JPH0527455B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a plasma processing apparatus for sheet-like materials,
For details, in a vacuum container in a plasma atmosphere,
This invention relates to a device that performs low-temperature plasma treatment by placing a sheet material along the outer peripheral surface of a rotating drum-shaped discharge electrode.

[Prior Art] In recent years, plasma treatment has attracted attention as a treatment method for improving the chemical, physical, mechanical, optical or electrical properties or surface structure of sheet materials such as plastic films and fabrics. . In other words, plasma treatment can improve the adhesion, friction properties, texture, gloss or color fastness of sheet materials, or improve the antistatic, surface hardening, roughening, anti-blocking, or darkening of dyed materials. It is known that this can be achieved (for example, see Japanese Patent Application Laid-open Nos. 18737-1987 and 149441-1980).

Conventionally, this type of plasma processing apparatus for sheet-like materials has a drum-shaped discharge electrode fixed to a rotating shaft that passes through the vacuum container, and a rod-shaped discharge electrode facing the drum-shaped discharge electrode, which is provided inside the vacuum container. . and,
For example, by insulating the vacuum vessel from the electric circuit to which both discharge electrodes are connected, plasma discharge from both discharge electrodes to the vacuum vessel is prevented,
Prevents power consumption.

[Problems to be Solved by the Invention] However, in the past, since the drum-shaped discharge electrode was directly fixed to the rotating shaft, the rotating shaft was also in a charged state. For this reason, plasma is discharged from the rod-shaped discharge electrode also to the rotating shaft, resulting in wasted power.

In addition, plasma processing equipment for sheet-like materials generally requires large-scale equipment due to the wide range of sheet-like materials to be treated. Processing capacity must be provided. In other words, it is necessary to further increase the input power of the plasma processing apparatus, which originally creates a plasma atmosphere, to increase the plasma density, thereby improving the processing capacity. However, in a vacuum vessel in a plasma atmosphere with low electrical resistance, if the above input is increased, a locally large amount of electricity will be generated between the vacuum vessel and the electrical discharge circuits that are insulated from each other inside the vacuum vessel. Due to this, narrow corners, for example, between the rotating shaft passing through the vacuum vessel and the vacuum vessel adjacent to this rotating shaft, are insufficiently insulated, and current can flow inside the vacuum vessel. , the inner wall of the vacuum vessel emits light, and an instantaneous abnormal arc discharge occurs. Therefore, the plasma discharge state becomes unstable and continuous operation is not possible.

This invention was made in view of the above-mentioned conventional problems, and allows continuous operation with a large amount of power flowing.
Moreover, it is an object of the present invention to provide a plasma processing apparatus for a sheet-like material that prevents wastage of power, that is, can be used industrially.

[Means for Solving the Problems] In order to achieve the above object, the sheet material plasma processing apparatus of the present invention first includes a vacuum container that is
It is insulated from an electric circuit connecting the drum-shaped first discharge electrode and the opposing second discharge electrode. An insulating member is interposed between the cylindrical portion of the drum in the first discharge electrode and the rotating shaft passing through the vacuum container.

[Function] According to the present invention, since the vacuum container is insulated from the electric circuit, it is possible to prevent loss caused by discharge of plasma into the vacuum container. In particular, since the insulating member is interposed between the rotating shaft and the cylindrical part, the entire rotating shaft is insulated from the first discharge electrode.
There is no possibility that plasma discharge will occur from the discharge electrode to the rotating shaft.

Further, the rotating shaft is insulated from the first discharge electrode,
In addition, since the vacuum container is insulated from the electric circuit, there is no risk of insufficient insulation in the part between the vacuum container and the penetration part of the rotating shaft, that is, the narrow corner, where the rotating shaft passes through. There is no risk of abnormal arc discharge occurring.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

In FIG. 1 showing a first embodiment of the present invention, a vacuum vessel 1 includes a drum-shaped drum electrode (first discharge electrode) 2 and a number of rod electrodes (first discharge electrode) facing the drum electrode 2. 2 discharge electrode) 3 and
installed in parallel. Both these discharge electrodes 2, 3
A voltage is applied between them from an AC power source 4 via a transformer 5 and an electric circuit 6 that connects both the discharge electrodes 2 and 3.

