JP5588915B2 - Cycloolefin polymer structure and method for producing the same - Google Patents

Description

  The present invention relates to a structure mainly composed of a cycloolefin polymer and having a large number of micro holes on the surface. The present invention also relates to a method for producing a cycloolefin polymer structure having such a surface structure.

  A polymer structure having a morphology in which a large number of micropores are opened on the surface can provide a larger surface area than a structure having a smooth surface, and thus can be suitably used as a gas absorbent, a catalyst support, or the like. . A typical method for producing such a polymer structure includes a method using a pore-forming agent. For example, a pore-forming agent (such as camphor) is added to the composition corresponding to the target polymer structure, and after forming into a desired outer shape (or during molding), the above-mentioned pore-forming agent is removed. By doing (volatilizing), a pore structure is introduced into the polymer structure as the final object. However, according to this method, the polymer may be damaged or altered by the heat treatment for removing the pore forming agent, so that there is a concern that the form and characteristics of the final target product may be deteriorated.

  On the other hand, cycloolefin (cyclic olefin) polymers generally have features such as excellent transparency, high glass transition temperature and decomposition temperature, low water absorption, high moisture barrier properties, and good mechanical properties. Is a useful material. Patent Document 1 describes a technique for producing a cyclic olefin resin fiber by electrostatic spinning (electrospinning) of a polymer solution in which a cyclic olefin resin is dissolved in a volatile solvent. As other technical documents related to electrospinning, Patent Documents 2 and 3 can be cited.

JP 2010-111978 A JP 2010-502855 A International Publication No. 2004/091785

  However, none of these patent documents disclose a cycloolefin polymer (hereinafter sometimes referred to as “COP”) structure having a large number of micropores on the surface, and a COP having such a unique surface structure. The structure and its manufacturing method have not been established yet. This invention is made | formed in view of this situation, The main objective is to provide the COP structure which has many micropores on the surface, and its manufacturing method.

In accordance with the present invention, a method is provided for manufacturing a COP structure having a number of micropores on the surface. The production method includes a step of preparing a polymer solution in which COP is dissolved in a mixed solvent of an aromatic hydrocarbon solvent and N, N-dialkylformamide (solution preparation step). Here, the polymer solution satisfies both of the following conditions (A) and (B).
(A) The mass of the COP contained in the polymer solution (hereinafter also referred to as “Wp”) is the mass of the COP Wp and the mass of the aromatic hydrocarbon solvent (hereinafter referred to as “Wh”). And 35% by mass or less of the total mass (that is, Wp / (Wp + Wh) ≦ 0.35).
(B) The mass of the N, N-dialkylformamide contained in the polymer solution (hereinafter sometimes referred to as “Wa”) is the total mass of the mass of the polymer and the mass of the aromatic hydrocarbon solvent. (Ie, Wa / (Wp + Wh) ≦ 0.3).
The manufacturing method also includes a step (molding step) of forming a COP structure from the polymer solution. In the molding process, a voltage is applied between a nozzle to which the polymer solution is supplied and a collector to generate a jet of polymer solution from the nozzle toward the collector. And the said solvent is volatilized from this jet and the COP structure which has many micro holes on the surface is formed.

  According to such a manufacturing method, a COP structure having a specific shape having a large number of micropores on the surface is obtained from the polymer solution (hereinafter also referred to as “COP solution”) in one step by using an electrospinning technique. be able to. This molding step can be suitably carried out even at room temperature (usually 0 ° C. to 40 ° C., typically 20 ° C. to 30 ° C.). Therefore, damage to the COP due to heating can be avoided. One preferred example of the aromatic hydrocarbon solvent in the technology disclosed herein is toluene. A preferred example of N, N-dialkylformamide is N, N-dimethylformamide (DMF).

  In one embodiment of the technology disclosed herein, the polymer solution includes a mass of the COP contained in the polymer solution of 28 mass% or less of the mass of the COP and the mass of the aromatic hydrocarbon solvent (that is, Wp / (Wp + Wh) ≦ 0.28) is used, and in the molding step, the polymer structure having a shape in which particles are connected by a fiber is formed. According to such an embodiment, a COP structure having a particle portion and a fiber portion connecting the particle portion and having a large number of micropores on the surface of any portion can be obtained from the polymer solution in one step.

