JP2006169641A - Diaphragm and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide diaphragms (exclusive of automobile diaphragms) having excellent wear resistance, hard to deteriorate, and further having excellent water repellency, and to provide a method for producing the same. <P>SOLUTION: The diaphragm comprises a carbon film F having wear resistance and water repellency formed on the outer surface S4'. And its production method is also provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a diaphragm used in a diaphragm pump and the like used in an artificial heart and a method for manufacturing the diaphragm.

  A polymer material such as silicon rubber is used as a diaphragm material employed in a diaphragm pump or the like employed in an artificial heart.

  However, a diaphragm made of a polymer material has a problem that it is easily worn and deteriorated by contact with a fixture of the diaphragm, and a fluid such as a liquid handled by the diaphragm is easily attached.

  Therefore, an object of the present invention is to provide a diaphragm (excluding a diaphragm for automobiles) excellent in wear resistance, hardly deteriorated, and excellent in water repellency, and a method for producing the same.

In order to solve the above-mentioned problems, the present invention provides a diaphragm (excluding a diaphragm for automobiles) in which a carbon film having wear resistance and water repellency is formed on a part or all of the surface.
The present invention also provides a method for producing a diaphragm (excluding automobile diaphragms), which includes a step of forming a wear-resistant, water-repellent carbon film on part or all of the surface.

  Examples of part or all of the surface of the diaphragm on which the carbon film is formed include a contact surface with another article such as a fixture for the diaphragm, a contact surface with a fluid such as a liquid handled by the diaphragm, and the like.

  The diaphragm according to the present invention has a wear-resistant and water-repellent carbon film formed on a part or all of the surface thereof, so that the part is not easily worn or deteriorated by friction with other articles. It is difficult for liquid to adhere to the part.

  Examples of the diaphragm according to the present invention include various diaphragms used in artificial hearts and various fluid circuits.

  The diaphragm base in the present invention can be exemplified by a case where at least the film forming surface is made of an organic material, for example, at least one organic material selected from rubber, resin, and carbon.

  Examples of the rubber include natural rubber, butyl rubber, ethylene propylene rubber, chloroprene rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, acrylic rubber, nitrile rubber, urethane rubber, silicon rubber, and fluorine rubber.

  Among the resins, examples of the thermosetting resin include phenol / formaldehyde resin, urea resin, melamine / formaldehyde resin, epoxy resin, furan resin, xylene resin, unsaturated polyester resin, silicon resin, diallyl phthalate resin, and the like.

  Thermoplastic resins include vinyl resins (polyvinyl chloride, polyvinyl dichloride, polyvinyl butyrate, polyvinyl alcohol, polyvinyl acetate, polyvinyl formal, etc.), polyvinylidene chloride, chlorinated polyether, polyester resins (polystyrene, Styrene / acrylonitrile copolymer), ABS, polyethylene, polypropylene, polyacetal, acrylic resin (polymethyl methacrylate, modified acrylic, etc.), polyamide resin (nylon 6, 66, 610, 11 etc.), cellulose resin (ethyl cellulose) , Cellulose acetate, propyl cellulose, acetic acid / butyric acid cellulose, cellulose nitrate, etc.), polycarbonate, phenoxy resin, fluororesin (ethylene trifluoride, tetrafluoroethylene, tetrafluoroethylene Propylene, vinylidene fluoride, etc.), polyurethanes, and the like can be exemplified.

  A typical example of the carbon film in the present invention is a DLC (Diamond Like Carbon) film. The DLC film has good lubricity, is difficult to wear due to friction with other articles, and the substrate coated with the film has flexibility by adjusting its thickness. Is a carbon film having an appropriate hardness so as not to impair the inherent flexibility of the substrate. Also, the water repellency is good. Furthermore, the film can be formed easily, such as being formed at a relatively low temperature.

  In any case, the carbon film can be formed on each substrate with good adhesion, and can function sufficiently as a protective film for the substrate. It may be within a range that does not impair flexibility.

In the method of the present invention, prior to the carbon film formation, as a pretreatment, the film formation surface of each substrate is subjected to a pretreatment gas such as a fluorine (F) -containing gas, hydrogen (H ₂ ) gas, and oxygen (O ₂ ). You may expose to the plasma of the at least 1 sort (s) of pretreatment gas chosen from gas. In this case, in the diaphragm of the present invention, the base is subjected to such pretreatment.

