JP2020025608A - Member having antibacterial membrane, and method for manufacturing the same - Google Patents

Abstract

To provide a member having a membrane which shows sufficient antibacterial properties over a long period of time.SOLUTION: A member has a base material and a membrane formed on the base material, and the membrane includes amorphous carbon and zeolite containing metal which is dispersed in the amorphous carbon.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a member having a film having antibacterial properties and a method for producing the same.

  Diamond-like carbon (DLC) has attracted attention as a surface coating material in various fields. Silver (Ag) is known to have antibacterial properties. Non-Patent Document 1 describes that a mixed film of Ag particles and DLC (Ag-DLC film) exhibits antibacterial properties.

F. R. Marciano et al. , "Antibacterial activity of DLC and Ag-DLC films produced by PECVD technology", Diamond and Related Materials Volume 18, 10-10-August 10, August 9-August 10, 2008.

  According to Non-Patent Document 1, the Ag-DLC film shows high antibacterial properties for 3 hours after the film formation, but after 24 hours from the film formation, it becomes about the same antibacterial property as the DLC film not containing Ag, Insufficient long-term antibacterial properties. Therefore, an object of the present invention is to provide a member having a film exhibiting sufficient antibacterial properties for a long time, and a method for producing the same.

According to the first aspect,
A substrate,
Having a film formed on the substrate,
The membrane is
Amorphous carbon,
A member including zeolite containing metal is provided.

  According to the second aspect, the amorphous carbon is formed into a film on the base material by a filtered cathodic vacuum arc method while mixing and spraying the zeolite containing the metal with the carrier gas, so that the amorphous carbon is formed in the amorphous carbon. A method for manufacturing a member is provided, comprising forming a film in which the zeolite is dispersed on the substrate.

It is an outline sectional view of a member concerning an embodiment. It is a figure which shows notionally an example of the structure of the zeolite which contains metal. FIG. 2 is a schematic configuration diagram of a film forming apparatus.

[Member with membrane]
Hereinafter, an embodiment of a member will be described with reference to the drawings. As shown in FIG. 1, the member 100 has a film 30 formed on the base material 10. The film 30 is a film having antibacterial properties, and includes zeolite 70 (see FIG. 2) containing amorphous carbon 50 and metal 90.

(1) Base material 10
The base material 10 may have various shapes depending on the use of the member 100, and may be made of various materials. For example, it may be made of resin, silicon, titanium, stainless steel, or the like.

(2) Film 30
The film 30 covers the surface of the substrate 10. The film 30 has a first surface 32 that contacts the substrate 10 and a second surface 34 that is opposite to the first surface 32.

The amorphous carbon 50 has carbon atoms forming bonds using sp ² hybrid orbitals (sp ² hybrid carbon atoms, sp ² -C atoms) and carbon atoms forming bonds using sp ³ hybrid orbitals ( sp ³ hybridized carbon atoms, including ^sp 3 -C atom). Such an amorphous carbon 50 can be formed by a PVD method (physical vapor deposition method), a CVD method (chemical vapor deposition method), or the like. Examples of the PVD method include an ionization evaporation method, an ion beam sputtering method, a magnetron sputtering method, a laser evaporation method, an arc ion plating method, and a filtered cathodic vacuum arc (FCVA) method. Examples of the CVD method include a microwave plasma CVD method, a DC plasma CVD method, a high-frequency plasma CVD method, and a magnetic field plasma CVD method using a hydrocarbon gas as a raw material. In particular, in the FCVA method, at room temperature, the amorphous carbon 50 can be formed uniformly and with a high adhesive force on a surface having a complicated shape.

  The amorphous carbon 50 may contain hydrogen. Thereby, the stress of the film 30 can be reduced.

On the second surface 34 of the film 30, the ratio of the number of sp ² -C atoms to the total number of sp ² -C atoms and the number of sp ³ -C atoms in the amorphous carbon 50 is 15 to 85 atomic%. May be. When the proportion of the number of sp ² —C atoms is less than 15 at%, that is, when the proportion of the number of sp ³ —C atoms exceeds 85 at%, the compressive stress of the film is very large, and the hardness of the film is low. Tends to be too high. When the proportion of the number of sp ² -C atoms exceeds 85 atomic%, that is, when the proportion of the number of sp ³ -C atoms is less than 15 at%, the film is soft and tends to be damaged or peeled. is there.

