JPS60250038A - Pre-painting treatment method and equipment for synthetic resin products - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION A0 Object of the Invention (1) Field of Industrial Application The present invention relates to a method and apparatus for pre-painting treatment of synthetic resin products.

(2) Conventional technology Painting on synthetic resin products has become extremely popular these days due to demands such as adding marketability, but synthetic resins have a higher adhesion strength than other materials such as metals and wood. For example, with polypropylene resin, the adhesion strength when directly applied is almost zero. Therefore, when painting synthetic resin products, it is necessary to perform pretreatment to improve the adhesion strength, and conventional What has generally been carried out is etching treatment using trichloride solution or steam.In other words, by this etching treatment, the surface of the synthetic resin product to be painted is made into a finely roughened surface, which is then coated with a primer and then coated with a predetermined color. However, this type of etching process requires a waste liquid treatment device, and the working environment is also poor.

In order to overcome these drawbacks, plasma pretreatment has been proposed, in which O, gas, N, and ionized O, gas, and
Alternatively, Ar gas is injected and the surface of the synthetic resin product to be coated is activated by the energy of the ionized molecules. Although this plasma treatment solves the problems of waste liquid treatment and work environment, plasma treatment has not yet reached the stage of completion as a practical technology, and furthermore, it is difficult to apply to mass production systems because it is a batch process. be.

(3) Problems to be Solved by the Invention The present invention has been made in view of the above circumstances, and allows synthetic resin products to be continuously pretreated with plasma, making it possible to apply them to mass production systems. The purpose of the present invention is to provide a method and device for pre-painting treatment of synthetic resin products.

B. Structure of the Invention Part (1) Means for Solving Problems According to the method of the present invention, a pre-painting treatment is applied to an exhaust chamber, a processing chamber, and a dispensing chamber which are successively arranged so as to be able to communicate with and shut off from each other. Ensure that the synthetic resin products to be treated pass through in sequence,
The first step is to reduce the pressure to a preset first degree of vacuum while keeping the processing chamber and the dispensing chamber isolated from each other, and after the synthetic resin product is put into the exhaust chamber which is isolated from the processing chamber, the exhaust is discharged. a second step of reducing the pressure in the chamber to the first degree of vacuum; and a third step of communicating between the exhaust chamber and the processing chamber and transferring the synthetic resin product from the exhaust chamber to the processing chamber, and then cutting off the exhaust chamber and the processing chamber. a fourth step of reducing the pressure in the processing chamber to a second degree of vacuum lower than the first degree of vacuum; and a fifth step of plasma-treating the synthetic resin products in the processing chamber.
step, a sixth step of returning the pressure in the processing chamber to the first degree of vacuum, and a step of communicating between the processing chamber and the dispensing chamber and transferring the synthetic resin product from the processing chamber to the dispensing chamber, and then shutting off the processing chamber and the dispensing chamber. The seventh step, in which the pressure in the dispensing chamber is returned to atmospheric pressure, and the eighth step, in which the synthetic resin product is dispensed, are sequentially performed.

In addition, in the apparatus of the present invention, a conveying means for penetrating the inside of the casing configured in a tunnel shape and conveying the synthetic resin product to be subjected to painting pretreatment is arranged, and the inside of the casing is moved in the conveying direction of the conveying means. The casing is provided with four shutters that can be opened and closed to divide the casing into an exhaust chamber, a processing chamber, and a dispensing chamber in order along the casing. first suction means for reducing the pressure to a degree are individually connected to each other;
A second suction means for reducing the pressure to a second degree of vacuum, which is lower than the first degree of vacuum, is connected to the processing chamber, and a plasma generation means is also connected to the processing chamber.

(2) Synthetic resin products to be pretreated are transported sequentially to the exhaust chamber, treatment chamber, and discharge chamber, but each chamber is transported from the exhaust chamber to the treatment chamber and from the treatment chamber to the discharge chamber. Since the pressure is reduced to the first degree of vacuum and the pressure inside the dispensing chamber is returned to atmospheric pressure when dispensing from the dispensing chamber, the synthetic resin product is smoothly conveyed. Further, in the processing chamber, pre-painting treatment using plasma is performed in a state where the pressure is reduced to the 2nd X air degree.

