JP3212822B2 - Perforated tubular substrate to be treated, method for treating the same, and apparatus for treating perforated tubular substrate to be treated - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for forming an inner surface of a porous tube-shaped substrate by an atmospheric pressure glow plasma process.
The present invention relates to a perforated tubular substrate to be surface-modified, a method for treating the substrate, and a perforated tubular substrate treating apparatus.

[0002]

2. Description of the Related Art Conventionally, low pressure glow discharge plasma treatment under reduced pressure is known as a method for modifying the surface of plastic by coating or the like. Plasma CV under these reduced pressure
D, plasma polymerization method and the like include a method in which a substrate to be processed such as a plastic sheet is placed in a processing container such as a vacuum chamber, and a plasma treatment is performed on the sheet-shaped substrate to be processed in the depressurized processing container. Proposed.

However, in the case of low-pressure glow discharge plasma processing, fluctuations in the degree of vacuum greatly affect the processing results, so that vacuum system management is very important. The larger the processing vessel, the more difficult it is to maintain the vacuum system. In addition, there is a problem that the processing cost is increased because the vacuum condition is maintained.

Further, when the object to be processed is in the form of a tube,
It is difficult to introduce plasma into the inner surface of the tube, and the processing becomes non-uniform.In particular, if the tube is soft, the pressure is reduced to cause deformation such as crushing of the tube. It ’s difficult to do,
In the case of a porous tube composed of a plurality of holes, it was almost impossible to selectively treat each hole, as well as to treat only the inner surface.

Therefore, the present invention applies a recently developed atmospheric pressure glow plasma processing method to a porous tubular material such as a plastic material under atmospheric pressure without forming a vacuum system. An object of the present invention is to provide a manufacturing method in which discharge plasma processing can be performed and the processing cost is advantageous.

[0006]

Means for Solving the Problems [1] The present invention relates to a gas or a processing gas or a glow discharge for stably generating a glow discharge in a hole of a porous tubular substrate to be processed under a pressure near atmospheric pressure. By applying an AC voltage and performing an atmospheric pressure glow plasma treatment in an atmosphere of a mixed gas of a gas and a processing gas for stably generating the gas, or while continuously introducing the mixed gas. Provided is a method for treating a porous tube-shaped substrate to be treated for modifying the surface of pores of the substrate.

[2] The present invention is directed to a tube along the length direction.
Multi-hole tube with multiple holes formed inside the tube
The substrate to be processed has a glow discharge that is stably generated.
Gas, processing gas or glow discharge
In the atmosphere of the mixed gas of the gas to be produced and the processing gas,
Applies AC voltage while continuously introducing the mixed gas.
In addition, by performing atmospheric pressure glow plasma processing,
The present invention provides a porous tube-shaped substrate to be treated in which all or some of the pores are subjected to surface modification. [3] The present invention has an electrode body in which a high voltage side electrode and a ground side electrode made of a conductive material are mounted on a cylindrical insulator , and a porous tube-shaped substrate to be treated disposed in the electrode body. A gas introduction line is connected to the hole, and a branch bar is connected to the gas introduction line.
Provided is a processing apparatus for a porous tube-shaped substrate to which a gas introduction line and / or a processing gas introduction line for stably generating a glow discharge are connected via a lube and / or a mixing tank .

[0008] Here, the plasma treatment in the present invention means various plasma surface treatment methods such as plasma-initiated polymerization, plasma CVD, and plasma graft polymerization.
It can be applied to any of these processes, and is not limited to one.

[0009] The pressure near the atmospheric pressure means that the plasma region is formed in a region where plasma is formed by using a device such as a vacuum pump without reducing the pressure (vacuum) as in low-pressure plasma processing. When the gas is replaced with a mixed gas of a gas for stably generating glow discharge and a processing gas, or when the gas is introduced continuously, the gas is continuously discharged from a gas outlet opened to the atmosphere. In this state, the plasma region is at a pressure near the atmospheric pressure.