In addition, the present inventors have previously reported that when the ratio of the number of sp ³ -C atoms to the sum of the number of sp ² -C atoms and the number of sp ³ -C atoms exceeds 50 atomic%, in particular, sp ^It has been found that when the ratio of the number of ^2- C atoms is 23 to 43 atomic%, amorphous carbon has a characteristic that proteins, cells, bacteria, and the like are particularly difficult to adsorb.

However, when metal nanoparticles having antibacterial properties such as silver are dispersed in amorphous carbon, the number of sp ² -C atoms and the number of sp ³ -C atoms in amorphous carbon are lower than when metal nanoparticles are not dispersed. ^sp 3 ratio of the number of -C atom has been known to be low (P.Pisarik et al to the sum of., "Antibacterial, mechanical and surface properties of Ag-DLC films prepared by dual PLD for medical applications" Materials Science and Engineering: C Volume 77, 1 August 2017, Pages 955-962).

In this regard, in the film 30 of the member 100 according to the embodiment, since the metal 90 is included in the zeolite 70, the amorphous carbon 50 and the metal 90 hardly come into contact with each other. Thereby, the ratio of sp ³ —C atoms is maintained without substantially changing, so that characteristics in which proteins, cells, bacteria, and the like are not easily adsorbed can be maintained for a long time. In addition, even if the ratio of the number of sp ² -C atoms to the total number of sp ² -C atoms and the number of sp ³ -C atoms in the amorphous carbon 50 is 15 to 85 atomic% over the entire film 30. well, the proportion of ^sp 2 -C atoms may be less than 50 atomic%.

Zeolite 70 is a kind of aluminosilicate, represented by the general _{formula xM 2 / n O · Al 2} O 3 · ySiO 2 · zH 2 O. Here, n is the valence of the ion exchangeable cation M. As shown in FIG. 2, the zeolite 70 has a three-dimensional network skeleton composed of aluminum atoms, silicon atoms, and oxygen atoms.

  The zeolite 70 may be either a natural zeolite or a synthetic zeolite. Specifically, for example, A-type zeolite, X-type zeolite, Y-type zeolite, T-type zeolite, high silica zeolite, sodalite, mordenite, analcyme, clinobutyrolite, chabazite, erionite and the like. But not limited thereto.

  The zeolite 70 contains a metal 90 having antibacterial properties. As shown in FIG. 2, the metal 90 is taken into pores in the three-dimensional skeleton of the zeolite 70. The metal 90 may be included in the zeolite 70 in an ionic state. By replacing at least a part of the ion-exchangeable cation M in the zeolite 70, for example, sodium ion, calcium ion, potassium ion, magnesium ion, iron ion and the like, with a metal ion having antibacterial properties, the zeolite 70 The metal 90 can be included in an ion state. Alternatively, the metal 90 may be included in the zeolite 70 in a state of nanoparticles.

  The metal 90 having antibacterial properties is not particularly limited, and may include, for example, at least one selected from the group consisting of silver, mercury, platinum, copper, cadmium, gold, cobalt, nickel, and lead. May include.

  In general, when nanoparticles of a metal having antibacterial properties such as silver are dispersed in an amorphous carbon film, the metal nanoparticles move to the surface of the amorphous carbon film and aggregate with time, and the amorphous carbon film It is known that coarse metal particles appear on the surface. Therefore, a film in which metal nanoparticles are dispersed in an amorphous carbon film cannot have antibacterial properties due to metal nanoparticles for a long time. In addition, since the surface of the amorphous carbon film is covered with the metal particles, the characteristics of the amorphous carbon (for example, a property that protein and the like are not easily adsorbed, a high hardness, a slidability, a high durability, and the like) are deteriorated with time. . On the other hand, in the film 30 of the member 100 according to the embodiment, the metal 90 is dispersed in the amorphous carbon 50 while being held in the pores of the zeolite 70. The metal 90 retained in the zeolite 70 takes a longer time to be released from the zeolite 70 and travel through the membrane 30 to the second surface 34. Therefore, formation of aggregates due to excessive supply of the metal 90 to the second surface 34 of the film 30 is suppressed. Therefore, the film 30 can have antibacterial properties for a long time, and can also prevent the characteristics of the amorphous carbon 50 from being impaired.