Examples of the fluorine-containing gas include fluorine (F ₂ ) gas, nitrogen trifluoride (NF ₃ ) gas, sulfur hexafluoride (SF ₆ ) gas, carbon tetrafluoride (CF ₄ ) gas, and silicon tetrafluoride (SiF). ₄ ) Gas, silicon hexafluoride (Si ₂ F ₆ ) gas, chlorine trifluoride (ClF ₃ ) gas, hydrogen fluoride (HF) gas and the like.

  By exposing the substrate to the plasma of the pretreatment gas, the substrate surface is cleaned or the substrate surface roughness is further improved. These contribute to the improvement of the adhesion of the carbon film, and a high adhesion carbon film can be obtained.

  When the film-forming surface of the substrate is made of an organic material such as rubber or resin, when the fluorine-containing gas plasma is used for the pretreatment, the substrate surface is terminated with fluorine, and when the hydrogen gas plasma is used, The substrate surface is hydrogen terminated. Since the fluorine-carbon bond and the hydrogen-carbon bond are stable, the carbon atom in the film forms a bond with the fluorine atom or the hydrogen atom on the surface of the substrate stably by the termination treatment as described above. And from these things, the adhesiveness of the carbon film formed after that and the said base | substrate can be improved.

  When oxygen gas plasma is employed, dirt such as organic matter adhering to the surface of the substrate can be removed particularly efficiently, and the adhesion between the carbon film formed thereafter and the substrate can be improved.

  In the present invention, the pretreatment of the substrate by plasma prior to the carbon film formation may be performed a plurality of times using the same type of plasma or using different types of plasma. For example, when the substrate is exposed to oxygen gas plasma and then exposed to fluorine-containing gas plasma or hydrogen gas plasma to form a carbon film thereon, the surface of the substrate is cleaned and then the surface is fluorine-terminated or hydrogen-terminated. As a result, the adhesion between the carbon film to be formed thereafter and the surface of the substrate becomes very good.

  As a carbon film forming method in the present invention, a plasma CVD method, a sputtering method, an ion can be used as a method of forming a film in a temperature range that does not cause thermal damage to a substrate using a material having relatively poor heat resistance such as rubber and resin. A plating method and the like can be given. In particular, when the plasma CVD method is used, the plasma pre-treatment of the deposition target substrate and the carbon film formation can be performed with the same apparatus.

As a plasma source gas for forming a carbon film by plasma CVD, methane (CH ₄ ), ethane (C ₂ H ₆ ), propane (C ₃ H ₈ ), butane (C ₄ ), which are generally used for forming a carbon film, are used. H _10), acetylene (C ₂ H _2), benzene (C ₆ H _6), 4 fluorinated carbon (CF _4), 6 fluorinated 2 carbon (C ₂ F ₆₎ carbon compounds such as gases, and optionally A mixture of these carbon compound gases with hydrogen gas, inert gas or the like as a carrier gas can be used.

  As described above, according to the present invention, it is possible to provide a diaphragm excellent in wear resistance, hardly deteriorated, and excellent in water repellency, and a method for producing the same.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of an example of a film forming apparatus that can be used for manufacturing a diaphragm according to the present invention. FIG. 3A is a cross-sectional view of an example of a diaphragm according to the present invention, and FIG. 3B is a view showing a cross-section of an example (ball) of a carbon film-covered sports equipment.

  This device has a vacuum chamber 1 to which an exhaust device 11 is attached, and an electrode 2 and an electrode 3 are installed in a position opposite to the electrode 2 in the chamber 1. The electrode 3 is grounded, and a high frequency power source 23 is connected to the electrode 2 via a matching box 22. In addition, the electrode 2 is provided with a heater 21 for heating a film formation substrate supported thereon to a film formation temperature. Further, a gas supply unit 4 is attached to the chamber 1 so that a plasma source gas can be introduced into the chamber 1. The gas supply unit 4 includes one or more plasma source gas gas sources 431, 432,... Connected via mass flow controllers 411, 412,.

