JP2894726B2 - Reaction mixture for bulk polymerization containing microcapsules and method for producing norbornene-based polymer - Google Patents

Description

The present invention relates to a reactive compound solution comprising a cycloolefin monomer having a norbornene group and a norbornene-based cycloolefin obtained by bulk polymerization of the reactive compound solution in a mold. The present invention relates to a method for producing a polymer. More specifically, the present invention relates to a method for producing a norbornene-forming cycloolefin polymer having less curing failure of a product and having good boss and rib filling properties by incorporating a heat-expandable microcapsule into a reactive compounding liquid.

[Problems to be solved by conventional technology and invention]

Polymers obtained by ring-opening polymerization of cycloolefin monomers having a norbornene skeleton, such as dicyclopentadiene (abbreviated as DCP) and methyltetracyclododecene (abbreviated as MTC), are well known. For example, U.S. Pat.Nos. 4,136,249, 4,178,424 and 4,13
Nos. 6,247 and 4,136,248 disclose such polymers.

Ring-opening polymerization of cycloolefin monomers gives unsaturated linear, branched and crosslinked polymers, depending on the type of monomer. These polymers have excellent properties for many applications, such as automotive and non-automotive body panels, equipment housings, furniture, window frames, cargo loading, electrical and electronic components, leisure goods, etc. It has been known.

Dicyclopentadiene is readily available as a by-product of ethylene production and is a versatile monomer for ring opening polymers. Regarding ring-opening polymers of dicyclopentadiene, U.S. Pat.Nos. 3,778,420 and 3,781,257,
No. 3,790,545, No. 3,853,830, No. 4,002,815
No. 4,239,874 and the like. Other examples of cycloolefin monomers are the bicyclic norbornenes and their substitutes, which are described in U.S. Pat.
No. 183, No. 2,721,189, No. 2,831,037, No. 2,93
No. 2,630, No. 3,330,815, No. 3,367,924, No. 3,4
No. 67,633, No. 3,836,593, No. 3,879,434, No. 4,
No. 010,021. Tetracyclododecene and its substitutions are also well-known cycloolefins. These are obtained by the Diels-Alder reaction of cyclopentadiene with bicyclic norbornene or a suitable substitute thereof. No. 3,557,07 for ring opening polymerization of tetracyclododecene and other bicyclic monomers.
It is described in No. 2.

Studies have been made on bulk ring-opening polymerization of cycloolefins. Bulk polymerization is defined as polymerization in the absence of materials or diluents for the monomers.
U.S. Pat. No. 4,426,502 (Minchuck) discloses a bulk polymerization process for norbornene-based monomers such as norbornene, dicyclopentadiene, tricyclopentadiene (cyclopentadiene trimer), tetracyclododecene and the like.

Early attempts at bulk polymerization of cycloolefins were:
In the absence of lumber the reaction was too fast and therefore uncontrollable. Moreover, the product was extremely dark and had poor physical properties and appearance.

Then another approach was attempted, which failed as well. The approach was to bisect the monomer, adding a catalyst to one and a cocatalyst to the other. The purpose was to mix the two monomer liquids at room temperature and then transfer the mixture into a heated mold where it would cure quickly. However, it was found that a reaction occurs instantly when the two monomer products come into contact, a solid polymer barrier is formed between the two monomer solutions, wrapping a part of each monomer solution and preventing mixing. .

U.S. Pat. No. 4,426,502 discloses an improved metathesis catalyst system for bulk ring opening polymerization of cycloolefins. The method comprises mixing an organoammonium molybdate or tungstate catalyst, an alkoxyalkylaluminum halide cocatalyst and a monomer at a temperature such that polymerization of the monomer is essentially inhibited for at least one hour;
Transferring the mixture to a mold maintained at a temperature such that polymerization of the monomer occurs within 2 minutes. The metathesis catalyst system disclosed in U.S. Pat. No. 4,426,502 can control the instantaneous reaction that occurs when two monomer liquids come into contact, and as a result, the two monomer liquids can be mixed well, so that reaction injection molding ( RIM) process was available.

In a typical RIM operation, the monomer and the two parts of the metathesis catalyst system (catalyst and cocatalyst) are separately mixed to prepare a reactive formulation and loaded into the mixing head of the RIM machine. Immediately after mixing, the monomer containing the catalyst and cocatalyst is injected into the mold.

Although the above metathesis catalyst system can control the bulk polymerization reaction, a molded article having a rigid structure can be obtained by the RIM method, but there are other problems that must be faced by the molder. For example, if one wishes to take advantage of the bulk polymerization of cycloolefins by the RIM process, the mold must be completely filled with the reactive formulation. When the molded article is a surface member, sink on the molded article surface is an important problem. Molded articles by the RIM method often have complicated shapes including bosses (protrusions) and ribs (rib-like reinforcement projections), and are likely to have such defects. In addition, these molded products are required to have a high level of quality such as excellent appearance and no odor. Furthermore, when manufacturing these molded products, it is required to mold a large number of them in as short a time as possible from the viewpoint of productivity.

By the way, since the RIM method using a norbornene-based cycloolefin monomer is a ring-opening polymerization reaction using a metathesis catalyst system, the polymerization reaction is inhibited by the incorporation of oxygen or moisture, causing poor curing and impairing the appearance of a molded article. In addition, the odor due to the remaining unreacted monomer often becomes a problem.

Therefore, conventionally, in order to prevent poor curing, a method in which the air in the mold is instantaneously extruded by the undiluted reaction solution, or a burr is emitted by increasing the filling amount, and the inside of the mold is exhausted,
A method in which the reaction solution is injected into the mold after the air in the mold is replaced with an inert gas to obtain a molded product (Japanese Patent Application Laid-Open No. 63-112124). A method has been proposed in which, by injecting, the air in a mold is pushed upward and exhausted to the outside through an air escape port to obtain a molded product without poor curing (Japanese Patent Laid-Open No. 63-112125). I have.

However, in these methods, prevention of curing failure is not always sufficient, and particularly when manufacturing a molded article having a complicated shape, the boss and rib portions are difficult to exhaust air, so curing failure is likely to occur, and It is extremely difficult to obtain a molded product of a predetermined shape because the filling of the boss and the rib portion is not sufficient.

It is also known to blend a foaming agent into a reactive blending liquid for RIM. In the RIM formulation, the blowing agent prevents the formulation from tending to shrink during polymerization (ie, prevents sink on the product surface) and prevents the flow of moist air into the mold cavity. The moist air deactivates the metathesis catalyst system and leaves the product surface moist.

U.S. Pat. No. 4,535,097 (Newberg) discloses a metathesis catalyst system incorporating a blowing agent during the polymerization of dicyclopentadiene. U.S. Pat.Nos. 4,458,037 and 4,496,668 for metathesis catalyst systems containing blowing agents.
Nos. 4,496,669, 4,568,660, 4,584,425,
4,598,102, 4,604,408, 4,696,985, 4,6
Nos. 99,963 and 4,703,068. These systems are commonly used in the RIM process or related processes and include blowing agents that do not adversely affect the metathesis catalyst system. These catalyst systems can include blowing agents such as low boiling organic compounds or inert gases.

When foaming agents such as nitrogen, carbon dioxide, chlorofluorocarbon, methylene chloride, and various low-boiling hydrocarbons (eg, butane, pentane, hexane, heptane, etc.) are used in the RIM formulation, the small bubbles generated are stable. It is necessary to add a surfactant in order to make the surface active. However, this surfactant inhibits the adhesion between the filler or reinforcement and the polymer matrix.

According to the present invention, the use of a microencapsulated foaming agent (microsphere) in the RIM formulation eliminates the need for the addition of a surfactant and solves this problem. Microspheres include a liquid foaming agent and are well known.

U.S. Pat. No. 3,615,972 (Molehouse et al.) Discloses a thermoplastic microsphere containing a liquid foaming agent. Such microspheres can be easily obtained using various materials.

U.S. Pat. No. 4,075,138 (Garner) discloses a process for making thermoplastic microspheres using 40-90 parts by weight of vinylidene chloride and 40-10 parts by weight of acrylonitrile.

An example of such a microcapsule is marketed under the trade name EXPANCEL. Expancel is a white spherical particle having a shell consisting essentially of a copolymer of vinylidene chloride and acrylonitrile. The shell formed of the polymer contains a foaming agent (liquid isobutane) under pressure.

