JP2000063546A - Surface-treating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface-treating apparatus using an atmospheric low- temperature plasma discharge, capable of preventing air from flowing in the plasma discharge region, capable of retaining a sufficiently low air concentration in the treating chamber and having a high discharge efficiency and surface effect in an atmospheric gas. SOLUTION: When processes comprising (1) bringing in a substrate between a pair of electrodes facing each other, (2) making the substrate pass through the space between the electrodes discharging plasma in an atmospheric gas to treat the surface of the substrate and (3) carrying out the treated substrate are conducted in a surface-treating apparatus, the surface-treating apparatus has a substrate-bringing closed chamber 22C having an inlet port 22 for a passage and a substrate-discharging closed chamber 27C having an egress part 27 of a passage, where the height difference between the inlet port 22 (or the egress part 27) and the electrode part 23 exists and the height of the inlet port 22 (or the egress part 27) is lower than that of the electrode part 23.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an atmospheric pressure plasma discharge suitable for a flat substrate such as a sheet, a film, a foil, a band or a plate. The present invention relates to a surface treatment device. 2. Description of the Related Art As a method of modifying the surface of a flat object such as a sheet, a film, a foil, a band, and a plate, a wet process such as a coating process, an immersion process in an acid alkali or the like is used. A treatment method, a corona discharge treatment, a flame treatment, a light reforming treatment method using ultraviolet rays or the like, or a dry treatment method such as a low-temperature plasma treatment has been proposed. Among such processing methods, the low-temperature plasma processing method has no influence on the material due to heat, can perform non-contact, high-speed, and uniform processing, and does not require treatment such as cleaning or drying after the processing. , Widely used. Note that the low-temperature plasma treatment here refers to a method for performing surface modification by bringing the surface of an object to be processed into contact with a treatment atmosphere in a low-temperature plasma state. The low-temperature plasma state is defined as a state in which a large number of freely movable positive ions and negative ions (including electrons) exist macroscopically while maintaining electrical neutrality. Among the species that make up the plasma, refers to the plasma state in which the average energy of the electrons is greater than the average energy of the ions and neutral species. " ing. [0004] However, since low-temperature plasma is generated only in a vacuum, there is a problem that the apparatus becomes large and the process becomes complicated. Further, there is also a problem that it is difficult to continuously process a sheet-like material or the like because the process is performed in a vacuum device. [0005] In order to solve such a problem, a processing method called an atmospheric pressure plasma discharge processing method has been proposed. In this atmospheric pressure plasma discharge treatment method, the space between opposed electrodes having a dielectric material is filled with helium gas or a mixed gas containing helium gas as a main component, and a high voltage is applied between the electrodes. The surface of the object to be treated is treated in the atmospheric pressure low-temperature plasma discharge region generated by the above. This atmospheric pressure low temperature plasma treatment is performed as described in JP-A-3-143930.
There has been proposed a method of continuously discharging a sheet-like workpiece. FIG. 1 is a schematic cross-sectional view showing an example of a conventional surface treatment apparatus using atmospheric pressure plasma discharge. In this figure, a processing chamber 1 is formed of a hollow solid, and the processing chamber 1 is provided with a base material passage entrance 2 and a passage exit 7. Inside the processing chamber 1, a pair of electrodes 3 and 3 ′ provided with a dielectric are provided so as to face the substrate 8. A high voltage can be applied from a high voltage power supply 4 between these electrodes 3 and 3 '. The processing chamber 1 is provided with a gas supply port 5 and a gas exhaust port 6. Helium gas or a mixed gas containing helium gas as a main component can be supplied to the gas supply port 5. Helium gas or a mixed gas containing helium gas as a main component inside the processing chamber 1 can be exhausted from the gas exhaust port 6. The base material 8 passes between the electrodes 3 and 3 ′ through the passage entrance 2, and the treated substrate 9 passes through the passage exit 7 and is wound up. In this surface treatment apparatus, helium gas or a mixed gas containing helium gas as a main component is supplied to the processing chamber 1 through a gas supply port 5, and helium gas or helium gas inside the processing chamber 1 is mainly used. The mixed gas as a component is exhausted from the gas exhaust port 6. However, as described in Japanese Patent Application Laid-Open No. 3-143930, a conventional atmospheric pressure plasma continuous treatment apparatus has a plasma discharge region and a passage entrance and a passage exit of a substrate to be treated. Since both are provided on