The vacuum container 1 is made of stainless steel and is filled with extremely low pressure plasma processing gas by a gas container 7 filled with plasma processing gas and a vacuum exhaust device 8 for evacuating the inside of the vacuum container 1. It is kept in the same condition. On both sides of this vacuum container 1, other vacuum containers 1A and 1B each having an unwinding machine 11 and a winding machine 13 installed therein are flange-jointed. A is a sheet-like material that is guided by a large number of guide rolls 12 from an unwinding machine 11 and wound up by a winding machine 13 along the outer peripheral surface of the drum electrode 2 that is being driven to rotate. In other words,
The sheet-like material A of the unwinder 11 is continuously subjected to low-temperature plasma treatment on the drum electrode 2 in the vacuum container 1 held in a plasma atmosphere, and then wound up by the winder 13 .

In FIG. 2, the drum electrode 2 has a water jacket (cooling passage) 2a through which a cooling medium with low conductivity such as distilled water or silicone oil flows.
is provided in the cylindrical portion 2c of the drum. Both side wall portions 2b of this drum electrode 2 are curved inward into a spherical shape, and are fixed to a rotating shaft 17 at the center via insulating members 14, 15 and a joint 16. The insulating member 14 is a ring having a U-shaped cross section and is made of, for example, a glass lining with excellent weather resistance. On the other hand, the insulating member 15 has an annular shape,
For example, it is made of polycarbonate. A rubber ring 30 is disposed in an annular groove provided in the side wall 2b of the drum electrode 2, and is connected to the drum electrode 2 and the joint 16.
A seal is formed between the insulation member 14 and the insulation member 14 lined with the insulation member 14. Reference numeral 31 denotes a rubber ring, which is disposed in an annular groove provided in the joint 16 and connects the joint 16 and the rotating shaft 17.
There is a seal between the two. Note that the space between the joint 16 and the insulating member 14 is sealed because the insulating member 14 is lined with the joint 16. Therefore, the internal space 2d of the drum electrode 2
is sealed against the internal space 1a of the vacuum container 1.

The rotating shaft 17 is driven by a motor (not shown) provided outside the vacuum container 1, and has bearings 18 and 19 at a penetrating portion 17a penetrating the vacuum container 1 and a left end portion 17b, respectively. Via bearings 18a and 19a,
It is pivotally supported by the vacuum container 1. In other words, the rotation axis 1
7 penetrates the drum electrode 2, and the drum electrode 2
It protrudes from both side wall portions 2b, 2b, and is pivotally supported at the protruding portions on both sides. 18b
is a mechanical seal, which is provided on the bearing portion 18 and seals the internal space 1a of the vacuum container 1 from the atmosphere.

The rotating shaft 17 is provided with two elongated holes 17c that open from its right end 17d into the internal space 2d of the drum electrode 2. In this long hole 17c,
As shown in FIG.
It is inserted with e. A cooling medium flows through the cooling passage 20a inside the copper tube 20,
It communicates in series with the water jacket 2a via a flexible tube 21 shown in FIG.

Reference numeral 32 in FIG. 3 is a gas joint, and the plasma processing gas in the gas container 7 in FIG. It is for supplying to the internal space 2d of the drum electrode 2 shown in the figure. In addition, long hole 1
7c is the third
As shown in the figure, it is sealed from the atmosphere with a rubber ring 33. That is, the internal space 2d of the drum electrode 2 in FIG. 2 is filled with plasma processing gas,
It is maintained at a higher pressure than the internal space 1a of the vacuum container 1.

Both ends 3a of the plurality of rod electrodes 3 are fixed to a pair of support members 22. This support member 2
2 is supported by the vacuum container 1 via an insulator 23.

One end of the electrical circuit 6 is inserted into the vacuum container 1 via an introduction terminal 6a that insulates the vacuum container 1 from the electrical circuit 6, and is connected to the rod electrode 3. The other end is connected to the drum electrode 2 via a slip ring 25, a copper tube 20, a conducting wire 27, and the like. That is, the vacuum container 1 is electrically insulated from the electric circuit 6 and is maintained in a grounded state. Note that the electric circuit 6 and both discharge electrodes 2 and 3 are kept ungrounded and strictly insulated from the vacuum vessel 1.

In the above configuration, in the present invention, since the vacuum vessel 1 is insulated from the electric circuit 6, there is no possibility that plasma will be discharged from the rod electrode 3 to the vacuum vessel 1, so that power consumption can be prevented. In particular, insulating members 14 and 15 are interposed between the cylindrical portion 2c of the drum electrode 2 and the rotating shaft 17 to insulate both 2 and 17. In other words, since the rotating shaft 17 is insulated from the drum electrode 2, there is no possibility that plasma will be discharged from the rod electrode 3 to the rotating shaft 17, so that power consumption can be prevented.