According to the present invention, air in a processing vessel (such as a cylindrical electrode tube) for generating the above-mentioned electric discharge is generated by using a gas for stably generating a glow discharge or a gas for generating a glow discharge stably and a processing gas. After replacing with a mixed gas of
After the replacement, a gas for stably generating a glow discharge or a mixed gas of a gas for stably generating a glow discharge and a processing gas is continuously introduced into the processing container while the pressure is reduced to a value close to the atmospheric pressure. This is achieved by applying an AC voltage to form a glow plasma region and modifying the surface of the substrate to be treated.

Here, it is important to apply an AC voltage in the atmospheric pressure glow plasma processing, and the frequency of the AC voltage is determined by a processing method such as plasma CVD, plasma grafting, plasma polymerization, and a processing speed (film formation). Speed, etc.), the type of the plasma-polymerizable monomer to be introduced, the type of the substrate to be treated, etc., are appropriately set, and are not limited to a specific frequency. 13.56 MHz in the processing of the plastic substrate of the invention
(Radio waves) The following frequencies are desirable.

In the above process, the atmospheric pressure glow plasma region may be simply replaced with a mixed gas of a gas for stably generating a glow discharge and a processing gas, but it is more preferable to introduce the mixed gas continuously. The mixing ratio between the gas for stably generating glow discharge and the processing gas is such that the processing gas concentration is 10% by volume or less, preferably 5% to 0.01% with respect to 100 of the gas for stably generating glow discharge. .

Here, the gas for stably generating the glow discharge is, for example, a so-called inert gas alone such as helium, argon, neon, krypton, xenon, or nitrogen, or helium and another inert gas such as helium / argon. Not only a mixed system of but also a mixed gas of argon / ketone, argon / methane and the like can be used. Preferred are helium, argon, argon / helium, and argon / ketone. is not.

The polymer material whose surface of the pores is to be modified as the substrate to be treated may be any material, for example, polyethylene (PE), polypropylene (PP), polyethylene terephthalate, polyurethane, polyamide, polychloride Vinyl, polyvinylidene chloride, polyvinylidene fluoride, polycarbonate, polyacetal, polyester, silicone resin, polytetrafluoroethylene, acrylic resin, polyacrylic acid, polyacrylamide, polymethyl methacrylate, polyvinyl acetate, polyvinyl alcohol, polyacrylonitrile, polystyrene, Polylactic acid, polysulfone, polyethylene oxide, polyetheretherketone, polyethersulfone, ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, d Len - tetrafluoroethylene copolymer, hexafluoropropylene - tetrafluoroethylene copolymer, it can be used ABS resin, etc., not to be limited thereto.

Examples of the processing gas include vinyl polymerizable monomers such as ethylene, propylene, isobutene, vinyl chloride, vinylidene chloride, tetrafluoroethylene, propylene hexafluoride, ethylene trifluoride, vinylidene fluoride, and butyl acetate. Such as saturated hydrocarbons, methane tetrafluoride, monosilane, disilane, ethylene oxide, and ammonia,
Originally, even a compound that is non-polymerizable, by being introduced as a mixed gas with a gas that stably generates glow discharge, as a polymer on the surface of the pores of the substrate to be treated,
Any material can be used as long as it can be introduced as a graft chain, a thin film, or the like, and can modify the surface of the pores of the substrate to be treated, and is not limited to the above.

