KR900002718B1 - Counter electrode frr corona discharge treatment - Google Patents

Abstract

A counter-electrode (62), used in corona discharge treatment of a plastics body (1) between discharge- and counter-electrodes (50,62), consists of an electrode base (63) having a shape conforming with the undersurface of a moulded item to be subjected to corona discharge working and a conductive layer (4) formed inside of the electrode base. This is useful in the corona discharge treatment of polyolefin mouldings prior to painting, adhesive coating or printing. It provides a uniform stable corona discharge, without damage to the moulding.

Description

Counter electrode for corona discharge treatment

1 to 7 show one embodiment in which the present invention is embodied, and FIG. 1 is a cross-sectional view showing the mounting panel pad and the counter electrode means cut back and forth.

2 is a cross-sectional view of the same left and right cut.

3 is a perspective view of an installation panel pad.

4 is a front view of the corona discharge treatment apparatus.

5 is a right side view of the device.

6 is a plan view of the Y-axis moving means.

7 is a schematic diagram showing a connection between a discharge electrode and a high frequency application means.

* Explanation of symbols for main parts of the drawings

1: mounting panel pad 50: discharge electrode

62: counter electrode 63: electrode base material

64: conductive layer

The present invention relates to a counter electrode used for corona discharge treatment of a resin molded article.

Since polyolefin resins, such as polypropylene, have few polar groups, it has the characteristic that a paint, an adhesive agent, a printing agent, etc. are hard to adhere to the surface.

When coating, adhering, printing, etc. to the surface of the said resin here, it is necessary to perform a modification process to the surface as the pretreatment, and to improve the said adhesiveness.

As a modification treatment of a three-dimensional resin molded article made of this polyolefin resin, conventionally, an acid solution treatment using a flame treatment (flame treatment), a dichromic acid solution or the like has been performed, but in recent years, a plasma treatment has also been performed. Since the plasma treatment can activate almost the entire surface of the resin molded product at once, the plasma treatment has a great effect on the coating and adhesion pretreatment of bumpers and moles for automobiles.

However, the plasma treatment requires a reduced pressure of the plasma gas, which requires a lot of vacuum chambers, vacuum pumps, valve devices, carrier gases, etc., and requires expensive equipment, and it takes a long time to depressurize the vacuum chamber. . In addition, the batch process is inevitably required in any process, and automation of the process is difficult, and there is also a problem that the vacuum is cut for each process, and the next decompression takes time.

Here, although this inventor pays attention to the corona discharge process performed as a reforming process of a resin film, when employ | adopting this processing method for the reforming process of a 3D resin molded article, many difficulty comes. One of them is that when a molded article has various three-dimensional shapes, a large air electrode having a roll-like or flat plate-like electrode has a large air layer between the resin and a large gap with the discharge electrode. This is a spot that will not occur.

Therefore, although it is conceivable to form the counter electrode in a shape substantially the same as the shape of the back surface of the three-dimensional resin molded article, in this case, an electrode base material having the same shape as the back surface of the three-dimensional resin molded article is formed, and a thin film type is formed on this surface. The counter electrode is formed by covering the conductive layer.

By the way, when arrange | positioning a three-dimensional resin molded article on the counter electrode formed by the said method, the following problem can be considered.

That is, in the case where the three-dimensional resin molded article is provided with through portions such as perforations and cutouts, the conductive layer is exposed from the portions to the discharge electrode side. Therefore, it is conceivable that the corona discharge is scattered and sufficient corona discharge treatment is not performed when the discharge electrode is positioned on the penetrating portion during the corona discharge. For this reason, a buffer plate made of a dielectric material must be provided at the portion facing the through portion of the counter electrode, and an extra manufacturing process is required.

The present invention is a counter electrode disposed on the back surface of the to-be-processed surface of the corona discharge-treated molded article and facing the discharge electrode through the molded article, in order to solve the above problems, having the same or substantially the same shape as the back surface of the molded product for the corona discharge treatment. The means which consists of the formed electrode base material and the conductive layer formed in the inside is employ | adopted.