  In another aspect of the technology disclosed herein, as the polymer solution, the mass of the COP contained in the polymer solution is less than 20 mass% of the mass of the COP and the mass of the aromatic hydrocarbon solvent (that is, In the molding step, an independent particulate polymer structure is formed using Wp / (Wp + Wh) <0.20). According to such an embodiment, a COP structure having an independent particle shape and having a large number of micropores on the surface can be obtained from the polymer solution in one step.

  The polymer solution can be suitably prepared by a procedure including, for example, preparing a solution in which COP is first dissolved in an aromatic hydrocarbon solvent and adding N, N-dialkylformamide to the solution. According to this procedure, Wa / (Wp + Wh) can be easily adjusted, so that a COP structure having a desired shape can be more reliably produced.

  According to the present invention, a novel COP structure is also provided. The COP structure is formed as independent particles having an average size of 5 μm to 25 μm. Macroscopic depressions are formed in the outer shape of the particles. And the said particle | grain has many micropores in the surface of this external shape. The average opening size of the microholes is 50 nm to 150 nm. Such a COP structure is an irregularly shaped particle having a macroscopic depression in addition to having a large number of micropores on the surface, thereby effectively increasing the surface area per volume. Such a COP structure can be useful as, for example, an adsorbent or a catalyst carrier.

  As the COP in the COP structure or COP structure production method disclosed herein, a norbornene monomer having a —COOR group (where R is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms) is ( A co) polymerized norbornene polymer can be preferably employed. Such a COP structure can be excellent in at least one of adhesiveness, adhesiveness, miscibility and hydrophilicity by having a —COOR group (polar group) derived from the monomer structure. Moreover, by having a norbornene structure, it may be excellent in at least one of amorphous properties, heat resistance and water absorption.

It is a schematic diagram which shows schematic structure of an electrospinning apparatus. 2 is an SEM image (10,000 times) of the COP structure obtained in Example 1. FIG. 3 is a SEM image (300 times) of a COP structure obtained in Example 2. 3 is a SEM image (6,000 times) of a COP structure obtained in Example 2. 3 is a SEM image (15,000 times) of a COP structure obtained in Example 2. 2 is a SEM image (60,000 times) of a COP structure obtained in Example 2. FIG. 4 is an SEM image (1,000 times) of a COP structure obtained in Example 3. 6 is an SEM image (2,000 times) of the COP structure obtained in Example 4. 4 is an SEM image (60,000 times) of a COP structure obtained in Example 4. 4 is an SEM image (60,000 times) of a COP structure obtained in Example 4. 6 is an SEM image (600 times) of a COP structure obtained in Example 5. 6 is an SEM image (30,000 times) of the COP structure obtained in Example 5. 6 is an SEM image (3,000 times) of a COP structure obtained in Example 6. 6 is a SEM image (60,000 times) of the COP structure obtained in Example 6.

  Hereinafter, preferred embodiments of the present invention will be described. It should be noted that technical matters other than the contents particularly mentioned in the present specification and necessary for the implementation of the present invention can be grasped as design matters for those skilled in the art based on the prior art. The present invention can be carried out based on the technical contents disclosed in the present specification and the common general technical knowledge in the field.

<Cycloolefin polymer (COP)>
The COP structure in the technology disclosed herein typically comprises a composition containing COP as a main component (that is, a component exceeding 50% by mass). Here, COP (cycloolefin polymer) refers to a polymer having a cyclic olefin structure. Typical examples include (co) polymers containing at least one compound selected from norbornene compounds, monocyclic olefins, cyclic conjugated dienes and vinyl alicyclic hydrocarbons in the monomer composition; such (co) polymers And the like.

  As a preferred example of the COP in the technology disclosed herein, a COP containing at least one repeating unit represented by the following formula (I) can be mentioned. Another preferred example is COP containing at least one repeating unit represented by the following formula (II).

In the above formulas (I) and (II), m represents an integer of 0 to 4, and is typically 1. R ^{1 to} R ⁴ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms (preferably 1 to 6, for example, 1 to 3) (for example, an alkyl group). In a preferred embodiment, R ^{1 to} R ⁴ are each independently a hydrogen atom, a halogen atom (eg, Cl), or a methyl group.

