JPS6121105A - Continuous low-temperature plasma polymerization apparatus - Google Patents

Abstract

PURPOSE:To deposit a homogeneous polymer thin film continuously to the surface of an article of continuous length such as fiber, tube, tape, etc., by attaching an earth electrode, a high-frequency output electrode and another earth electrode in the order to the surface of a cylindrical reaction tube, and generating plasma discharge between the electrodes. CONSTITUTION:A continuous article 5 to be treated is passed continuously through a cylindrical reaction tube 3 which can be evacuated. A raw material gas is supplied to the reaction tube 3 from the inlet 7, and glow discharge is generated by the capacity coupling to effect the deposition of a polymer thin film to the surface of the continuous article 5 by the plasma of the raw material gas. In the above process, a high-frequency output electrode 1 and a pair of earth electrodes 2b placed at both sides of the output electrode are attached to the outer surface of the above cylindrical reaction tube 3. The earth electrode is preferably composed of a movable electrode 15 having the form of ring or arc. EFFECT:Stable electrical discharge can be generated along the radial and longitudinal directions of the reaction tube 3.

Description

Detailed Description of the Invention (Objective of the Invention) (Industrial Application Field) The present invention utilizes plasma generated by glow discharge to
The present invention relates to an apparatus for continuously depositing polymeric thin films on the surface of elongated objects such as rods, hollow systems, tubes, and tapes.

(Prior Art) Recently, there has been active development of technology for depositing polymeric thin films on various substrates using glow discharge plasma, but there is still little application to long objects. For example, JP-A No. 58-12
No. 0859 discloses a continuous low-temperature plasma polymerization apparatus for fabric, which is an example in which a plasma treatment chamber and a polymerization chamber are arranged separately, and graft polymerization is performed after the basic surface is activated with plasma. be. Also, literature A CS I nd
, Eng, Chem.

Prod, Res, Dev, Item 153, No. 1, Volume 23 (1984) attempts to continuously perform plasma polymerization of a nitrogen-containing compound in a polysulfone hollow system and utilize it in a reverse osmosis membrane. In this example, magnetic force is used to limit the discharge area between the electrodes, but since the electrodes are inside the reaction tube, changes in current and voltage values over time due to polymer deposition on the electrode surface have not been reported. ing.

(Problems to be Solved by the Invention) In order to continuously deposit a homogeneous plasma-polymerized thin film on the surface of a long object, it is necessary to solve several fundamental problems. One is that the discharge voltage and discharge current are stable during long-term polymerization operations.

The second reason is that the discharge area is limited to the required space, and that the plasma state is almost uniform within the reaction tube. Since the polymer is formed by activating the raw material gas mainly consisting of Since the reaction is a complex reaction that involves not only polymerization but also some degree of depolymerization, limiting the discharge region, which is the substantial reaction region, is an important factor in determining film quality.Furthermore,
In a plasma reaction, a surface reaction due to adsorption or collision of the raw material gas and its excited species on the surface of a long workpiece and a reaction in the gas phase proceed simultaneously, so the relationship between the raw material gas supply port and the discharge position, or the discharge Due to the polymeric membrane quality for spacing,
There was a problem in that it had to be changed each time.

(Structure of the Invention) (Means for Solving the Problems) The present invention provides an apparatus for continuously depositing a plasma-polymerized thin film on the surface of a long object, using a cylindrical reaction tube and providing an electrode on the outside thereof. Regarding the generation of glow discharge due to capacitive coupling, the electrode structure is such that ground electrodes are placed on both sides of the high-frequency output electrode.

Further, the electrodes have an annular or arcuate shape that covers almost the entire circumference of the reaction tube, and all electrodes have a movable structure so that they can be placed at appropriate positions in the reaction tube.

(Function) By adopting a high frequency power source and using an external electrode method,
This eliminates changes in current and voltage over time due to plasma polymer deposition on the electrodes, which is a problem with internal electrode methods. In the external electrode method, discharge due to capacitive coupling and discharge due to inductive coupling are considered, but capacitive coupling is superior because of the homogeneity of discharge within the reaction tube.