Since the counter electrode of the present invention is composed of an electrode substrate formed the same as or substantially the same as the shape of the back surface of the three-dimensional resin molded article, and a conductive layer formed therein, a penetration portion of the light-transmitting or cutout portion is formed in the three-dimensional resin molded article. Even when provided, the conductive layer is not exposed to the discharge electrode side from the portion. Therefore, even when the discharge electrode is located above the light projection or the cutout portion, it is possible to generate a uniform corona discharge without scattering the corona discharge from the discharge electrode. The process is performed.

EMBODIMENT OF THE INVENTION Hereinafter, the Example which actualized this invention is described according to drawing.

First, the molded article subjected to the corona discharge treatment in this embodiment will be briefly described as saying that the molded article has a three-dimensional shape as a three-dimensional resin molded article. In addition, the resin mentioned here points out the synthetic resin which is a dielectric material especially.

According to the present embodiment, the three-dimensional resin molded article subjected to corona discharge treatment is an automobile installation panel pad (1) formed of PP resin, which is a dielectric material, as shown in FIGS. ) A skin panel sheet made of resin is adhered to each other so that an installation panel pad is formed.

The mounting panel pad 1 has an angled corner portion 5 at the boundary between the upper surface 2 and the front surface 3 and the boundary between the upper surface 2 and the side surface 4.

Moreover, two shallow dish parts 6 and 7 are provided on the left and right sides of the mounting panel pad upper surface 2. Therefore, as shown in FIG. 2, the corner | corner 9 of a j-shape exists in the bottom edge of the dish parts 6 and 7, respectively. Further, the air outlet 10 of the side defroster is formed at the left end of the upper surface 2, and two recirculation and air control air outlets 11 and 12 are formed at the right and left sides of the front surface 3, respectively. . Each outlet 10, 11, 12 has a substantially quadrangular shape, and R-shaped corner portions 13 are formed at the edges and four corners.

As described above, the mounting panel pad 1 is a three-dimensional resin molded article, and is characterized by having many corner portions 5, 8, 9, 13.

Next, an apparatus for corona discharge treatment of the mounting panel pad 1 will be described.

The corona discharge treatment apparatus is mounted on a base 80 formed in two stages front and back by a metal frame. When the apparatus is divided, A: the mounting panel pad 1 is fixed as well as the electrode against the back side thereof. The counter electrode means A grounded at the first end of the base 80, B: corona discharge treatment, and a moving means for moving it three-dimensionally, and are arranged at the second end of the base 80, Discharge electrode means (B), C: high frequency applying means (C) disposed on the shelf 14 on the left side of the base 80 to apply high frequency between the electrodes, and D: electrode moving means (B). It is composed of a control unit (D) grounded on the right side of the base 80 to control. Hereinafter, the detail of each part A-D is demonstrated in order.

Counter electrode means A

As shown in FIG. 1, FIG. 2, FIG. 4, and FIG. 5, the hollow electrode stand 61 is provided in the 1st stage of the base 80, and an installation panel is provided in the upper part of the electrode stand 61. As shown in FIG. The counter electrode 62 formed so as to conform to the three-dimensional shape inside the pad 1 is provided, and the mounting panel pad 91 is supported from the inside.

This counter electrode 62 is comprised from the electrode base material 63 made of epoxy resin in which the three-dimensional shape of the back surface of the said installation panel pad 1 was formed in the same shape, and the thin-film conductive layer 64 formed in the inside. .

For this reason, even if the said mounting panel pad 91 is arrange | positioned on this counter electrode 62, the conductive layer 64 is not exposed to the discharge electrode 50 from the ejection opening 10, 11, 12. Therefore, even when the discharge electrode 50 during the corona discharge is located on the outlets 10, 11 and 12, the corona discharge is not scattered, and further, the corona discharge is returned to the back side of the outlet 10, 11 and 12. The discharge process is performed.

In addition, the counter electrode 62 is filled with a molten epoxy resin on the back surface of the installation panel pad 1 until it becomes about 5 mm thick. Then, silver powder as a conductor is spray-coated with a paint (painting die). It is formed by forming the conductive layer 64 and further filling the same molten epoxy resin as above.

As described above, the counter electrode 62 of the present embodiment is provided with a conductive layer 64 inside the electrode base 63 to prevent the corona discharge from scattering in the outlets 10, 11, 12 as in the prior art. To do this, it is not necessary to provide a buffer plate made of a dielectric at a portion facing the ejection openings 10, 11, and 12 of the opposing electrode and to perform a process of blocking the ejection openings 10, 11, and 12, and thus the opposing electrode 62 itself. Can be formed simply and inexpensively, and is effective for reducing equipment costs and improving reproducibility.