It is known that when heated, these microcapsules soften the thermoplastic shell and expand when the contained hydrocarbons volatilize. The microcapsules are lightweight, elastic, and expand at a predetermined temperature, so that they can be applied in a wide range as described below.

(1) Forming a three-dimensional pattern on wallpaper or fabric by blending it with printing ink. (2) Decreasing the density of fiber products such as paper and cardboard,
(3) Lightening and impact resistance of plastic products, (4) Improvement of adaptability and weight of paint and putty, (5) Improvement of cable performance, (6) Sensitivity of explosives (7) Synthetic foam (8) Alternative to conventional foaming agents for some resins as disclosed in JP-A-60-244511 Applying microencapsulated foaming agents to the RIM process It is described in JP-A-60-244511. The heat expandable microcapsules are activated during the curing step of the RIM method.

The patent describes the use of microcapsules containing a low-boiling liquid hydrocarbon in a shell formed of a copolymer of vinylidene chloride and acrylonitrile, together with a foaming agent, for the RIM of polyurethane elastomers. In addition, heat shrinkage of the molded article is suppressed, and the molded article is said to be free of sink marks. The amount of the microcapsules used is 0.001 to 20 parts by weight per 100 parts by weight of the reaction solution. Although this patent does not deny the application of polyurethane to other systems or other synthetic resins, it does not disclose that it is particularly effective for cycloolefin monomers.
Moreover, there is no disclosure of using microcapsules in the ring-opening polymerization system of cycloolefins by RIM, or of using thermally expandable microcapsules alone.

[Problems to be solved by the invention]

The present invention is based on the finding that the addition of microspheres to a system for bulk polymerization of cycloolefins provides the advantages of a blowing agent without the use of surfactants.

In one aspect, the present invention provides a liquid mixture (A) containing a cycloolefin monomer having a norbornene group and a metathesis cocatalyst, and a liquid mixture (B) containing a cycloolefin monomer having a norbornene group, a metathesis catalyst, and thermally expandable microcapsules. Wherein the thermally expandable microcapsules in the mixture (B) have a water content of 5% by weight or less and (a) are not expanded And the compounding amount is 0.05 to 5% by weight based on the total weight of the reactive polymer solution, or (b) the unexpanded one, and the compounding amount is based on the total volume of the reactive polymer solution. 1 to 50% by volume on the basis of a reactive compounding solution for bulk polymerization.

The present invention further provides a blended liquid (A) containing a cycloolefin monomer having a norbornene group and a metathesis cocatalyst, and a blended liquid (B) containing a cycloolefin monomer having a norbornene group, a metathesis catalyst, and thermally expandable microcapsules. A method for producing a norbornene-based cycloolefin polymer, which comprises mixing a mixture with a mixing head, and then injecting the reactive compound solution obtained by the mixing into a mold including a cavity mold and a core mold to perform reaction injection molding. The heat-expandable microcapsules in the liquid mixture (B) have a water content of 5% by weight or less, and (a) are unexpanded, and the amount thereof is a reactive polymer liquid. Or 5 to 5% by weight based on the total weight of the reactive polymerized liquid, or A norbornene system wherein the reactive mixture is injected into a mold in which the temperature of the cavity mold is maintained at a temperature higher than the temperature of the core mold by 5 ° C. or more. Provided is the production of a cycloolefin polymer.

In the present invention, as the heat-expandable microcapsules, synthetic resin microcapsules encapsulating a vaporizable expander, wherein the temperature capable of achieving its own maximum expansion ratio is in the range of 70 to 200 ° C. By using
By extruding air or moisture that causes thermal expansion due to the reaction heat of the reaction solution in the mold and inhibits polymerization, it is possible to obtain a molded product (norbornene-based cycloolefin polymer) free from poor curing.

By using a metathesis catalyst system consisting of a metathesis catalyst and a metathesis cocatalyst with a heat generation start time at 30 ° C. of 0.5 minutes or more, the heat-expandable microcapsules can be expanded efficiently and their functions can be fully exhibited. be able to.

The vaporizable expanding agent preferably has a boiling point of 60 ° C. or less, and the shell is preferably a thermoplastic synthetic resin insoluble in a cycloolefin monomer and having a softening temperature of 180 ° C. or less.

The heat-expandable microcapsules may be pre-expanded or non-expanded. Their diameter is preferably between 2 and 200 μm. Particularly preferred is that which is commercially available under the trade name Expancel, which comprises isobutane encapsulated in a shell of vinylidene chloride-acrylonitrile copolymer.
The amount of the microencapsulated vaporizable inflating agent in the reaction solution (depending on whether or not the microcapsules are expanded) is 0.05% in the case of unexpanded microcapsules such as Expancel 551DU. -5% by weight, and in the case of expanded microcapsules such as Expancel 551DE, it is 1-50% by volume.

The amount of the expanded microcapsules used for producing a molded article having a foam structure is 1 to 50% by volume, preferably 10 to 50% by volume, based on the total volume of the reactive mixture. The density of swollen microcapsules is usually 0.027-0.0
The density is 55 g / cm ³ , but the density may be increased by adhering calcium carbonate or titanium oxide to the particles (for example, a density of 0.3 g / cm ³ ). For the purpose of preventing shrinkage during polymerization in a mold, unexpanded microcapsules are added in an amount of 0.05 to 5% by weight, more preferably 0.1 to 1% by weight, based on the total weight of the reactive mixture. However, unexpanded microcapsules, expanded microcapsules or mixtures thereof can be used for any purpose. In order to polymerize these reactive compound liquids into solid molded products,
It is preferable to use RIM, RTM (resin transfer molding) or a casting method.

Further, according to the present invention, a preferred structure of a solid molded article formed of a polymer obtained by bulk ring-opening polymerization of a cycloolefin monomer having microcapsules dispersed therein has two or more finished surfaces. is there. One example of a preferred structure is reinforced with a reinforcing material such as a glass mat or a polyester fiber mat.

The reactive formulation for bulk polymerization provided by the present invention contains a cycloolefin monomer having a norbornene skeleton, a metathesis catalyst system, and a microencapsulated vaporizable expanding agent.

Cycloolefin Monomer The cycloolefin monomer used in the present invention is a bicyclic or polycyclic norbornene having at least one norbornene group represented by the following formula (I), and may have a substituent. It is not necessary.

Specific examples of preferred cycloolefin monomers include, for example, norbornene, dicyclopentadiene, dihydrodicyclopentadiene, sidiropentadiene trimer, tetracyclododecene, cyclopentadiene tetramer, hexacycloheptadecene, and substituted products thereof. Is exemplified.

The substituent may be any as long as it does not adversely affect the catalyst, and examples thereof include an alkyl group having 1 to 20 carbon atoms, an alkenyl group, an alkylidene group, an aryl group, and 3 to 12 carbon atoms.
And the like. Resinous monomers disclosed in Japanese Patent Application No. 63-248906 and polyfunctional cycloolefins functioning as crosslinking agents described in US Pat. No. 4,701,510 are also preferred cycloolefin monomers. Further, those having a polar substituent such as ester, nitrile, ether, halogen, pyridyl and the like may be used.

Particularly preferred monomers are represented by the following formulas (II), (III) and (IV).

In the formula, R and R ¹ are each hydrogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group, an alkylidene group and an aryl group,
And R ¹ are bonded to form 2 to 12 carbon atoms together with 2 carbon atoms in the ring.
Selected from saturated or unsaturated cyclic groups (including two derived from the aforementioned rings).