Furthermore, as described above, the rotating shaft 17 is insulated from the cylindrical portion 2c of the drum electrode 2, and the vacuum vessel 1
is insulated from the electric circuit 6, so the rotating shaft 1
7 and the vacuum container 1 are not charged, the portion between the penetrating portion 17a of the rotating shaft 17 and the bearing portion 18 of the vacuum container 1 adjacent thereto, that is, the narrow corner, is insufficiently insulated. There is no risk of it happening. Therefore, since there is no risk of abnormal arc discharge occurring on the inner wall of the vacuum vessel, continuous operation can be achieved. Further, since the rotating shaft 17 protruding from the vacuum container 1 to the outside is maintained in an uncharged state, there is no risk of electric shock to the operator.

Furthermore, as described above, since the rotating shaft 17 is not charged, there is no risk of arc discharge occurring in the mechanical seal 18b, which is exposed to a plasma atmosphere and has a complicated structure. Therefore, it can withstand long-term continuous operation.

Similarly, in the bearing 19a,
Since there is no risk of arc discharge occurring, the bearing 19a can be provided within the vacuum vessel 1 in a plasma atmosphere. Therefore, the heavy drum electrode 2 can be supported by the bearings 18a, 19a on both sides of the rotating shaft 17, so that the diameter of the rotating shaft 17 and the size of the bearings 18a, 19a can be reduced.

By the way, in this embodiment, the inner space 2d of the drum electrode 2 is formed by the rubber rings 30 and 31.
It is sealed from the internal space 1a of the vacuum container 1. Here, the internal space 2d of the drum electrode 2
is maintained at a higher pressure than the internal space 1a of the vacuum container 1 via a gas coupling 32 or the like. Therefore, since the plasma gas in the internal space 1a does not enter the internal space 2d, the internal space 2
Since there is no possibility of causing plasma discharge within d, plasma discharge is stabilized. Furthermore, when the plasma processing gas is introduced from the gas container 7 (see FIG. 1) into the internal space 2d, the plasma processing gas in the vacuum container 1 is There is no risk of deterioration in purity. Note that it is also possible to connect the internal space 2d to the atmosphere through the small hole 17f of the rotating shaft 17 shown in FIG.

By the way, the insulating member 14 shown in FIG. 2, which is exposed to the plasma atmosphere, is a glass lining with excellent weather resistance, so there is no risk of it being subjected to low-temperature plasma treatment or deteriorating due to arc discharge.
Therefore, there is no risk that the insulating member 14 itself will be corroded or that impure gas will be generated within the vacuum container 1. As the insulating member 14, in addition to the glass lining, ceramics, fine ceramics, or heat-resistant, ultraviolet-resistant, or electron beam-resistant plastics may be used alone or in combination.

FIG. 4 shows a second embodiment of the invention.

In this embodiment, the cylindrical portion 2c of the drum electrode 2
is fixed to the rotating shaft 17 via a flat insulating member 40 with a hole in the center. This drum electrode 2 has an insulating member 41 fixed to its side surface 2e with bolts 42 as shown in FIG.
3 is fitted, and the side surface portion 2e becomes the insulating member 4.
It is covered with 1. The internal space 2d of the drum electrode 2 includes an insulating member 40, rubber rings 30, 31
It is completely sealed off from the internal space 1a of the vacuum container 1 and the atmosphere.

In FIG. 4, the rotating shaft 17 has a long hole 17g.
A pipe 17h is inserted into the long hole 17g, and cooling passages 44 and 45 through which a cooling medium flows are provided inside and outside the pipe 17h. 46 is a short pipe (piping material) made of an insulator such as rubber, and is connected to the cooling passages 44, 45.
is communicated with the water jacket 2a.

In this embodiment, a slip ring 25 is provided inside the vacuum container 1, and this slip ring 25 is provided inside the vacuum container 1.
5 is connected to the side surface 2e of the drum electrode 2 via the conducting wire 47.
connected to a part of The rest of the structure is the same as that of the first embodiment, and the same or corresponding parts are given the same reference numerals and detailed explanation thereof will be omitted.

According to this embodiment, the side surface 2 of the drum electrode 2
Since the portion e is covered with the insulating member 41, unnecessary plasma discharge to the side surface portion 2e is prevented. Furthermore, this prevents the temperature from rising in the vicinity of both side surfaces 2e of the drum electrode 2, so that the entire surface of the sheet-like material can be uniformly plasma-treated.