In the above formulas (I) and (II), X ¹ , X ² and Y ¹ , Y ² are each independently a hydrogen atom, 1 to 10 carbon atoms (preferably 1 to 6, for example 1 to 3). A hydrocarbon group (for example, an alkyl group), a halogen atom, a halogenated hydrocarbon group having 1 to 10 carbon atoms (preferably 1 to 6, for example, 1 to 3), a — (CH ₂ ) _n COOR ¹¹ or — (CH ₂ ) _n OCOR ¹² (wherein R ¹¹ and R ¹² are each a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms (preferably 1 to 6, for example 1 to 3) (for example, an alkyl group). N represents an integer of 0 to 10 (for example, an integer of 0 to 3, preferably 0 or 1, typically 0). Preferably, X ¹ , X ² and Y ¹ , Y ² are each independently a hydrogen atom, a halogen atom (eg, Cl), or —COOR ¹¹ (R ¹¹ is a hydrogen atom or 1 to 3 carbon atoms (eg, 1 ) Alkyl group).

In a preferred embodiment, the cycloolefin polymer may be a norbornene polymer obtained by (co) polymerizing a norbornene monomer having a —COOR group (R is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms). . As a typical example of such a norbornene polymer, m is 1, R ¹ in the above formula (I) is an alkyl group having 1 to 3 carbon atoms (for example, a methyl group), and X ¹ is —COOR ¹¹ (R ¹¹ is Examples thereof include a polymer containing a repeating unit which is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms (for example, a methyl group), and R ² and Y ¹ are both hydrogen atoms.

  As COP in the technique disclosed here, the repeating unit represented by the above formula (I) or (II) is included in a proportion exceeding 50 mass% (preferably 70 mass% or more, for example, 90 mass% or more). Those can be preferably employed. Alternatively, it may be a COP substantially composed of a repeating unit represented by the above formula (I) or (II). Such COP is, for example, a monomer having a structure that forms a repeating unit represented by the above formula (I) or (II) by polymerization (for example, ring-opening polymerization), or the above repeating unit by polymerization and post-treatment (for example, hydrogenation). Can be produced by (co) polymerizing a monomer having a structure to form Examples of the monomer that can be copolymerized with the monomer having a structure forming the repeating unit represented by the above formula (I) or (II) include olefins such as ethylene and propylene; vinyl compounds such as vinyl acetate and vinyl chloride (vinyl group). And compounds having an acryloyl group or a methacryloyl group, such as acrylic acid, methacrylic acid, and esters thereof (for example, alkyl esters such as methyl methacrylate).

  A commercially available COP material may be used as part or all of the COP in the technology disclosed herein. Examples of such commercially available products include TOPAS (registered trademark) (manufactured by TOPAS Advanced Polymers), APPEL (registered trademark) (manufactured by Mitsui Chemicals), ZEONEX (registered trademark) (manufactured by ZEON CORPORATION), and ZEONOR (registered trademark). (Manufactured by Zeon Corporation), Arton (registered trademark) (manufactured by JSR Corporation) and the like.

The weight average molecular weight (Mw) of COP is not particularly limited as long as the COP structure disclosed herein is suitably formed. For example, a COP having an Mw of about 1 × 10 ⁴ to 20 × 10 ⁴ can be preferably used. If Mw is too small, it may be difficult to control the outer shape of the COP structure, or the characteristics (low water absorption, mechanical strength, etc.) of the structure may be easily deteriorated. When Mw is too large, the viscosity of the COP solution becomes too high, and it may be difficult to stably form the jet of the COP solution in the molding process. In addition, "the weight average molecular weight of COP" here means the value of standard polystyrene conversion based on gel permeation chromatography (GPC).

<Preparation of COP solution>
In the COP structure manufacturing method disclosed herein, a COP solution having a predetermined composition is ejected from a nozzle to which a voltage is applied by electrostatic force, and the solvent is removed from the COP solution to form a COP structure.

  The COP solution contains one or more aromatic hydrocarbon solvents and one or more N, N-dialkylformamides as a solvent. As the aromatic hydrocarbon solvent, a solvent which is liquid at 25 ° C. and has a boiling point of 200 ° C. or less (preferably 60 ° C. or more and 200 ° C. or less) can be preferably used. For example, toluene, xylene (any isomer of o-, m-, and p- can be used), benzene, ethylbenzene, and the like can be used alone or in appropriate combination. In a preferred embodiment, the main component of the aromatic hydrocarbon solvent contained in the COP solution (that is, the component exceeding 50% by mass of the aromatic hydrocarbon solvent) is toluene. Of the aromatic hydrocarbon solvent, 75% by mass or more (further 90% by mass or more) may be toluene, or substantially all may be toluene.