Specific examples of preferred monomers include, for example, dicyclopentadiene, methyltetracyclododecene, hexacycloheptadecene, methylhexanecycloheptadecene, 2-norbornene, 5-methyl-2-norbornene, 5,6-dimethyl-2 -Norbornene, 5-ethyl-
2-norbornene, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, 5-butyl-2-
Norbornene, 5-hexyl-2-norbornene, 5-
Octyl-2-norbornene, 5-phenyl-2-norbornene, 5-dodecyl-2-norbornene, 5-isobutyl-2-norbornene, 5-octadecyl-2-norbornene, 5-isopropyl-2-norbornene, 5
-P-toluyl-2-norbornene, 5-α-naphthyl-2-norbornene, 5-cyclohexyl-2-norbornene, dihydrodicyclopentadiene (cyclopentene-cyclopentadiene copolymer), methylpentadiene dimer, ethylcyclopentadiene dimer, tetracyclododecene, 9-ethyl-tetracyclo [6,2,1,1 ^3,6,
0 ^2,7] dodecene-4 (i.e. ethyl tetracyclododecene), 9-propyl-tetracyclo [6,2,1,1 ^3,6,
0 ^2,7 ] dodecene-4,9-hexyltetracyclo [6,2,
1,1 ^3,6, 0 ^2,7] dodecene-4,9-decyl-tetracyclo [6,2,1,1 ^3,6, 0 ^2,7] dodecene -4,9,10- dimethyl tetracyclododecene [ 6,2,1,1 ^3,6, 0 ^2,7] dodecene-4,9-methyl, 10-ethyl-tetracyclo [6,2,1,1 ^3,6, 0 ^2,7] dodecene -4, 9-cyclohexyltetracyclo [6,2,1,
1 ^3,6, 0 ^2,7] dodecene-4,9-chloro-tetracyclo [6,2,1,1 ^3,6, 0 ^2,7] dodecene-4,9-bromo-tetracyclo [6,2, 1,1 ^3,6, 0 ^2,7] dodecene-4,9-fluoro-tetracyclo [6,2,1,1 ^3,6, 0 ^2,7] dodecene-4,9
- isobutyl tetracyclododecene [6,2,1,1 ^3,6, 0 ^2,7] dodecene -4,9,10- dichlorotetrafluoroethane cyclo [6,2,1,1 ^3,6, 0
^2,7 ] dodecene-4 and the like.

Particularly preferred reactive blended liquids in the present invention are norbornene, methylnorbornene, tetracyclododecene, methyltetracyclododecene, dihydrodicyclopentadiene, dicyclopentadiene, 5-ethylidene-
2-norbornene, hexacycloheptadecene, cyclopentadiene trimer, and any one or more of cyclopentadiene tetramer,
Thereby, a homopolymer or a copolymer is obtained.

Up to about 20% by weight of cyclopentadiene (or polymerized units of cyclopentadiene) may be contained in the monomer component and the polymer obtained using the same.

In the present invention, a polymer formed by using a crosslinkable monomer can be of a thermosetting type. The crosslinkable monomer is a polycyclic norbornene monomer having two or more reactive double bonds, and specific examples thereof include dicyclopentadiene, tricyclopentadiene, and tetracyclopentadiene. Therefore, when the norbornene-based monomer and the crosslinkable monomer are the same, it is not necessary to use any other crosslinkable monomer.

The tricyclic or higher norbornene-based monomer can also be obtained by heat-treating dicyclopentadiene. The conditions of the heat treatment include, for example, dicyclopentadiene in an inert gas atmosphere at a temperature of 120 to 250 ° C.
A method of heating for 5 to 20 hours is exemplified. By this heat treatment, a monomer mixture containing tricyclopentadiene and unreacted dicyclopentadiene is obtained.

Furthermore, monocyclic cycloolefins such as cyclobutene, cyclopentene, cyclopentadiene, cyclooctene, cyclododecene and the like, which can be subjected to ring-opening polymerization together with one or more of the above-mentioned norbornene-based monomers, can be used in combination within a range not to impair the object of the present invention. .

Metathesis Catalyst System The reactive blend of the present invention contains a metathesis catalyst system. The catalyst system includes a metathesis catalyst and a cocatalyst. Individual feedstocks of the reactive blend contain only either the metathesis catalyst or the cocatalyst. In preparing the reactive mixture of the present invention, any metathesis catalyst capable of ring-opening polymerization of a cycloolefin monomer having a norbornene group can be used. Preferred catalyst systems are those capable of polymerizing the cycloolefin monomers described above or monomer mixtures containing up to about 20% by weight of cyclopentadiene. These metathesis catalysts, for example,
JP-A-58-127728, JP-A-58-129013, JP-A-59-51911,
Nos. 60-79035, 60-186511 and 61-126115.

In order to efficiently expand the heat-expandable microcapsules used in the present invention and to sufficiently exert their functions, it is preferable that the microcapsules have an appropriate polymerization activity, and usually have a moderate polymerization activity.
An exothermic onset time (time from the time when the polymerization reaction is suddenly started after mixing the monomer and the catalyst system) at 0.5 ° C is 0.5 minutes or more, preferably 0.5 to 30 minutes, particularly preferably about 1 to 5 minutes. Used.

Specific examples of the metathesis catalyst include tungsten, molybdenum, tantalum halides, oxyhalogenates, oxides, organic ammonium salts, and the like.
Suitable examples include tungsten compounds such as tungsten hexachloride, tungsten oxytetrachloride, tungsten oxide, tridodecylammonium tungstate, tri (tridecyl) ammonium tungstate, trioctylammonium tungstate; molybdenum pentachloride,
Molybdenum oxytrichloride, tridodecyl ammonium molybdate, methyl tricaprylammonium molybdate, tri (tridecyl) ammonium molybdate,
Molybdenum compounds such as trioctyl ammonium molybdate; tantalum compounds such as tantalum pentachloride; Among them, it is preferable to use a catalyst that is soluble in the norbornene-based monomer used in the reaction, and from that viewpoint, an organic ammonium salt is awarded.

These compounds are unstable to air and moisture,
Therefore, it should be handled under a dry inert atmosphere such as nitrogen. Molybdenum and tungsten halides are very reactive with cycloolefin monomers, causing polymerization of the monomers even when stored at room temperature, resulting in the formation of undesirable gels or particulate polymers after a few hours. Therefore, it is difficult to use these compounds as catalysts when long-term storage is required.

If necessary, a Lewis base such as benzonitrile and tetrahydrofuran and a chelating agent such as acetylacetone and alkyl acetoacetate can be used in combination, whereby early polymerization can be prevented.

Further, when the metathesis catalyst is a halide, the catalyst can be solubilized in the norbornene-based monomer by pre-treatment with an alcohol-based compound or a phenol-based compound.

Ammonium molybdate and tungstate described in US Pat. No. 4,426,502 are preferred metathesis catalysts. These catalysts can be handled at room temperature even in the presence of air or moisture. These catalysts are more stable to cycloolefin monomers than molybdenum halides and tungsten halides, and the catalyst / monomer solution does not cause monomer polymerization. The use of ammonium molybdate and tungstate catalyst facilitates mixing of the catalyst with other components of the polymerization system.

Preferred organoammonium molybdates and tungstates are represented by the following formulas:

[R ₄ N] _{(2y-6x) M x O} y ▲ [R ¹ ₃ NH] _{▼ (2y-6x) M x} O y where, O is oxygen, M represents molybdenum or tungsten, x and y is the number of M atoms and oxygen atoms, and valence +6 is given to M atoms and valence -2 is given to oxygen atoms. R and R ¹ may be the same or different and are selected from hydrogen, an alkyl group and an alkylene group having 1 to 20 carbon atoms, and an alicyclic group having 5 to 16 carbon atoms.

In a preferred embodiment, R is an alkyl group having 1 to 18 carbon atoms, and the total number of carbon atoms of all R is 20 to 7
2, more preferably 25 to 48, and each R ¹ is an alkyl group having 1 to 18 carbon atoms, and all R ¹
Have a total carbon number of 15 to 54, more preferably 21 to 42. Wherein all R and R ¹ or part thereof may be different even in the same as described in U.S. Patent No. 4,426,502.

Preferred specific examples of the organic ammonium molybdate and tungstate include, for example, tridodecylammonium molybdate and tungstate, tri (tridecyl) ammonium molybdate and tungstate, trioctylammonium molybdate and tungstate, and the like. Molybdenum (III) acetylacetonate and halogen-free soluble organic molybdenum and tungsten compounds can also be used as metathesis catalysts.

Examples of the cocatalyst used in the present invention include alkylaluminum halides, alkoxyalkylaluminum halides, aryloxyalkylaluminum halides, and organotin compounds.
Examples include ethylaluminum dichloride, diethylaluminum monochloride, ethylaluminum sesquichloride, diethylaluminum iodide, methylaluminum sesquichloride, tetrabutyltin, a pre-reaction product of an alkylaluminum halide and an alcohol.

