JP2003039475A - Fine bubble containing member for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive member for a vehicle light in weight, showing high rigidity and enough impact strength and to provide its manufacturing method. SOLUTION: A member containing fine bubbles for a vehicle is made of a crosslinked polymer molded item having many fine bubbles wherein (1) to crosslinked polymer molded item is obtained by mixing a monomer solution A (solution A) of a metathesis polymerizable cyclic olefin containing a metathesis polymerization catalyst-based catalyst component and a monomer solution B (solution B) of a metathesis polymerizable cyclic olefin containing a metathesis polymerization catalyst-based activating agent component, injecting the mixture liquid of the raw materials into a mold, polymerizing and crosslinking it in the mold, (2) the crosslinked polymer molded item has many bubbles having an average diameter of not more than 100 μm and (3) the crosslinked polymer molded item has a specific gravity in the range of 0.55 to 0.95.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is resistant to impact, has excellent durability, can be recycled without the need for fiber reinforcement, and produces almost no incineration residue during disposal by incineration.
The present invention relates to a pollution-free, integrally molded vehicle member that does not generate toxic gas and a method for manufacturing the same, and particularly to a vehicle characterized by being lightweight, high in rigidity, excellent in impact resistance, and inexpensive. The present invention relates to a molded article and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, a vehicle exterior member such as a bumper or a body, which is required to have impact resistance, is generally made of metal. In recent years, some plastic products are used due to the demand for weight reduction, but impact resistance is not sufficient, the demand for weight reduction is not sufficiently satisfied, and both needs are satisfied at the same time. There was nothing. For example, a vehicle member for a certain application is molded using fiber reinforced plastic (FRP), which is known to have high strength, and in particular, an unsaturated polyester resin reinforced with glass fiber is used. Often molded. When molding a vehicle member using the unsaturated polyester resin reinforced with glass fibers, there is a problem that a large amount of dust containing glass fibers is generated and the working environment becomes poor.
In addition, the vehicle member using such an FRP has a heavy weight and has a drawback that cracks easily occur due to the impact when dropped during transportation or when pebbles are hit during construction. Furthermore, since the molded product of FRP contains glass fiber, it is difficult to crush and crush it at the time of disposal, and even if it is incinerated, a large amount of glass fiber remains and it takes time and labor to process it.

Therefore, the present inventors previously used a metathesis-polymerizable cyclic olefin, such as dicyclopentadiene, which can be obtained at a low cost, to produce a vehicle member molded article molded by the RIM (reaction injection molding) method utilizing metathesis polymerization. It has been put to practical use. This molded product is used for automobile bumpers, air deflectors, air spoilers, golf cart bodies, construction machinery bodies, agricultural machinery bodies, etc., and has reduced weight, improved impact resistance, and greatly simplified the manufacturing process. Has been achieved. However, in recent years, there has been a strong demand for further price reduction and further weight reduction for energy saving.

[0004]

SUMMARY OF THE INVENTION The main object of the present invention is to provide an inexpensive vehicle member that is lightweight, has high rigidity, and has sufficient strength against impact, and a method for manufacturing the same. I am trying.

[0005]

DISCLOSURE OF THE INVENTION As a result of intensive studies conducted by the present inventors in order to solve the above-mentioned object of the present invention, the material of the molded article for vehicle is made of dicyclopentadiene containing a large number of fine bubbles. As a cross-linked polymer, by finding the effect of two birds with one stone to reduce the amount of expensive resin raw material used and at the same time provide high rigidity by setting the size of the bubbles and the specific gravity of the cross-linked polymer within a specific range, the present invention Reached