  The N, N-dialkylformamide used together with the aromatic hydrocarbon solvent is preferably a liquid at 25 ° C. and having a boiling point of 200 ° C. or lower (preferably 60 ° C. or higher and 200 ° C. or lower). For example, N, N-dimethylformamide, N, N-diethylformamide, N, N-diisopropylformamide and the like can be used alone or in appropriate combination. The type and amount of N, N-dialkylformamide are set so that the aromatic hydrocarbon solvent used in the COP solution and the N, N-dialkylformamide are miscible (at least not phase-separated in the COP solution). It is preferable. In a preferred embodiment, the main component of N, N-dialkylformamide contained in the COP solution (that is, the component exceeding 50% by mass of N, N-dialkylformamide) is N, N-dimethylformamide. Of the N, N-dialkylformamide, 75% by mass or more (more preferably 90% by mass or more) may be N, N-dimethylformamide, or substantially all may be N, N-dimethylformamide. .

  The composition of the COP solution preferably satisfies Wp / (Wp + Wh) ≦ 0.35, where the mass of COP contained in the COP solution is Wp and the mass of the aromatic hydrocarbon solvent is Wh (condition (A) ). If Wp / (Wp + Wh) is too large, the viscosity of the COP solution becomes too high, and it becomes difficult to stably generate a jet of the COP solution, and it becomes difficult to obtain a COP structure having the desired outer shape. There can be. In one embodiment of the technology disclosed herein, the COP solution satisfying 0.25 <Wp / (Wp + Wh) ≦ 0.35 (for example, 0.28 <Wp / (Wp + Wh) ≦ 0.35). It can be preferably used. As the COP solution in another embodiment, a solution satisfying 0.10 <Wp / (Wp + Wh) <0.30 (for example, 0.20 ≦ Wp / (Wp + Wh) ≦ 0.28) can be preferably used. In still another embodiment, a material satisfying 0.00 <Wp / (Wp + Wh) <0.25 (for example, 0.01 ≦ Wp / (Wp + Wh) <0.20) can be preferably used. A COP solution having Wp / (Wp + Wh) in an appropriate range can be used according to the outer shape of the target COP structure.

  The composition of the COP solution in the technique disclosed herein is that the mass of COP contained in the COP solution is Wp, the mass of the aromatic hydrocarbon solvent is Wh, and the mass of N, N-dialkylformamide is Wa. 0 <Wa / (Wp + Wh) ≦ 0.3 is preferably satisfied (condition (B)). If Wa / (Wp + Wh) is too large, it may be difficult to form a COP structure having a large number of minute holes on the surface. In a preferred embodiment, a COP solution that satisfies 0.01 ≦ Wa / (Wp + Wh) ≦ 0.25 (for example, 0.05 ≦ Wa / (Wp + Wh) ≦ 0.20) is used.

  The method for preparing such a COP solution is not particularly limited. For example, first, COP is dissolved in an aromatic hydrocarbon solvent to prepare a solution satisfying the desired Wp / (Wp + Wh) (COP aromatic hydrocarbon solvent solution), and N, N-dialkylformamide is added to this solution and mixed. Thus, a method of preparing a COP solution can be preferably employed. According to this method, it is easy to prepare a COP solution that satisfies the above conditions (A) and (B) (in other words, it is easy to adjust Wa / (Wp + Wh) and Wp / (Wp + Wh)).

  The COP solution in the technology disclosed herein may further contain another solvent in addition to the aromatic hydrocarbon solvent and the N, N-dialkylformamide. As said other solvent, toluene, xylene, benzene, ethylbenzene etc. can be used, for example. In a preferred embodiment, the total amount of the aromatic hydrocarbon solvent and N, N-dialkylformamide is 70% by mass or more (for example, 90% by mass or more) among all the solvents constituting the COP solution. Usually, a COP solution containing substantially no solvent other than the aromatic hydrocarbon solvent and N, N-dialkylformamide can be preferably used.