the same plane, helium gas or a mixed gas containing helium gas as a main component in the processing chamber does not stay in the processing chamber but leaks out of the processing chamber from the entrance of the passage and the exit of the passage. The air that flows into the plasma discharge region along with the substrate that travels in a localized manner increases the air concentration in the processing chamber, lowers the discharge efficiency, and fails to provide a sufficient processing effect. In order to sufficiently lower the air concentration in the processing chamber, there is a problem that helium gas or a mixed gas containing helium gas as a main component must be supplied to the processing chamber more than necessary. SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and has been developed in a surface treatment apparatus using an atmospheric pressure low-temperature plasma discharge. The air concentration in the room is prevented from increasing, the air concentration in the processing chamber can be kept sufficiently low, and the discharge efficiency is high and the surface treatment effect is high in a helium gas or a mixed gas atmosphere containing helium gas as a main component. It is an object of the present invention to provide a surface treatment apparatus using atmospheric pressure low-temperature plasma discharge. The above objects can be attained by the present invention. That is, the invention according to claim 1 includes a step of carrying in a base material so that the base material can pass between a pair of opposedly provided electrodes, and applying a high voltage to the base material in an atmosphere gas. In a surface treatment apparatus having a step of performing a surface treatment by passing between the electrodes having generated plasma discharge and a step of carrying out the substrate to be treated, a hermetically sealed substrate provided with a passage entrance portion. A sealing chamber provided with a carry-in chamber and a passageway exit portion, wherein a height difference is provided between the passageway entrance portion and the passageway exit portion and the electrode portion; And a passage outlet portion provided at a position lower than the electrode portion. In the present invention, helium gas has a lower specific gravity than air, and utilizes the property that helium gas is unevenly distributed above air when a mixed gas of helium gas and air is contained in a closed container. A height difference is provided between the passage portion entrance and the passage exit of each of the substrate and the substrate to be processed and the electrode portion in the plasma discharge region, and the passage entrance and the passage of the substrate and the substrate to be treated, respectively. By providing each of the passage outlets at a position lower than the electrode portion in the plasma discharge region, helium gas or a mixed gas containing helium gas as a main component in the treatment chamber is retained in the treatment chamber, and the passage entrance and the passage exit are provided. From the processing chamber. Therefore, the helium gas or the mixed gas containing helium gas as a main component in the processing chamber is kept in the processing chamber by the above-mentioned surface processing apparatus, and is prevented from leaking out of the processing chamber from the passage passage entrance and the passage passage outlet. Alternatively, even if the mixed gas containing helium gas as a main component is not supplied more than necessary, the air concentration in the processing chamber can be sufficiently reduced, the discharge efficiency of the processing chamber itself can be increased, and an object to be processed having a large processing effect can be obtained. An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 2 (a) and FIG.
(B) is the perspective view and transverse cross section of the surface treatment apparatus of this invention, respectively. The surface treatment apparatus of the present invention will be described with reference to FIG. A pair of electrodes 23 and 23 ′ provided in the processing chamber 21 so as to face each other in the processing chamber 21, a power supply 24 for applying a voltage to the electrodes, and a pair of electrodes 23 and 23 ′ provided on the passage 22 side of the substrate 28 of the processing chamber Base material loading chamber 22c and a nip roll portion 22 provided at a passage entrance 22 of the substrate loading room.
a, 22a ', a roll 22b provided above the base material loading chamber (near the processing chamber entrance), and a base material discharge chamber provided on the passage 27 side of the processing target material 29 in the processing chamber 21. 27c
A nip roll portion 27a, 27a 'provided at a passage outlet 27 of the base material unloading chamber; a roll 27b provided above the base material unloading chamber 27c (near the processing chamber outlet);
Gas supply port 25, a gas exhaust port 26, and a gas supply device A connected to the supply port 25 for supplying a mixed gas.
And an exhaust gas treatment device B connected to the exhaust port 26 for exhausting gas in the processing chamber. The processing chamber 21 is formed of a hollow three-dimensional body. The processing chamber 21 is provided with electrodes 23 and 23 ′ provided with a dielectric so as to face a passage of a substrate 28 to be processed. I have. A high-voltage power supply 2 is provided between these electrodes 23 and 23 '.