That is, according to the present invention, the following vehicle member molded article is provided. 1. A vehicle member comprising a crosslinked polymer molded product containing a large number of fine bubbles, wherein the crosslinked polymer molded product is (1) a monomer liquid comprising a metathesis polymerizable cyclic olefin containing a catalyst component of a metathesis polymerization catalyst system. A (solution A) and a monomer solution B (solution B) composed of a metathesis-polymerizable cyclic olefin containing an activator component of a metathesis polymerization catalyst system are mixed, and the raw material mixed solution is injected into a mold to produce the metal. It was obtained by polymerization and crosslinking reaction in a mold, (2) contains a large number of bubbles having an average diameter of 100 μm or less, and (3) has a specific gravity of 0.5.
A member for vehicles containing fine bubbles, characterized in that it is in the range of 5 to 0.95. 2. The vehicle member according to 1 above, wherein the vehicle member is an exterior member. 3. The vehicle member according to 2 above, wherein the exterior member is a shock absorbing member. 4. The vehicle member according to the above 2, wherein the exterior member is a body of a construction machine or an agricultural machine. 5. Monomer liquid A consisting of a metathesis polymerizable cyclic olefin containing a catalyst component of a metathesis polymerization catalyst system (solution A) and monomer liquid B consisting of a metathesis polymerizable cyclic olefin containing an activator component of a metathesis polymerization catalyst system
(Solution B) is mixed, and the raw material mixture is poured into a mold, and a crosslinked polymer molded product obtained by causing polymerization and crosslinking reaction in the mold is obtained. (1) Average diameter 100 μm or less A method for producing a vehicle member composed of a crosslinked polymer molded product containing a large number of bubbles of the size of (2) and having a specific gravity of 0.55 to 0.95, wherein the solution A and / or Alternatively, a predetermined high pressure is applied to the solution B to dissolve the gas, the solution A and the solution B are mixed, and the raw material mixed solution is injected into a mold to cause polymerization and crosslinking reaction in the mold and foaming. A method for manufacturing a vehicle member, the method comprising molding a vehicle member by using the above method. 6. The above-mentioned 5 characterized in that the gas is nitrogen gas
Manufacturing method of the vehicle member.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below.

As the metathesis-polymerizable cyclic olefin for forming the crosslinked polymer which constitutes the vehicle member of the present invention, a metathesis-polymerizable cycloalkene group is contained in the molecule in an amount of 1
Those containing ~ 2 are used. A compound having at least one norbornene skeleton in the molecule is preferable. Specific examples of these include dicyclopentadiene,
Tricyclopentadiene, cyclopentadiene-methylcyclopentadiene co-dimer, 5-ethylidene norbornene, norbornene, norbornadiene, 5-cyclohexenyl norbornene, 1,4,5,8-dimethano-
1,4,4a, 5,6,7,8,8a-octahydronaphthalene, 1,4-methano-1,4,4a, 5,6
7,8,8a-octahydronaphthalene, 6-ethylidene-1,4,5,8-dimethano-1,4,4a, 5
6,7,8,8a-octahydronaphthalene, 6-ethylidene-1,4-methano-1,4,4a, 5,6,7,
8,8a, -octahydronaphthalene, 1,4,5,8
-Dimethano-1,4,4a, 5,8,8a-hexahydronaphthalene, ethylene bis (5-norbornene) and the like can be mentioned, and a mixture thereof can also be used. Particularly, dicyclopentadiene or a mixture thereof containing 50 mol% or more, preferably 70 mol% or more is suitably used.

If desired, a metathesis-polymerizable cyclic olefin having a polar group containing a different element such as oxygen or nitrogen can be used as a copolymerization monomer. Such a copolymerizable monomer also preferably has a norbornene structural unit, and the polar group is an ester group,
Ether groups, cyano groups, N-substituted imide groups, halogen groups and the like are preferable. Specific examples of the copolymerization monomer include 5-methoxycarbonylnorbornene and 5- (2-
Ethylhexyloquine) carbonyl-5-methylnorbornene, 5-phenyloxymethylnorbornene, 5-cyanonorbornene, 6-cyano-1,4,5,8-dimethano-1,4,4a, 5,6,7, Examples thereof include 8,8a-octahydronaphthalene, N-butyl nadic acid imide, and 5-chloronorbornene.

