JPS62112632A - Electrode for corona discharge and corona discharge treatment using same - Google Patents

Abstract

PURPOSE:To perform the corona discharge treatment of a three-dimensional resin molding uniformly within a short time, by generating corona discharge from a flat discharge part of a shape nearly the same as the treatment surface of the molding. CONSTITUTION:An electrode 50 for corona discharge is formed by attaching a flat discharge part 52 with its surface having grooves in the form of a lattice and having a shape nearly the same as the three-dimensional shape of the treatment surface of a three-dimensional resin molding 1 to the end of a rod-like held part 50. A counter electrode 63 is formed on the surface of a counter electrode base 62 of a shape coinciding with the shape of the back of the molding 1 and provided on an electrode mount 61, and the molding 1 is fitted on this electrode 63. The electrode is set so that the corners of the molding 1 may be opposed to the bends 52a and 52b of the discharge part 52, a high-frequency is impressed between the electrodes 50 and 63 to generate corona discharge from tetragonal prism-like protrusions 54 formed among the grooves 53 and perform the corona discharge treatment of the molding 1.

Description

[Detailed Description of the Invention] Object of the Invention (Industrial Field of Application) The present invention relates to a corona discharge electrode for corona discharge treatment of the surface of a three-dimensional resin molded article, and a corona discharge treatment method using the same. It is.

(Prior Art) Since polyolefin synthetic resins such as polypropylene do not have polarity, they have the characteristic that paints, adhesives, printing, etc. are difficult to adhere to their surfaces. Therefore, when painting, adhering, printing, etc. are performed on the surface of the resin, it is necessary to perform a modification treatment on the resin surface as a pretreatment to improve the adhesion.

Conventionally, plasma treatment, corona discharge treatment, and the like have been considered as modification treatments for molded articles made of polyolefin resins.

Since the plasma treatment is performed by flowing plasma gas into a vacuum chamber, almost the entire surface of the resin molded product can be activated at once, making it ideal for painting and pretreatment of three-dimensional resin molded products such as automobile bumpers and moldings. The process has achieved great results.

On the other hand, the corona discharge treatment activates the resin molded product by inserting the resin molded product between adjacent electrodes, and is therefore used for modifying thin film-like resin molded products. However, no prior art has been found for corona discharge treatment of the three-dimensional resin molded article of the present invention.

(Problems to be Solved by the Invention) In the corona discharge treatment, the thin film is inserted between a discharge electrode formed in a rod shape and a roll counter electrode formed in a roll shape, and the thin film is inserted between the two electrodes. distance is 3~
Because the tube was extremely narrow (around 400 mm), it was impossible to insert a three-dimensional resin molded product with a three-dimensional effect, and since a rod-shaped discharge electrode was used, corona discharge treatment took a long time.

Therefore, an object of the present invention is to provide an electrode for corona discharge that not only enables corona discharge treatment even for three-dimensional resin molding with a three-dimensional effect, but also enables corona discharge treatment in a short time, and a corona discharge using the electrode. The purpose is to provide a processing method.

Structure of the Invention (Means for Solving the Problems) Therefore, the present invention provides a planar corona discharge electrode that faces closely to the surface to be treated of a three-dimensional resin molded product, the discharge portion of which is is formed in substantially the same shape as the shape of the surface to be treated of the three-dimensional resin molded article, and the second invention adopts a means in which the shape of the surface to be treated is formed almost the same as the shape of the surface to be treated of the three-dimensional resin molded article. While generating corona discharge from a corona discharge electrode having a planar discharge portion, the electrode is brought relatively close to the three-dimensional resin molded product.

(Function) According to the present invention, since the corona discharge electrode is provided with a planar discharge portion formed in substantially the same shape as the surface to be treated of the three-dimensional resin molded product, the electrode is When placed near a three-dimensional resin molded product, uniform corona discharge treatment can be applied to all surfaces to be treated of the resin molded product.

Further, according to the second invention, since the corona discharge electrode of the first invention which has the above-mentioned effect is utilized, corona discharge occurs even when placed between electrodes of a three-dimensional resin molded product that is thicker than a film. Therefore, it is not only possible to perform corona discharge treatment on three-dimensional resin molded products, but also the treatment time can be shortened because all the surfaces to be treated can be treated with corona discharge in - times of corona discharge. I can do it.

(Example) An example embodying the present invention will be described below with reference to FIGS. 1 to 6.