The polymerizable monomers that are applied to the surface of the pores of the substrate to be treated and then subjected to atmospheric pressure glow plasma treatment include acrylic acid, methacrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, and n- Alkyl (meth) acrylates such as propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate; 2-hydroxyethyl (meth) ) Hydroxyalkyl (meth) acrylates such as acrylate and 2-hydroxypropyl (meth) acrylate, methylaminoethyl (meth) acrylate, ethylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) ) Rate such as alkylaminoalkyl (meth) acrylates, methoxyethyl (meth)
Alkoxyalkyl (meth) acrylates such as acrylate and ethoxyethyl (meth) acrylate;

Acrylamide, methacrylamide, N-
Dialkyl (e.g., alkyl (meth) acrylamide, N-dimethyl (meth) acrylamide, N-diethyl (meth) acrylamide, such as methyl (meth) acrylamide, N-ethyl (meth) acrylamide, i-propyl (meth) acrylamide, etc. Meth) acrylamides,
Acrylonitrile, methacrylonitrile, acryloyl morpholine, acryloyl pyrrolidine, acryloyl piperidine, vinyl pyrrolidone, vinyl proline, vinyl silane, vinyl pyridine, vinyl pyridine, vinyl polymerizable monomers can be used, and those limited to those described above. is not.

According to the atmospheric pressure glow discharge plasma treatment of the present invention, for example, a hydrophilic monomer is used as the polymerizable monomer to be applied to the surface of the processing gas or the hole of the substrate to be processed. By using, the hydrogel layer can be easily formed while the surface of the pores of the substrate to be treated is made hydrophilic.

As an example, the surface of the pores of a polyethylene tube can be made hydrophilic . Further, it is known that the surface of the hydrogel has little adhesion of thrombus and blood cell components, and is known to exhibit antithrombotic properties, so that a material having excellent antithrombotic properties can be produced.

Furthermore, the process gas, the use of the tetrafluoroethylene gas, that to form a pseudo-film surface polytetrafluoroethylene pores of the treated substrate (PTFE), hydrophobizing the surface of the hole Can be. PTFE
Is a useful plastic material having an inert surface and excellent lubricity and chemical resistance, but its physical properties are insufficient in flexibility and its use range is limited.

Here, by using a soft PVC, a soft polyurethane or the like as the substrate to be treated , the pores of the soft PVC or the like are formed.
A PTFE thin film can be formed on the surface of the substrate, and it is possible to improve lubricity and chemical resistance only on the surface of the holes while maintaining the physical properties (flexibility) of the bulk of the substrate to be treated. it can.

Further, PTFE is known to be less adsorbed by blood components such as platelets and to be excellent in antithrombotic properties. At the same time, PTFE can be imparted with antithrombotic properties.
It is possible to manufacture a medical material having a bulk property of soft PVC and a pore surface of PTFE property.

The atmospheric pressure glow plasma processing of the present invention can be performed, for example, using a processing apparatus 1A having an electrode body 1 and a gas introduction line 6 as shown in FIG. The electrode main body 1 is attached to the cylindrical insulator made of a conductive material by alternately spiraling a high-voltage electrode 2 and a ground electrode 3 made of a conductive material on a cylindrical insulator made of plastic, ceramics, etc. (May be attached or buried in an insulator). The electrode body 1 is shown in FIG.
As shown in the figure, the high voltage side electrode 2 and the ground side electrode 3 are arranged in a double helix along the inside. At this time, the width of each electrode 2, 3 is preferably three times or less the diameter of the cylindrical electrode body 1, and the distance between the electrodes is preferably 10% to 200% of the width of the electrode plate.

Upstream of the gas introduction line 6, a gas introduction line 6a for stably generating a glow discharge such as helium and a processing gas introduction line 6b are connected via a mixing tank 6A for uniformly mixing the respective gases. A mixed gas of a gas such as helium for stably generating a glow discharge and a processing gas is distributed to gas introduction lines 6c and 6d by a gas branch valve 6B connected downstream of the gas introduction line 6 and introduced into the holes. Is done. Mass flow control valves 5a and 5b are provided in the middle of the gas introduction lines 6a and 6b to introduce and mix the processing gas introduced into the hole of the substrate 4 to be treated and a gas such as helium for stably generating a glow discharge. The ratio and the like can be adjusted.