(3) Example An example of the present invention will be described below with reference to the drawings. First, in FIGS. 1 and 2, the casing 2 of the painting pretreatment device 1 is configured in a tunnel shape,
The synthetic resin products 3 to be subjected to pre-painting treatment are sequentially conveyed within the casing 2, whereby the synthetic resin products 3 are continuously subjected to pre-painting treatment.

The casing 2 is fixed on a pedestal 4, and on the pedestal 4, a charging zone 5 is provided on one end side of the casing 2, and a dispensing zone 6 is provided on the other candle side.

The casing 2 is provided with first to fourth shutters 51 to S4 along the transport direction T of the synthetic resin product 3 in order to divide the inside of the casing 2 into an exhaust chamber 8, a processing chamber 9, and a dispensing chamber 10.
is provided so that it can be opened and closed freely.

That is, the first shutter S1 is arranged at one end of the casing 2, the fourth shutter S4 is arranged at the other end of the casing 2, and the second and third shutters S2 and S3 divide the inside of the casing 2 into three equal parts in the longitudinal direction. are placed in the respective positions. Each of the shutters 51 to S4 has first to fourth opening/closing driving means M disposed corresponding to the upper part of the casing 2.
1 to M4 are individually driven up and down. Moreover, each of the shutters 51 to S4 is configured to maintain sufficient airtightness between both sides of the shutters 51 to S4 when the shutters 51 to S4 are lowered and closed.

A conveying means 11 for conveying the synthetic resin product 3 is provided on the pedestal 4 from the loading zone 5 through the inside of the casing 2 to the dispensing zone 6, and is provided on the pedestal 4 from the input zone 5 to the unloading zone 6.
12 are arranged close to each other. Moreover, this conveyance means 1
1 is an input zone 5, an exhaust chamber 8, a processing chamber 9, and a discharge chamber 10.
A portion corresponding to the dispensing sea 76 is configured to be able to operate independently, and these independent portions are driven by first to fifth transport drive means 01 to C5 arranged below the pedestal 4.

The synthetic resin product 3 is mounted on a truck 13, and the truck 13 is conveyed in the conveying direction 7 according to the rotation of each roller 12.

The inside of the exhaust chamber 8 and the dispensing chamber 10 is heated to a first degree of vacuum, for example 2.
In order to reduce the pressure to 0 Torr, first suction means 14 are individually connected to the exhaust chamber 8 and the discharge chamber 10, respectively. Further, a second suction means 15 is connected to the processing chamber 9 in order to reduce the pressure inside the processing chamber 10 to a second vacuum level lower than the first vacuum level, for example, 0.4 Torr.

Here, considering the characteristics of the vacuum pumps used as each suction means 14 and 15, the starting time is short and the ultimate vacuum degree is 10-1 to 10 TO? -r, it is desirable to use the rotary pump 16 as the first suction means 14 for reducing the pressure to the first degree of vacuum, for example, 20 Torr.
6 and piping. By the way, the ultimate vacuum degree of the rotary pump is 10 to 10 Torr as mentioned above.
However, after reaching approximately l Toyτ, the pumping speed decreases. On the other hand, a mechanical booster is a vacuum pump that can reach a vacuum level with a higher pressure, and this mechanical booster can reach a vacuum level of about 10 Torr. However, the mechanical booster weighs 2g.
The drawback is that the speed at which the temperature reaches Torr is slow.

Therefore, the second suction means 15 for reducing the pressure to a second degree of vacuum, for example, 0.4 Torr, is constituted by a combination of a rotary pump 17 and a mechanical booster 18, as shown in FIG.

In FIG. 3, a mechanical booster 18 is connected to the processing chamber 9 via a first electromagnetic valve 19, and a rotary pump 17 is connected in series to the mechanical booster 18 via a second electromagnetic valve 20.

Also, a bypass pipe 22 that bypasses the mechanical booster 18
is equipped with a third solenoid valve 21. In such a second suction means 15, the first to third electromagnetic valves 19 to 21 are opened and the rotary pump 17 is operated to pump the inside of the processing chamber 9 to 207.
The pressure is reduced to 0.4 Torr, and then the third solenoid valve 21 is closed to operate the mechanical booster 18, and the rotary pump 1T continues to operate, thereby reducing the pressure to 0.4 Torr.