The monomer solution A (solution A) in the present invention contains a catalyst component of a metathesis polymerization catalyst system. As such a catalyst component, a halide or ammonium salt of a metal such as tungsten, rhenium, tantalum or molybdenum is used, but a tungsten compound is particularly preferable from the viewpoint of reactivity of dicyclopentadiene. As such a tungsten compound, tungsten hexahalide, tungsten oxyhalide, etc. are preferable, and more specifically, tungsten hexachloride, tungsten oxychloride, etc. are preferable. Further, organic ammonium tungstate or the like can also be used. It has been found that when such a tungsten compound is directly added to the monomer, it immediately starts cationic polymerization, which is not preferable. Therefore, such a tungsten compound is preferably suspended in an inert solvent such as benzene, toluene, chlorobenzene and the like in advance and solubilized by adding a small amount of an alcohol compound and / or a phenol compound to be used. Further, as described above, it is preferable to add about 1 to 5 mol of Lewis base or chelating agent to 1 mol of the tungsten compound in order to prevent undesired polymerization. Examples of such additives include acetylacetone, acetoacetic acid alkyl esters, tetrahydrofuran, and benzonitrile. When a polar monomer is used, it may be a Lewis base itself as described above, and it may have its action even if the above compound is not added. As described above, the monomer liquid A (solution A) containing the catalyst component has substantially sufficient stability.

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

In the present invention, the solution A and / or the solution B to which a foaming agent or a foaming gas (which may be referred to as a foaming gas), which is a feature of the invention described later, is added.
By mixing and injecting into the mold, a molded product of the target crosslinked polymer can be obtained. However, if the above composition is left as it is, the polymerization reaction is initiated very quickly, so that curing may occur before it sufficiently flows into the molding die, which may cause a problem. In such a case, it is preferable to use an activity regulator. As such a regulator, Lewis bases are generally used, and above all, ethers, esters, nitriles and the like are used. Specific examples include ethyl benzoate, butyl ether, diglyme and the like. Such regulators are generally
It is used by adding it to the solution (solution B) containing the activator component of the organometallic compound. When a monomer having a Lewis base is used as described above, it can also serve as a regulator.

The amount of the metathesis polymerization catalyst system used is, for example, when a tungsten compound is used as the catalyst component, the ratio of the tungsten compound to the raw material monomer is
It is about 1,000 to 1 to 15,000, preferably about 2,000 to 1 on a molar basis, and when an alkylaluminum is used as the activator component, the aluminum compound to the above raw material monomer is used. The ratio of about 100: 1 to 10,000: 1, preferably 2 on a molar basis.
The vicinity of 00: 1 to 1,000: 1 is used. Further, the chelating agent and the activity controlling agent as described above can be appropriately adjusted and used depending on the amount of the catalyst system used by experiments.

The molded article of the crosslinked polymer obtained by the present invention may further contain various additives depending on the purpose thereof in order to improve or maintain the characteristics thereof in practical use. Such additives include fillers, pigments, antioxidants, light stabilizers, flame retardants, polymer modifiers and the like.
Such additives cannot be added after the crosslinked polymer of the present invention has been molded, and therefore, when added, it is necessary to add them to the above-mentioned raw material solution in advance.

The simplest method is the solution A described above.
And a solution B may be added in advance to either or both of them, but in that case, they do not react to a certain extent with the catalyst component and activator component having strong reactivity in the liquid and do not react to some extent. In addition, it must not interfere with the metathesis polymerization. Inevitably, even if the reaction is unavoidable, if it does not substantially inhibit the polymerization or does not inhibit it in a short time, it is mixed with a monomer to prepare a third liquid, and immediately before the polymerization. Mixtures can also be used. A method in which the polymerization catalyst or activator is used as the third liquid and the above additives are added to solution A or solution B not containing the third liquid is also conceivable. Further, in the case of a solid filler, when the two components are mixed and the shape is such that the voids can be sufficiently filled immediately before starting the polymerization reaction or during the polymerization, it is filled in the molding die. It is also possible to keep it. In addition, it is preferable to add an antioxidant to the molded product according to the present invention. Therefore, it is desirable to add a phenol-based or amino-based antioxidant to the solution in advance. Specific examples of these antioxidants include 2,6-di-t-butyl-p-cresol,
N, N'-diphenyl-p-phenylenediamine, tetrakis [methylene (3,5-di-t-butyl-4-hydroxycinnamate)] methane and the like can be mentioned.

