JPS6173746A - Method for treating resin molding with plasma - Google Patents

Abstract

PURPOSE:To modify uniformly, by fixing resin moldings to a rotatable mount and rotating it normally and reversely to generate a turbulent air flow in a chamber in treating the moldings with plasma in a vacuum chamber. CONSTITUTION:A mount 10 provided with a rotating shaft 11 is arranged in a vacuum chamber 1 and resin moldings 9 to be treated are fixed to the mount 10. The chamber 1 is evacuated and plasma of, e.g., oxygen is introduced into the chamber. The moldings 9 are irradiated with plasma to modify the surfaces of the moldings. In this case, the mount 10 is normally and reversely rotated repeatedly around the rotating shaft 11 to generate a turbulent air flow in the chamber 1. In this way, the moldings 9 apart from the shaft 11 and those near the shaft 11 are equally treated with plasma and variability due to a difference in the position of fixture is decreased. Therefore a lot of the moldings 9 can be treated at once.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a plasma treatment method for resin molded articles.

[Prior Art] Molded products made of olefin resins such as polypropylene and polyethylene are inferior in paint film adhesion due to their non-polar properties.

Therefore, these resin molded products are subjected to surface modification by irradiating them with so-called cold plasma, which is obtained by exciting gases such as air, oxygen, argon, helium, etc. using microwaves. There is.

The plasma processing is performed by housing the object to be processed in a chamber, reducing the pressure inside the chamber, introducing plasma from a plasma generator into the chamber, and irradiating the object to be processed. If the process is performed while the device is stationary within the chamber, the process will be non-uniform.

Therefore, a method has been proposed in which the object to be processed is mounted on a suitable mount and irradiated with plasma while the object to be processed revolves and/or rotates within a chamber (JP-A-58-2
(See Publication No. 08326).

[Problems to be Solved by the Invention] However, the method described in the above publication has the following problems. □ (1) The circumferential speed of the workpiece attached near the center of the chamber is smaller than the circumferential speed of the workpiece attached near the outer periphery.
As a result, the plasma processing varies greatly depending on the distance of the object to be processed from the center of rotation.

(2) In order to reduce the variation in tiJ 11),
If all the objects to be processed are attached near the outer periphery, the number of objects to be processed that can be accommodated in the chamber will be limited, resulting in poor productivity per batch.

(3) Furthermore, in the embodiment of the publication, the processing time is 60 seconds, and the number of revolutions and rotations during that time is several revolutions.

By the way, when a molded article of polypropylene, polyethylene, etc. is subjected to plasma treatment, the treatment time when the fixed surface thereof is continuously irradiated with plasma is usually about 10 to 20 seconds.

From this point of view, the processing time of 60 seconds is too long, and if the processing time is set to about 10 to 20 seconds in order to increase productivity, the revolution of the object to be processed during that time,
The number of rotations is only half a revolution or one revolution, so uniform processing cannot be expected.

In view of the above points, the present invention aims to provide a plasma processing method that can satisfy both uniform processing and productivity.

Means for Solving the Problem] That is, the present invention is a plasma processing method in which a resin molded product housed in a vacuum chamber is irradiated with plasma to modify its surface, and the object to be treated is mounted on a pedestal having a rotating shaft. , relates to a plasma processing method for a resin molded article, characterized in that a turbulent air flow is generated in a vacuum chamber by repeatedly rotating the pedestal in the normal and reverse directions around a rotation axis.

[Function] By generating turbulence in the vacuum chamber as described above, the contact between the object to be processed and the plasma is not affected much by the relative position or relative angle between the object to be processed and the plasma discharge port, and the This will be achieved almost uniformly and in a short time.

[Effect] As a result, objects mounted close to the rotating shaft of the stand and objects mounted far from the rotating shaft are processed to almost the same extent, and there is less variation in mounting depending on the position. Therefore, a large number of objects to be processed can be accommodated in the vacuum chamber at once, and productivity per batch is increased.

Furthermore, since the processing time per batch is shortened, the overall productivity is further improved.

[Embodiment] Next, the present invention will be explained in detail based on the drawings.

FIG. 1 is a schematic explanatory diagram showing an embodiment of a plasma processing apparatus used in the method of the present invention, and FIG. 2 is a diagram showing (X), -(
It is an enlarged sectional view taken along the line X).

In FIGS. 1 and 2, (1) is a vacuum chamber for processing an object to be processed. (2) is a vacuum pump, which is used to maintain the inside of the chamber (1) at a predetermined degree of vacuum. (3) is a gas cylinder for air, oxygen, argon, helium, etc., and the gas is transferred from the cylinder (3) to the pipe (4).
is sent to the plasma generator (5) through the microwave generator (6), where it is excited by microwaves from the microwave generator (6) and turned into a plasma state, and the generated plasma is sent from the discharge port (8) of the plasma introduction tube (71) to the chamber ( 1) and irradiates the object to be treated (9).

