JP4603422B2 - Surface treatment method for resin tanks - Google Patents

Description

  The present invention relates to a surface treatment method for adding a gas barrier property to a resin tank (container) such as a resin fuel tank, a processing apparatus, and a resin tank subjected to a gas barrier surface treatment.

For example, in a gasoline gasoline tank made of resin, gas barrier properties are added using sulfur trioxide or a gas such as fluorine, chlorine, bromine, etc., in order to prevent the vaporized gasoline from being diffused into the atmosphere. Surface treatment techniques are known.
In this case, it is necessary to remove the excess gas without reacting with the resin using a removing device.
However, if there is a large amount of residual gas, it is necessary to frequently replace this removal filter, which has been one of the causes of high costs.
In addition, since the conventional surface treatment apparatus is a batch treatment method in which a large number of articles to be treated are prepared in a treatment tank, it is difficult to surface-treat only the inside or the outside of the resin tank.
Japanese Patent Application Laid-Open No. 2005-36260 discloses a rotary CVD film forming apparatus, but the efficiency is still not high in that high-frequency supply means, gas introduction means, and the like are provided in each chamber.

Japanese Patent Laid-Open No. 2005-36260

  In view of the above technical problem, the present invention can reduce the amount of the reactive gas used by efficiently reacting the reactive gas with the resin surface, and is effective in shortening the processing time and having high productivity. It is an object of the present invention to provide a surface treatment method and apparatus for tank manufacturing and a surface treatment product.

The surface treatment method for a resin tank according to the present invention has a plurality of chambers for respectively accommodating resin tanks, and the inside of the tank or before or after the step of preheating the tank and the step of preheating the tank And / or a step of reducing the pressure inside the chamber in order to reduce the pressure outside, and applying a gas barrier surface treatment to the reduced pressure chamber before connecting the chamber in which the residual gas exists, And a step of preliminarily performing a surface treatment, and a step of depressurizing the inside of the chamber into which the residual gas has been fed and then injecting a reactive gas .

The present invention is characterized in that the resin tank is reacted with a reactive gas while being heated and held at a predetermined temperature.
Therefore, the decompression in the chamber may be performed after the tank is preheated or before.
The reason why the reactive gas is injected into the decompressed portion here is that it is not always necessary to decompress the entire chamber. For example, when the surface treatment only needs to be performed inside the resin tank, only the inside of the tank is used. The pressure is reduced, and a reactive gas is injected into the reduced pressure portion for surface treatment.

Particularly characteristic in the present invention is that the step of injecting the reactive gas into the decompressed portion includes the step of injecting the residual gas used for the surface treatment of the previous resin tank, and the step of newly injecting the reactive gas. It is a point which has.
In order to add gas barrier properties to the resin surface, when reacted with a reactive gas such as sulfur trioxide gas or fluorine gas, unreacted sulfur trioxide gas or fluorine gas remains.
The unreacted sulfur trioxide gas or fluorine gas still remains sufficiently reactive.
Thus, by preliminarily surface-treating the next resin tank using this residual gas, it is possible to reduce the amount of gas used and improve productivity.

  When such a surface treatment method is used, a product obtained by selectively surface-treating only one of the inside, only the outside, and both inside and outside of the tank is obtained. For example, a product such as a gasoline fuel tank is obtained.

As an apparatus suitable for the surface treatment according to the present invention, an apparatus that selectively performs gas barrier surface treatment on only the inside, only the outside, or both inside and outside of the tank is preferable. A rotary drive device in which the chambers are arranged in a rotary shape, a heating means for the article to be processed housed in the chamber, a decompression means in the chamber, and a reactive gas injection means into the decompressed chamber, respectively, at predetermined positions It is good to have.