In addition, since the water jacket 2a communicates with the cooling passages 44 and 45 via the short tube 46 made of an insulator, the current flowing from the drum electrode 2 to the rotating shaft 17 through the cooling medium becomes small.
7 from the drum electrode 2 more strictly.

Furthermore, since the drum electrode 2 is assembled in the atmosphere, the internal space 2d of the drum electrode 2 is filled with air and is not in a plasma atmosphere, so local light emission in this internal space 2d is reduced, causing plasma discharge. is stabilized.

Note that the sixth embodiment also applies to the second embodiment shown in FIG.
As shown in the figure, the side surface 2e of the drum electrode 2 can be covered with an insulating member 41.

FIG. 7 shows another plasma processing apparatus for sheet-shaped materials to which the present invention is applied. In this diagram,
9 and 10 are preliminary vacuum chambers, which are provided with a plurality of seal rolls (not shown) and a seal chamber (not shown) in the traveling direction of the sheet material A, and by vacuum suctioning the inside of the seal chamber, The pressure is reduced stepwise from atmospheric pressure to help maintain a predetermined pressure inside the vacuum container 1.

Although not shown, the unwinding machine 11 in FIG.
The present invention is also applicable to a device in which the winder 13 is disposed in the vacuum container 1 together with both electrodes 2 and 3.

[Effects of the Invention] As explained above, according to the present invention, it is possible to prevent waste of power in a plasma processing apparatus for sheet-like materials that consumes a large amount of power, and also to prevent abnormal arc discharge. The processing equipment gains industrial processing capacity and becomes capable of continuous operation.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention, FIG. 2 is a vertical cross-sectional view of FIG. 1, FIG. 3 is a vertical cross-sectional view of the right end clearly showing the rotation axis, and FIG. A vertical cross-sectional view showing the second embodiment, FIG. 5 is a cross-sectional view showing how to attach an insulating member covering the side surface of the drum electrode, and FIG. 6 is a cross-sectional view showing how to attach the insulating member covering the side surface to the drum electrode shown in FIG. FIG. 7 is a schematic diagram of another plasma processing apparatus for sheet-like materials to which the present invention is applied. DESCRIPTION OF SYMBOLS 1... Vacuum vessel, 1a... Inner space, 2... First discharge electrode (drum electrode), 2a... Cooling passage (water jacket), 2b... Side wall portion, 2c... Cylindrical portion, 2d... Internal space, 2e... Side part, 3...
Second discharge electrode (rod electrode), 6... Electric circuit, 7
...Gas supply source (gas container), 14, 15, 40
... Insulating member, 17 ... Rotating shaft, 17a, 17b
...Protruding part (penetrating part, left end part), 41... Insulating member, 44, 45... Cooling passage, 46... Piping material (short pipe), A... Sheet-like material.

Claims (1)

[Scope of Claims] 1. A drum-shaped first discharge electrode that is fixed to and rotates on a rotating shaft that penetrates the vacuum container and has a sheet-shaped material along its outer circumferential surface; A plasma processing apparatus for a sheet-like material in which a second discharge electrode is provided inside a vacuum container, wherein the vacuum container is electrically insulated from an electric circuit connecting both of the discharge electrodes; A plasma processing apparatus for a sheet-like material, wherein an insulating member is interposed between a cylindrical portion of a drum in one discharge electrode and the rotation shaft to insulate the first discharge electrode and the rotation shaft. 2. The first discharge electrode is characterized in that the inner space of the drum is connected to a gas supply source containing a plasma processing gas and maintained at a pressure higher than the pressure in the inner space of the vacuum container. A plasma processing apparatus for sheet-like materials according to claim 1. 3. The plasma processing apparatus for sheet-like materials according to claim 1, wherein the first discharge electrode has an internal space of the drum connected to the atmosphere. 4. The plasma processing apparatus for a sheet-like material according to claim 1, wherein the first discharge electrode has a drum whose internal space is sealed. 5. The first discharge electrode is provided with a cooling passage through which a cooling medium flows, and the cooling passage is communicated with a cooling passage provided inside the rotating shaft via a piping material made of an insulator. A plasma processing apparatus for sheet-like materials according to claim 1, characterized in that: 6. The plasma processing apparatus for a sheet-like material according to claim 1, wherein the first discharge electrode has a side surface covered with an insulating member. 7 The rotating shaft passes through the first discharge electrode and protrudes from both side walls of the first discharge electrode,
2. A plasma processing apparatus for a sheet-like material according to claim 1, wherein the plasma processing apparatus for a sheet-like material is pivotally supported at each of the protrusions on both sides.