[Discharge electrode means (B)]

As shown in Figs. 4 to 6, the discharge electrode means B is the same as the corona discharge electrode 50 and the X-axis moving means 20 for moving it in the X-axis (left and right) directions. Y-axis moving means for moving in the axial (front and rear) direction and Z-axis moving means 40 for moving in the Z-axis (up and down) direction in the same manner.

In the X-axis moving means 20, the base 80 is provided with two guide rods 28 extending in the horizontal direction. The turntable 26 for supporting the next Y-axis moving means 30 is provided in the said guide rod 28 so that sliding in the X-axis direction is possible. That is, the support member 23 is provided in the lower surface of the turn table 26, and both the guide rods 28 are inserted through the support member 23, and the turn table 26 is slidable.

In addition, the screw coupling portion 23 is attached to the left and right sides of the support member 23 in the lower surface of the turn table 26, and one screw shaft 27 is screwed to the screw coupling portion 29. . A gear 21a is provided at the right end of the screw shaft 27, and the gear 21a is engaged with the gear 21b of the servo motor 25 provided at the right end of the base 80.

Accordingly, when the servo motor 25 rotates, the screw shaft 27 rotates through the gears 21a and 21b, so that the turntable 26 together with the screw coupling portion 29 screwed to the screw shaft 27 is rotated. It moves in the X-axis direction.

Next, two bearings 35 are provided on both sides of the upper surface of the turntable 26 in the Y-axis moving means 30, respectively. Between the left and right bearings 35, two screw shafts 31 are rotatably installed and impossible to move forward and backward, and both sides 31 extend in parallel in the horizontal direction. A gear 36a is provided before and after each screw shaft 31, and each gear 36a meshes with the gear 36b of the servo motor 32 provided at the rear end of the base 80.

The two screw shafts 31 are screwed with screwing portions 34 spanning both shafts 31, and a Y-axis arm 33 extending forward is provided at the central portion of the screwing members 34. have. The following Z axis moving means 40 is fixed to the front end of the Y axis arm 33.

Therefore, also in the Y-axis moving means 30, the rotation of the servomotor 32 is transmitted in the order of the gear 36, the screw shaft 31, and the screw engaging member 34, and the Z-axis moving means 40 is Y. It is adapted to move in the axial direction.

Next, in the Z-axis moving means 40, the fixed table 41 is vertically fixed to the front end of the Y-axis arm 33. Two guide rods 42 are fixed to the front end of the fixed table 41, and both rods 42 extend in parallel in the vertical direction.

Sliding members 44 spanning the two guide rods 42 are provided so as to be slidable, and female screws (not shown) are formed in the central portion of the sliding members 44. A screw shaft 46 extending upward is screwed into the female screw, and the screw shaft 46 is directly connected to the rotary shaft 47 of the servo motor 45 provided on the fixing table 41.

On the other hand, the Z-axis arm 43 extending downward is fixed to the central portion of the sliding member 44 at the upper end thereof, and the discharge electrode 50 for corona discharge is almost always perpendicular to the lower end of the Z-axis arm 43. It is held in a state. Therefore, when the servo motor 45 is rotated, the screw shaft 46 rotates so that the Z-axis arm 44 and the discharge electrode 50 are lifted and lowered through the sliding member 44.

The discharge electrode 50 disposed in the air has a rod-like gripped portion 51 formed of stainless steel and has a diameter of about 6 mm that is made of stainless steel and attached to the tip of the gripped portion 51. A spherical discharge tip 52 is provided. As described above, the gripped portion 51 is always held in a substantially vertical state by the Z-axis arm 43, and is inclined so as not to move even when moved by the respective moving means 20, 30, 40.

As shown in FIG. 7, it is preferable to provide a mesh-shaped protective cylinder 53 formed of stainless steel or the like around the discharge electrode 50. This is because the protective cylinder 53 can prevent high frequency noise from being radiated during corona discharge.

[High frequency application means (C)]

As shown in FIG. 4 and FIG. 7, the counter electrode 62 and the discharge electrode 50 are connected with the high frequency application means C which consists of the high frequency oscillator 16 and the high voltage transformer 17. As shown in FIG. In addition, direct grounding is also taken from the high frequency oscillator 16 to counter the high frequency noise.