Among these cocatalysts, alkoxyalkylaluminum halides and aryloxyalkylaluminum halides have an appropriate pot life at room temperature even when the catalyst components are mixed, and are therefore advantageous in operation (for example, see JP-A-59-51911). issue). In the case of alkylaluminum halides, there is a problem that polymerization starts immediately when the catalyst is mixed.In this case, use an activity modifier such as ethers, esters, ketones, nitriles, and alcohols in combination. Can control the initiation of polymerization. (For example, JP-A-58-129013, 61-
US Patent No. 4,426,502 discloses bulk polymerization of cycloolefins using a tungsten or molybdenum catalyst and a modified cocatalyst. The alkylaluminum halide cocatalyst is modified into an alkoxyalkylaluminum halide or an aryloxyalkylaluminum halide by reaction with an alcohol or a compound containing an active hydroxyl group, which is used in a polymerization reaction. This preliminary reaction involves oxygen,
It can be performed by using alcohol or phenol. Hindered phenols do not form phenoxyaluminum groups and are relatively inert, as described at column 4, bottom of this patent. Replacing part of the alkyl group in the aluminum compound with an alkoxy group or an aryloxy group reduces the reducing power of the cocatalyst, thereby allowing all catalyst components to come into contact at room temperature, resulting in thermal activity The bulk polymerization of cycloolefin is performed by the conversion.

With unmodified alkylaluminum halide cocatalyst, the reaction is very fast. In some cases, co-catalysts,
The active catalyst species is wrapped in the polymer formed when the catalyst and the monomer come into contact with each other, and the polymer cannot proceed with the other monomer in the system because it cannot be contacted. Preferred modifiers are described in U.S. Pat. No. 4,426,502.

As described in U.S. Pat. No. 4,426,502, for bulk polymerization, the cocatalyst preferably contains at least halogen, alkoxy or aryloxy and alkyl groups in addition to aluminum. Certain halogen-free cocatalysts can be used in the presence of a suitable metathesis catalyst. Examples of preferred halogen-free cocatalysts for use in bulk polymerization are alkylaluminum cocatalysts, especially combinations of trialkylaluminums with alkyltin oxides, especially bis (alkyltin) oxides. Halogen-free cocatalysts are described in U.S. Pat. No. 4,701,510.

Specific examples of alkylaluminum halides or alkylaluminum cocatalysts include monoalkylaluminum dihalide (RAlX ₂ ), dialkylaluminum monohalide (R ₂ AlX), and alkylaluminum sesquihalide (R
₃ Al ₂ X ₃ ), combinations of trialkylaluminum (R ₃ Al) and iodine sources, and mixtures thereof. In the above formula, R is an alkyl group having 1 to 12, preferably 2 to 8 carbon atoms, and X is a halogen selected from chlorine, iodine, bromine and fluorine.

Specific examples of such alkyl aluminum halide and alkyl aluminum include, for example, ethyl aluminum dichloride, diethyl aluminum iodide, ethyl aluminum diiodide, diethyl aluminum chloride, propyl aluminum dichloride, propyl aluminum diiodide, isobutyl aluminum dichloride, ethyl aluminum dichloride Examples thereof include bromide, methylaluminum sesquichloride, methylaluminum sesquibromide, trioctylaluminum, triethylaluminum, and triisobutylaluminum.

The cocatalyst enhances the activity of the metathesis catalyst system by reacting with the activator. The activator is usually a halometal compound represented by the following formula.

During R _m YX _n type, m is 0 to 4, n is 1-5. R is each selected from hydrogen, alkyl, alkenyl, alkoxy, aryl, alkaryl, saturated and unsaturated cyclic groups, and Y is selected from tin, lead, magnesium, antimony, boron, germanium and silicon X is a halogen, preferably chlorine, each selected from chlorine, bromine, iodine and fluorine.

Among them, a halosilane compound represented by the following formula is a preferred activator.

During R _m SiX _n Formula, m is 0 to 3, n is 1-4. R is hydrogen, an alkyl group having 1 to 12 carbon atoms, an alkoxy group,
An alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 18 carbon atoms, an alkaryl group having at least one alkyl group having 1 to 4 carbon atoms on an aromatic ring, a saturated or unsaturated group having 5 to 12 carbon atoms; Selected from monocyclic bicyclic and polycyclic cyclic groups.
Particularly preferably, R is selected from hydrogen, alkyl having 1 to 6 carbon atoms and alkoxy groups. Specific examples of preferred activators include, for example, dimethylmonochlorosilane,
Dimethyldichlorosilane, diphenyldichlorosilane,
Examples include tetrachlorosilane.

Further, halogenated hydrocarbons such as chloroform and carbon tetrachloride (for example, JP-A-60-79035) may be used in combination.

The above activators are usually used in a proportion of 5 mol or less, preferably 0.1 to 4 mol, per mol of the cocatalyst.

The metathesis catalyst is generally used in an amount of about 0.01 to 50 mmol, preferably 0.1 to 1 mol, per mol of the norbornene monomer.
Used in the range of 0 mmol. The activator (cocatalyst)
The catalyst component is used in a range of usually 0.1 to 200 (molar ratio), preferably 2 to 10 (molar ratio).

It is preferable that both the metathesis catalyst and the cocatalyst be dissolved in a monomer before use. However, the metathesis catalyst and the cocatalyst may be suspended or dissolved in a small amount of a solvent as long as the properties of the product are not substantially impaired.

Heat-expandable microcapsules The heat-expandable microcapsules used in the present invention are obtained by encapsulating a liquid foaming agent in expandable thermoplastic polymer particles. Such blowing agents are typically manufactured as thermoplastic microcapsules containing a liquid blowing agent comprising a low boiling liquid.

These microcapsules are well known in the art. For example, U.S. Pat. No. 3,615,972 (Monohouse et al.) Describes blowing agents wrapped with expandable thermoplastic polymers, and such blowing agents can be readily obtained using a variety of materials. . The microcapsule shell should be selected so that it does not dissolve or significantly swell in the cycloolefin monomer used in the present invention. In order to obtain the desired expansion of the capsule, a material which does not penetrate the blowing agent should be used as the thermoplastic polymer. In addition, the thermoplastic polymer must not deactivate the metathesis catalyst or cocatalyst or inhibit polymerization of the cycloolefin monomer. If the metathesis catalyst is deactivated, a solid, hard product cannot be obtained. The thermoplastic polymer must not contain free hydroxyl or acid groups. Further, the thermoplastic polymer preferably has a softening point of about 180 ° C. or less. Here, the softening point refers to the temperature at which the thermoplastic capsule expands. It is desirable that the capsule expands at a temperature not higher than the maximum exothermic temperature of the bulk polymerization, and the preferable range of the softening point is 60 to 120.
° C, particularly preferably 80 to 100 ° C.

The thermally expandable microcapsule particles used in the present invention generally hardly act as a solvent for (1) an organic monomer suitable for forming a thermoplastic resin having desired physical properties and (2) a produced polymer. It is obtained by preparing an aqueous dispersion with a liquid foaming agent. The monomer becomes solid spherical particles by polymerization, and wraps the liquid foaming agent therein.

Preferred monomers are alkenyl aromatic monomers and are represented by the following formula:

In the formula, Ar is an aromatic hydrocarbon residue having a benzene nucleus or a halogenated aromatic hydrocarbon residue. Specific examples of such a monomer include, for example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, ethylstyrene, vinylxylene, chlorostyrene, bromostyrene and the like. Various other styrene derivatives can also be used, such as vinylbenzyl chloride, pt-butylstyrene, and the like.

Acrylate monomers can be used alone or in combination with alkenyl aromatic monomers. The acrylate monomer is generally represented by the following formula.

In the formula, R is an alkyl group having 1 to 12 carbon atoms, and R ¹ is hydrogen or a methyl group. Specific examples of the acrylate monomer include, for example, methyl methacrylate, ethyl acrylate, propyl acrylate, butyl acrylate,
Examples thereof include butyl methacrylate, lauryl acrylate, 2-ethylhexyl acrylate, and ethyl methacrylate.