The gas introduction lines 6c and 6d are provided downstream of the gas branch valve 8 corresponding to the number of holes in the substrate to be processed. For example, if the substrate has two holes, the gas branch valve 6
B, three if the substrate to be treated has three holes, three are provided and connected to the substrate to be treated 4 (in this case, a gas introduction line (for example, depending on the treatment purpose in the hole of the substrate to be treated) 6c, 6d)
Can be set freely.) Also,
By the gas branch valve 6B, for example, a gas (or a mixed gas with a processing gas) such as helium that stably generates a glow discharge is introduced into only one of the two holes, and the mixed gas or the like is introduced into the other hole. By blocking the gas flow path so as not to flow in, the hole portion can be selectively subjected to the atmospheric pressure glow plasma treatment, and the inner surface treatment can be performed.

For example, inside the electrode body 1, a substrate 4 to be processed having one end open to the atmosphere and the other end connected to a gas introduction line 6.
(For example, a tube having a two-hole structure), the mass flow control valves 5a and 5b provided in the gas introduction lines 6a and 6b are opened to cover the mixed gas of the gas A and the processing gas B for generating the glow discharge stably. The glow plasma region is continuously introduced into the processing base material 4 and an AC voltage is applied under a pressure close to the atmospheric pressure to form a glow plasma region and perform the processing.

At this time, the atmospheric pressure glow plasma can be excited only in the holes in the substrate 4 where the mixed gas exists in the electrode body 1. On the inner surface of the inner hole, the outer surface maintains the properties of the substrate. Further, at this time, by using different processing gases to be introduced into both holes of the substrate to be processed 4 having a two-hole structure, for example, it is possible to simultaneously perform different processes such as hydrophobizing one and hydrophilizing one. Is possible. In the case of a substrate to be treated having three or more holes, the substrate can be selectively treated similarly to the substrate to be treated 4 having two holes.

Further, the electrode main body in which the arrangement of the electrodes on the high voltage side and the ground side is double-helical is used as the electrode main body.
In addition to (FIG. 2), electrode bodies 12 and 13 having a structure in which electrodes are arranged as shown in FIGS. 3 and 4 to be described later can also be used. In these, the atmospheric pressure glow plasma treatment can be performed. It is not limited to the electrode shape.

FIG. 3 is a schematic diagram of another processing apparatus 12A. The ring-shaped high-voltage electrode 2 and the ground-side electrode 3 are arranged inside the cylindrical electrode body 12. At this time, the distance between the electrodes 2 and 3 is the same as that of the high pressure side electrode 2 formed in a ring shape.
And 10% to 200% of the width of the ground electrode 3 is preferable.
Further, in the case of a long object, it can be arranged and processed alternately in multiple stages as shown in FIG. Similarly to the processing apparatus 1A, the processing apparatus 12A can connect the gas introduction line 6 to the hole of the substrate 4 to be processed.

FIG. 4 is a schematic diagram of another processing apparatus 13A. The high voltage side electrode 2 and the ground side electrode 3 are arranged facing the inner side of the cylindrical electrode body 13. At this time, the distance between each of the electrodes 2 and 3 is preferably 10% to 200% of the width of the high-voltage side electrode 2 and the ground-side electrode 3, and the width of each electrode 2 and 3 depends on the inner diameter of the cylindrical electrode body 13. Set with. The processing apparatus 13A can also connect the gas introduction line 6 to the holes of the substrate 4 to be treated, as in the processing apparatus 1A. However, as shown in FIG. (6f), two gas introduction lines 6
By connecting the mixing tank 6A to which a and 6b are connected, a mixed gas can be introduced into each hole, and an atmospheric pressure glow plasma treatment can be performed.

FIG. 5 is a schematic view of another electrode body 14, in which a lubricant 8a is coated (applied) on the inner surface and a conductive wire mesh (mesh) 8 is interposed on the outer periphery to ground the high voltage side electrode 2 and ground. By arranging the side electrodes 3 alternately, the uniformity of the treatment can be improved.
Atmospheric pressure glow discharge plasma processing can be performed more stably in a gas atmosphere such as nitrogen gas. Electrode body 1
4 also has gas introduction lines 6, 6c, 6 in the holes of the substrate 4 to be treated in the same manner as the electrode bodies 1, 13 of the processing apparatuses 1A, 13A.
d, 6e and 6f can be connected.