"Three-dimensional resin molded product" First, we will explain the three-dimensional resin molded product modified according to the present invention. It refers to something that has three-dimensional unevenness.

As shown in FIG. 6, the three-dimensional resin molded product subjected to the corona discharge treatment in this example is a component l of an automobile instrument panel pad (hereinafter abbreviated as instrument panel 1) made of PP resin. And PVC on the surface
By adhering a resin skin sheet, it becomes an instrument panel pad product.

The instrument panel 1 is composed of an upper surface 2, an upright surface 4, and a second upper surface 5. The upper surface 2 and the upright surface 5 form a first corner portion 10, and the upright surface 4 and the second upper surface 5 A second corner portion 11 is formed.

"Corona Discharge Treatment Apparatus" Next, an apparatus for subjecting the instrument panel 1 to corona discharge treatment will be described together with the corona discharge electrode of the present invention.

As shown in FIGS. 1 to 5, the corona discharge treatment apparatus used in this example is composed of the following means, which are mounted on the top and side of the two-stage step-like base A. They are arranged separately.

That is, the corona discharge treatment apparatus includes a high frequency applying means B consisting of a high frequency oscillator 16 and a high frequency transformer (not shown) disposed on the shelf 14 on the left side of the base A, and a second high frequency applying means B on the left side of the base A.
Electrode moving means C arranged in the tiers and counter electrode means fixed to the first tier of the base A so as to face the corona discharge electrode 50 held by the electrode moving means C. and a control unit E arranged on the right side of the base A to control the electrode moving means C.

The electrode moving means C is an X-axis moving means 20 for moving the corona discharge electrode 50 in the X-axis (left and right) direction indicated by arrow X, and also for moving it in the Y-axis (front and back) direction indicated by arrow Y. X-axis moving means 30, and X-axis moving means 40 for moving in the Z-axis (up and down) direction, also indicated by arrow Z.
It is composed of.

In the X-axis moving means 20, two guide rods 28 are fixed on the base A in parallel and horizontal direction.

A turntable 26 for supporting the X-axis moving means 30 is provided on the guide rod 28 so as to be slidable in the X-axis direction. Note that a threaded portion 29 is provided on the bottom surface of the turntable 26.
A supporting member 23 is attached, and the guide rods 28 of the two books are inserted through the supporting member 23.

Further, one screw shaft 27 is screwed into the threaded portion 29 between the two guide rods 28, and a gear 21a is attached to one end thereof. This gear 21a is the gear 11b of the rotating shaft 22 of the servo motor 25.
The rotation of the servo motor 25 is transmitted to the screw shaft 27.

Therefore, the rotation of the servo motor 25 is caused by the rotation of the turntable 26.
, and the X-axis moving means 30 moves in the X-axis direction.

As shown in FIG. 4, two bearings 35 are provided on both sides of the turntable 26 in the X-axis moving means 30, and two screw shafts 31 are rotatably attached to these bearings 35. It is attached so that it cannot move forward or backward, and both shafts 31 extend parallel to each other and in the horizontal direction. A gear 36 is attached to one end of each of these screw shafts 31, and is connected to a rotating shaft 37 of a servo motor 32.

A threaded member 34 spanning the same shafts 31 is threaded onto the two screw shafts 31, and one end of a Y-axis arm 33 extending forward is attached to the center of the threaded member 34. The other end of the Y-axis arm 33 is provided with an X-axis moving means 4.
0 is fixed.

Therefore, also in the X-axis moving means 30, the servo motor 32
The rotation is transmitted to the gear 36, screw 31, and threaded member 34, so that the X-axis moving means 40 moves in the Y-axis direction.

In the X-axis moving means 40, a plate-shaped fixed table 41 is vertically fixed to the other end of the Y-axis arm 33. Two guide rods 42 are fixed to the front side of the fixed table 41 in parallel and in the vertical direction, and a sliding member 44 is slidably attached to both guide rods 42 so as to straddle them.

(not shown) provided in the center of the sliding member 44
A screw shaft 46 extending upward is screwed into the screw shaft 46 , and the screw 46 is directly connected to a rotating shaft 47 of a servo motor 45 installed on the top of the fixed table 41 .

On the other hand, the upper end of a downwardly extending Z-axis arm 43 is fixed to the center of the sliding member 44, and a corona discharge electrode 50 is held and held at the lower end of the Z-axis arm 43.

Therefore, when the servo motor 45 is rotated, the screw shaft 46 is rotated, and the Z-axis arm 43 and the corona discharge electrode 50 are moved up and down via the sliding member 44.