In the molded product of the present invention, another polymer may be added in the monomer solution state. As such a polymer additive, the elastomer is effective in enhancing the impact resistance of the molded product and controlling the viscosity of the solution. Examples of the elastomer used for such purpose include a wide range of elastomers such as styrene-butadiene-styrene triblock rubber, styrene-isoprene-styrene triblock rubber, polybutadiene, polyisoprene, butyl rubber, ethylene propylene-diene terpolymer, and nitrile rubber. be able to.

Further, the crosslinked polymer molded article of the present invention is compared with a crosslinked polymer of a metathesis-polymerizable cyclic olefin represented by dicyclopentadiene or tricyclopentadiene produced by reaction injection molding (RIM molding). It contains a large number of uniform and fine bubbles. The greatest feature of this is that it achieves weight reduction, wall thickness, and high rigidity. The average size of the bubbles is 100
Must be smaller than μm diameter. If it is larger than 100 μm, it becomes brittle and the strength as a vehicle member decreases. 1 μm
Smaller bubbles are generally difficult to make, and the effect of containing bubbles is small. In the present invention, the specific gravity of the crosslinked polymer molded product is in the range of 0.55 to 0.95. When the specific gravity is less than 0.55, the polymer has a large number of relatively large bubbles (cavities) or small bubbles are connected to each other, resulting in deterioration of strength and impact resistance. When the specific gravity is larger than 0.95, the weight reduction of the polymer, which is the object of the present invention, is not effective. The present invention achieves weight reduction by forming fine bubbles in a cross-linked polymer (in a molded article), and at the same time, when the bubbles are the same size or small as defects unavoidably present in the polymer, By utilizing the phenomenon that the original mechanical strength of the vehicle is not significantly reduced, this is applied to a vehicle member that is required to be lightweight and have high bending rigidity. Therefore, as mentioned above, the size of the bubbles of the present invention is 100 μm or less, preferably 50 μm or less,
More preferably, it should be 30 μm or less. The majority of the bubbles of the present invention (about 70% or more) are independent bubbles, and it is preferable that they are mutually connected and do not substantially form continuous bubbles. If there are many continuous bubbles,
It may not have sufficient strength against impact.

The number of the bubbles can be determined by observing the cross section of the polymer (molded product) with a microscope and measuring the number. In the present invention, 100
100 pieces / mm ² when observed under a microscope from 2 times to 200 times
When the above-mentioned air bubbles were present, a polymer (molded product) satisfying both strength and weight reduction was stably obtained.

The average size of the bubbles in the present invention is obtained by cutting out a cross section in the plate thickness direction of the crosslinked polymer constituting the vehicle member molded article of the present invention and observing it with a microscope such as an electron microscope at a magnification of 100 to 200 times. And the observed bubble diameters are averaged. The observed and measured sample portion when observed at a magnification of 100 times had an area of 1 mm × 0.8 mm. Observation samples were collected from three locations in the plate thickness direction. The size of the bubbles observed when the cross section was cut out was
Not all are the diameter of that bubble. That is, when the bubbles are formed into spheres, the cross section to be cut has various cut surfaces from the diameter portion of the sphere to the end of the sphere. Assuming that all the bubbles are perfect spheres of uniform size, the average diameter of the cut surfaces observed when randomly cut is calculated to be about 0.74 times the diameter of the spheres. The "average size of bubbles" is not corrected or considered. That is, in the present invention, as described above, it is a simple average of the cut surfaces of bubbles observed under a microscope.