  Although not particularly limited, it is appropriate that the ratio of the nonvolatile content (COP structure forming component) contained in the COP solution is usually 30% by mass or less (for example, 1 to 30% by mass) of the COP solution. is there. If the ratio of the non-volatile content (hereinafter also referred to as “NV”) is too large, the viscosity of the COP solution becomes too high, and it becomes difficult to stably generate the jet of the COP solution. It may be difficult to obtain a COP structure. In one embodiment of the technology disclosed herein, as the COP solution, one having an NV of 23% by mass or more and less than 30% by mass (for example, 25% by mass or more and less than 30% by mass) can be preferably used. As the COP solution in another embodiment, one having NV of 10% by mass to 25% by mass (for example, 15% by mass to less than 23% by mass) can be preferably used. In still another embodiment, those having an NV of 15% by mass or less (typically 1% by mass or more and 12% by mass or less, for example, 3% by mass or more and less than 10% by mass) can be preferably used.

  The viscosity of the COP solution is not particularly limited as long as the COP structure disclosed herein is suitably formed.

<Formation of COP structure>
The molding process in the technology disclosed herein can be performed using an electrospinning apparatus having a general configuration. An example of a typical apparatus configuration is schematically shown in FIG. The electrospinning apparatus 10 includes a solution holding tank 12 for holding the COP solution 1, a nozzle 14 connected to the holding tank 12, a high-voltage power supply 16 connected to the nozzle 14, and a tip of the nozzle 14 from the holding tank 12. And a pump 18 for controlling the solution supply rate to the head. By placing a grounded collector 22 in front of the nozzle 14, filling the COP solution 1 from the holding tank 12 to the tip of the nozzle 14, and operating the high-voltage power supply 18 to apply a voltage to the nozzle 14, The COP solution 1 can be ejected from the tip of the nozzle, and a COP structure can be formed between the nozzle tip and the collector 22. The apparatus 10 may be configured to include a plurality of nozzles 14.

  The magnitude of the voltage applied to the nozzle 14 is not particularly limited, and can be appropriately adjusted so that a stable jet is formed. The preferable applied voltage may vary depending on the viscosity of the COP solution, the distance to the collector, the outer shape of the target COP molded body, and the like. Usually, it is appropriate to apply a voltage of about 5 kV to 100 kV (for example, 5 kV to 20 kV). The inner diameter of the nozzle 14 is not particularly limited, and can be, for example, about 0.01 mm to 0.05 mm. The supply rate of the COP solution to the nozzle 14 is not particularly limited. Usually, it is appropriate to set it to about 1 μL / min to 100 μL / min (for example, 5 μL / min to 20 μL / min).

  The distance from the tip of the nozzle 14 to the surface of the collector 22 can be, for example, about 5 cm to 30 cm (typically 15 cm to 25 cm). The pressure in the region from the tip of the nozzle 14 to the surface of the collector 22 (the region where the COP structure is formed from the COP solution) may be normal pressure (typically atmospheric pressure), and is increased or decreased. It may be. The temperature in the region may be room temperature (typically about 15 ° C. to 35 ° C.), and may be heated or cooled. From the viewpoint of promoting the removal of the solvent, it is advantageous to heat the region (for example, warm to about 40 ° C to 60 ° C). However, since excessive heating can cause damage to the properties of the intended COP structure, it is desirable to avoid heating exceeding 100 ° C. According to the technique disclosed herein, even if the region is at room temperature (in other words, without intentional heating), the COP structure can be formed from the COP solution in one step.

<Form of COP structure; independent particle>
According to one aspect of the technology disclosed herein, a COP structure that is in the form of independent particles and has a large number of micropores on the surface of the particles is provided. The average size of the COP structure (COP particles) may be, for example, about 5 μm to 100 μm (typically 10 μm to 50 μm). Here, the average size of the COP particles is the passing length of at least 5 (preferably 10 or more) particles along a predetermined direction in the field of view in a scanning electron microscope (SEM) image of the particles. Can be obtained by measuring and averaging the results.

The micropores formed on the surface of the COP particles typically have a generally crater shape (round dish shape or bowl shape). The formation density of the microholes can be, for example, about 10 to 100 per 1 μm ² of the surface of the COP particles. The average opening size of the micro holes can be, for example, about 10 nm to 300 nm (typically 20 nm to 200 nm). This average aperture size is obtained by measuring the length of at least 10 or more (preferably 20 or more) micro-holes along a predetermined direction in the field of view in the SEM image of the COP particles, and calculating the result as an arithmetic average. This can be grasped. Typically, the average depth of the microholes is smaller than the average opening size of the microholes. COP particles having a large number of such micropores on the surface are excellent in mechanical strength as compared to a form in which the whole COP particles are porous (sponge-like form). In addition, since the microholes are less likely to be clogged (clogged) as compared to the sponge-like COP particles, deterioration such as a substantial reduction in surface area is less likely to occur. This is advantageous in applications such as gas adsorbing materials, water treatment materials, and catalyst carriers.

