JP2003040984A - Member for medical apparatus containing many minute bubbles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive medical member molded product which is lightweight and has high rigidity and enough strength to a shock and a production method therefor. SOLUTION: The medical member comprises a cyclic olefin cross-linked polymer obtained by polymerizing and molding a metathesis-polymerizable monomer at the same time in the presence of a polymerization catalyst. It is a homogenous foam in which many bubblers having an average diameter of 100 μm or less are contained and a specific gravity is a range of 0.55-0.98.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a medical device member containing a large number of fine bubbles. More specifically, the present invention relates to a member for a medical device, which comprises a crosslinked polymer molded product of a metathesis polymerizable monomer and contains a large number of fine bubbles, and a method for producing the member. Such a medical device member is strong against impact, has excellent durability, and can be recycled without the need for fiber reinforcement, and produces almost no incineration residue at the time of waste incineration. It is integrally molded, and in particular, it is lightweight, has high rigidity, is excellent in impact resistance, has less sink marks, and is inexpensive, and can be suitably used as an exterior member for medical equipment.

[0002]

2. Description of the Related Art Conventionally, metals and plastics have been used for medical device members. Among them, particularly for large-sized members for medical devices, metal or fiber reinforced plastic (FRP) known to have high strength, in particular, unsaturated polyester resin reinforced with glass fiber has been generally used. There is a problem that the weight becomes heavy with metal, and when molding glass fiber reinforced unsaturated polyester resin for medical device parts, a large amount of dust containing glass fiber is generated and the working environment becomes poor. It was Moreover, it takes FRP
The medical device member using is also heavy in weight, and has a drawback that cracks are easily generated by an impact when an object hits the member. 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, and carry out molding and polymerization at the same time by utilizing metathesis polymerization, particularly RIM (reaction injection molding) method. Have been put into practical use. This molded product has achieved weight reduction, improved impact resistance, and greatly simplified manufacturing process as a medical member. However, in recent years, there has been a strong demand for further price reduction and further weight reduction for energy saving.

[0004]

DISCLOSURE OF THE INVENTION It is an object of the present invention to provide an inexpensive medical component molded article which is lightweight, has high rigidity, and has sufficient strength against impact, and a method for producing 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 a molded article for medical use 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 medical device member molded article is provided. 1. A member for medical devices containing a large number of fine bubbles, the member comprising a crosslinked polymer molded product obtained by simultaneously polymerizing and molding a metathesis polymerizable monomer in the presence of a polymerization catalyst. Combined molded product has (1) average diameter 1
Contains a large number of air bubbles with a size of 00 μm or less, and (2)
A member for a medical device containing a large number of fine bubbles, which has a specific gravity of 0.55 to 0.98.

2. The cross-linked polymer molded product is a monomer liquid A (solution A) composed of a metathesis polymerizable cyclic olefin containing a metathesis polymerization catalyst system catalyst component, and a metathesis polymerizable cyclic olefin containing a metathesis polymerization catalyst system activator component. Is mixed with a monomer liquid B (solution B), and the solution A and / or the solution B is dissolved in a gas by applying a pressure to the solution A and / or the solution B. The member for a medical device according to the above 1, which is obtained by simultaneously performing polymerization and molding by injecting into a mold and foaming in a mold.

3. A crosslinked polymer molded product obtained by simultaneously polymerizing and molding a metathesis polymerizable monomer in the presence of a polymerization catalyst, wherein the crosslinked polymer molded product contains (1) a large number of bubbles having an average diameter of 100 μm or less. And (2) a method for producing a member for a medical device containing a large number of fine bubbles having a specific gravity of 0.55 to 0.98 in a mixture of the metathesis polymerizable monomer and a polymerization catalyst. A method for producing a member for a medical device, which comprises dissolving a gas that does not affect a polymerization reaction in, and then injecting the mixture into a mold and foaming the mixture in the mold to mold the mixture.

4. A monomer liquid A (solution A) containing a metathesis polymerizable cyclic olefin containing a catalyst component of a metathesis polymerization catalyst system and a monomer liquid B containing a metathesis polymerizable cyclic olefin containing an activator component of a metathesis polymerization catalyst system (solution B) ) Is mixed with solution A and / or
Alternatively, the solution B and the solution B are mixed after the pressure is applied to the solution B to dissolve the gas, and the raw material mixed solution is injected into the mold and foamed and molded in the mold. 4. The method for manufacturing a member for a medical device according to 3 above.