The vehicle member of the present invention comprises a metathesis-polymerizable cyclic olefin crosslinked polymer. By the way, the normal specific gravity of the resin is in the range of 1.0 to 1.2. The molded product for a vehicle member of the present invention, which contains bubbles and has a specific gravity in the range of 0.55 to 0.95, does not reduce the mechanical strength and is lightened only by the reduced specific gravity. And we were able to achieve lower prices by saving the resin used. further,
Strong bending rigidity and high impact resistance are required for exterior members such as air spoilers and air deflectors that receive strong wind pressure, and exterior members such as bodies of construction machinery and agricultural machinery. In such a case, in the present invention, the plate thickness can be increased by the amount corresponding to the weight reduction, and since the bending rigidity is proportional to the cube of the thickness, a significant improvement in bending rigidity can be achieved. The preferable range of the specific gravity is 0.60 to 0.85.

Various well-known methods can be used for producing such uniform and fine bubbles. Generating gas by mixing gas while stirring with a mixer, etc. to mechanically foam it, adding a low boiling point compound as a foaming agent to physically foam it, or by a chemical reaction of two components The method of chemically foaming is well known. However, it is difficult to accurately and reproducibly produce fine bubbles by these methods, and in the present invention, a gas is dissolved in a monomer liquid (one or both of solution A and solution B) at high pressure. A method of injecting them into a mold and then foaming the gas in the mold can be preferably used.

As an example of the method for producing a vehicle member containing a large number of bubbles according to the present invention, a gas for foaming is added to at least one of the solution A and the solution B to be dissolved, and then the solution A and the solution B are dissolved. Mix B. The mixed raw material mixture is poured into a mold to cause polymerization and crosslinking reaction in the mold. With these reactions, the gas dissolved in the solution foams, and a foamed shape occurs in the crosslinked polymer molded product. In this way, foaming occurs along with the polymerization and the crosslinking reaction in the mold, and a foamed molded product is obtained.

The method for manufacturing a vehicle member of the present invention will be described in detail below.

As a preferable manufacturing method, a device for supplying a gas for foaming is added to a normal reaction injection molding (RIM) device as a foaming reaction injection molding device, and further, pressure resistance of a mold, a monomer liquid tank, etc., This is performed by using a structure having improved pressure controllability. Before the foam molding, the raw material monomer liquid A and the monomer liquid B are separately stored so as not to cause a reaction, and are stored in the A tank and the B tank which can be hermetically stored. A tank containing each of these monomer liquids and /
Or, introducing gas from the gas supply device into the B tank,
The introduced gas is dissolved in the respective monomer liquids in the A tank and / or the B tank at a predetermined pressure. In this case, the gas for foaming introduced may be any gas as long as it acts as a foaming gas such as carbon dioxide gas, nitrogen gas or argon gas, but nitrogen gas or carbon dioxide gas is preferably used. Since carbon dioxide gas has a higher diffusivity than other gases, it was easy to saturate and dissolve it in the monomer liquid. However, when dicyclopentadiene is used as a raw material monomer using carbon dioxide gas, there occurs a disadvantage that reactivity is hindered,
It has a drawback that the shelf life of the monomer liquid is short. On the other hand, since nitrogen gas is inert and does not hinder the polymerization reaction, it is more preferably used in the present invention.

Further, in order to dissolve the foaming gas in each of the monomer liquids, for example, when only the pressure is applied at room temperature to dissolve the gas, the gas is supplied to the A tank and / or by the gas supply means equipped with a pressurizing device. Alternatively, the pressure is fed to the B tank, and the A tank and / or the B tank are pressurized to at least 1 MPa or more. For example, it is performed by applying a pressure of 6 MPa or more in about 10 hours, or by applying a pressure of 8 MPa or more in about 3 to 5 hours. In addition,
When dicyclopentadiene is used as the monomer,
From the viewpoint of accurately controlling the polymerization reaction, the monomer liquid is
It is preferable to control at a predetermined temperature selected according to its reactivity (activity).