The high frequency oscillator 16 uses the product of Dandex (brand name HV 05-2) which produces | generates the high frequency of 20-30KHz and maximum output 350W. The high voltage transformer 17 is for applying a high voltage between the electrodes 63 and 50 by boosting the high frequency output of the high frequency oscillator 16. Similarly, a product of Dandex (trade name Super-C) is used.

[Control unit (D)]

A control circuit (not shown) using a computer or the like is assembled in the control unit D, and the X, Y, and Z axes are provided in the control circuit to move the discharge electrode 50 near the surface of the installation panel pad 1. An exercise program for controlling the operation of the moving means 20, 30, 40, a program for controlling the start and stop of the operation of the high frequency application means C, and the like are written.

The control unit D and the high frequency applying means C are arranged at a considerable interval with the base 80 interposed therebetween, and the power supply is taken independently. It is for preventing the computer of the control unit D from malfunctioning by the high frequency noise leaking from the high frequency applying means (C). For the same reason, the cord connecting the high frequency oscillator 16, the high voltage transformer 917 and the discharge electrode 50 must be securely sealed.

5, the exhaust means E for discharging gas, such as ozone which generate | occur | produces at the time of a corona discharge process, is arrange | positioned in the position of the base 80 back from the said counter electrode means A. It is becoming.

By the way, the method to generate power generation treatment of the installation fan pad 1 using the corona discharge treatment apparatus comprised as mentioned above is demonstrated.

First, when contaminants or the like caused by a releasing agent or a hand work adhere to the formed installation panel pad 1, it is preferable to perform a pretreatment for washing this with an organic solvent such as trichloroethane. It is for surely performing a corona discharge process. However, the pretreatment does not need to be performed in the absence or milder release or milder condition.

Next, as shown in FIG. 1, FIG. 2, FIG. 4, and FIG. 5, the mounting panel pad 1 is fitted to the counter electrode 62 of the counter electrode means A. As shown in FIG. At this time, the entire surface of the counter electrode 62 is the back surface of the mounting panel pad 1 because the entire surface of the counter electrode 62 is formed in substantially the same shape as the three-dimensional shape of the back surface of the mounting panel pad 91. Make sure you touch the whole thing.

Therefore, almost all of the mounting panel pads 1 formed of the dielectric PP resin are electrically coupled to the counter electrode 62, and the gap between the counter electrode 62 and the discharge electrode 50 is always small. It is also possible. As a result, corona discharge tends to be generated from the discharge electrode 50.

If the surface of the counter electrode 62 and the back surface of the mounting panel pad 1 are not in contact with each other now, and an air layer is formed therebetween, the air layer acts as an insulating layer, making corona discharge less likely to occur. In this embodiment, this air layer is reliably removed to realize the electrical coupling.

Next, by operating the exhaust means E, the control unit D is switched to set the moving means 20, 30, 40 on each axis in the discharge electrode means B as the start position of the corona discharge treatment. do. At this time, ① the gripped portion 51 of the discharge electrode 50 is always supported in a vertical state, and ② the discharge tip 52 is spaced about 10 mm upward from the left end of the front edge of the installation panel pad 1. Is located.

Next, when the high frequency oscillator 16 of the high frequency application means C is operated, the high frequency output is boosted by the high voltage transformer 17, and a high frequency of 25 KV is applied between the counter electrode 62 and the discharge electrode 50. In this case, corona discharge occurs in the atmosphere between the portion of the discharging tip portion 52 facing the upper surface 2 and the upper surface 2, and the corona discharge treatment of the upper surface 2 is started.

The X, Y, Z axis moving means 20, 30, 40 move in each direction by rotation of the servo motors 25, 32, 45 operating based on the control signal from the control unit D, The discharge electrode 50 moves near the surface of the installation panel pad 1.

In addition, although the moving speed of the said discharge electrode 50 can be set arbitrarily within the range of 1-250 mm / sec under the said discharge conditions, in this embodiment, it considers 150 mm in consideration of sufficient corona discharge effect and the shortening of processing time. / Sec.

