particular, the long-fiber-reinforced norbornene-based resin molded product has excellent mechanical strength and uniform strength distribution because the fiber reinforcing material and the resin are uniformly integrated over the entire molded product. This long-fiber-reinforced norbornene-based resin molded product has a bending strength of 150 Mpa or more measured according to JIS K-7055. In addition, since there is uniform mechanical strength over the entire molded product, variation in bending strength is small. In addition, during the measurement of the bending strength, partial peeling of the surface or the like does not occur in the course of reaching the half of the breaking load of the sample.

[0025]

EXAMPLES Hereinafter, the method for producing the norbornene-based resin molded product of the present invention will be described in detail with reference to examples. Comparative Example 1 Continuous glass strand of glass long fiber cut into 500 mm × 500 mm in an iron cavity of a 500 mm × 500 mm × 5 mm plate-forming mold.
Five plies of a mat (M9600, manufactured by Asahi Fiber Glass Co., Ltd.) were installed. In addition, this glass mat is 1 degree at 110 degreeC.
Drying was performed in advance for a time.

A stock solution of a norbornene-based monomer consisting of 90% by weight of dicyclopentadiene and 10% by weight of a cyclopentadiene trimer (asymmetric trimer) is placed in two containers. Diethylaluminum chloride at a concentration of 40 mmol, 1,3-dichloro-
2-Propanol was added to a concentration of 48 mmol (Solution A). On the other hand, tri (tridecyl) ammonium molybdate was added to the monomer at a concentration of 10 mmol (solution B).

The mold was maintained at about 30 ° C. by flowing water through a temperature control pipe penetrating the mold. The same volumes of the liquids A and B were mixed by a low-pressure mixing and injection machine and immediately poured. After the filling of the polymerization reaction liquid was completed, a curing reaction was performed for 10 minutes, and the mixture was taken out of the mold. Therefore, it was impossible to maintain the shape as a flat glass fiber-reinforced resin molded article. The unreacted liquid remained, the stickiness was large, and it could not be used for measurement of bending strength. The viscosity of the mixture of the liquid A and the liquid B injected into the mold is 5
cps (25 ° C.).
The time required for the viscosity to reach 1,000 cps was 10 minutes.

[0028] was prepared long glass fiber-reinforced norbornene resin molded article in the same manner as in Example 1 Comparative Example 1. However, immediately after the mixed reaction solution was injected into the mold, the mold temperature was raised to about 80 ° C. by flowing hot water of 80 ° C. through the second series of temperature control pipes penetrating the mold. Let cure for a minute. When the molded article was taken out of the mold, the reaction was completed up to the surface of the molded article, and there was no stickiness. 15mm × 120mm × 5m from molded product
A sample of m was cut out and subjected to a bending test at a distance between spans and a test speed of 2.5 mm / min according to JIS K-7055, and the bending strength was 160 MPa. No partial peeling of the surface occurred during the measurement of the bending strength.

Comparative Example 2 In the same manner as in Comparative Example 1, a long glass fiber reinforced norbornene resin molded product was produced. However, the mold was preheated to 80 ° C. before the polymerization reaction solution was injected into the mold. When the molded product was removed from the mold 10 minutes after the completion of the reaction liquid injection,
The reaction was completed up to the surface of the molded product, but there was an incompletely filled portion of the resin away from the gate, and the glass fiber floated white.

[0030]

As shown in the above comparative example, in the production of a long-fiber-reinforced norbornene-based resin molded product, when the polymerization reaction liquid is poured into a preheated mold, the polymerization reaction liquid Since the polymerization starts and the viscosity increases before the permeation into the reinforcing material sufficiently throughout the mold, a homogeneous and high-strength resin molded product cannot be obtained (Comparative Example 2). If the mold is not preheated, sufficient curing cannot be achieved in a short time. In particular, the curing progresses at the center of the molded product, but the reaction heat is radiated at the surface of the molded product, so that the curing is insufficient (Comparative Example 1).

In the method of the present invention, the viscosity is relatively low.
In addition, since the polymerization reaction liquid having a slow rise in the polymerization reaction is injected into a mold that has not been preheated, the reaction liquid uniformly permeates the entire reinforcing material. In addition, since the mold is heated immediately after the injection is completed, the reaction liquid hardens substantially uniformly not only at the center of the molded product but also over the surface layer. Therefore, the long fiber reinforcing material and the resin are uniformly and densely integrated over the entire molded article, and the mechanical strength and other physical properties are good, and a uniform molded article over the entire molded article can be obtained.

(Preferred Embodiment) A method for producing a norbornene-based resin molded article of the present invention, that is, a method for producing a norbornene-based resin molded article by bulk-polymerizing a norbornene-based monomer in a mold, comprising: 1) (a) It has a viscosity of 3 to 100 cps at 25 ° C., and (b) when the polymerization reaction is started at 25 ° C., the time until the viscosity reaches 1,000 cps is 3
(2) A method for producing a norbornene-based resin molded product, which comprises: injecting a bulk polymerization reaction solution having a slow rise in reaction time of not less than 10 minutes into a mold; The preferred embodiments are summarized as follows.

(1) The viscosity of the polymerization reaction solution is 3 to 100 cps at 25 ° C., more preferably 5 to 75 cps. (2) When the polymerization reaction of the polymerization reaction solution is started at 25 ° C., the time required for the viscosity to reach 1,000 cps is 3 to 60 minutes. (3) After completion of the injection of the polymerization reaction solution, the mold is heated to 50 to 100 ° C.
Heat to (4) The polymerization reaction solution contains an activity regulator selected from alcohol and halo alcohol.

(5) The amount of the activity modifier of the above item (4) is in the range of 1.0 to 1.5, more preferably 1.1 to 1.4, in terms of the molar ratio of the activity modifier / activator. (6) The norbornene-based monomer is mass-polymerized in a mold in which a reinforcing material, more preferably a long fiber reinforcing material, is previously arranged. (7) The long fiber reinforcement of the preceding paragraph (6) is a glass long fiber reinforcement, more preferably a continuous glass strand mat.

Claims (2)

[Claims] 1. A method for producing a norbornene-based resin molded product by bulk-polymerizing a norbornene-based monomer in a mold, comprising: (1) (a) having a viscosity of 3 to 100 cps at 25 ° C., (B) When the polymerization reaction is started at 25 ° C., the time until the viscosity reaches 1,000 cps is 3 hours.
A method for producing a norbornene-based resin molded product, comprising: injecting a polymerization reaction liquid having a slow rise in reaction for at least one minute into a mold, and (2) immediately heating the mold to 50 ° C. or more after completion of the injection. . 2. The method according to claim 1, wherein the norbornene-based monomer is subjected to bulk polymerization in a mold in which a long fiber reinforcing material is disposed.