In this way, by utilizing the characteristics of the rotary pump 17 and the mechanical booster 18, 0.4 To
A pressure reduction to rr is quickly achieved. In addition, in Fig. 3, mechanical booster 1 is shown to show the basic configuration.
Although the second suction means 15 was constructed by combining one unit of each of the mechanical booster 18 and the rotary pump 17, the mechanical booster 18 and the rotary pump 1
It is sufficient to determine the number of 7.

In FIG. 4, a plasma generating means 23 is connected to the processing chamber 9. As shown in FIG. This plasma generating means 23 has one end commonly connected to an Ot gas supply source 24, a gas supply source 25, and both supply sources 24 and 25, and the other end inside the processing chamber 9. A plasma introduction tube 26 that is plunged into the plasma introduction tube 26, a shower tube 27 provided at the other end of the plasma introduction tube 26, a plasma generator 28 provided covering the middle of the plasma introduction tube 26, and a microwave applied to the plasma generator 28. and a microwave oscillator 29 for supplying the microwave.

For example, two rows of such plasma generating means 23 are connected to the processing chamber 9 depending on the processing amount.

In the plasma generation means 23, O, gas and Nt
While the gas is flowing through the plasma introduction tube 26, a microwave of, for example, 24 soMHz is applied from the microwave oscillator 29, and O and gas molecules are ionized to become plasma, which is introduced into the processing chamber 9.

Next, the operation of this embodiment will be explained. The process up to the pre-painting treatment of the synthetic resin product 3 is divided into eight steps, and each step will be explained in sequence below.

[First step] First, the second step. The third and fourth shutters 52 and 53°S4 are closed, and the processing chamber 9 and the dispensing chamber 10 are isolated from each other. In this state, the second suction means 15 and the first suction means 14 are operated to vacuum the inside of the processing chamber 9 and the dispensing chamber 10.
Reduce pressure to 0 Torr. .

[Second step] After moving the cart 13 in the loading zone 5 into the exhaust chamber 8 by the conveying means 11 and putting the synthetic resin product 3 placed on the cart 13 into the exhaust chamber 8, the first shutter is moved. Close S1. Next, the i1 suction means 14 is operated to reduce the pressure in the exhaust chamber 8 to 2Q Torr.

[Third Step] The second shutter S2 is opened, the exhaust chamber 8 and the processing chamber 9 are communicated, and the trolley 13 carrying the synthetic resin product 3 is transferred from the exhaust chamber 8 to the processing chamber 9. At this time, the pressure in the exhaust chamber 8 and the processing chamber 9 is 20 Torr, and there is no pressure difference, so that the synthetic resin product 3 is smoothly transferred.

Thereafter, the second shutter S2 is closed, air is gradually introduced into the exhaust chamber 8, the pressure inside the exhaust chamber 8 is gradually returned to atmospheric pressure, and when the pressure is restored to atmospheric pressure, the first shutter S1 is closed. is opened to prepare for the next injection of 30 synthetic resin products.

[Fourth step] The mechanical booster 18 of the second suction means 15 is newly activated to adjust the inside of the processing chamber 9 to a second X vacancy, for example, Q, 4T.
Reduce pressure to orr. At this time, the inside of the processing chamber 9 is already 2
Since the pressure has been reduced to 0 Torr, the pressure is 0.4 Torr.
The mechanical booster 18 quickly reduces the pressure to rr.

[Fifth step] When the pressure inside the processing chamber s is reduced to 0.4 Torr, the plasma generation means 23 generates plasma
, gas, and N gas are introduced into the processing chamber 9, and the synthetic resin product 3 is subjected to plasma treatment for a predetermined time at a pressure of, for example, I Torr.

In such plasma treatment, the addition reaction of the synthetic resin and the extraction reaction of atoms by ionized Ot gas are carried out as follows.

RH+0. ' →ROOM ROOH-+RO-+80・RH+20・→R・10B・102 Furthermore, the following reaction occurs between oxygen, synthetic resin, and active ingredient.