Homopolymers and copolymers such as vinyl chloride, vinylidene chloride, acrylonitrile, and vinyl bromide can also be used as the polymer forming the particles. Suitable are copolymers of styrene, vinyl acetate and butadiene with at least one of these monomers. It is also preferable to use a crosslinking monomer together with these.

Vinyl esters of the following formula are also frequently used as monomers.

In the formula, R is an alkyl group having 1 to 17 carbon atoms, and specific examples of this type of monomer include vinyl acetate, vinyl butyrate, vinyl stearate, vinyl laurate,
Examples thereof include vinyl myristate and vinyl propionate.

Various kinds of liquid foaming agents are used as the liquid foaming agent contained in the shell made of a polymer, and this foaming agent needs to be volatile at the softening temperature of the shell. Above all, 100 ℃
Foaming agents that volatilize below are preferred, and those that volatilize below 60 ° C. are particularly preferred. Specific examples of such a liquid foaming agent include, for example, ethane, ethylene, propane, propene, butane, isobutane, neopentene, acetylene,
Examples include hexane, heptane, and mixtures thereof.

Other preferable liquid foaming agents include, for example, chlorofluorocarbons and tetraalkylsilanes.

EXPANCEL, micro light (MICR)
Of interest are the microcapsules marketed under the trade names OFITE), MIRALITE and Matsumoto Microspheres. Expancel is commercially available in wet unexpanded, dry unexpanded, wet unexpanded, dry unexpanded forms. Certain types of Expancel initially have an average particle size of 10 to 17 μm, and when expanded expand to an average particle size of 40 to 60 μm. The preferred particle size of the unexpanded and unexpanded microcapsules is 200 μm or less, especially 2 to 200 μm. These microcapsules have a shell formed of a copolymer of vinylidene chloride and acrylonitrile. This shell contains a blowing agent (liquid isobutane) under pressure.

When trying to make a structural foam, it is preferable to add the expanded vinylidene chloride microcapsules to the monomer mixture. Structural foam is by volume
It is preferable to use dry, pre-expanded microcapsules which are commercially available under the trade name Expancel DE 551 in order to produce such foams, having a porosity of 10 to 50%.

The expansion start temperature of the non-expandable microcapsules is determined by the composition of the shell and the type of the liquid foaming agent, but is preferably 50 ° C or higher, particularly preferably about 70 ° C or higher. It is preferable that the maximum expansion temperature of the expandable microcapsule (that is, the temperature at which the maximum expansion ratio is achieved) is about 70 to 200 ° C, particularly about 100 to 180 ° C.

Unexpanded microcapsules typically have a specific gravity of about 1 or more, but may be partially expanded to reduce specific gravity if desired. The specific gravity of unexpanded or partially expanded microcapsules is typically about 0.6-1.5,
Particularly preferred is a range of 0.8 to 1.3.

The blending amount of the non-expandable microcapsules (including partially expanded ones) may be appropriately selected within a range that does not greatly impair the mechanical properties of the molded product. -5% by weight, especially about 0.05-2% by weight, particularly about 0.1-1% by weight. Within this range, the specific gravity depends on the mold pressure conditions during molding, but the specific gravity is 0.95.
It can be a molded product of g / ml or more. On the other hand, when the amount of use increases, the molded article has a so-called foam shape, and the mechanical properties are significantly reduced instead of having a low specific gravity.

The heat-expandable microcapsules usually contain about 30% by weight of water because they are synthesized by an emulsion polymerization method. When this undried product is used, not only the dispersibility with the reaction raw materials is poor, but also the polymerization activity may be reduced (hardening failure). Therefore, the heat-expandable microcapsules are dried before use to reduce the water content to 5% by weight or less, preferably 1% by weight.
The amount is particularly preferably 0.1% by weight or less.

Drying methods include freeze drying, vacuum drying, heating drying,
There is ventilation drying, etc.
Heating above ℃ must be avoided as it may initiate thermal expansion.

Additives In addition to the heat-expandable microcapsules, various additives can be added to the reactive blend, each of the feedstocks, and the solid molded article to modify the physical properties of the cycloolefin polymer. Specific examples of additives include, for example, fillers, pigments, antioxidants, light stabilizers, plasticizers, reinforcing materials, impact modifiers, and internal release agents.

As the antioxidant, there are various antioxidants for plastics / rubbers such as phenol type, phosphorus type and amine type.
Metal stabilizers such as zinc stearate, lead salicylate, cadmium benzoate, calcium salts, and aluminum salts can also be used to prevent discoloration and improve weather resistance.

The impact modifier (elastomer) is added to improve the impact resistance and to prevent sedimentation of the pigment. As the elastomer, natural rubber, polybutadiene, polyisoprene, styrene-butadiene copolymer (SBR), styrene-butadiene-styrene block copolymer (SBS), styrene-
Examples include isoprene-styrene block copolymer (SIS), ethylene-propylene-diene terpolymer (EPDM), ethylene vinyl acetate copolymer (EVA), and hydrides thereof. These elastomers can be used as a mixture of two or more. The blending ratio of the elastomer can be appropriately determined according to the molecular weight of the elastomer, the desired viscosity of the reaction solution, and the like, but is usually 10% by weight or less, and preferably 1 to 8% by weight.

Due to the short polymerization time, the additives are added to the reactive formulation before the cycloolefin monomer is fed to the mold.
Also, it is often desirable to add additives to each feedstock to form the reactive blend.

Reinforcing materials such as glass fiber mats and preforms can also be used to modify the cycloolefin polymer.
If these reinforcing materials do not hinder the flow of the monomer reaction solution, the reinforcing materials can be set in the mold cavity before the supply of the monomer reaction solution. One example of a stiffener that can be used is one that can improve bending modulus without significantly reducing impact resistance. Specific examples of usable fillers include, for example, glass, wollastonite, mica, carbon black, talc, calcium carbonate and the like. What is necessary is just to select the compounding quantity of a filler suitably according to desired performance.

Solid molded article The reactive compound liquid of the present invention is a bulk polymerization method, preferably RIM.
It is made into a solid molded product by the method. The resulting solid molded article is a non-prevented microcapsule (usually having an average particle size of
m, preferably 2 to 20 μm) may be contained in an amount of 0.05 to 5% by weight, preferably 0.05 to 2% by weight, and more preferably 0.1 to 1% by weight. Pre-expanded microcapsules (usually having an average particle size of 10-100 μm, preferably 10-7
5 μm) is generally used for producing foams, and the amount used is 1 to 50% by volume, preferably 10 to 50% by volume.

Preferred moldings have at least two finished surfaces, which result from improved mold filling by the addition of expandable microcapsules. When using unexpanded microcapsules, the microcapsules undergo significant expansion during the molding process. A density gradient occurs corresponding to the temperature of the member during the forming process. The existence of this density gradient is evidenced by the lower density compared to the component in the absence of microcapsules.

Another preferred embodiment is a molded article reinforced with a woven or nonwoven mat. Specific examples of the fibers include synthetic fibers, glass fibers, and carbon fibers. In accordance with the present invention, fiber pop-through on the surface is reduced and the fibers are not visible to the naked eye where the polymer matrix is opaque.

Bulk Polymerization of Reactive Blend In a preferred embodiment, the reactive blend is made into a solid article by the RIM method. That is, a norbornene-based polymer, that is, a molded article is produced by a method in which a norbornene-based cycloolefin monomer is introduced into a mold having a predetermined shape and is subjected to bulk polymerization in the mold in the presence of a metathesis catalyst system.

Two parts of the metathesis catalyst system (catalyst and cocatalyst)
Are separately mixed with the monomers, and the heat-expandable microcapsules are blended with the blended liquid containing the catalyst to form the feedstock of the present invention. It is preferable that these mixtures have excellent storage stability so as to maintain a gel-free state for 30 days or more. These mixtures are mixed as two separate reactant streams at the mixing head of the RIM machine and then injected into a preheated mold where they polymerize to form a foam. The heat-expandable microcapsules may be added only to the metathesis catalyst-containing monomer mixture since the activity of the cocatalyst may be reduced and the polymerization may be inhibited if the microcapsules are added to the monomer mixture containing the cocatalyst.