4, a high voltage can be applied. The processing chamber 21 is provided with a loading chamber 22c and a loading chamber 27c having a hollow three-dimensional structure having a passage entrance 22 for the base material and a passage exit 27 for the substrate to be treated. And nip roll portions 22a, 22a 'and 27a, 2a, 2
7a 'and rolls 22b and 27b provided near the entrance of the processing chamber and near the exit of the processing chamber above the loading chamber 22c and the unloading chamber 27c. The nip rolls 22a, 22a 'and 27a, 27a' improve the hermeticity of helium gas or a mixed gas containing helium gas as a main component in the processing chamber 21 and sufficiently increase the air concentration in the processing chamber 21. It is provided in order to lower. The processing chamber 21 has a gas supply port 25,
A gas outlet 26 is provided. This gas supply port 25
, A helium gas or a mixed gas containing helium gas as a main component can be supplied. Helium gas or mixed gas in the processing chamber 21 can be exhausted from the gas exhaust port 26. Then, the base material 28 is provided at the nip roll portion 22 provided at the base material passageway entrance of the loading chamber 22c.
a, 22 a ′, and are transported into the processing chamber 21 through the roll 22 b provided above the base material passageway entrance, where the electrodes 23, 23
, And passes through a roll 27c provided above the outlet of the substrate passage in the discharge chamber 27c, and nip roll portions 27a and 27a 'provided at the outlet of the substrate passage. . Here, it is necessary that at least one of the electrodes 23 and 23 'is covered with a dielectric. This is for preventing the discharge from being concentrated and realizing the glow discharge. The substrate 28 passing through the passage 2 is drawn out of the feeder Ra and wound up by the feeder Rb. These feeder parts Ra, R
b is rotatably driven by a driving mechanism (not shown).
'. The gas supply port 25 is a port through which helium gas or a mixed gas containing helium gas as a main component supplied from the gas supply device A flows into the processing chamber 21. A is connected. The gas supply device A includes a gas mixer, a gas cylinder with a regulator, and the like. The gas exhaust port 26 is a port for discharging the gas supplied into the processing chamber 21, and the gas exhaust port 26 is connected to the exhaust gas processing apparatus B via a pipe. The high-voltage power supply 24 is a power supply for applying a high voltage to the electrodes to cause a discharge, and may use either AC or DC. In the alternating current, any frequency band of low frequency, high frequency, and microwave can be used. The substrate 28 is subjected to an atmospheric pressure plasma discharge treatment while passing between the electrodes 23, 23 from the state of being wound on the feeder portion Ra, and is wound. The thickness of the substrate 28 is not particularly limited as long as it can pass through the gap between the electrodes 23 and 23 ′ in a flat state. Next, the surface treatment apparatus of the present invention will be described more specifically with reference to examples. However, it is not limited to the following embodiment. <Example 1> 400 m width using the surface treatment apparatus of the present invention
m, 25 μm thick biaxially stretched polyester film
It was passed at a speed of 0 m / min to perform surface treatment. In the surface treatment apparatus of the present invention, the width of the discharge portion of the electrode 3 is 600
mm, length 400mm, width of processing chamber 1 is 700mm
Met. The interval between the electrodes 3 was 5 mm. The frequency of the voltage of the power supply 4 was 5 kHz, the voltage was 6 kV, and the output was 2 kW. The gas composition was 100% helium gas, and the supply and discharge rates of the gas filling the inside of the processing chamber 1 were 20 liter / min. <Example 2> The same processing as in Example 1 was performed except that the supply amount and discharge amount of the gas for filling the inside of the processing chamber 1 were set to 40 L / min. Comparative Example 1 A biaxially stretched polyester film having a width of 520 mm and a thickness of 25 μm was passed through a conventional surface treatment apparatus at a speed of 20 m / min to perform a surface treatment. In the conventional surface treatment apparatus, the width of the discharge part of the electrode 103 was 600 mm, the length was 400 mm, and the width of the treatment chamber 101 was 700 mm. The interval between the electrodes 103 was 5 mm. The frequency of the voltage of the power supply 104 is 5 kHz, and the voltage is 6
kV and output were 2 kW. Gas composition is helium gas 1
The gas supply amount and the discharge amount for filling the inside of the processing chamber 101 were set to 20 L / min. <Comparative Example 2> The supply amount and discharge amount of gas for filling the inside of the processing chamber 101 were 40 liter / min.