FIG. 6 is a schematic view of another processing apparatus 15A. The electrode body 15 is constituted by inserting an insulating tube 9 made of a glass tube or the like into an insulating housing 16 made of, for example, glass. The high voltage side electrode 2 and the ground side electrode 3 are arranged in a double spiral around the outer periphery of the insulating tube 9, and the inner surface is coated with a lubricant 8 a made of, for example, Teflon or the like. The space formed between the insulating tube 9 and the insulating housing 16 is filled with insulating oil 17 such as silicone oil, for example, and cooled or heated while circulating through the circulation pipe 18 and the heat exchanger 10. By doing so, it is possible to set and manage the processing temperature. Processing unit 15
A can also connect the gas introduction lines 6, 6c, 6d, 6e, 6f to the holes of the substrate 4 to be processed, similarly to the processing apparatuses 1A, 13A.

In the electrode body 15, the arrangement of the electrodes 2 and 3 is not limited to that shown in FIG. 6, and the arrangement shown in FIGS. be able to.

[0034]

EXAMPLES [Experimental Example 1] A soft polyvinyl chloride porous tube having an outer diameter of 12.0 mm having two holes with an inner diameter of 5.0 mm was washed, dried and set as a sample in the electrode body 1 of FIG. A mixed gas of (1) helium / methane tetrafluoride (CF ₄ ), (2) helium / ammonia (NH ₃ ), (3) argon / propylene hexafluoride (HFP) is continuously introduced into both holes. Then, an AC voltage of 20 kHz was applied under a pressure near the atmospheric pressure for 10 minutes to perform an atmospheric pressure glow plasma treatment. (4) After applying and drying vinylpyrrolidone (VPy), helium gas was continuously introduced into the holes, and an AC voltage of 20 kHz was applied under a pressure near the atmospheric pressure for 10 minutes to perform an atmospheric pressure glow plasma treatment. . Then, the contact angle with respect to water was measured for each sample.

[Results of Experimental Example 1] Table 2 shows the measurement results of the contact angles. For untreated PVC,
CF ₄ / He and HFP / Ar show an increase in the contact angle, and NH ₃ / He and VPy / He show a decrease in the contact angle. Hydrophobization was confirmed. Table 1, Change in contact angle after atmospheric pressure glow discharge plasma treatment

[Experimental Example 2] A porous polyethylene porous tube having an outer diameter of 10.0 mm having two holes with an inner diameter of 4.0 mm was washed and dried to obtain a sample, which was set on the electrode body 1 of FIG. A mixed gas of propylene / hexafluoride (HFP) is continuously introduced into both holes, and an AC voltage of 20 kHz is applied at a pressure near the atmospheric pressure for 10 minutes to perform an atmospheric pressure glow plasma treatment. The processing was confirmed by surface analysis by the ATR-IR method. [Results of Experimental Example 2] ATR-IR measurement results are shown in FIG. The surface subjected to the atmospheric pressure glow plasma treatment is 1300 to 1100 cm ^-1.
A new absorption which appears to be due to a C—F bond appeared, and the formation of a thin film of HFP on the inner surface of the polyethylene porous tube was confirmed.

Experimental Example 3 A polyurethane porous tube having an outer diameter of 10.0 mm having two holes with an inner diameter of 4.0 mm was washed and dried to obtain a sample.
Helium / propylene hexafluoride (HFP) mixed gas is continuously introduced into one of the holes in the porous tube, and an AC voltage of 10 kHz under a pressure near the atmospheric pressure is applied for 10 minutes. Atmospheric pressure glow plasma treatment was performed by applying the voltage. At this time, no gas is introduced into the other one of the holes, and only one of the holes is selected. The processing was confirmed by surface analysis by the ATR-IR method.