In the present invention, a low-molecular-weight and easily-diffusible component is used, so that the reaction liquid stream can be easily mixed. A typical mixing head has an orifice having a diameter of about 0.032 inches and a jet velocity of about 400 feet / second. If the pot life at room temperature is more than one hour, the two reaction stock solutions are mixed in a mixer such as a static mixer or a power mixer, and then mixed into a mold.
The injection or injection can be performed once or a predetermined number of times. (See, for example, JP-A-59-51911).
Also, a mixture of the bi-reactive compounding liquids can be continuously supplied into a molding die. In the case of this method, there are advantages that the device can be miniaturized and that it can be operated at a low pressure.

The mold temperature is usually 30 ° C or higher, preferably 40 to 200 ° C,
Particularly preferably, it is 50 to 130 ° C. Mold pressure is about 5-5
0 psi. An exothermic reaction quickly occurs in the mold, and a polymer having a foamed structure is obtained. In the present invention, it is necessary to provide a temperature difference between the cavity mold of the mold, that is, the product surface side, and the core mold, that is, the side having the ribs and bosses. If the cavity mold side and the core mold side are maintained at the same temperature, the whole polymerizes uniformly and the polymerization rate is extremely rapid, so that the expansion of the heat-expandable microcapsules is hindered. Is difficult to achieve. The temperature difference between the cavity mold side and the core mold side is 5 ° C. or more, preferably 10 ° C. or more, particularly preferably 10 to 50 ° C., and it is better to keep the cavity mold at a high temperature. give.

The polymerization time may be appropriately selected, but is usually shorter than about 20 minutes, preferably 5 minutes or less, but may be longer.

〔Example〕

Hereinafter, the present invention will be described more specifically with reference to examples. In the Examples, Comparative Examples and Reference Examples, parts and percentages are
Unless otherwise specified, it is based on weight.

Examples 1 to 3 and Comparative Examples A to D show the physical properties of the flat plates obtained by polymerization of the reactive blended liquid of the present invention prepared using the feedstock of the present invention.

The composition A is a combination of the composition A100 (0.5) shown in Table 1 and the composition A100 (0.75) shown in Table 2, and the composition A100 (0.
The molar ratio of n-propyl alcohol / aluminum cocatalyst in 5) was 0.5, and that of compound A100 (0.75) was 0.75, and the above molar ratio was adjusted to 0.6 by combining both.

Composition A was prepared as follows. In a 60 gallon reactor equipped with an impeller, diene 55 (butadiene rubber,
Firestone), Clayton D-1102 (styrene-butadiene block copolymer, Shell Chemical), dicyclopentadiene (DCP) (99% purity, Versicol) and ethylidene norbornene (ENB) (Union Carbite) Then added 17 pounds of DCP and 3 pounds of ENB. After reducing the pressure of the system to 25 to 50 mmHg and then heating to 85 to 95 ° C to dissolve the rubber,
Twenty pounds of the azeotrope of DCP / ENB / water was removed from the system.

The order of addition of diethylaluminum chloride (DEAC), n-propanol and silicon tetrachloride is very important in preventing rubber crosslinking. n-Propanol was measured in a 1 quart bottle and diluted with 600 g of the dicyclopentadiene solution in the reactor. Undiluted diethylaluminum chloride was added to the reactor, then diluted n-propanol solution was added, more silicon tetrachloride was added, and then stirred for 15 minutes. Thereafter, degassing was performed for about 1 hour under reduced pressure while slowly stirring. One sample was removed for testing and the remainder was transferred to a plastic drum under a nitrogen purge.

Composition B was a solution of formulation B100 (2112) shown in Table 3.

Composition B was prepared according to the following procedure with the composition shown in Table 3. Diene 55, Clayton D-1102, Mark 2112
(Phosphite antioxidant, Argus), DCP and E
NB was added to the reactor, followed by 17 pounds of DCP and 3 pounds of ENB. The system is evacuated to 20-25 mmHg, then 80-95 ° C
After heating to dissolve the rubber, 20 lbs of an azeotrope of DCP / ENB / water was removed from the system.

Molybdate catalyst solution represented by [(C ₁₂ H ₂₅ ) ₃ NH] ₄ MO ₈ O ₂₆ (48% by weight solution in DCP / ENB = 90/10 (weight ratio))
Was added and mixed for 30 minutes, and then degassed for about 1 hour while stirring slowly. One sample was removed for testing and the remainder was transferred to a plastic drum under a nitrogen purge.

Molding procedure Krauss-M that can store composition A and composition B in 20 gallons each
affei RIM machine was used. The viscosity of the liquid mixture is 100 cps, the temperature after the reaction is 35 ° C, the composition A / composition B ratio is 1.0, the molar ratio of n-propanol / aluminum cocatalyst is 0.7, the top temperature of the mold is 60 ° C, and the bottom temperature of the mold. Was 70 ° C. and the curing time was 1 minute, and these conditions were substantially common throughout Examples 1-3. The top temperature of the mold and the bottom temperature of the mold correspond to the core mold temperature and the cavity mold temperature in general reaction injection molding, respectively. n-
Formula A100 (0.5) / Formula A100 (0.75) = 40/60 to make the propanol / aluminum cocatalyst molar ratio about 0.7.
(Weight ratio) and additional n-propanol was added to composition B in the form of 10% by weight of DCP / ENB = 90/10. Microcapsules [Expancel 55
1 DU, Expancel (water content 1.0% by weight)] was added to composition B. After the microcapsules were wetted with a small amount of composition B, they were added to the storage tank of composition B and mixed well. These compositions A and B are specific examples of the feedstock in the present invention.

The mold used consisted of two heated plates with unsealed square annular spacers, with an inlet in the center of the upper plate. The obtained plate is length,
The width and thickness were 24 inches, 18 inches and 1/8 inch, respectively. The cocatalyst is sensitive to moisture and oxygen and the R of DCP
In IM, shrinkage occurs at the time of polymerization, and moist air is sucked into the mold cavity. Therefore, when molding without the Expancel 551 DU, the surface of the molded product is generally in a wet state. However, the addition of EXPANCEL 551 DU eliminates shrinkage and leaves the surface dry. In addition, since expansion occurs inside the flat plate, both surfaces of the flat plate are kept in contact with the mold surface, and each surface is completely replicated.

Example 1 The compositions A and B were mixed in a ratio of about 1: 1 with Krauss-Maffei RIM.
The mixture was mixed by a machine and injected into a mold according to the above conditions. Expancel 551 DU was added to Composition B. Experiment 2
The operation was repeated (X and Y), and the physical properties of the obtained plate are shown in Table 4.

Comparative Example A Two experiments were performed in the same manner as in Example 1 except that Expancel 551 DU was not used (i and ii), and the physical properties of the obtained flat plate are shown in Table 4.

The heat distortion temperature (HDT) was measured according to ASTM D-648, the Izod impact strength was measured according to ASTM D-256, and the flexural modulus and flexural strength were measured according to ASTM D-790. These values were measured similarly in the following examples.

From these results, it can be seen that even if a small amount of Expancel 551 DU is added, the physical properties of the obtained molded article are hardly impaired, and the conversion of the monomer is slightly decreased.

Example 2 In the same manner as in Example 1, the compositions A and B were mixed to prepare a reactive blended liquid, and molded into a solid molded product. Composition B was supplemented with Expancel 551 DU. A glass fiber mat (Owens Corning Fiberglass M-8610) was set in a mold, and a reactive compound solution was injected. Expancel 551
The amounts of DU and glass fiber mat were 0.21% by weight and 24.5% by weight, respectively. Table 5 shows the physical properties of the obtained flat plate.

Comparative Example B The experiment was performed twice in the same manner as in Example 2 except that Expancel 551 DU was not blended (i and ii). Table 5 shows the physical properties of the obtained flat plate.

From this result, it can be seen that in the case of a highly reinforced molded article, the addition of EXPANCEL 551 DU slightly reduces the monomer conversion, but does not decrease the physical properties.

Example 3 An experiment was conducted in the same manner as in Example 2 except that the used amount of the glass fiber mat was reduced to 13.25% by weight, and the physical properties of the obtained flat plate are shown in Table 6.

Comparative Example C An experiment was performed in the same manner as in Example 3 except that Expancel 551 DU was not used. The results are shown in Table 6.

From these results, it can be seen that when the amount of the glass fiber mat used is small, the physical properties and the conversion are only slightly reduced even when the foaming agent is added.