Reference numeral (10) denotes a pedestal for mounting the object to be processed (9), which is fixed to a rotating shaft (11) passing through the center of the chamber (1) and rotated around the rotating shaft. The rotating shaft (11) is driven by a drive device (12).

The frame (10) is fixed at right angles to a rod member (20) extending radially from the rotating shaft (11) and a mounting jig fixed to the tip of the rod member (20), for example, the rod member (20). The object to be processed (9) is attached to a part of the one-character corner of the rod member (20) and the rod member (21).

As described above, the object to be processed (9) is attached to the pedestal (10), and the pedestal (10) is repeatedly rotated forward and reversed around the rotation axis (11).

At this time, if the plasma discharge ports (8) are not dispersed and are concentrated in one place, for example, the process can be made more effective by rotating the entire body in a fixed direction (for example, in the direction of the arrow) while repeating reversals. . If this occurs, the stand (
An example of the axis trace of the movement of an arbitrary point (A) on the object to be processed (9) caused by the rotational movement of 10) is shown in FIG. In FIG. 3, the horizontal axis is the distance from point A to any point on the circumference, and the vertical axis is time. In FIG. 3, (ω indicates a normal rotation (rotation in the direction of the arrow in FIG. 2)), and (b) indicates a reverse rotation.

The rotation conditions for generating turbulence vary depending on the position and number of plasma discharge ports (8), the reversal angle of the pedestal (10), etc., but the number of reversals is 3 to 60 times/min, and the rotation speed in a certain direction is 0 to 30 times/min. times/minute is a rough guide.

In Fig. 2, the mounting jig (21) is attached only to the tip of the rod member (20), but the mounting jig (21) is also attached to the middle part.
21) may be attached, and a larger number of objects to be processed (9) may be attached.

FIG. 4 is a sectional view showing another embodiment of the pedestal (10) used in the present invention, in which a shaft member ( 2
2) is attached, and an inverted T-shaped attachment jig (23) is rotatably attached to the shaft member (22). The object to be processed (9) is attached to the attachment jig (23).

The pedestal (10) shown in Fig. 4 is rotated forward and reversed around the rotating shaft (11) in the same way as the one shown in Fig. 2 (if necessary, it is rotated repeatedly in the same direction as a whole rotation), in which case the mounting jig (23) is attached to the shaft member (2
2), so it is rotatably attached to the rotating shaft (11
) causes an oscillating motion by normal rotation and reversal, making it easier to generate turbulence and achieving better uniform processing.

[Example] Next, the present invention will be explained in detail with reference to Examples.

Example 1 A breadboard cover with a cross-sectional shape is molded from polypropylene,
This was subjected to plasma treatment using the apparatus shown in FIGS. 1 and 2.

The processing conditions are as follows.

Vacuum chamber internal pressure 0.5 toll gas: 02 Gas flow rate: 20Jl/min Microwave generation crab 500W Distance from rotating shaft (1) to object to be processed (9): Approx. 50c
m Rotation conditions Bi-reverse angle 120 degrees 3 times Forward rotation angle 180 degrees 3 times Treatment time: 20 seconds The outer surface of the plasma-treated Pamba cover was coated with urethane paint (R-263 manufactured by Nippon B Chemical ■), and
It was baked at ℃ for 1 hour to form a coating film with a thickness of 35 μm.

The adhesion of the resulting coating film was evaluated using a cross-cut peeling test (JIS 5).
400).

The results are shown in Table 1. In Table 1, the front, upper, and lower surfaces respectively refer to the front, upper, and lower surfaces of the breadboard cover, which has a generally U-shaped cross section.

Comparative Example Plasma treatment was carried out in the same manner as in Example 1, except that the stand (10) was only rotated in one direction without being reversed, and then painting was carried out, and the resulting coating film was adhered. I looked into gender. The results are shown in Table 1.

Example 2 Plasma treatment was carried out in the same manner as in Example 1, except that the plasma treatment apparatus shown in FIG. 4 was used, and then coating was performed, and the adhesion of the resulting coating film was examined. The results are shown in Table 1.

Table 1

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram showing an embodiment of a plasma processing apparatus used in the method of the present invention, and FIG. 2 is a diagram showing (X)-(X
3 is a graph showing the axis trace of an arbitrary point on the object to be processed during plasma processing, and FIG. 4 is a schematic sectional view showing another embodiment of the plasma processing apparatus. (Main symbols in the drawings) (1) Two vacuum chambers (5): Plasma generator (9): Processed object (10): Frame (11): Rotating shaft 21

Claims (1)

[Claims] 1. In a plasma treatment method in which a resin molded article housed in a vacuum chamber is irradiated with plasma to modify its surface, an object to be treated is mounted on a mount having a rotating shaft, and the mount is rotated around the rotating shaft. A plasma processing method for resin molded products, which is characterized by generating turbulent airflow in a vacuum chamber by repeatedly rotating forward and reverse. 2. The method according to claim 1, wherein the object to be processed is attached via an attachment jig that is rotatably attached to a pedestal.