[Results of Experimental Example 3] ATR-IR measurement results are shown in FIG. Is the spectrum of the untreated pore, and is the spectrum of the pore subjected to the atmospheric pressure glow plasma treatment. Shows the spectrum of polyurethane, while HFP
1300 which is an absorption region of CF bond by forming a thin film
Since the absorption around ~ 1100 cm ^-1 is increasing,
The pore-selective inner surface treatment of the inner surface of the polyurethane porous tube of the HFP thin film was confirmed.

[0039]

As described above, according to the present invention, in a gas atmosphere in which a glow discharge is stably generated without maintaining a high vacuum in a plasma region and a container, a pressure near an atmospheric pressure is applied. An AC voltage is applied to form a glow plasma region, and processes such as plasma-initiated polymerization, plasma CVD, and plasma graft polymerization can be performed.

The present invention requires no equipment and equipment for forming a vacuum system and is advantageous in cost as compared with the conventional low-temperature glow plasma method, and limits the material, shape and properties of the substrate to be treated. Without this, it is possible to selectively perform surface treatment of the pores such as grafting and thin film formation.

[Brief description of the drawings]

FIG. 1 shows an example of a processing apparatus according to the present invention.

FIG. 2 is an enlarged view of the double helix electrode of FIG. 1;

FIG. 3 shows another example of the shape of the processing apparatus.

FIG. 4 shows another example of the shape of the processing apparatus.

FIG. 5 shows another example of the shape of the processing apparatus.

FIG. 6 shows an example of a processing apparatus.

FIG. 7 shows ATR-IR measurement results of an atmospheric pressure glow plasma processing tube obtained in Experimental Example 2.

FIG. 8 shows ATR-IR measurement results of an atmospheric pressure glow plasma processing tube obtained in Experimental Example 3.

[Explanation of symbols]

1A, 12A, 13A, 15A Processing apparatus 1, 11, 12, 13, 14, 15 Electrode main body 2 High voltage side electrode 3 Ground side electrode 4 Substrate to be processed (plastic tube) 5a, 5b Mass flow control valve 6a, 6b, 6c , 6d, 6e, 6f Gas introduction line 6A Mixing tank 6B Branch valve 7 High frequency power supply 8 Wire mesh (mesh) 8a Lubricant 9 Insulation tube 10 Heat exchanger 16 Insulating housing 17 Insulating oil (silicone oil) 18 Circulation pipe Untreated pores of the tube Propylene hexafluoride / helium treated pores of the polyurethane porous tube

Claims (3)

(57) [Claims] 1. A gas for generating a glow discharge stably or a processing gas, or a mixture of a gas for generating a glow discharge stably and a processing gas, at a pressure near the atmospheric pressure in the pores of a porous tube-shaped substrate to be processed. By applying an AC voltage and performing an atmospheric pressure glow plasma treatment in a gas atmosphere or while continuously introducing the mixed gas, the surface of the pore surface of the porous tubular substrate to be treated is surface-modified. A method for treating a porous tubular substrate to be treated, characterized by the following. 2. The inside of the tube along the length of the tube.
Multi-hole porous substrate with multiple holes formed
Gas or process for stably generating glow discharge.
Gas and gas that stably generate glow discharge
In an atmosphere of a gas mixture with a natural gas, or
While introducing continuously, an AC voltage is applied and the atmospheric pressure
-A porous tube-shaped substrate to be treated , wherein the surface of the holes is modified to all or some of the holes by performing a plasma treatment . 3. An electrode body in which a high-voltage side electrode and a ground side electrode made of a conductive material are mounted on a cylindrical insulator , and a hole of a porous tubular substrate to be processed disposed in the electrode body is provided. Connect the gas introduction line and branch valve to the gas introduction line
And / or a gas introduction line for stably generating glow discharge and / or a treatment gas introduction line connected via a mixing tank .