By the corona discharge treatment accompanying the above reciprocating movement, the whole surface of the installation panel pad 1 is corona discharge-processed, and adhesiveness, such as an adhesive agent, improves. The improvement of the wettability by the corona discharge treatment of this embodiment is about the same as the conventional frame treatment (flame treatment).

As shown in FIG. 2, when the discharge electrode 50 passes above the outlets 10, 11, 12 and the plate portions 6, 7, the discharge electrode 50 is lowered only by the drop. Is moved to. At this time, since the conductive layer 64 is not exposed in the portion of the counter electrode 62 facing the outlets 10, 11, 12, the corona discharge is not scattered. Therefore, the inner side and the back side of the outlet 10, 11, 12, the bottom face of the dish part 6, 7, the corner parts 9, 13, etc. are also reliably and uniformly corona-discharge-treated. Furthermore, even when the skin sheet is wound up and adhered to the back surface side of the ejection openings 10, 11 and 12 during the adhesion of the skin sheet, the corona discharge treatment is performed to the back surface so that both can be securely bonded.

In the phenomenon of the corona discharge treatment, a large amount of electrons generated by the discharge impinge on the synthetic resin (PP in this embodiment), and the collision energy partially destroys the bond between carbon and hydrogen, and oxidizes the surface of the synthetic resin. It is considered to be ionized and activated.

In addition, since the corona discharge is widened from the discharge tip 52 as shown in FIG. 7 with an extremely uniform discharge pattern, the chamber of the installation panel pad 1 at that time is sufficiently processed. This is because the discharge tip 52 is spherical (curved), so that the corona discharge is uniformly dispersed without focusing on one point (point or corner).

As described above, according to the corona discharge treatment apparatus of the present embodiment, large-scale facilities such as a vacuum chamber, a vacuum pump, a valve mechanism, a carrier gas, and a preparation time required for decompression are unnecessary in the conventional plasma processing, and the discharge electrode 50 is not required. The surface of the PP resin mounting panel pad 1 can be modified by only generating the corona discharge treatment in the air and moving it. Therefore, not only the equipment cost and the equipment space can be greatly reduced, but also the processing time can be shortened.

Furthermore, the corner portions 5, 8, 9, 13 can also be reliably processed since the discharge electrode 51 having the curved tip portion at least is moved along the surface of the mounting panel pad 1.

In addition, this invention is not limited to the said Example, For example, it can also be changed and actualized as shown below.

(1) As the conductive layer 64 of the counter electrode 62, all metals such as Au, Cu, Al, and Zn can be used, in addition to the conductive paint of the above embodiment.

(2) As the method for forming the conductive layer 64, any method of forming such as brushing, vacuum deposition, sputtering, etc. can be used in addition to the plasma coating in the above embodiment.

(3) It is also possible to change the structure of the X, Y, Z axis moving means 20, 30, 40 in the discharge electrode means B0, or to use a multi-joint robot or the like instead. In addition, a three-dimensional moving mechanism may be provided in the counter electrode means B, and the mounting panel pad 1 may be moved to approach the discharge electrode 50.

(4) The present invention, in addition to the installation panel pad 91, in addition to the bumper for cars, the mall for cars, the fenders of motorcycles, in addition, all three-dimensional, such as painting, bonding, printing, etc. required after molding of various industrial equipment, household goods, etc. Not only can it be used as a counter electrode of a resin molded article, it can also be used as a counter electrode of a two-dimensional resin molded article.

As described above, the counter electrode for corona discharge treatment of the present invention is composed of an electrode substrate formed on the same or substantially the same as the back surface of the molded article for corona discharge treatment, and a conductive layer formed therein, such as perforations and cutouts. Even a molded article having a penetrating portion exhibits an excellent effect that the corona discharge treatment can be uniformly performed at any portion without scattering the corona discharge in the penetrating portion.

Claims (2)

The counter electrode 62 which is disposed on the back surface of the to-be-processed surface of the corona discharge-treated molded product 1 and faces the discharge electrode 50 via the molded product 1, is the back surface of the molded product for corona discharge treatment 1. An opposite electrode for corona discharge treatment, comprising: an electrode base material 63 formed in the same or substantially the same shape as the electrode base; and a conductive layer 64 formed therein. The counter electrode for corona discharge treatment according to claim 1, wherein the conductive layer (64) is made of a conductive paint.

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