Next, while maintaining the pressure and temperature from the temperature range of about 20 ° C. to 45 ° C., each monomer liquid is sent to the mixing head which communicates with the A tank and the B tank and mixes the two monomer liquids, The two liquids are uniformly mixed in this mixing head section. Each component (each monomer liquid) is transported by using a pump or the like. Then, the mixed two liquids are sent to a mold, and the mixed components undergo a polymerization and crosslinking reaction to be solidified to obtain a molded product. Foaming is carried out in a solution state just before solidification in the mold and / or at a stage where viscosity is increasing due to progress of polymerization reaction, and a foamed molded article containing a large number of bubbles is obtained.

That is, the monomer liquid in which the gas is dissolved in advance undergoes a sudden change in pressure and / or temperature in the mold, and the solubility of the gas is lowered to cause foaming. In this case, either the pressure or the temperature may be changed, but when the gas is saturated by high pressure, a device equipped with a pressure adjusting valve is used as a mold pressure control device, and the pressure adjusting valve is used to It is preferable to control the pressure in the mold so as to sharply decrease it. The temperature and pressure of the mold are controlled, but the temperature rapidly rises and the pressure also changes due to the polymerization reaction of the mixed two liquids. Such rapid changes in temperature and pressure also contribute to foaming. The mold temperature of the large septic tank is set to about 30 ° C to 110 ° C immediately before the polymerization reaction starts,
The pressure inside the cavity (cavity) is set in the range of 0 to 5 MPa, preferably in the range of 0.05 to 4 MPa.

In order to adjust the bubble diameter and the number of bubbles in the crosslinked polymer molded product, the mold temperature and pressure are adjusted by using the mold pressure controller and / or the mold temperature controller. It is preferably carried out by appropriately controlling the internal pressure and / or temperature. The bubble diameter and the number of bubbles in the foamed polymer (molded product) can also be adjusted by controlling the gas concentration in the monomer liquid.

The crosslinked polymer molding of the present invention contains a large number of cells produced by such a method, thereby achieving weight reduction and saving the amount of expensive resin used as compared with moldings of the same size. it can. The specific gravity of the crosslinked polymer molded product of the dicyclopentadiene polymer containing no bubbles is about 1.0.
However, in the present invention, the specific gravity was 0.55 to 0.95, and significant reduction in weight and reduction in manufacturing cost was achieved without lowering strength and rigidity. In addition, the reduction in weight allows the plate thickness to be increased, and the bending rigidity is greatly improved. In particular, exterior components of vehicles that require impact resistance, such as bumpers for automobiles, trucks, buses, etc., air spoilers, air deflectors, and construction machines that are subject to various impacts and collisions when used at construction sites. In the body of, the body of agricultural machinery that has a lot of chances of collision such as pebbles, and the body of a motorcycle, etc.
The vehicle member of the present invention exerts a great effect as an exterior component.

One of the general features of the cyclic olefin cross-linked polymer molded article used in the present invention is that it has excellent impact resistance. Usually, even if dropped, solid matters such as pebbles collide with each other. Is not easily broken. Basically, it is not necessary to particularly use a reinforcing material such as glass fiber. However, the flexural modulus is generally lower than those using these reinforcing materials, and there has been a demand for improvement in a portion that becomes a step, a portion that is likely to be stepped on, and a portion that is subjected to pressure such as wind pressure. As means for solving this, the vehicle member molded product of the present invention has a thickness of 1.
It has been found that the thickness can be increased from 2 times to 1.8 times, which is extremely effective in improving bending rigidity.

The structure of the vehicle member of the present invention is not particularly limited as long as it is a foamed molded product obtained by cross-linking polymerization of a metathesis-polymerizable cyclic olefin.

[0032]

EXAMPLES The vehicle member molded product of the present invention will be specifically described with reference to the following examples.