  In a preferred embodiment, the COP particles are irregularly shaped particles having macroscopic depressions. According to the COP particle of this form, it is possible to stably provide a wider surface area by having the macro depressions in addition to the micro holes. The number of the macro depressions may be, for example, about 1 to 10 (typically 2 to 8, preferably 3 to 7) as an average value per particle.

  Such COP particles can be preferably manufactured by any of the COP structure manufacturing methods disclosed herein. As the COP solution used in the above production method, a solution satisfying 0.01 ≦ Wp / (Wp + Wh) <0.20 and satisfying 0.01 ≦ Wa / (Wp + Wh) ≦ 0.25 can be preferably used. In a preferred embodiment, a COP structure consisting essentially only of COP particles (ie, free of fibers) can be formed (typically formed in one step from a COP solution) in the molding process.

<Form of COP structure; particle with fiber>
According to another aspect of the technology disclosed herein, a COP structure in which particles are connected by a fiber is provided. The average size of the particle portion included in the COP structure (which can be grasped in the same manner as the average size of the independent particles described above) can be, for example, about 5 μm to 100 μm (typically 10 μm to 50 μm). The average thickness of the fiber portion can be, for example, about 0.2 μm to 2 μm. Here, the average thickness of the fiber portion is determined by measuring the width of at least 5 (preferably 10 or more) fibers along the direction perpendicular to the fiber extending direction in the SEM image of the COP structure. It can be grasped by arithmetically averaging the results. In a preferred embodiment, the average size of the particle part is at least twice (typically 2 to 20 times) the average thickness of the fiber part.
A large number of micropores are formed on the surface of at least the particle part (typically both the particle part and the fiber part) of the COP structure. The formation density, average opening size, shape, and the like of the micro holes may be the same as those of the above-described COP particle micro holes.
Such a COP structure can be preferably manufactured by any of the COP structure manufacturing methods disclosed herein. As the COP solution used in the above production method, a solution satisfying 0.20 ≦ Wp / (Wp + Wh) ≦ 0.28 and satisfying 0.01 ≦ Wa / (Wp + Wh) ≦ 0.25 can be preferably employed.

<Form of COP structure; fiber>
According to yet another aspect of the technology disclosed herein, a fiber-like (typically substantially particle-free) COP structure is provided. The average thickness of the COP structure (COP fiber) may be, for example, about 0.15 μm to 2 μm. Here, the average thickness of the COP fiber is measured in the SEM image of the fiber by measuring the width of at least 5 (preferably 10 or more) fibers along the direction orthogonal to the fiber extending direction, It can be grasped by arithmetically averaging the results. The fiber portion may have a circular cross-sectional shape orthogonal to the direction in which the fiber extends, or an irregular shape (for example, a flat circle). The fiber portion may be generally straight or twisted.
A large number of minute holes are formed on the surface of the COP fiber. The formation density, average opening size, shape, and the like of the micro holes may be the same as those of the above-described COP particle micro holes.
Such COP fibers can be preferably manufactured by any of the COP structure manufacturing methods disclosed herein. As the COP solution used in the above production method, a solution satisfying 0.28 <Wp / (Wp + Wh) ≦ 0.35 and satisfying 0.01 ≦ Wa / (Wp + Wh) ≦ 0.25 can be preferably used.

<Application of COP structure>
The COP structure provided by the technology disclosed herein has a number of micropores on the surface in addition to the features of COP (for example, one or more of heat resistance, low water absorption, mechanical properties, etc.). By having the structural feature of having, it can be preferably applied to various uses. Examples of such applications can include catalyst carriers, antimicrobial carriers, and other various supports.
As a use form as a catalyst carrier, metal nanoparticles as a catalyst component are supported (preferably uniformly dispersed) on the surface of a COP structure (for example, COP particles) as a carrier, The form utilized for acceleration | stimulation of a chemical reaction (hydrogenation reaction of cinnamaldehyde in supercritical carbon dioxide, hydrogenation reaction of an aromatic nitro compound, etc.) is illustrated.
As the antibacterial agent carrier, for example, it can be used in a form in which Ag nanoparticles as an antibacterial component are supported on the surface of a COP structure (for example, COP particles) as a carrier. In addition, by attaching a metal or metal oxide to the surface of the COP structure as a support (evaporation, plating, etc.), using the surface structure of the COP structure, the metal or metal oxide is mainly used. A porous surface can be provided.