5. Said gas is nitrogen gas, The manufacturing method of the member for medical devices of said 3 or 4 characterized by the above-mentioned.

[0011]

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 constituting the member for a medical device of the present invention, those containing 1-2 metathesis-polymerizable cycloalkene groups in the molecule are used. A compound having at least one norbornene skeleton in the molecule is preferable. Specific examples thereof 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, 5,6,6
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 necessary, a metathesis-polymerizable cyclic olefin having a polar group containing a different element such as oxygen and 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 metathesis catalyst system includes halides of metals such as tungsten, rhenium, tantalum and molybdenum as catalyst components, salts such as ammonium salts, and alkylated compounds of metals of groups I to III of the periodic table as activator components. Examples thereof include a composite catalyst composed of an organometallic compound mainly containing a compound such as tetraalkyltin, an alkylaluminum compound, and an alkylaluminum halide compound, or a catalyst composed of a ruthenium carbene complex.

The former is generally polymerized by mixing two liquids of a monomer liquid A containing a catalyst component and a monomer liquid B containing an activator component B. The latter is generally polymerized by mixing a monomer solution and a catalyst component.

In the latter, the polymerization generally does not proceed instantaneously, but the polymerization reaction can be accelerated by increasing the temperature. However, in the former, the polymerization reaction is fast and the polymerization moldability is excellent. It is suitable.

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 liquid 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 gas for foaming (sometimes 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 product 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 properties 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. In particular, some medical device members are required to have flame retardancy, and it is important to add a flame retardant.

The easiest 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. When the flame retardant and the flame retardant auxiliary are added, the method of adding with the third liquid is useful. 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 and tetrakis [methylene (3,5-di-
t-butyl-4-hydroxycinnamate)] methane and the like.

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, in the present invention, a surfactant can be added in order to form stable fine bubbles in the molded product, and such a surfactant should not affect the metathesis polymerization reaction. Although not particularly limited, specific examples thereof include a fluorine-based surfactant and a silicone-based surfactant.

Furthermore, the crosslinked polymer molded article in the present invention, casting or reaction injection molding (RIM molding) of metathesis polymerizable cyclic olefin dicyclopentadiene and tricyclopentadiene to be manufactured as a representative example crosslinked polymer It contains a large number of relatively 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 should be smaller than 100 μm diameter. 100μ
If it is larger than m, it becomes brittle and the strength as a medical device decreases. Bubbles smaller than 1 μm are generally difficult to produce, and the effect of containing bubbles is small. In the present invention, the specific gravity of the polymer (molded product) is defined. 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 0.98, the effects of weight reduction of the polymer and reduction of sink mark which are the objects of the present invention are not obtained. 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 device is not significantly reduced, this is applied to medical device members that are required to be lightweight and have high bending rigidity. Therefore, as described above, the bubble size of the present invention is 100 μm or less, preferably 50 μm or less.
It should be less than or equal to μm, and more preferably less than or equal to 30 μm. 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 bubbles per unit volume is preferably at least 1 × 10 ⁶ cells / cm ³ .

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 cross-linked polymer constituting the vehicle member molded article of the present invention and observing 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 all the cut surfaces observed under the microscope.

The medical device member molded article of the present invention comprises a metathesis-polymerizable cyclic olefin cross-linked polymer. By the way, the normal specific gravity of the resin is in the range of 1.0 to 1.2. The medical device member molded article of the present invention, which contains air bubbles and has a specific gravity in the range of 0.55 to 0.98, is lightweight as much as the specific gravity becomes small without lowering the mechanical strength. We were able to achieve cost reductions by reducing costs and reducing the amount of resin used. From another point of view, according to the present invention, it is possible to increase the plate thickness by an amount corresponding to the weight reduction, and since the bending rigidity is proportional to the cube of the thickness, it is possible to significantly improve the bending rigidity. The preferable range of the specific gravity is 0.60 to 0.60.
It is 0.90.

Various 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 added to the monomer liquid (when using two liquids, one or both of solution A and solution B) at high pressure. A method of dissolving (gas) and injecting them into a mold and then foaming the gas in the mold can be preferably used.