  In order to supply the metal 90 to the second surface 34 of the membrane 30 in an appropriate amount and at an appropriate rate, the content (content) of the zeolite 70 on the first surface 32 of the membrane 30 is determined during the formation of the membrane 30. 34 may be higher than the content (content) of zeolite 70. An appropriate amount of metal 90 is released from the zeolite 70 in the membrane 30 and moves to the second surface 34, so that the second surface 34 exhibits antibacterial properties.

  For example, a configuration may be employed in which the content of zeolite 70 is gradually reduced from the first surface 32 to the second surface 34 by giving a gradient of the content of zeolite 70 in the thickness direction of the membrane 30. Second surface 34 may not include zeolite 70. As another example, the film 30 includes, on the first surface 32 side, a layer containing only the zeolite 70 containing the metal 90 and an amorphous carbon layer formed on the layer containing only the zeolite 70. May be. The amorphous carbon layer may or may not include the zeolite 70 containing the metal 90. In any of the examples, the zeolite 70 including the metal 90 may not be contained in a region having a predetermined thickness from the second surface 34 in the film 30. By controlling the thickness, the supply amount and the supply speed of the metal 90 to the second surface 34 can be controlled.

  In the member 100, a plurality of the films 30 described above may be stacked on the base material 10.

Further, as described above, when metal nanoparticles having antibacterial properties such as silver are dispersed in amorphous carbon, the ratio of the number of sp ³ -C atoms in the amorphous carbon is smaller than that in the case where metal nanoparticles are not dispersed. It is known to be lower. On the other hand, in the membrane 30 of the member 100 according to the embodiment, the metal 90 is held in the pores of the zeolite 70 at least immediately after the formation of the membrane 30. As a result, in the formation process of the film 30, since the amorphous carbon 50 and the metal 90 do not contact, to the total number of the number of ^sp 3 -C atom of ^sp 2 -C atoms in the amorphous carbon 50 of ^sp 2 -C atoms The ratio of the numbers can be easily controlled to an appropriate value. In particular, the ratio of sp ³ -C atoms can be kept high. The amorphous carbon 50 is in contact with the skeleton of aluminum, silicon, and oxygen atoms of the zeolite 70, but the skeleton of the zeolite 70 affects the hybrid orbitals that contribute to the bonding of the amorphous carbon 50 for the following reasons. Do not give. The zeolite 70 is a composite oxide of aluminum and silicon, and its skeleton is mainly composed of a chemical bond between aluminum and oxygen and a chemical bond between silicon and oxygen. The chemical bond between aluminum and oxygen and the chemical bond between silicon and oxygen are more thermodynamically stable than the chemical bond between aluminum and carbon and the chemical bond between silicon and carbon. Therefore, the atoms in the skeleton of the zeolite 70 do not form bonds with the carbon atoms in the amorphous carbon 50, and do not affect the bonds of the carbon atoms in the amorphous carbon 50.

As described above, the amorphous carbon 50 having an appropriate ratio of sp ² -C atoms is unlikely to adhere to proteins, cells, bacteria, and the like. Therefore, by setting the ratio of the sp ² —C atoms of the amorphous carbon 50 to an appropriate value, the film 30 can have higher antibacterial properties. In particular, even when the content of the metal 90 in the film 30 is 10 atomic% or less, the film 30 can have sufficient antibacterial properties. By reducing the content of the metal 90, the manufacturing cost of the film 30 can be suppressed and the durability of the film 30 can be improved.

  The member 100 according to the embodiment may be used for, for example, medical instruments, medical materials, house building materials, and daily necessities. The membrane 30 may be arbitrarily arranged depending on the use of the member 100. The film 30 may be formed so as to cover the entire surface of the substrate 10 or may be formed only partially on the surface of the substrate 10. If the member 100 is used in a medical device, the membrane 30 may be provided in an area of the member 100 that may be exposed to bacteria. Since the film 30 has an antibacterial effect, the growth of bacteria can be suppressed. The member 100 may be used alone, or a plurality of members 100 may be used in combination.