Microcapsules as a foaming agent In order to examine the function of a microcapsule as a foaming agent, a product obtained using a microencapsulated foaming agent (Example 1) and a product obtained without using the same (Comparative Example) The density was compared with that of D).

Comparative Example D The above compositions A and B were mixed at a ratio of 1.21: 1, and the mixture was polymerized to produce a flat plate. The molding conditions were as follows: the viscosity of the mixture was 100 cps, the temperature of the reaction solution was 35 ° C, the n-propanol / aluminum cocatalyst (molar ratio) was 0.62, and the upper temperature of the mold was
The mold temperature was 60 ° C., the bottom temperature of the mold was 70 ° C., and the curing time was 1 minute. No Expancel was added to Composition B. The density of the reactive liquid mixture was 0.97 g / cm ³ , and the density of a flat plate obtained from this liquid mixture was 1.03 / cm ³ .

The density of the reactive formulation of Example 1 (containing 0.21% by weight of Expancel 551 DU) was 0.97, almost the same as Comparative Example D.
It was 05G / cm ^3, but the density of the plate made from the blend solution was 0.93 g / cm ^3. The true density of Expancel 551 DU is 1.3 g / cm ³ . The low density of the molded article indicates that the microcapsules expand in the molded article and function as a foaming agent.

Improvement of Fillability in Mold by Microcapsules Examples 4 to 6 show that the proper filling of the microencapsulated foaming agent improves the filling in the mold.

Examples 4-6 were performed using bottles dried at 105 ° C for at least 1 hour. After drying, the bottle was removed and cooled to room temperature while purging with nitrogen. Monomer mixture (dicyclopentadiene / ethylidene norbornene) as described in Example 1. The rubber (diene 55) and antioxidant (mark 2112) were placed in the bottle and the bottle was rotated until the rubber was dissolved. n-Propanol, diethylaluminum chloride and silicon tetrachloride were successively added with stirring, dedusted under reduced pressure, and replaced with nitrogen. The spout provided with a nitrogen inlet was attached to the bottle, and the mixture was injected into a nitrogen-purged 60 ° C. mold with the bottle inverted. The temperature of the components in the mold was detected and recorded with a thermocouple at about 1-1.5 cm from the edge of the plate.
The time until the start of heat generation is Ex.ET (minutes), and the maximum heat generation temperature is Max.Tamp. Five minutes after the peak of heat generation, the mold was opened and the flat plate was taken out. The monomer conversion was measured by a thermobalance method using a DuPont 1090 thermal analyzer.
All components volatilized at 0 ° C. were calculated as unreacted monomers. Physical properties were measured in the same manner as in Example 1.

Example 4 A RIM compounding solution was prepared according to the above-mentioned method, and 0.4 g of Expancel 551 DU (corresponding to 0.2% by weight of the whole) was added. This mixed solution was put in a mold and polymerized. The composition of the blended liquid is as shown in Table 7 and the Expancel 551 DU was used.
Did not impair the metathesis catalyst system.

Example 5 A RIM formulation was prepared according to the procedure described above, except that the amount of n-propanol was increased to reduce the activity of the cocatalyst, and 0.4 g of Expancel 551 DU (0.2% by weight of the total).
Was added. Slight sink marks were observed on one side of the obtained flat plate. This example shows that the activity of the metathesis catalyst system can be controlled by the amount of Expancel 551 DU. The composition of the reactive mixture and the physical properties of the obtained flat plate
It is shown in the table.

Example 6 A RIM compound solution was prepared according to the above-mentioned method, and 0.8 g of Expancel 551 DU (0.4% by weight of the whole) was added. No sink marks were observed on any side of the obtained flat plate, and it was much brighter than the flat plate of Example 5. This example shows that, when the blending amount of EXPANCEL 551 DU is appropriately selected, the filling property into the mold becomes good and the appearance of both sides of the flat plate is excellent. Table 7 shows the composition of the reactive compound solution and the physical properties of the obtained flat plate.

Example 7 Molding with glass mat Example 7 A RIM compounding liquid was prepared according to Examples 4 to 6, and polymerization was performed. Clayton D-1102 was used as an impact resistance improver, and a mold having a space volume of 9 × 7 × 1/16 inch and being injected from the center was used. Owens Corning glass fiber mat M-8610 in advance
It was set at a rate of 2.0OZ / ft ^2. 0.3 g of Microlite 126 (Pierce & Stevens Indust)
rial Group) (equivalent to 0.2% polymer total).
Degassing of the blend was not performed. The weight of the obtained plate is
119 g and a glass content of 30% by weight. The plate was easily released from the mold coated with the epoxy film, but adhered to the untreated mold. In the flat plate of the present invention, the exposure of the fiber to the surface was greatly reduced as compared with the case where the microlite 126 was not blended. Table 8 shows the composition of the reactive compound solution and the polymerization conditions.

Example 8 An experiment was performed in the same manner as in Example 7, except that the filling amount of the glass mat was increased to 38.5 g. The obtained plate is about 12
2 g and a glass content of about 32%. A mold having both surfaces coated with epoxy resin was used. Degassing of the blend was not performed. The molded flat plate slightly adhered to the epoxy resin surface of the mold. This example shows that when a heat-expandable microcapsule is added to a liquid mixture, it can be filled well in a mold even when a glass mat is contained. The microcapsules were not filtered out of the formulation due to the presence of the glass mat. Fiber exposure to the slab was greatly reduced. Table 8 shows the composition of the reactive compound solution and details of the polymerization.

Examples 9 to 14 Examples 9 to 14 show that polymerization can be performed even when the blending amount of the heat-expandable microcapsules is changed. The composition of the reactive mixture was as shown in Table 9 and was prepared in the same manner as in Examples 4 to 6.

Polymerization did not occur in Examples 9 to 11 in which Expancel 551 DU was blended at 46.7% by weight, 22.6% by weight, and 9.0% by weight, respectively, but polymerization proceeded in Example 12 at 4.4% by weight.

In Example 14 in which 6.0% by weight of Expancel 551 DU was blended in a blended liquid using a cocatalyst not modified with alcohol, the conversion was 81.4%. Low conversion indicates that the amount of Expancel 551 DU is somewhat too high.

In Example 13, in which 50% by volume of Expancel 551 DU was blended with the blended liquid using the alcohol-modified cocatalyst, the conversion was 88.1%. The conversion will be improved if less alcohol is used. When the blending amount becomes 50% by volume, the mixture becomes difficult to flow, and when it exceeds that, RIM
The viscosity becomes too high for use in the method.

Similar experiments were performed except for using microcapsules dried with nitrogen for Examples 14 and 13, and the conversions were 82.1% and 69.6%, respectively, with no clear conclusions.

Comparison of these values with Examples 14 and 13 shows that the use of dry Expancel DU increases the conversion and decreases with Dry Expancel DE.

Example 15 To 100 parts of dicyclopentadiene (DCP), 6.5 parts of styrene-isoprene-styrene block copolymer (SIS) (Quintac 3420, trade name of Nippon Zeon Co., Ltd.) are added and mixed. This solution was placed in two containers, and to one of them, diethylaluminum chloride (DEAC) was added to DCP at a concentration of 41 mmol, n-propyl alcohol at a concentration of 41 mmol, and silicon tetrachloride at a concentration of 21 mmol. (Solution A). On the other hand, tri (tridecyl) ammonium molybdate was added to DCP to a concentration of 10 mmol, and 4 parts of a phenolic antioxidant (Ethanox 702, manufactured by Ethyl Corporation) and 100 parts of vinylidene chloride were added per 100 parts of DCP. 0.44 parts of a heat-expandable microcapsule (Expancel DU-551, manufactured by Nippon Philite Co., Ltd.) having a shell formed of an acrylonitrile copolymer was added (Solution B).

The above microcapsules were obtained by drying a commercially available product at 60 ° C. for 2 hours under a nitrogen atmosphere, and had a water content of 0.
It was less than 1%.

The onset time of heat generation of this catalyst system at 30 ° C. (the time until the polymerization reaction started rapidly after mixing both reaction solutions) was about 3 minutes.

