JPH0359094B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a counter electrode for corona discharge treatment used for corona discharge treatment of various products such as synthetic resins and glass.

(Prior Art) Various products made of polyolefin-based synthetic resins have few polar groups in the polyolefin-based synthetic resin, so paints, adhesives,
It has the characteristic that printing etc. are difficult to adhere to. Therefore, when applying paint, adhesion, printing, etc. to the surface of the product, it is necessary to perform a modification treatment on the surface as a pretreatment to improve the adhesion.

As a modification treatment for products made of polyolefin-based synthetic resins, the applicant has focused on corona dielectric treatment, which is performed as a modification treatment for resin films. There are many difficulties in applying it to processing.

One of these is that when products have various three-dimensional shapes, conventional roll-shaped or flat counter electrodes create a large air space between them and the discharge electrode. The problem is that corona discharge no longer occurs due to the large spacing.

Therefore, it has been considered to form the counter electrode in substantially the same shape as the back surface of the three-dimensional resin product, and in this case, an electrode base material having the same shape as the back surface of the three-dimensional resin product is formed. This surface is coated with a thin conductive layer.

(Problems to be Solved by the Invention) However, the following problems can be considered with the counter electrode formed by the above method.

That is, when the three-dimensional resin product is provided with an opening such as a through hole or a notch, the conductive layer is exposed from that part to the discharge electrode side. Therefore, when a discharge electrode undergoing corona discharge is located in the opening, intense sparks are generated between the discharge electrode and the conductive layer, disturbing the corona discharge, and the surface adjacent to the opening is sufficiently corona-discharged. Discharge treatment may not be possible. Furthermore, when the conductive layer is made of metal foil when the product has a complicated shape, there are also problems in that it lacks followability to the shape due to its complexity, and it takes time and effort to apply the metal foil.

Structure of the Invention (Means for Solving the Problems) In order to solve the above problems, the present invention forms a protective layer on the back side of the product, and forms a conductive layer on the back side of the protective layer by a metal spraying method. On the other hand, a method is adopted in which a counter electrode for corona discharge treatment is manufactured by forming an electrode base material on the conductive layer and then removing the product.

(Function) By employing the above means, the present invention functions as follows.

By forming a protective layer on the back side of the product, even if there is an opening, the corona discharge electrode and the conductive layer will not directly face each other through this opening. Further, since the conductive layer is formed by metal spraying, it can easily follow the shape of any product, and the thickness of the conductive layer can be made uniform.

(Example) This invention will be described below as a three-dimensional synthetic resin product for an automobile instrument panel pad (hereinafter referred to as
An embodiment in which an instrument panel pad (referred to as an instrument panel pad) is used as a counter electrode for corona discharge treatment will be described with reference to FIGS. 1 and 2.

First, the instrument panel pad 2 that is placed on the surface of the counter electrode 1 of the present invention and subjected to corona discharge treatment will be described.

The instrument panel pad 2 has a substantially horizontal U-shape in cross section, and is formed into a three-dimensional shape from a front surface 3, an upper surface 5 having two through holes 4, and a rear surface 6. After discharge treatment, PVC (polyvinyl chloride) is applied to the surfaces of these surfaces 3, 5, and 6.
A resin skin sheet is attached.

Next, an apparatus for performing corona discharge treatment on the surface of the instrument panel pad 2 will be explained.

The corona discharge treatment apparatus used in this method includes a high frequency application means B, an electrode moving means C, a corona discharge electrode 18 whose tip is a spherical ball electrode attached to the tip of the electrode moving means C, and a corona discharge electrode 18 whose tip is a spherical ball electrode. It is comprised of a counter electrode means D provided to face the electrode 18, and a control unit E for controlling the high frequency application means B and electrode moving means C.

The counter electrode means D includes a counter electrode 1 formed of a protective layer 11 on which the instrument panel pad 2 is placed, a conductive layer 12 formed on the back surface of the protective layer 11 by metal spraying, and a back surface of the conductive layer 12. an electrode base material 13 formed to cover the conductive layer 12;
It is composed of.