Other than the above, the same processing as in Example 1 was performed. <Comparative Example 3> The supply amount and discharge amount of gas for filling the inside of the processing chamber 101 were 60 liter / min.
Other than the above, the same processing as in Example 1 was performed. Table 1 shows the results obtained by measuring the water contact angles of the surfaces of the thus-treated Examples 1 and 2 and Comparative Examples 1 to 3 in total of five types of the objects to be treated in accordance with the following test methods. The contact angle was measured by using a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd., CA-Z type). The unit is angle. [Table 1] From the results of Examples 1 and 2 and Comparative Examples 1 to 3,
Hydrophilic treatment is performed by filling with helium gas,
As the supply amount and the discharge amount of the helium gas filling the processing chamber were larger, the air concentration in the processing chamber was lower, so that the discharge efficiency was higher and the processing effect was larger. Example 1 and Comparative Example 1, Example 2 and Comparative Example 2
Although the supply amount and the discharge amount of the helium gas are the same in Examples 1 and 2, however, in both Examples 1 and 2, since both the entrance of the passage and the exit of the passage of the object are located lower than the plasma discharge region, Helium gas or a mixed gas containing helium gas as a main component in the chamber is kept in the processing chamber to prevent the gas from leaking out of the processing chamber from the passage entrance and the passage exit, and the air concentration in the processing chamber is sufficiently lower. As a result, the discharge efficiency was increased, and the treatment effect became larger. Since the same processing effects are obtained in Example 1 and Comparative Example 3, it can be said that Comparative Example 3 wastes helium gas more than necessary. From the above, the helium gas in the processing chamber is kept in the processing chamber by the surface processing apparatus of the present invention.
Surface treatment that prevents leakage from the passageway entrance and passageway exit to the outside of the processing chamber, keeps the concentration of air in the processing chamber low enough without supplying helium gas more than necessary, increases discharge efficiency, and increases surface treatment efficiency. Equipment can be provided. Thereby, an object to be treated having a large surface treatment effect can be obtained. According to the surface treatment apparatus of the present invention, in order to prevent air from flowing into the processing chamber, helium gas or a mixed gas containing helium gas as a main component is allowed to remain in the processing chamber and pass therethrough. It prevents leakage from the inlet and the passageway outlet to the outside of the processing chamber, and can maintain a sufficiently low air concentration in the processing chamber without supplying helium gas or a mixed gas mainly composed of helium gas more than necessary. An object to be processed having a large processing effect can be obtained with increased efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a conventional surface treatment apparatus using atmospheric pressure plasma discharge. FIG. 2A is a perspective view of a surface treatment apparatus using an atmospheric pressure plasma discharge of the present invention. (B) is a cross-sectional view of the surface treatment apparatus using atmospheric pressure plasma discharge of the present invention. [Description of Signs] 1, 21 processing chamber 2, 22 base material passage entrance 3, 23 electrode 3 ', 23' electrode 4, 24 high-voltage power supply 5, 25 gas supply port 6, 26 gas discharge port 7, 27 Substrate passage exit 8, 28 Substrate 9, 29 Substrate to be processed 22a, 22a 'Nip roll 22b Nip roll 22c Inlet side substrate loading chamber 27a, 27a' Nip roll 27c Outlet side substrate to be transported A Gas supply device B Exhaust gas treatment equipment Ra, Rb Feeder roll

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Claims (1)

Claims: 1. A step of loading a base material so that the base material can pass between a pair of opposed electrodes, and applying a high voltage to the base material in an atmosphere gas. A surface treatment apparatus having a step of performing a surface treatment by passing between the electrodes having generated the plasma discharge and a step of carrying out the substrate to be treated. An airtight chamber provided with a material loading chamber and a passageway outlet, a height difference between the passageway entrance, the passageway exit, and the electrode, The surface treatment apparatus, wherein the section and the passage exit section are provided at a position lower than the electrode section.