A preferred method for producing a member for a medical device containing a large number of bubbles of the present invention is to add a gas for foaming to at least one of the solution A and the solution B and dissolve them, and then to dissolve these solution A and Mix Solution 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 of manufacturing the medical device member of the present invention will be described in detail below. As a preferable manufacturing method, a normal reaction injection molding (RIM) as a foaming reaction injection molding apparatus is used.
Adding a device for supplying foaming gas to the device,
This is performed by using a mold, a monomer liquid tank, or the like having a structure with improved pressure resistance and 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. Then, a gas is introduced from a gas supply device into the A tank and / or the B tank containing these respective monomer liquids, and the introduced gas is present in the A tank and / or the B tank at a predetermined pressure, respectively. Dissolve in the monomer solution of. In this case, the foaming gas to be introduced is
Any gas may be used as long as it acts as a foaming gas such as carbon dioxide gas, nitrogen gas, argon gas and helium 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 is a disadvantage that the reactivity is impaired, and the monomer liquid has a short shelf life. 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 and dissolved at room temperature, 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. Alternatively, the liquid A and / or the liquid B may be liquefied or densified with the gas at an extremely low temperature and a predetermined pressure is applied.
A mixing device is provided in the liquid supply pipe, and gas is introduced into the portion from the gas supply device, and the introduced gas is dissolved in each monomer liquid while pressurizing. For example 6MP
A gas having a temperature of −60 ° C. at a pressure of a or higher is introduced and melted. The pressure for dissolving the gas is preferably as high as possible, but 2 MPa to 20 MPa is a preferable range for practical use. More preferably 5 MPa to 18 MPa
Is the range.

Next, while maintaining the pressure and temperature from the temperature range of about 20 ° C. to 45 ° C., each monomer solution is sent to the mixing head which communicates with the A tank and the B tank and mixes the two monomer solutions. The two liquids are mixed uniformly in the 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 rapid change in pressure and / or temperature in the mold, the solubility of the gas is lowered, and foaming occurs. 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 is set to 20 ° C to 120 ° C immediately before the start of the polymerization reaction. Preferably 3
It is in the range of 0 ° C to 110 ° C. The pressure inside the cavity (cavity) is set within the range of 0 to 5 MPa. The range is preferably 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 can be 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 molded article of the present invention contains a large number of cells produced by such a method, thereby achieving weight reduction and saving the amount of resin used as compared with a molded article of the same size. The specific gravity of the dicyclopentadiene polymer containing no bubbles is about 1.03, but in the present invention, the specific gravity is 0.55 to 0.98, and the weight and manufacturing cost are greatly reduced without lowering the strength and rigidity. Achieved a reduction of. Also, the weight reduction makes it possible to increase the plate thickness,
Bending rigidity is greatly improved. Further, in the molded product of the present invention, the sink mark on the surface of the molded product, which is usually generated in a portion having a rib or a boss, is remarkably reduced, and a molded product excellent in appearance can be manufactured.

The large member for medical equipment of the present invention can be raised, for example, the exterior part or bed part of a diagnostic device such as CT, X-ray, MR, NM. In addition, covers for measuring devices such as blood and bone density or clinical chemistry testing devices, and exterior parts for treatment devices such as hyperthermia treatment machines and dental treatment machines can be given. Alternatively, a medical bed member such as an operating table, a stretcher, or a bed may be used.

The structure of the molded member for medical equipment of the present invention is as follows:
There is no particular limitation as long as it is a foamed molded product obtained by cross-linking polymerization of a metathesis-polymerizable cyclic olefin.

[0037]

EXAMPLES The molded articles for medical device members 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) Tungsten hexachloride 2
8 parts by weight 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 to 1 part of toluene.
The solution dissolved in 1 part by weight was added and stirred for 1 hour, then a solution consisting of 18 parts by weight of nonylphenol and 14 parts by weight of toluene was added and stirred for 5 hours under a nitrogen purge. 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) 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 a side cover shape of the thermotherapy machine was used. The cover was a thermotherapy device cover having a size of 450 mm in length and 1200 mm in width and slightly curved, and the thickness was adjusted to 4.5 mm. Thickness is 4mm and height is 20m.
Two vertical ribs having a length of m and a length of 400 mm are provided.