More specifically, the surface of the protective layer 11 is formed to be substantially the same or the same shape as the back surface of the instrument panel pad 2, and the thickness is constant at any portion. In addition, the same protective layer 1
1 is made of heat-resistant epoxy resin, which is a synthetic resin with excellent heat resistance and oxidation resistance, and the portion exposed from the through hole 4 will not be thermally deformed or oxidized by corona discharge, which will be described later. In addition, the conductive layer 12 and the corona discharge electrode 18 are prevented from directly opposing each other.

Note that the synthetic resin with excellent heat resistance refers to one having a softening temperature of 100°C or higher, preferably one having a melting temperature of 180°C or higher.

As shown in FIG. 2, the conductive layer 12 is formed by spraying a highly conductive metal melted by arc spraying from a thermal spraying machine 14 onto the entire back surface of the protective layer 11. It is formed by twisting. The arc spraying method generates an arc between two metal wires by applying a high DC voltage between the two metal wires, and converts the metal melted by the arc into microparticles on the order of μm. This is a method of spraying using high-pressure compressed air, and the thermal spray machine 14 sprays fine particles on the order of μm.

In this embodiment, Cu, which is a highly conductive metal, is sprayed to a thickness of about 6 μm to 20 μm, so that the resistance of the conductive layer 12 is 10 Ω/□. Therefore, this conductive layer 12 follows the three-dimensional shape of the back surface of the protective layer 11, is formed to have a substantially uniform thickness in all parts, and has extremely high conductivity. Further, one end of the conductive layer 12 is grounded and connected to a high voltage transformer 20, which will be described later.

The electrode base material 13 is made of ordinary epoxy resin so that the conductive layer 12 is not exposed to the outside. This is to prevent severe sparks from being generated between the exposed portion and the corona discharge electrode 18 during corona discharge if the conductive layer 12 is exposed.

The high frequency applying means B is composed of a high frequency oscillator 19 that generates high frequency waves, and a high voltage transformer 20 that boosts the high frequency waves generated therein. As the high frequency oscillator 19, for example, 20 to 30K
Hz, a product manufactured by Tantetsu Co., Ltd. (product name HV05-2) that generates high frequency waves with a maximum output of 350 W is used, and the high voltage transformer 20 is also a product made by Tantech Co., Ltd. (product name Super C). Therefore, a high frequency of 0 to 350 W is applied between the corona discharge electrode 18 and the conductive layer 12.

The electrode moving means C is constituted by a moving mechanism (not shown) for moving the corona discharge electrode 18 to an arbitrary position in a three-dimensional direction, and is connected to the control unit E. The control unit E is constituted by a microcomputer, etc., and has an operating program for operating the electrode moving means C and a program for controlling the start and stop of operation of the high frequency application means B being written therein.

Next, in order to subject the surface of the instrument panel pad 2 to corona discharge treatment using the corona discharge treatment apparatus configured as described above, the instrument panel pad 2 is placed on the surface of the protective layer 11, and the switch of the control unit E is turned on. Turn on.

Then, the electrode moving means C uses the moving mechanism to move the corona discharge electrode 18 to a position close to the edge of the rear surface 6 of the instrument panel pad 2 (indicated by the two-dot chain line in FIG. 1), which is the starting position of the corona discharge treatment.
Move to. Thereafter, the high frequency application means B is activated, and the gap between the corona discharge electrode 18 and the conductive layer 12 is
While applying a high frequency of 28 KV, it moves three-dimensionally along the shape of the surface of the instrument panel pad 2 (as shown by the dashed-dotted arrow in FIG. 1). Therefore, corona discharge occurs between the corona discharge electrode 18 and the surface of the instrument panel pad 2, and these surfaces 3, 5, 6
corona discharge treatment is performed.