Example 1 (Production of Raw Material Liquid: Preparation of Solution A) 28 parts by weight of tungsten hexachloride was added to 80 parts by weight of dry toluene under a nitrogen stream, and then 1.3 parts by weight of t-butanol was added. A solution dissolved in 1 part by weight of toluene was added and stirred for 1 hour, and then a solution of 18 parts by weight of nonylphenol and 14 parts by weight of toluene was added and stirred under a nitrogen purge for 5 hours. Further, 14 parts by weight of acetylacetone was added. Stirring was continued overnight under a nitrogen purge while expelling by-produced hydrogen chloride gas to prepare a polymerization catalyst solution. Next, with respect to a monomer mixture consisting of 95 parts by weight of purified dicyclopentadiene (purity 99.7% by weight, the same below) and 5 parts by weight of purified ethylidene norbornene (purity 99.5% by weight, the same below), ethylene-containing 70 mol% Ethylene-propylene-
The above polymerization catalyst solution was added to a solution containing 3 parts by weight of ethylidene norbornene copolymer rubber and 2 parts by weight of Etanox 702 as an oxidation stabilizer, and a tungsten content of 0.01 mo.
A monomer liquid A (solution A) containing a catalyst component in addition to 1 / liter was prepared.

(Preparation of Solution B) 70 mol% of ethylene content based on a monomer mixture consisting of 83 parts by weight of purified dicyclopentadiene and 5 parts by weight of purified ethylidene norbornene.
3 parts by weight of ethylene-propylene-ethylidene norbornene copolymer rubber was dissolved in a solution of trioctyl aluminum 85 and dioctyl aluminum iodide 1
5, the activator mixture for polymerization prepared by mixing the diglyme at a molar ratio of 100 has an aluminum content of 0.03 mol /
A monomer liquid B (solution B) containing an activator component was prepared by adding it at a ratio of becoming a litter.

(Mold) A mold incorporating the shape of the front bumper of an ordinary small passenger car was used. The bumper has a nut-shaped insert member for attachment to the body of a passenger car. The plate thickness is 6.4 mm.

(Molding) A bumper made of a foamed molded product was produced using the mold and the foaming reaction injection molding machine described above. Nitrogen gas was dissolved in both monomer liquids A and B at 45 ° C. at 9 MPa. Subsequently, the fixed side mold temperature was 90 ° C., the movable side mold temperature was 60 ° C., the cavity internal pressure was 0.3 MPa, and reaction injection molding was performed. The obtained foamed product had a specific gravity of 0.
66, the average bubble size inside was 31 μm. Also,
The number of bubbles per unit area measured from electron microscopic observation of the cross section was 368 / mm ² .

(Evaluation as Bumper) The obtained bumper was attached to the front of the automobile for testing, and the US standard PA was used.
Speed 2.5MPH (approx. 4km shown on RT581)
/ Hour) barrier collision test. In the bumper of the present invention, functional parts such as a lamp were not damaged at all, and the bumper itself was extremely slight in damage as compared with the current commercialized product.

COMPARATIVE EXAMPLE 1 AND EVALUATION OF PHYSICAL CHARACTERISTICS Using the monomer solutions A and B prepared in the above-mentioned examples, using a usual RIM molding apparatus, the same shape as the examples but the plate thickness was set to 4. A bumper having a size of 5 mm was manufactured as a comparative example. Samples for measuring physical properties were cut and evaluated from the bumper of this comparative example and the bumper of the above-mentioned example. The evaluation results are shown in Table 1.

[0039]

[Table 1]

Note: [rigidity] is [bending elastic modulus x plate thickness cubed]
Calculated as proportional to.

From the evaluation results shown in Table 1, the weight, that is, the amount of the resin used was saved by 15%, the reduction in bending strength was suppressed while the weight was reduced, and the bending rigidity was increased about twice. From this result, the great effect of the present invention was proved.

[Example 2] Using the same raw material liquid and foaming reaction injection molding machine as in Example 1, only the mold was changed to mold the body of the forklift. However, the plate thickness of the body is 5.5 mm, and the molding conditions are as follows.