However, when a high-frequency output electrode and one ground electrode are arranged and discharge is caused by capacitive coupling, the discharge area spreads to both sides of the high-frequency output electrode, and the area varies greatly depending on the high-frequency output and the pressure inside the reactor. do. In contrast, in the present invention, two ground electrodes are provided and placed on both sides of the high-frequency output electrode, thereby confining the discharge area between these three electrodes, stabilizing the discharge area, and substantially reducing the plasma reaction. By limiting this to this region, the homogeneity and reproducibility of the polymerized thin film deposited on the surface of the long object to be processed is improved.

In addition, the adoption of annular or arc-shaped electrodes helps stabilize the discharge, and the movable structure of the electrodes allows the discharge interval and relative position to the source gas supply port to be set as required. I have to.

(Example) The apparatus according to the present invention will be described in detail based on an example shown in the drawings.

FIG. 1 is a schematic diagram of the entire apparatus. The long workpiece 5 is unwound from the unwinding drum 10 placed in the supply chamber 9,
After passing through the guide rollers 6a and running approximately at the axial center of the cylindrical reaction tube 3, it is guided to the guide rollers 6b and wound onto the winding drum 11. Three electrodes are arranged in series around the outer periphery of the cylindrical reaction tube, and the center is a high frequency output electrode 1 connected to a high frequency generation power source (not shown), and both ends are ground electrodes 2a, 2.
b and is grounded.

When high frequency power is applied when the inside of the device is under reduced pressure, glow discharge is generated in the area between the ground electrodes 2a and 2b.

The raw material gas introduced here from the raw material gas supply lower receives electron impact within this discharge region, becomes activated, and deposits a plasma-polymerized thin film on the surface of the traveling long workpiece 5.

Initial evacuation of the entire apparatus and evacuation during operation are performed by a vacuum pump (not shown) connected to the exhaust hole 4 attached to the winding chamber 8. Further, although not shown, a drive device for the unwinding drum 10 and the winding drum 11, a tension control device for the long workpiece 5, a gas supply system section connected to the raw material gas supply port, etc. are attached.

FIGS. 2 and 3 are schematic diagrams of electrode portions suitably used in the present invention. It has an annular or arcuate structure with a curvature along the outer periphery of the cylindrical reaction tube. This applies to both the high frequency output electrode and the ground electrode. In the case of FIG. 2, the annular electrode 15 has a terminal fixing hole 13 to which a lead wire is connected and an adjustment screw hole 12 for fixing it to the cylindrical reaction tube 3.
is attached.

In the case of FIG. 3, the half molds are combined to form the electrode 15, with a lead wire terminal fixing hole 13 and a cylindrical reaction tube 3.
Adjustment screw holes 1.4a, 14b, 14 for fixing to
c, 14d are attached. Either of them can be attached to any position on the cylindrical reaction tube, and the position and spacing can be adjusted as necessary to set a desired discharge area.

(Effects of the Invention) The apparatus of the present invention is effective in depositing a continuous and homogeneous plasma-polymerized thin film on the surface of a long object such as a fiber, rod, hollow system, tube, or tape. This is due to the electrode structure and arrangement of the present invention, which allows stable discharge to occur within the cylindrical reaction tube in the diameter and length directions of the reaction tube, and also because the discharge voltage and discharge current are constant over a long period of time. The plasma-polymerized thin film deposited on the substrate also has stable physical properties over its entire length. Furthermore, since the electrodes have a movable structure, the desired film quality can be adjusted by changing the electrode position and spacing.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of a continuous low temperature plasma polymerization apparatus according to the present invention. Figures 2 and 3 are
It is a saw schematic diagram showing an example of an electrode part. In FIG. 1, 1 is a high frequency output electrode, 2a and 2b are ground electrodes, 3 is a cylindrical reaction tube, and in FIGS. 2 and 3,
I5 is an electrode.

Claims (3)

[Claims] (1) While continuously running a long workpiece in a cylindrical reaction tube that can be depressurized, a raw material gas is supplied, and a glow discharge is caused by capacitive coupling, and the plasma of this raw material gas is generated by the long workpiece. In an apparatus for depositing a polymeric thin film on the surface of a treated object, an electrode is provided outside the cylindrical reaction tube, and the electrode is a high-frequency output electrode and a pair of ground electrodes placed on both sides sandwiching the high-frequency output electrode. A continuous low-temperature plasma polymerization device characterized by the following. (2) The continuous low temperature plasma polymerization apparatus according to claim 1, wherein the electrode is annular or arcuate. (3) The continuous low temperature plasma polymerization apparatus according to claim 1 or 2, wherein the electrode has a movable structure.