  For example, in manufacturing the sports equipment shown in FIG. 3B using this apparatus, the sports equipment base S1 is disposed on the electrode 2 with the contact surface S1 'with another article facing the facing electrode 3. Then, the inside of the chamber 1 is brought to a predetermined degree of vacuum by the operation of the exhaust device 11. Next, one or more of fluorine-containing gas, hydrogen gas and oxygen gas are introduced into the chamber 1 from the gas supply unit 4 as a pretreatment gas, and a high frequency is supplied from the high frequency power source 23 to the electrode 2 via the matching box 22. Electric power is supplied, whereby the introduced pretreatment gas is turned into plasma, and surface treatment of the substrate S1 is performed under the plasma. This surface treatment (pretreatment) is desirably performed, but is not necessarily required.

  Next, after evacuating the chamber 1 again as necessary, a carbon compound gas is introduced from the gas supply unit 4 into the chamber 1 as a film forming source gas, and high frequency power is supplied from the high frequency power source 23 to the electrode 2. Thereby, the introduced carbon compound gas is turned into plasma, and a carbon film is formed on the surface of the substrate S1 under the plasma.

  During the surface treatment and film formation, when the substrate is, for example, a three-dimensional structure, for example, a part of the substrate is brought into contact with the electrode 2, and the substrate is rotated by a rotation driving means (not shown). Surface treatment and film formation are performed almost uniformly on the contact surface with other articles.

  In this way, as shown in FIG. 3B, the carbon film F was formed almost uniformly on the contact surface (outer surface) S1 ′ of the sports equipment base S1 (ball in the illustrated example) with other articles. Carbon film-coated sporting goods are obtained.

  When the diaphragm according to the present invention is manufactured using this apparatus, the surface treatment and carbon film formation are performed on the outer surface S4 ′ (see FIG. 3A) of the diaphragm base S4 in the same manner as the manufacture of the sporting goods. As shown in FIG. 3A, a carbon film-covered diaphragm in which the carbon film F is formed almost uniformly on the outer surface S4 ′ of the diaphragm base S4 is obtained.

  In carrying out the method of the present invention, the film forming apparatus shown in FIG. 2 can be used in place of the apparatus shown in FIG. 1. In this case, even when the base is a three-dimensional structure, the film is efficiently formed on the surface of the base. can do.

  The apparatus shown in FIG. 2 is an inductively coupled plasma CVD apparatus, and has a vacuum vessel 1 ′. An induction coil electrode 5 is wound around the outer periphery of the vessel 1 ′. A matching box 51 and a high frequency power source 52 are connected. Further, a heater 21 ′ for heating the film formation substrate S <b> 1 to a film formation temperature is provided outside the vacuum container 1 ′.

  An exhaust device 11 ′ is connected to the vacuum vessel 1 ′ by piping, and a film supply source gas supply unit 4 ′ is connected by piping. A gas for supplying one or more film forming source gases connected to the gas supply unit 4 ′ via mass flow controllers 411 ′, 412 ′,... And valves 421 ′, 422 ′,. Sources 431 ′, 432 ′,... Are included.

  FIG. 2 shows a state in which a carbon film is formed on the sports equipment base S1 as a reference example, but a carbon film can also be formed on the diaphragm base S4. When the carbon film is formed on the substrate using this apparatus, it is the same as the surface treatment and carbon film formation on the substrate using the apparatus of FIG. Performed by applying power. Also in this case, it is desirable to perform surface treatment (pretreatment), but it is not always necessary.

  Next, using the apparatus shown in FIG. 1, a DLC film is formed on the surface of a test piece made of terpolymer rubber (EPDM) of ethylene-propylene-diene monomer or polyimide, which is used as a material for the diaphragm. Experimental examples (Experimental examples 1 to 5 for EPDM and Experimental examples 6 to 10 for polyimide) will be described.