  Note that the term “medical device” includes all that can be generally referred to as a medical device, and specifically includes artificial joints, artificial bones, artificial teeth, artificial roots, artificial hearts, artificial heart valves, artificial blood vessels, and artificial blood vessels. Anus, artificial ureter, artificial pleura, artificial prosthesis, stent (including vascular stent and bronchial stent), guide wire, catheter, indwelling catheter, pacemaker electrode, pacemaker lead wire, contact lens, artificial lens, electric scalpel, needle , Blood bags, blood collection tubes, scalpels, endoscopes, filters such as blood filters, channels such as blood circuits, tubes such as blood supply tubes, forceps, artificial lungs, artificial heart-lung machines, dialysis devices, orthopedics Instruments, cochlear implants, artificial eardrums, artificial vocal cords, cannulas, coils for treating cerebral arteries, artificial pancreas, acupuncture and moxibustion instruments, electrodes, sutures, wound dressings, wounds Including Mamoruzai, waste tube, orthopedic implants, pacemakers and the like.

[Method of manufacturing members]
A method for manufacturing the member 100 will be described. FIG. 3 is a diagram conceptually showing the structure of the film forming apparatus 1 for forming the film 30 on the base material 10.

The film forming apparatus 1 mainly includes an arc plasma generating unit 110, a filter unit 120, a film forming chamber unit 130, and an atomizer 150. The arc plasma generating section 110 is connected to the film forming chamber section 130 by a duct-shaped filter section 120. The pressure of the film forming chamber unit 130 is set to about 10 ⁻⁴ to 10 ⁻⁶ [Torr] by a vacuum device not shown.

  The arc plasma generator 110 includes a graphite target 111 as a cathode and an anode (striker) (not shown). When a DC voltage is applied to the target 111, an arc discharge occurs, thereby generating an arc plasma. Neutral particles and charged particles generated from the target 111 by the arc plasma fly through the filter unit 120 toward the film forming chamber unit 130.

  The filter unit 120 is provided with a duct 123 around which an electromagnet coil 121 is wound, and an ion scanning coil 125. The duct 123 is bent twice in two orthogonal directions between the arc plasma generating unit 110 and the film forming chamber unit 130, and the electromagnet coil 121 is wound around the outer periphery thereof. Since the duct 123 has such a bent structure (double bend structure), neutral particles in the duct 123 are removed by colliding with and accumulating on the inner wall surface. The Lorentz force acts on the charged particles in the duct 123 by passing a current through the electromagnet coil 121, and the charged particles are concentrated in the center area of the duct cross section, fly along the bend of the duct, and are guided to the film forming chamber section 130. I will That is, the electromagnetic coil 121 and the duct 123 constitute a narrow-band electromagnetic spatial filter that allows only the charged particles to pass with high efficiency.

The ion scanning coil 125 can move the beam of charged particles entering the deposition chamber 130 through the duct 123 in any direction. A holder 131 is provided in the film forming chamber section 130, and the substrate 10 is set on the surface of the holder 131. The holder 131 rotates by a motor 135. The beam of charged particles directed by the ion scanning coil 125 is incident on the surface of the base material 10 held by the holder 131. A negative bias voltage is applied to the holder 131 by the power supply 137, and thereby, charged particles incident on the base material 10 are accelerated. The accelerated charged particles are deposited on the substrate 10. Thereby, a dense amorphous carbon film is uniformly formed on the substrate 10. By adjusting the bias voltage, the content of sp ² -C atoms and sp ³ -C atoms in amorphous carbon can be controlled.

  The atomizer 150 mixes a zeolite powder containing a metal with a carrier gas and sprays the mixed gas into the film forming chamber unit 130. Thereby, the zeolite is introduced into the film forming chamber unit 130. For example, argon or helium gas is used as a carrier gas, and the carrier gas is introduced into the atomizer 150 at a predetermined flow rate within a range of 0.1 to 30 sccm. In the atomizer 150, zeolite powder containing a metal is placed in advance. When the carrier gas passes through the atomizer 150, the zeolite powder is transported together with the carrier gas to the film forming chamber 130.

  The zeolite powder containing a metal is obtained by contacting the zeolite powder with an aqueous solution containing metal ions, and replacing the ion-exchangeable cations in the zeolite with the metal ions in the aqueous solution. The amount of metal content (inclusion) of zeolite can be controlled by adjusting the concentration of metal ions in the aqueous solution. A commercially available zeolite powder containing metal may be used.