In addition, a control circuit (not shown) using a microcomputer or the like is incorporated in the control unit E, and the control circuit includes x, y, Control the operation of axis moving means 20.30.40? 111 and a program for controlling the start and stop of operation of the high frequency application means B are written.

Furthermore, an exhaust means F is disposed at the inner lower part of the base A for exhausting gas such as ozone generated during the corona discharge treatment.

“Electrode” The corona discharge electrode 50 held at the tip of the Z-axis arm 43 is connected to the high-frequency oscillator 16. This electrode 50 is made of stainless steel and has a diameter of about 2
It is composed of a dragon rod-shaped gripped part 51 and a planar discharge electrode 52 as a discharge part attached to the tip of the gripped part 51.

The discharge electrode 52 has approximately the same three-dimensional shape as the treated surface of the instrument panel 1, and its end portion is formed to be slightly larger than the instrument panel 1. Therefore, a first bent part 52a corresponding to the first corner part 10 of the instrument panel 1 and a second bent part 52b corresponding to the second corner part 11 are provided.

In addition, lattice grooves 53 are formed on the surface of the discharge electrode 52 facing the instrument panel 1, and square columnar protrusions 54 are formed between each lattice groove 53. Four corners 55 are formed on the lower surface of each of the protrusions 54, and corona is irradiated from these corners 55.

Therefore, this discharge electrode 52 is connected to the instrument panel 1,
When each bent portion 52a, 52b and each corner portion 1O211 are brought close to each other so as to correspond to each other, the discharge electrode 52 covers the entire surface to be treated of the instrument panel 1, and the discharge electrode 52
Which surface 2 of the instrument panel 1 is the distance between 2 and the instrument panel 1?
．． 4.5 is always constant, and the surface 2, 4.5
It is now possible to perform corona discharge treatment on everything at once.

Further, since corona is irradiated from each corner 55 of the planar discharge electrode 52, uniform corona discharge is generated on each surface 2, 4.5 of the instrument panel 1 despite the large planar discharge electrode 52. This makes it possible to perform corona discharge treatment on three-dimensional resin molded products, for which corona discharge treatment was previously impossible.

A counter electrode means is provided on the upper surface of the first stage of the base 1 and below the corona discharge electrode 50.

In this counter electrode means, as shown in FIG.
A ladder-shaped electrode stand 61 is arranged on the base A. A counter electrode base material 62 formed to match the shape of the back surface of the instrument panel 1 is provided on the electrode stand 61, and a counter electrode 63 is formed on the surface by metal plating, vacuum deposition, sputtering, conductive paint coating, etc. The coating is formed by pasting aluminum foil or other means.

Note that the counter electrode base material 62 is obtained, for example, by using the instrument panel 1 as a mold, pouring an epoxy resin into the back surface thereof, and causing the resin to react and harden.

"Cobra Discharge Treatment" Now, a method of corona discharge treatment of the instrument panel 1 using the corona discharge treatment apparatus configured as described above will be described.

First, if the molded instrument panel 1 has stains caused by a mold release agent or manual labor, a cleaning process is performed using an organic solvent.

Next, as shown in FIG. 2.3.5, the instrument panel 1 is fitted onto the counter electrode means, and the counter electrode 63 and the back surface of the instrument panel 1 are brought into contact.

After the exhaust means F is operated, the control unit E is turned on, and the electrode moving means B is turned on.

The Y- and Z-axis moving means 20, 30.40 are moved to the starting position of the corona discharge treatment, that is, in this embodiment, as shown in FIG.
, are each corner of the instrument panel 1 to, 11. Set it so that it corresponds to At this time, the distance between the planar discharge electrode 52 and the instrument panel 1 is always constant on any surface of the instrument panel 1, and is 311 in this embodiment.
is set to . A high frequency of 28 KV is applied between the discharge electrode 50 and the counter electrode 63.

Corona discharge is irradiated onto the instrument panel 1 from each corner 54 of the discharge electrode 52, and corona discharge processing starts.

The X, Y, and Z axis moving means 20, 30.40 are moved by the rotation of a servo motor 25°32.45 based on a signal from the control unit E, and the corona discharge electrode 50 is moved toward the instrument panel 1.
The vehicle stops at a position a predetermined distance away from the vehicle (in this embodiment, the left end of the instrument panel 1) and maintains this distance.