(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 30 ° C. at 15 MPa. Next, the fixed mold temperature was 90 ° C, the movable mold temperature was 60 ° C, and the cavity internal pressure was 1.0 MPa.
Was reaction injection molded. The obtained foamed product had a specific gravity of 0.67 and an average cell size of 40 μm. Sinks caused by ribs are slightly observed on the surface of the molded product, but when the depth of the sink is measured, it is 0.02 to 0.03 mm.
Met.

(Evaluation as Side Cover of Thermotherapy Device) The obtained cover was attached as a side cover of the thermotherapy device. The thermotherapy machine was actually operated, but the cover part could be used without deformation.

[Comparative Example 1 (and evaluation of physical properties)] Using the monomer solutions A and B prepared in the above-mentioned examples, ordinary RIM was performed.
Using the molding apparatus, using the same mold as in the example, the thickness is 3.0.
Molding was performed so as to be mm. The depth of the sink marks formed in the molded product was 0.4 to 0.5 mm. Samples for measuring physical properties were cut and evaluated from the cover of this comparative example and the cover of the above-mentioned example. The evaluation results are shown in Table 1.

[0044]

[Table 1] Note: [Rigidity] was calculated as being proportional to [flexural modulus x plate thickness cubed]. From the evaluation results in Table 1, the flexural rigidity increased more than twice while keeping the weight light. From this result, the great effect of the present invention was proved.

[0045]

EFFECTS OF THE INVENTION According to the present invention, it is possible to provide a molded article for medical device material which is lightweight, has sufficient strength against impact, has a significantly small sink mark, and has high bending rigidity.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B29L 31:00 B29L 31:00 (72) Inventor Masanori Abe 2-1, Hinodemachi, Iwakuni-shi, Yamaguchi Teijin Meto F-term in the technical center (reference) 4F206 AA03 AB04 AC05 AG20 AH63 AR12 AR15 JA01 JA04 JF01 JF04 JF21 JF41 JL02 JM04 JN11 JN27 4J032 CA34 CA35 CA38 CA43 CA46 CB03 CD03 CD04 CE06 CG00

Claims (5)

[Claims] 1. A member for a medical device containing a large number of fine bubbles, the member comprising a crosslinked polymer molded product obtained by simultaneously polymerizing and molding a metathesis polymerizable monomer in the presence of a polymerization catalyst. And the cross-linked polymer molded article contains (1) a large number of bubbles having an average diameter of 100 μm or less, and (2) a specific gravity in the range of 0.55 to 0.98. A medical device member containing fine air bubbles. 2. The crosslinked polymer molded product contains a monomer liquid A (solution A) composed of a metathesis-polymerizable cyclic olefin containing a metathesis polymerization catalyst-based catalyst component and a metathesis polymerization catalyst-based activator component. A monomer liquid B (solution B) composed of a metathesis-polymerizable cyclic olefin is mixed, pressure is applied to the solution A and / or the solution B to dissolve a gas, and then the solution A and the solution B are mixed to mix the raw materials. The member for a medical device according to claim 1, which is obtained by simultaneously performing polymerization and molding by injecting a liquid into a mold and causing foaming in the mold. 3. A crosslinked polymer molded product obtained by simultaneously polymerizing and molding a metathesis polymerizable monomer in the presence of a polymerization catalyst, wherein the crosslinked polymer molded product has (1) an average diameter of 1
Contains a large number of air bubbles with a size of 00 μm or less, and (2)
A method for producing a medical device member containing a large number of fine bubbles having a specific gravity in the range of 0.55 to 0.98,
After dissolving a gas that does not affect the polymerization reaction in the mixture of the metathesis polymerizable monomer and the polymerization catalyst,
A method for producing a member for a medical device, which comprises injecting the mixture into a mold and allowing the mixture to foam and mold. 4. A monomer liquid A (solution A) composed of a metathesis-polymerizable cyclic olefin containing a catalyst component of a metathesis polymerization catalyst system and a monomer composed of a metathesis-polymerizable cyclic olefin containing an activator component of a metathesis polymerization catalyst system. Liquid B (solution B) is mixed, pressure is applied to solution A and / or solution B to dissolve the gas, and then solution A and solution B are mixed, and the raw material mixed liquid is injected into the mold. The method for manufacturing a member for a medical device according to claim 3, wherein the molding is performed by foaming in the mold. 5. The method for manufacturing a medical device member according to claim 3, wherein the gas is nitrogen gas.