  By introducing the metal-encapsulated zeolite into the film forming chamber 130 by the atomizer 150 while introducing the charged particles of carbon into the film forming chamber 130 by the arc plasma generating unit 110 and the filter unit 120, the charged particles (carbon ions) are removed. A metal-containing zeolite is deposited on the substrate 10. Thereby, a film (antimicrobial film) composed of amorphous carbon and zeolite encapsulating metal dispersed in the amorphous carbon is formed on the base material 10.

  By adjusting the flow rate of the carrier gas introduced from the atomizer 150 into the film forming chamber unit 130, the content of zeolite containing metal in the film can be controlled. By changing the flow rate of the carrier gas during the film formation, a concentration gradient of the metal-encapsulated zeolite can be provided in the thickness direction of the film.

  An antimicrobial film may be formed only on a part of the surface of the substrate 10. In this case, after the region of the base material 10 where the antimicrobial film is not formed is covered with a mask, the base material 10 may be set on the holder 131 to form the antimicrobial film.

  Note that the film forming apparatus 1 is an apparatus for forming amorphous carbon by a filtered cathodic vacuum arc (FCVA) method, but the method for forming amorphous carbon is not limited to the FCVA method. Amorphous carbon can be formed by PVD (physical vapor deposition) or CVD (chemical vapor deposition). Examples of the PVD method include an ionization evaporation method, an ion beam sputtering method, a magnetron sputtering method, a laser evaporation method, an arc ion plating method, and an FCVA method using a carbon target as a raw material. Examples of the CVD method include a microwave plasma CVD method, a DC plasma CVD method, a high frequency plasma CVD method, and a magnetic field plasma CVD method using a hydrocarbon gas as a raw material. The above-described FCVA method is preferable in that a substrate having a complicated shape can be uniformly coated and a film having a high adhesion to the substrate even at room temperature can be formed.

  As described above, the preferred embodiments of the present invention have been described, but the present invention is not limited to these embodiments.

DESCRIPTION OF SYMBOLS 1 Film-forming apparatus 10 Base material 30 Film 32 1st surface 34 2nd surface 50 Amorphous carbon 70 Zeolite 90 Metal 100 Member 110 Arc plasma generating unit 120 Filter unit 130 Film-forming chamber unit 150 Atomizer

Claims (11)

A substrate,
Having a film formed on the substrate,
The membrane is
Amorphous carbon,
A zeolite containing metal;   The member according to claim 1, wherein the zeolite including the metal is dispersed in the amorphous carbon.   The member according to claim 1, wherein the metal includes at least one selected from the group consisting of silver, mercury, platinum, copper, cadmium, gold, cobalt, nickel, and lead.   The member according to claim 3, wherein the metal includes silver. The film has a first surface in contact with the substrate, and a second surface opposite the first surface;
The member according to any one of claims 1 to 4, wherein a content of the zeolite on the first surface is higher than a content of the zeolite on the second surface. The amorphous carbon, according to any one of claims 1-5 containing a carbon atom forming a bond with a carbon atom and sp ³ hybrid orbital to form a bond with sp ² hybrid orbital Members. In the film, the sp ² hybrid orbital with respect to the sum of the number of carbon atoms forming a bond using the sp ² hybrid orbital and the number of carbon atoms forming a bond using the sp ³ hybrid orbital The member according to claim 6, wherein the ratio of the number of carbon atoms forming a bond by using is 15 to 85 atomic%. In the film, the sp ² hybrid orbital with respect to the sum of the number of carbon atoms forming a bond using the sp ² hybrid orbital and the number of carbon atoms forming a bond using the sp ³ hybrid orbital The member according to claim 6, wherein the ratio of the number of carbon atoms forming a bond by using is less than 50 atomic%. On the second surface of the film, the number of carbon atoms forming a bond using the sp ² hybrid orbital and the number of carbon atoms forming a bond using the sp ³ hybrid orbital member according to any one of claims 5-8 percentage of the number of carbon atoms forming the bond with sp ² hybrid orbital is 15 to 85 atomic%.   A medical device, a building material, or a daily necessity comprising the member according to claim 1. By mixing and spraying a zeolite encapsulating metal with a carrier gas and forming a film of amorphous carbon on a substrate by a filtered cathodic vacuum arc method, a film in which the zeolite is dispersed in the amorphous carbon is formed. A method for producing a member, comprising forming the member on a substrate.

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