  Several examples relating to the present invention will be described below, but the present invention is not intended to be limited to those shown in the examples.

Using the electrospinning apparatus having the same configuration as in FIG. 1, COP structures according to Examples 1 to 6 were manufactured under the following molding conditions.
[Molding condition]
Voltage: 13kV
COP solution supply rate: 15 μL / min
Atmospheric temperature: 30 ° C
Nozzle inner diameter: 0.01mm
Distance from nozzle tip to collector surface: 20cm

<Example 1>
A 30 mass% toluene solution of a cycloolefin polymer (JSR Corporation, trade name “ARTON F5023”) was prepared, and a COP structure was produced by applying the above molding conditions. Although the polymer jet was unstable, a fiber-like structure could be obtained. When the form of this structure was observed by SEM (Hitachi Ltd., model “H4700” was used hereinafter), as shown in FIG. 2, it was a fiber with a smooth surface (no microholes). confirmed. The average fiber thickness based on SEM observation was about 0.5 μm.

<Example 2>
A polymer solution according to this example was prepared by adding and mixing 0.11 times (that is, 11 parts by mass) of DMF to 100 parts by mass of a 10% by mass toluene solution of the same cycloolefin polymer as in Example 1. The COP structure was produced by applying the above molding conditions to this polymer solution.
The result of observing the form of this COP structure by SEM is shown in FIGS. As shown in FIGS. 3 and 4, according to this example, an independent (non-complexed with fiber) particulate structure was obtained. The particle size based on SEM observation was approximately in the range of 10 μm to 50 μm, and the average particle size was 20 μm. As well shown in FIGS. 5 and 6, a large number of micro holes were formed on the entire surface of each particle. The opening size of the microhole based on SEM observation was approximately in the range of 50 nm to 150 nm, and the average opening size was 100 nm.

<Example 3>
A polymer solution according to this example was prepared by adding and mixing 0.111 times (ie, 11.1 parts by mass) of DMF with 100 parts by mass of a 25% by mass toluene solution of the same cycloolefin polymer as in Example 1. did. The COP structure was produced by applying the above molding conditions to this polymer solution.
The result of observing the form of this COP structure by SEM is shown in FIG. As shown in the figure, according to this example, a structure in which particles are connected by thin fibers was obtained.
Regarding the part of the particles, the particle size was generally in the range of 10 μm to 30 μm and the average particle size was 15 μm. Many micro holes were formed on the entire surface of each particle in the same manner as in Example 2. The opening size of the microholes was approximately in the range of 50 nm to 150 nm, and the average opening size was 100 nm.
Regarding the fiber part, the average thickness was 0.5 μm. Many fine holes were formed on the surface of the fiber part as well as the particle part. The opening size of the microholes was approximately in the range of 50 nm to 150 nm, and the average opening size was 100 nm.

<Example 4>
A polymer solution according to this example is prepared by adding and mixing 0.167 times (ie, 16.7 parts by mass) of DMF with 100 parts by mass of a 25% by mass toluene solution of the same cycloolefin polymer as in Example 1. did. The COP structure was produced by applying the above molding conditions to this polymer solution.
The result of observing the form of this COP structure by SEM is shown in FIGS. As shown in the figure, according to this example, a structure in which particles are connected by thin fibers was obtained.
Regarding the particle portion, the particle size was generally in the range of 5 μm to 15 μm, and the average particle size was 8 μm. As well shown in FIG. 9 (enlarged SEM image of the particulate portion), many micro holes were formed on the entire surface of each particle in the same manner as in Example 2. The opening size of the microholes was approximately in the range of 50 nm to 150 nm, and the average opening size was 100 nm.
For the fiber part, the average width was 0.5 μm. As well shown in FIG. 10 (enlarged SEM image of the fiber portion), a large number of minute holes were also formed on the surface of the fiber portion. The opening size of the microholes was approximately in the range of 50 nm to 150 nm, and the average opening size was 100 nm.
In the structures according to Examples 2 and 3, the outer shape of the particle part was roughly symmetric, whereas in the structure according to this example, the particle part was slightly stretched in the fiber extending direction. Had an external shape.