Experimental example 1
In the carbon film formation using the apparatus of FIG. 1 described above, the DLC film was formed directly on the outer surface of the test piece without performing the pretreatment of the test piece with the pretreatment gas plasma.
Specimen material EPDM
Size 20cm x 20cm x thickness 1cm
High frequency electrode 2 size 40cm × 40cm
Deposition conditions
Deposition source gas Methane (CH ₄ ) 100 sccm
High frequency power frequency 13.56MHz, 300W
Deposition vacuum 0.1 Torr
Deposition rate 500 l / min
Deposition time 20min

Experimental example 2
In Experimental Example 1, prior to film formation, the test piece was pretreated with hydrogen gas plasma under the following conditions. The film forming conditions were the same as in Experimental Example 1.
Pretreatment conditions
Pretreatment gas Hydrogen (H ₂ ) 100 sccm
High frequency power frequency 13.56MHz, 300W
Processing vacuum 0.1 Torr
Processing time 5min

Experimental example 3
In Experimental Example 1, prior to film formation, the test piece was pretreated with fluorine compound gas plasma under the following conditions. The film forming conditions were the same as in Experimental Example 1.
Pretreatment conditions
Pretreatment gas Sulfur hexafluoride (SF ₆ ) 100 sccm
High frequency power frequency 13.56MHz, 300W
Processing vacuum 0.1 Torr
Processing time 5min

Experimental Example 4
In Experimental Example 1, prior to film formation, the test piece was subjected to a first pretreatment with oxygen gas plasma under the following conditions, and further with a second pretreatment with hydrogen gas plasma. The film forming conditions were the same as in Experimental Example 1.
First pretreatment condition
Pretreatment gas Oxygen (O ₂ ) 100 sccm
High frequency power frequency 13.56MHz, 300W
Processing vacuum 0.1 Torr
Processing time 5min
Second pretreatment condition
Pretreatment gas Hydrogen (H ₂ ) 100 sccm
High frequency power frequency 13.56MHz, 300W
Processing vacuum 0.1 Torr
Processing time 5min

Experimental Example 5
In the experimental example 1, prior to film formation, the test piece was subjected to a first pretreatment with oxygen gas plasma under the following conditions, and further with a second pretreatment with fluorine compound gas plasma. The film forming conditions were the same as in Experimental Example 1.
First pretreatment condition
Pretreatment gas Oxygen (O ₂ ) 100 sccm
High frequency power frequency 13.56MHz, 300W
Processing vacuum 0.1 Torr
Processing time 5min
Second pretreatment condition
Pretreatment gas Sulfur hexafluoride (SF ₆ ) 100 sccm
High frequency power frequency 13.56MHz, 300W
Processing vacuum 0.1 Torr
Processing time 5min

Experimental Example 6
In the carbon film formation using the apparatus of FIG. 1 described above, the DLC film was formed directly on the outer surface of the test piece without performing the pretreatment of the test piece with the pretreatment gas plasma.
Specimen material Polyimide
Size 20cm x 20cm x thickness 1cm
High frequency electrode 2 size 40cm × 40cm
Deposition conditions
Deposition source gas Methane (CH ₄ ) 100 sccm
High frequency power frequency 13.56MHz, 300W
Deposition vacuum 0.1 Torr
Deposition rate 500 l / min
Deposition time 20min

Experimental Example 7
In Experimental Example 6, prior to film formation, the test piece was pretreated with hydrogen gas plasma under the following conditions. The film forming conditions were the same as in Experimental Example 6.
Pretreatment conditions
Pretreatment gas Hydrogen (H ₂ ) 100 sccm
High frequency power frequency 13.56MHz, 300W
Processing vacuum 0.1 Torr
Processing time 5min

Experimental Example 8
In Experimental Example 6, prior to film formation, the test piece was pretreated with fluorine compound gas plasma under the following conditions. The film forming conditions were the same as in Experimental Example 6.
Pretreatment conditions
Pretreatment gas Sulfur hexafluoride (SF ₆ ) 100 sccm
High frequency power frequency 13.56MHz, 300W
Processing vacuum 0.1 Torr
Processing time 5min

Experimental Example 9
In Experimental Example 6, prior to the film formation, the test piece was subjected to a first pretreatment with oxygen gas plasma under the following conditions, and further with a second pretreatment with hydrogen gas plasma. The film forming conditions were the same as in Experimental Example 6.
First pretreatment condition
Pretreatment gas Oxygen (O ₂ ) 100 sccm
High frequency power frequency 13.56MHz, 300W
Processing vacuum 0.1 Torr
Processing time 5min
Second pretreatment condition
Pretreatment gas Hydrogen (H ₂ ) 100 sccm
High frequency power frequency 13.56MHz, 300W
Processing vacuum 0.1 Torr
Processing time 5min