R. 10, →ROO.

RO, 10R'H-+ ROH+R'- ROOe ten R'H-+ R00H ten R'.

ROO-+R'H-+ROR+HO- R-+R'o, -+ROR'R-10R'OO-+R00R' 2ROOH-+R=0+g, 10ROO・In this way, -0H1C is applied to the surface of the synthetic resin product 30. =O1-00H
It is estimated that polar groups such as , -0-, etc. are generated.

[Sixth step] Air is introduced into the processing chamber 9, and the pressure inside the processing chamber 9 is reduced to 2 C.
Return to VTorr.

[Seventh step] The third shutter S3 is opened, the processing chamber 9 and the discharging chamber 9 are communicated, and the trolley 13 carrying the synthetic resin product 3 is moved to the processing chamber 9.
from there to the dispensing chamber 10. At this time, the pressures in the processing chamber 9 and the discharging chamber 10 are 20 Torr, and there is no pressure difference, so the movement of the synthetic resin product 3 is performed smoothly. Thereafter, the third shutter S3 is closed to cut off the processing chamber 9 and the dispensing chamber 10.

[Eighth step] After introducing air into the dispensing chamber 10 and returning the pressure inside the dispensing chamber 10 to atmospheric pressure, the fourth shutter S4 is opened and the cart 13 is moved from the dispensing chamber 10 to the dispensing zone 6. move it to
The synthetic resin product 3 that has been subjected to painting pretreatment is taken out.

In this way, a series of pretreatment steps are completed.
By repeating the eighth step, the pre-painting treatment of the synthetic resin product 3 is performed one after another.

Painting is applied to the synthetic resin product 3 that has been subjected to the painting pretreatment as described above.

Table 1 shows the results of measuring the adhesion strength of the coating film after coating the test pieces that were actually pretreated using the coating pretreatment device 1.

Table 1 In Table 1, in test A, test pieces T1 to T5 made of polypropylene were treated with plasma for 20 hours.
In test B, the plasma treatment time was 1 sec.
In test C, the plasma treatment time was set to 10 seconds, and 10 consecutive treatments were performed. After pretreatment, each test piece T1 to T5 was coated with urethane paint, and then baked at 85°C for 30 minutes.
After a further 48 hours had passed, the adhesion strength was measured.

For further reference, the adhesion strength when coating without plasma pretreatment is shown.

As is clear from Table 1, the adhesion strength of the coating film that was pretreated with plasma showed a high value of about IK9/cm, whereas the adhesion strength of the coating film that was not pretreated showed
Only a low value of 0.03-0.05 kg/CTL can be obtained.

According to the painting pre-treatment device 1 as described above, it takes only about 1 minute to move the synthetic resin product 3 from the input zone 5 to the discharge zone 6 and pre-treat it, and the synthetic resin product 3 can be processed rapidly and continuously.

Effects of the C0 Invention As described above, according to the method of the present invention, synthetic resin products to be subjected to pre-painting treatment pass sequentially through the exhaust chamber, treatment chamber, and discharge chamber, which are successively arranged so as to be able to communicate with and shut off from each other. The first step is to reduce the pressure to a preset first degree of vacuum while keeping the processing chamber and the dispensing chamber isolated from each other, and the synthetic resin product is introduced into the exhaust chamber that is isolated from the processing chamber. Thereafter, a second step of reducing the pressure in the exhaust chamber to the first degree of vacuum, and a step of communicating between the exhaust chamber and the processing chamber to transfer the synthetic resin product from the exhaust chamber to the processing chamber, and then blocking the exhaust chamber and the processing chamber. and a fourth step of reducing the pressure in the processing chamber to a second degree of vacuum lower than the first degree of vacuum.
a fifth step in which the synthetic resin products in the processing chamber are plasma-treated; a sixth step in which the processing chamber pressure is returned to the first degree of vacuum; and a sixth step in which the processing chamber and the discharging chamber are communicated to remove the synthetic resin products from the processing chamber. A seventh step of shutting off the processing chamber and the dispensing chamber after transferring the product to the dispensing chamber, and an eighth step of discharging the synthetic resin product after the pressure in the dispensing chamber is allowed to return to atmospheric pressure are sequentially performed. Therefore, the pressure can be reduced to the second degree of vacuum necessary for plasma processing in the processing chamber in a short time, and the pressure difference when the synthetic resin product is moved between the exhaust chamber, processing chamber, and discharge chamber can be reduced. It is possible to carry out smooth movement without any need for cleaning, and pre-painting treatment of synthetic resin products can be carried out continuously using plasma.