At this time, when the corona discharge electrode 18 is located above the through hole 4, the corona discharge electrode 18 moves downward so that the side wall of the through hole 4 is also uniformly treated with corona discharge. Therefore, the counter electrode 1 and the corona discharge electrode 18 are brought close to each other, and corona discharge is performed directly on the counter electrode 1. However, the counter electrode 1 has a protective layer 11 covering the conductive layer 12 on its surface. This prevents intense sparks from occurring in this area and disturbing the corona discharge. Therefore, the entire instrument panel pad 2 can be uniformly subjected to the corona discharge treatment.

Further, the back surface of the protective layer 11 is coated with highly conductive material.
Conductive layer 12 with Cu deposited by metal spraying method
is formed, the conductivity of the conductive layer 12 can be increased, and the discharge efficiency in corona discharge can be increased.

Furthermore, since the conductive layer 12 is formed by metal spraying, even if the protective layer 11 has a complicated three-dimensional shape, it is easy to form the Cu to a uniform thickness on each part of the back surface of the protective layer 11. Can be done. Therefore, uniform corona discharge can be generated in any part of the instrument panel pad 2.

Further, since a ball electrode with a spherical tip is used as the corona discharge electrode 18, the corona discharge from the ball electrode can be uniformly distributed to the side surfaces of each through hole 4, and the corona discharge treatment can be performed efficiently.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be modified and embodied as shown below, for example.

(1) In each of the embodiments described above, a ball electrode was used as the corona discharge electrode 18, but a pin electrode or a rod electrode may also be used.

(2) As the electrode moving means C, it is also possible to use the device described in the application previously filed by the present application (Japanese Patent Application Laid-open No. 134053/1983).

(3) In the above embodiment, the instrument panel pad 2 is subjected to corona discharge treatment, but in addition to this,
The present invention can be implemented as a device used as a pre-treatment process in the painting process of mudguards and side moldings, a device used as a pre-treatment process in the hair-planting process of roof headers and front pillars, and the like.

(4) In the above embodiments, the present invention was embodied in the counter electrode 1 for corona discharge treatment of synthetic resin products, but it can also be embodied in the counter electrode 1 for corona discharge treatment of glass products.

(5) In the above embodiment, arc spraying was used as the electric spraying method as the metal spraying method, but other methods include plasma spraying, wire blast spraying, and
A flame spraying method and an explosive spraying method can be used as the gas spraying method.

(6) If the protective layer 11 is made of a material with low adhesion to the metal to be thermally sprayed, a primer layer may be provided.

(7) The metal forming the conductive layer 12 is the metal of this embodiment.
In addition to Cu, metals such as Au, Ag, Zn, and Al, and alloys with high conductivity can be used.

Effects of the Invention As detailed above, the present invention can increase the conductivity of the conductive layer, and even if the product has an opening, the corona discharge electrode and the conductive layer can directly face each other through the opening. Because there are no sparks, the entire surface to be treated can be uniformly treated with corona discharge. In addition, since the conductive layer is formed by metal spraying, unlike when using metal foil, it can easily follow the shape of any product, and the thickness of the conductive layer can be made uniform. This provides an excellent effect in that uniform corona discharge can be generated in any part.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment embodying the present invention, and FIG. 2 is a side sectional view showing a method of forming a conductive layer on the back surface of a protective layer by metal spraying. DESCRIPTION OF SYMBOLS 1... Counter electrode, 2... Product subjected to corona discharge treatment, 11... Protective layer, 12... Conductive layer, 13...
... Electrode base material, 18 ... Corona discharge electrode.

Claims (1)

[Claims] 1. A protective layer 11 is formed on the back side of the product 2, and a conductive layer 12 is formed on the back side of the protective layer 11 by metal spraying, while an electrode base material 13 is placed on the conductive layer 12. A method for manufacturing a counter electrode for discharge treatment, characterized by forming the product 2 and then removing the product 2. 2. The method of manufacturing a counter electrode for corona discharge treatment according to claim 1, wherein the conductive layer 12 is formed of Cu with a thickness of 6 μm to 20 μm on the back surface of the protective layer 11.