Experimental Example 10
In Experimental Example 6, prior to film formation, the test piece was subjected to a first pretreatment with oxygen gas plasma under the following conditions, and further with a second pretreatment with fluorine compound gas plasma. The film forming conditions were the same as in Experimental Example 6.
First pretreatment condition
Pretreatment gas Oxygen (O ₂ ) 100 sccm
High frequency power frequency 13.56MHz, 300W
Processing vacuum 0.1 Torr
Processing time 5min
Second pretreatment condition
Pretreatment gas Sulfur hexafluoride (SF ₆ ) 100 sccm
High frequency power frequency 13.56MHz, 300W
Processing vacuum 0.1 Torr
Processing time 5min

  Next, the DLC film-covered test piece obtained in the experimental examples 1, 2, 3, 4, and 5, the same untreated test piece (Comparative Experimental Example 1) in which no DLC film was formed, and the Experimental Example 6 , 7, 8, 9, 10 DLC film-coated test piece, untreated similar test piece not formed with DLC film (Comparative Experimental Example 2), friction coefficient with aluminum material and diamond material Were evaluated for wear characteristics and water repellency. Moreover, the adhesiveness of a DLC film and a test piece was evaluated about each DLC film coating | coated test piece obtained by Experimental Examples 1-10.

  The coefficient of friction is determined when the tip of an aluminum pin-shaped article is brought into contact with the surface of the test piece, and the pin is moved at a speed of 20 mm / sec with a load of 10 g applied to the pin-shaped article. The wear characteristics were determined by bringing the tip of a diamond-shaped article made of diamond into contact with the surface of the test piece and moving it at a speed of 20 mm / sec with a load of 100 g applied thereto for 1 hour. Evaluation was made by measuring the depth of wear. The film adhesion is obtained by bonding the cylindrical member to the surface of the film using an adhesive, pulling the cylindrical member in a direction perpendicular to the film to peel the film from the test piece body, and applying the force required for peeling. Evaluation was made by the tensile method to be measured. The water repellency was evaluated by placing water droplets on the test piece and measuring the contact angle.

In addition, when there is a liquid on the solid surface in the air, the contact angle is the angle between the tangent drawn to the liquid and the solid surface at the three-phase contact point of the solid, liquid, and gas. A corner is shown, and a larger value indicates better water repellency.
The results are shown in the following table
Coefficient of friction Wear characteristics Film adhesion strength Contact angle
(Μm / h) (kg / mm ² ) (°)
Experimental Example 1 1 0.9 2 100
Experimental Example 2 1 0.7 4 100
Experimental Example 3 1 0.7 4 100
Experimental Example 4 1 0.5 5 100
Experimental Example 5 1 0.5 5 100
Experimental Example 6 1 0.7 2 110
Experimental Example 7 1 0.6 4 110
Experimental Example 8 1 0.6 4 110
Experimental Example 9 1 0.5 5 110
Experimental Example 10 1 0.5 5 110
Comparative Experimental Example 1 3 2.5 -80
Comparative Experimental Example 2 3 1.8-85

  Thus, in each of the test pieces of Experimental Examples 1 to 5 and Experimental Examples 6 to 10 coated with the DLC film, the friction coefficient between the aluminum material is Comparative Experimental Example 1 and Comparative Experimental Example that are not coated with the DLC film. It can be seen that it is smaller than the test piece 2 and has good lubricity (slidability). Moreover, the abrasion characteristic value between diamond materials was also smaller than the test pieces of Comparative Experimental Examples 1 and 2 in which the DLC film was not coated.

  The strength of adhesion of each DLC film of Experimental Examples 1 to 10 to the test piece main body is that of the test pieces of Experimental Examples 2 to 5 in which the surface of the test piece main body was pretreated with plasma prior to the DLC film formation. The test piece of Experimental Example 1 that was not subjected to pretreatment and the test pieces of Experimental Examples 7 to 10 were larger than the test piece of Experimental Example 6 that was not subjected to pretreatment.