Using a gear pump and a power mixer, mix both reaction solutions into a mold with a rib and boss structure of a prescribed shape and a space volume of approximately 200 mm x 200 mm x 3 mm (mixing ratio of solution A / B 1/1). Immediate injection at normal pressure. Table 10 shows the temperature conditions on the core mold side (the side having the rib and boss structure) and the cavity mold side (the planar shape side) of the mold. In the mold, the core mold is set up and the cavity mold is set down, and the core surface and the cavity surface are held with a mold clamping pressure of 1 ton after the injection of the reaction solution.

The reaction was continued for 3 minutes after the inside of the system rapidly generated heat, to obtain a DCP polymer as a molded product. Table 10 shows the evaluation results of the obtained molded products.

The specific gravity of each molded article is about 1.01 g / ml,
Specific gravity of molded products without blending heat-expandable microcapsules
It was almost the same as 1.03 g / ml.

Note (* 1) The cured state of the molded product surface was evaluated in the following five stages.

5: There is no stickiness in the molded product at all.

4: Some stickiness remains on the boss and ribs.

3: Stickiness can be seen visually on the boss and ribs.

2: Stickiness remains on the boss and rib portions, and a slight stickiness remains on the back surface of the molded product.

1: Stickiness remains on the boss and the rib portion, and stickiness remains on the entire back surface of the molded product.

(* 2) State of Boss and Rib Part A mold having the boss and rib part on the core mold side was used to evaluate the moldability by the filling height of the resin.

The boss shape is upper diameter 14mmφ, lower diameter 20mmφ, height 20
It has a cylindrical shape of mm. The shape of the rib is a trapezoidal shape having a length dimension of an upper part 20 mm, a lower part 40 mm, a height 20 mm, and a thickness dimension of an upper part 2 mm and a lower part 3 mm.

 The height of the complete filling is 20 mm in each case.

(* 3) The odor of the molded product was evaluated on the following five levels.

5: No odor.

4: Slight odor, but does not affect product value.

3: Can be removed by washing (wiping with toluene, etc.).

2: There is an odor, which affects the product value.

1: No odor and no product value.

(* 4) The stain on the mold was evaluated in the following five stages.

5: No dirt.

4: There is some dirt on the boss and rib.

3: Stickiness can be seen visually on the boss and ribs.

2: Some stickiness remains on the core surface.

1: Stickiness remains on the entire surface of the core.

From the results shown in Table 10, it can be seen that when a temperature difference is provided between the cavity mold and the core mold of the mold, an excellent molded product can be obtained.

Example 16 An experiment was performed in the same manner as in Experiment No. 1-4 of Example 15 except that various systems having different exothermic onset times were used as the metathesis catalyst system. The results are shown in Table 11.

Note (* 5) of the metathesis catalyst system type M _1: except that the addition of n- propyl alcohol to be added to the solution A so that the 30 millimolar were prepared reaction solution in the same manner as in Example 1.

M _2: In the M _1, the concentration of n- propyl alcohol
The experiment was performed at a 37 mM concentration.

M _3: In the M _1, the concentration of n- propyl alcohol
The experiment was carried out with the concentration changed to 44 mM.

 The evaluation method is the same as in Table 10.

From this result, it can be seen that when the heat generation start time is short, the polymerization reaction occurs rapidly, so that the expansion of the heat-expandable microcapsules tends to be inhibited.

Example 17 An experiment was performed according to Experiment No. 1-4 of Example 15 except that the kind and the amount of the thermally expandable microcapsules were changed. The results are shown in Table 13. The shapes of the used microcapsules are as shown in Table 12.

Note (* 6) The drying condition is 2 hours at 60 ° C under nitrogen atmosphere.

(* 7) The sink of the molded product surface (smooth surface) was evaluated in the following five steps.

5: No sink marks.

4: Rib, boss equivalent part (part with rib, boss on the back side)
There are some sink marks on the surface with the mark, but there is no problem in product quality.

3: There are sinks in the ribs and boss equivalents, causing problems in product quality.

2: There are some sink marks other than the rib and boss equivalent parts.

1: There is a sink on the whole surface.

(* 8) The smoothness of the back surface (the portion with ribs and bosses) was evaluated on the following five levels.

5: Smooth 4: Some parts are not smooth. (Smoothness 80% or more) 3: There is about half smoothness.

2: Only part has smoothness.

1: No smoothness.

(* 9) Number of shots that can be molded without washing (removing organic substances on the mold surface with an organic solvent such as toluene).
This is the number of shots that can be formed up to boss and rib fillability (height) of 18 mm or more.

 Other evaluation methods are the same as in Table 10.

As shown in the control example in Table 13, when the heat-expandable microcapsules are not used, curing failure occurs from the first shot, and only those having no value as molded products can be molded.

On the other hand, when the heat-expandable microcapsules are used, the cured state is improved, the odor is reduced, and the shapes of the bosses and ribs, the smoothness of the surface, and the prevention of sink marks are all significantly improved. In addition, mold contamination has been significantly reduced, and the number of shots without cleaning the mold has been improved.

In particular, when a heat-expandable microcapsule having a small water content is used, the effect of these improvements is remarkable.

Example 18 An experiment was performed in the same manner as in Experiment No. 1-3 of Example 15, except that the core mold was set downward and the cavity mold was set upward.

The surface hardening state is at level 5, the boss is 20.0mm,
The ribs had a 20.0 mm filling. Odor and mold stain were also at a level of 5. Furthermore, no sink marks were observed on the product surface on the cavity mold side, and the back surface was smooth.

For comparison, an experiment was conducted in the same manner as described above except that the heat-expandable microcapsules were not added. The cured state of the surface was at level 2, the boss was filled with 19.8 mm, and the rib was filled with 19.9 mm. As a result, the odor and stain on the mold were as low as 2 and the smoothness of the product surface was at 4 level.

〔The invention's effect〕

ADVANTAGE OF THE INVENTION According to this invention, the surface hardening state is favorable compared with a prior art, and a norbornene-type polymer molded article which has complicated shapes, such as a boss and a rib, can be formed very efficiently. Moreover, the obtained molded article has no odor, is excellent in surface smoothness, and has a specific gravity almost the same as that in the case where no microcapsules are blended in a system in which a small amount of unexpanded microcapsules is blended. Also, it has excellent performance in mechanical properties.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kinichi Okumura 2-26, 1-301, Kajiwara, Kamakura City, Kanagawa Prefecture (72) Inventor Masayoshi Matsui 5-4-7, Chuo, Yamato City, Kanagawa Prefecture (72) Inventor Hajime Yamato Tohoku 2-21-22-2Koiso, Oiso-machi, Naka-gun, Kanagawa Prefecture (56) References JP-A-60-244511 (JP, A) JP-A-61-159409 (JP, A) JP-A-60-124634 (JP) , A) JP-A-60-49012 (JP, A)

Claims (3)

(57) [Claims] 1. A mixing liquid (A) containing a cycloolefin monomer having a norbornene group and a metathesis cocatalyst, and a mixing liquid (B) containing a cycloolefin monomer having a norbornene group, a metathesis catalyst and a heat-expandable microcapsule. A method for producing a norbornene-based cycloolefin polymer, which comprises performing reaction injection molding by mixing a reactive mixture obtained by mixing after mixing with a head into a mold including a cavity mold and a core mold. The heat-expandable microcapsules in the liquid mixture (B) are:
It has a water content of 5% by weight or less, and (A) is unexpanded, and its blending amount is 0.05 to 5% by weight based on the total weight of the reactive polymerization solution, or (B) It is a pre-expanded one, the blending amount of which is 1 to 50% by volume based on the total volume of the reactive polymerization liquid, and the temperature of the reactive mixture is 5 ° C. or more higher than that of the core mold by the temperature of the cavity mold. A method for producing a norbornene-based cycloolefin polymer, comprising performing injection molding by injection into a mold maintained at a temperature. 2. The heat-expandable microcapsule is a synthetic resin microcapsule encapsulating a vaporizable expander, and the temperature at which the maximum expansion ratio of the heat-expandable microcapsule can be achieved is in the range of 70 to 200 ° C. 3. The method for producing a cycloolefin polymer according to item 1. 3. A metathesis catalyst system comprising the metathesis catalyst and the metathesis cocatalyst has an exothermic onset time at 30 ° C.
3. The method for producing a norbornene-based polymer according to claim 1, wherein the time is 0.5 minutes or more.