<Example 5>
A polymer solution according to this example was prepared by adding and mixing 0.167 times (ie, 16.7 parts by mass) of DMF to 100 parts by mass of a 30% by mass toluene solution of the same cycloolefin polymer as in Example 1. did. The COP structure was produced by applying the above molding conditions to this polymer solution.
The result of observing the form of this COP structure by SEM is shown in FIG. 11 and FIG. As shown in the figure, the outer shape of the structure formed according to this example was ribbon-shaped. The average thickness of the ribbon was 10 μm. As well shown in FIG. 12, many micro holes were formed on the surface of the ribbon. The opening size of the microholes was approximately in the range of 50 nm to 150 nm, and the average opening size was 100 nm.

<Example 6>
The polymer solution according to this example is prepared by adding and mixing 0.667 times (ie, 66.7 parts by mass) of DMF to 100 parts by mass of a 30% by mass toluene solution of the same cycloolefin polymer as in Example 1. did. The COP structure was produced by applying the above molding conditions to this polymer solution.
The result of observing the form of this COP structure by SEM is shown in FIG. 13 and FIG. As shown in the figure, according to this example, a fiber-like structure having an average thickness of 2 μm was obtained. However, as shown well in FIG. 14, the surface of the COP structure according to this example is rough and non-uniform, and the surface structure (clear microholes are formed densely) like the structures according to Examples 2 to 5. Structure) was not observed.

  In Examples 1 to 6, the composition of the COP solution used for the production of the COP structure and the structure of the obtained COP structure are collectively shown in Table 1.

  As mentioned above, although this invention was demonstrated by suitable embodiment, such description is not a limitation matter and of course various modifications are possible.

1 cycloolefin polymer solution 10 electrospinning device 12 solution holding tank 14 nozzle 16 high voltage power supply 18 pump 22 collector

Claims (7)

A method for producing a cycloolefin polymer structure having a number of micropores on a surface comprising:
A solution preparation step of preparing a polymer solution in which a cycloolefin polymer is dissolved in a mixed solvent of an aromatic hydrocarbon solvent and N, N-dialkylformamide, wherein the polymer solution is subjected to the following conditions:
(A) The mass of the polymer contained in the polymer solution is 35% by mass or less of the total mass of the polymer and the aromatic hydrocarbon solvent; and
(B) The mass of the N, N-dialkylformamide contained in the polymer solution is not more than 0.3 times the total mass of the polymer and the aromatic hydrocarbon solvent;
Satisfy; and
A voltage is applied between a nozzle to which the polymer solution is supplied and a collector to generate a jet of the polymer solution from the nozzle toward the collector, and the solvent is volatilized from the jet, thereby causing a large number of minute particles on the surface. Forming step to form a cycloolefin polymer structure having holes;
A process for producing a cycloolefin polymer structure. The mass of the polymer contained in the polymer solution is less than 20% by mass of the total mass of the polymer and the aromatic hydrocarbon solvent,
The method of claim 1, wherein the forming step forms the polymer structure in a particulate form independent of the jet of the polymer solution. The mass of the polymer contained in the polymer solution is 28% by mass or less of the total mass of the polymer and the aromatic hydrocarbon solvent,
The method according to claim 1, wherein in the forming step, the polymer structure having a shape in which particles are connected by a fiber is formed from the jet of the polymer solution.   The method according to any one of claims 1 to 3, wherein the polymer solution is prepared by adding N, N-dialkylformamide to an aromatic hydrocarbon solvent solution of a cycloolefin polymer.   The cycloolefin polymer is a norbornene polymer obtained by (co) polymerizing a norbornene monomer having a -COOR group (wherein R is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms). 5. The method according to any one of items 1 to 4. A cycloolefin polymer structure comprising:
Formed as independent particles having an average size of 5 to 25 μm,
The particles have a large number of micro holes on the surface, and the average opening size of the micro holes is 50 nm to 150 nm,
The said particle | grain is a cycloolefin polymer structure which is a deformed particle which has a hollow on an external shape .   The cycloolefin polymer is a norbornene polymer obtained by (co) polymerizing a norbornene monomer having a -COOR group (R is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms). Structure.