  In each of the test pieces of Experimental Examples 1 to 5 and Experimental Examples 6 to 10 coated with the DLC film, the contact angle of water is larger than the test pieces of Comparative Experimental Example 1 and Comparative Experimental Example 2 that are not coated with the DLC film, It can be seen that the water repellency is good.

From the above, it can be seen that the diaphragm of the present invention in which a carbon film (particularly a DLC film) is formed on part or all of the surface of the diaphragm base is excellent in lubricity, wear resistance and water repellency. Since the slidability between the carbon film and other articles in contact with the carbon film is substantially the same as the slidability between the carbon film and the aluminum material, the sporting goods and bicycle parts of the present invention are not formed at the carbon film forming portion. It can be said that the slidability with other articles is excellent.
Furthermore, it can be seen that the carbon film formed after the pretreatment is excellent in adhesion.

  The present invention can be used to provide a diaphragm that can be used in a diaphragm pump for an artificial heart.

It is a figure which shows schematic structure of one example of the film-forming apparatus which can be used for manufacture of the diaphragm which concerns on this invention. It is a figure which shows schematic structure of the other example of the film-forming apparatus which can be used for manufacture of the diaphragm which concerns on this invention. FIG. (A) is a cross-sectional view of an example of a diaphragm according to the present invention, and FIG. (B) is a cross-sectional view showing an example of sports equipment for reference.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1 'Vacuum chamber 11, 11' Exhaust apparatus 2 High frequency electrode 21, 21 'Heater 22, 51 Matching box 23, 52 High frequency power supply 3 Ground electrode 4, 4' Plasma raw material gas supply part 5 Induction coil electrode S1 Film formation Sporting goods substrate S1 'Contact surface S4 with substrate S1 other article Sized film diaphragm substrate S4' Outer surface F of substrate S4 Carbon film

Claims (13)

A diaphragm (excluding automobile diaphragms), wherein a carbon film having abrasion resistance and water repellency is formed on a part or all of the surface. The diaphragm according to claim 1, wherein the carbon film is a DLC film. The film-forming surface of the base of the diaphragm is made of an organic material and is subjected to fluorine termination by being exposed to plasma of at least fluorine (F) -containing gas, and the film-forming surface of the base has the wear resistance, The diaphragm according to claim 1 or 2, wherein a water-repellent carbon film is formed. The film forming surface of the base of the diaphragm is made of an organic material and at least hydrogen-terminated by being exposed to hydrogen gas plasma, and the film forming surface of the base has the wear resistance and water repellency. The diaphragm according to claim 1 or 2, wherein a carbon film is formed. The diaphragm according to claim 3 or 4, wherein the organic material is rubber or resin. The diaphragm according to any one of claims 1 to 5, wherein the carbon film is a carbon film formed by a plasma CVD method. A process for producing a diaphragm (excluding automobile diaphragms), comprising a step of forming a wear-resistant, water-repellent carbon film on part or all of the surface. A base made of an organic material is used as the base of the diaphragm, and the film base of the diaphragm base is exposed to plasma of at least fluorine (F) -containing gas prior to the carbon film forming step. The diaphragm according to claim 7, wherein a pretreatment step is performed, and the carbon film formation step is performed by forming the wear-resistant and water-repellent carbon film on the film formation surface after the pretreatment step. Production method. A pretreatment step of adopting a substrate made of an organic material as a substrate of the diaphragm, and subjecting the film formation surface of the diaphragm substrate to hydrogen plasma at least prior to the carbon film forming step. 8. The method for manufacturing a diaphragm according to claim 7, wherein the carbon film forming step is performed by forming the wear-resistant, water-repellent carbon film on the film forming surface after the pretreatment step. The method for manufacturing a diaphragm according to claim 8 or 9, wherein, in the pretreatment step, after the film forming surface of the diaphragm base is exposed to oxygen gas plasma and cleaned, the termination treatment is performed. The method for manufacturing a diaphragm according to claim 8, 9 or 10, wherein the organic material is rubber or resin. The diaphragm manufacturing method according to claim 7, wherein the carbon film is formed by a plasma CVD method. The diaphragm manufacturing method according to claim 7, wherein the carbon film is a DLC film.