Further, according to the apparatus of the present invention, a conveying means for penetrating the inside of the casing configured in a tunnel shape and conveying the synthetic resin product to be subjected to painting pretreatment is arranged, The casing is provided with four shacks that can be opened and closed in order to divide the shack into an exhaust chamber, a processing chamber, and a dispensing chamber in order along the direction, and the exhaust chamber and dispensing chamber have predetermined indoor pressures. First suction means for reducing the pressure to a first degree of vacuum are individually connected, and a second suction means for reducing the pressure to a second degree of vacuum, which is lower than the first degree of vacuum, is connected to the processing chamber. At the same time, since the plasma generating means is connected, communication between the exhaust chamber, the processing chamber, and the discharging chamber can be easily established and interrupted, so that the synthetic resin product can pass through each of these chambers one after another. , it becomes possible to continuously apply plasma treatment to synthetic resin products between treatment chambers.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a vertical side view of the painting pretreatment device, FIG. 2 is a plan view of FIG. 1, and FIG.
The figure is a system diagram showing the configuration of the second suction means, and FIG. 4 is a system diagram showing the configuration of the plasma generation means. 1...Painting pre-treatment device, 2...Kasiig, 3...
・Synthetic resin product, 7... Conveyance direction, 8... Exhaust chamber,
9... Processing chamber, 10... Dispensing chamber, 11... Conveying means, 14... First suction means, 15... Second suction means, 16.17... Rotary pump, 18. ...Mechanical booster, 23...Plasma generation means patent applicant Honda Motor Co., Ltd.

Claims (3)

[Claims] (1) Synthetic resin products to be subjected to pre-painting treatment pass through the exhaust chamber, processing chamber, and dispensing chamber which are arranged in succession so that they can communicate with and shut off from each other. A first step of reducing the pressure to a preset first degree of vacuum while the process chamber remains shut off, and reducing the pressure in the exhaust chamber to the first degree of vacuum after introducing the synthetic resin product into the exhaust chamber which is isolated from the processing chamber. a second step in which the exhaust chamber and the processing chamber are communicated and the synthetic resin product is transferred from the exhaust chamber to the processing chamber, and then the exhaust chamber and the processing chamber are shut off; and a first vacuum is established in the processing chamber. a fourth step of reducing the pressure to a second degree of vacuum, which is lower than the second degree of vacuum; and a fifth step of plasma-treating the synthetic resin products in the processing chamber.
A sixth step in which the pressure in the processing chamber is returned to the first degree of vacuum; and a seventh step in which the processing chamber and the discharging chamber are communicated with each other to transfer the synthetic resin product from the processing chamber to the discharging chamber, and then the processing chamber and the discharging chamber are shut off. A method for pre-painting a synthetic resin product, characterized in that the step and the eighth step of discharging the synthetic resin product after returning the pressure in the dispensing chamber to atmospheric pressure are carried out in sequence. (2) A conveying means for conveying the synthetic resin product to be subjected to painting pretreatment is arranged to pass through the tunnel-shaped casing, and the inside of the casing is sequentially moved along the conveying direction of the conveying means. The casing is provided with four shutters that can be opened and closed to divide the chamber into an exhaust chamber, a processing chamber, and a dispensing chamber, and the exhaust chamber and dispensing chamber are provided with internal pressures up to a predetermined first degree of vacuum. First suction means for reducing the pressure are individually connected, and a second suction means for reducing the pressure to a second degree of vacuum lower than the first degree of vacuum is connected to the processing chamber. A pre-painting treatment device for synthetic resin products, characterized in that a generating means is connected. (3) The first suction means is a rotary pump, and the second
A pre-painting apparatus for synthetic resin products as set forth in claim (2), wherein the suction means is constructed by combining a rotary pump and a mechanical booster.