(Molding) Nitrogen gas was dissolved in both monomer liquids A and B at 10 MPa and 35 ° C., and the mold temperature on the fixed side was set to 90.
C., the movable mold temperature was 60.degree. C., and the cavity internal pressure was 0.6 MPa, and reaction injection molding was performed. The obtained foamed molded product has a specific gravity of 0.75 and an average average cell size of 55 μm.
was. The number of bubbles per unit area measured by observing the cross section with an electron microscope was 150 / mm ² .

COMPARATIVE EXAMPLE 2 AND EVALUATION OF PHYSICAL CHARACTERISTICS Using the monomer solutions A and B prepared in the above-mentioned examples, using a usual RIM molding apparatus, the shape was the same as in Example 2, but the plate thickness was 4 mm. A forklift body having a size of 0.0 mm was manufactured as a comparative example. Samples for measuring physical properties were cut out from the body of this comparative example and the body of the above-mentioned example and evaluated. The evaluation results are shown in Table 2.

[0045]

[Table 2]

Note: [rigidity] is [bending elastic modulus x plate thickness cubed]
Calculated as proportional to.

From the evaluation results in Table 2, the weight, that is, the amount of resin used was saved by 11%, and the bending rigidity was increased by about 1.4 times. As a result, it was found that the price of the forklift can be reduced, and the deformation of the body is reduced even when the forklift comes into contact with the cargo.

[0048]

According to the present invention, it is possible to provide a molded article for vehicle member which is lightweight, has sufficient strength against impact, and has high bending rigidity.

Front page continuation (51) Int.Cl. ⁷ Identification symbol FI theme code (reference) B29L 31:30 B29L 31:30 (72) Inventor Eiji Yoshida 2-1, Hinodemachi, Iwakuni-shi, Yamaguchi Teijin Meton Co., Ltd. Company Technical Center F-term (reference) 4F206 AA12 AB02 AB03 AC05 AD03 AG20 AH18 AH24 AR12 AR15 JA01 JA04 JF01 JF04 JN16 JN25 JN27

Claims (6)

[Claims] 1. A vehicle member comprising a crosslinked polymer molded product containing a large number of fine bubbles, wherein the crosslinked polymer molded product comprises (1) a metathesis-polymerizable ring containing a catalyst component of a metathesis polymerization catalyst system. Monomer liquid A consisting of olefin
(Solution A) and a monomer liquid B (solution B) composed of a metathesis-polymerizable cyclic olefin containing an activator component of a metathesis polymerization catalyst system are mixed, and the raw material mixed liquid is injected into the mold to obtain the mold. (2) Average diameter 1
Contains a large number of bubbles of size less than 00 μm, and (3)
A member for a vehicle containing fine bubbles, which has a specific gravity in the range of 0.55 to 0.95. 2. The vehicle member according to claim 1, wherein the vehicle member is an exterior member. 3. The exterior member is a shock absorbing member.
The vehicle member described. 4. The vehicle member according to claim 2, wherein the exterior member is a body of a construction machine or an agricultural machine. 5. A monomer solution A (solution A) comprising a metathesis polymerizable cyclic olefin containing a catalyst component of a metathesis polymerization catalyst system and a monomer comprising a metathesis polymerizable cyclic olefin containing an activator component of a metathesis polymerization catalyst system. Liquid B (solution B) is mixed, and a raw material mixed liquid is poured into a mold, and a cross-linked polymer molded product obtained by causing a polymerization and a cross-linking reaction in the mold is formed. A method for producing a vehicle member comprising a crosslinked polymer molded product containing a large number of air bubbles having a size of 100 μm or less, and (2) a specific gravity in the range of 0.55 to 0.95, wherein the solution A And / or a high pressure is applied to the solution B to dissolve the gas, the solution A and the solution B are mixed, the raw material mixed solution is injected into the mold, and the weight is increased in the mold. Method of manufacturing a vehicle member containing microbubbles, which comprises forming a vehicle member brought foamed with and allowed to cross-linking reaction. 6. The method for manufacturing a vehicle member according to claim 5, wherein the gas is nitrogen gas.