After a predetermined period of time, the discharge electrode 52 is returned to its original position to complete the corona discharge treatment for this portion, and is moved to the next portion by the X-axis moving means 30. When the corona discharge electrode 50 moves from the left end to the right end, this corona discharge treatment is completed.

On the surface of the instrument panel 1 that has been subjected to the corona discharge treatment, some of the bonds between carbon and hydrogen in polypropylene molecules are broken, and the molecules are ionized or oxidized and activated.

Therefore, when adhering a skin or the like to the surface of the instrument panel 1 that has been subjected to the corona discharge treatment, the surface modification effect such as improved adhesion is particularly important.

Further, since the planar discharge electrode 52 is formed in a shape substantially equal to the surface to be treated of the instrument panel 1 to be subjected to the corona discharge treatment, each bent portion 52a of the discharge electrode 52.

By arranging the corners 10.11 of the instrument panel 1 at a predetermined distance from the corners 10.11 of the instrument panel 1, all the surfaces 2, 4.5 of the instrument panel 1 can be subjected to the corona discharge treatment at once, and the corona discharge treatment time can be reduced. can be significantly shortened.

Further, according to the apparatus of this treatment method, after setting a certain distance, only vertical movement in the Z-axis direction is required, so this corona discharge treatment can be performed with a relatively simple control method.

Furthermore, since the discharge electrode 52 of this embodiment includes a plurality of protrusions 53 having corner portions 54, it is possible to stably emit corona discharge despite the large planar electrode, and the discharge reach distance is can also be made longer.

Note that the present invention is not limited to the above embodiments,
For example, it is also possible to implement it as shown below.

(1) The shape of the discharge electrode 52 is not limited to the shape of this embodiment. For example, if the three-dimensional resin molded product to be subjected to corona discharge treatment has a hemispherical shape, the inside may be hollowed out. A hemispherical discharge electrode may be used.

(2) In addition to this embodiment, the shape of the corner portion 54 of the discharge electrode 52 includes a conical protrusion 56 as shown in FIG.
The tip portion may be the corner portion, or any shape having a sharp tip may be used.

(3) The device is not limited to the device of this embodiment, and an industrial robot or the like may be used.

(4) Although the instrument panel 1 of this embodiment does not have a protrusion in the Z-axis direction, it can also be applied to a resin molded product that has a protrusion in the Z-axis direction. is possible.

Effects of the Invention As detailed above, in the present invention, the shape of the planar discharge portion is approximately the same as the shape of the treated surface of the three-dimensional resin molded product, so that the shape of the three-dimensional resin molded product is This provides an excellent effect in that uniform corona discharge treatment can always be performed on any surface.

Therefore, in the second invention that utilizes this corona discharge electrode, not only is it possible to perform corona discharge treatment on a three-dimensional resin molded product that has unevenness that is thicker than a film, but it is also possible to perform corona discharge treatment in a short time using a relatively simple control method. The excellent effect is that the corona discharge treatment can be carried out in a short period of time.

[Brief explanation of drawings]

1 to 5 show an embodiment embodying the present invention.
The figures are A1 front view of the main part of the present invention, FIG. 2 is a front view of the corona discharge treatment device, FIG. 3 is a partially cutaway side view of the corona discharge treatment device, FIG. 4 is a top view of the Y-axis moving means, and FIG. The figure is a sectional view showing a state of corona discharge treatment using the electrode of the present invention, FIG. 6 is a perspective view of a resin molded product, and FIG. 7 is an enlarged sectional view showing the cutting down of the discharge electrode. Three-dimensional resin molded product...1 Discharge electrode...52 Corona discharge electrode...50 Patent applicant Toyoda Gosei Co., Ltd. Agent
Patent Attorney On 1) Hironobu, Figure 6

Claims (1)

[Scope of Claims] 1. A planar corona discharge electrode (50) that faces closely to the surface to be treated of the three-dimensional resin molded product (1), the discharge portion (52) of which An electrode for corona discharge characterized by being formed in substantially the same shape as the shape of the treated surface of the resin molded product (1). 2. The discharge part (52) is the three-dimensional resin molded product (1)
The corona discharge electrode according to claim 1, characterized in that a plurality of corner portions (55) are provided in a portion facing the electrode. 3. While generating a corona discharge from the corona discharge electrode (50) having a planar discharge part (52) formed in almost the same shape as the surface to be treated of the three-dimensional resin molded product (1), A corona discharge treatment method characterized by bringing an electrode (50) relatively close to a three-dimensional resin molded product (1).