In the surface treatment method for adding gas barrier properties to the resin tank according to the present invention, the tank body is preheated before the surface treatment with the reactive gas to improve the reaction efficiency between the reactive gas and the tank body resin. Therefore, since a predetermined gas barrier property can be obtained with a small amount of gas, the life of the reactive gas removal filter can be extended by reducing the amount of gas used.
Moreover, the surface treatment time is shortened and the production efficiency is improved.
In the resin tank manufacturing apparatus according to the present invention, the residual gas of the gas used in the surface treatment process is recovered, and the residual gas is recycled and used for the preliminary surface treatment of the tank body before the main surface treatment. Therefore, the reaction rate of the gas injected into the chamber with the resin tank body can be increased, and the amount used can be reduced.
If the chamber is equipped with a tank inner gas inlet that connects to the tank body mouth and leads to the tank body hollow part, and a tank outer gas inlet that leads to the void outside the tank, surface treatment for adding gas barrier properties can be performed inside the tank. Since the surface treatment can be performed by selecting the side surface and the tank outer surface, the amount of gas used can be further reduced.

A surface treatment apparatus (hereinafter referred to as an apparatus) for adding a gas barrier property to a resin tank according to the present invention will be described with reference to the drawings.
FIG. 1 (a) shows an explanatory view of the main part of the apparatus 50 as viewed from above, and FIG. 1 (b) shows a longitudinal sectional view of the chamber.
In the apparatus 50, eight chambers 10 are arranged in a rotary shape on a substantially donut-shaped drive table 50a that is rotationally driven.
The number of chambers is appropriately set in consideration of production tact.
The resin tank body 1 which is subjected to the surface treatment and is used as the resin fuel tank 2 is sequentially stored in the chamber 10 in the tank mounting step 51, and the chamber table 50a is rotated in a rotary manner so The heating steps 52 a, 52 b, 52 c, the vacuuming step 53, the surface treatment step 54, the residual gas recovery step 55, and the tank take-out step 56 are sequentially transferred to take out from the chamber in the tank take-out step 56.
In addition, the number of processes is not limited because the preheating process has three stages in order to shorten the production tact.
A cylindrical connection switching unit 40 is disposed at the center of the circumferentially arranged chamber.
And the upper part of each chamber is connection pipes 40a-40h, such as a bellows pipe, and although not shown in figure, each pipe is also provided under these upper pipes, and is connected with the connection switching part 40.
The connection switching unit 40 connects tubes connected to the chambers to tubes 40j and 40k connected to the gas generator (gas injection device) 20 and the vacuum suction device 30, respectively, and tubes of other chambers. It is only necessary to switch the connection depending on the process, for example, a combination of a rotary joint, a valve, and a pipe, and the connection with each pipe is switched by rotating the connection hole position of the rotary joint. In addition, for example, the number of connected branch pipes provided with valves may be switched by opening and closing the valves of the branch pipes, and the structure is not limited.
Each chamber 10 is connected to the gas generator 20, the vacuum suction device 30, or another chamber via the connection switching unit 40.
The vacuum suction device 30 includes a detoxifying filter 31 that removes the sucked reactive gas.

As shown in a longitudinal sectional view of the chamber 10 in FIG. 1 (b), the chamber 10 has a chamber lid portion 11 and a chamber body portion 12 locked by a mounting bracket 19.
A sealing material (not shown) is provided on the mating surface of the lid portion 11 and the main body portion 12.
SUS (bellows) tubes 40a and 40i are connected to the tank inner gas inlet 14 projecting from the top of the lid 11 of the chamber 10 and the tank outer gas inlet 15 projecting from the middle of the lid 11 (see FIG. (Not shown).
In the tank body 1 to be subjected to the surface treatment, the mouth portion 1b of the tank body is attached to the mouth portion 14b of the tank inner gas inlet 14 of the chamber 10 with a seal member 18 interposed therebetween.
In the example shown in FIG. 1, the tank body concave portion 1 e is placed on the convex portion 12 a of the chamber 12 and stored in the chamber 10 so as to press the mouth portion 1 b toward the seal member 18.
The hollow portion 1a of the tank body 1 communicates with the pipe 40a from the mouth portion 1b through the tank inner gas inlet port 14, while the outer side 16 of the void tank body between the tank body 1 and the chamber 10 is a tank outer gas. It communicates with the pipe 40 i through the injection port 15.
Thus, by providing the tank inner gas inlet 14 leading to the tank body hollow portion 1a and the tank outer inlet 15 leading to the void portion 16 outside the tank body, surface treatment of the inner surface 1c of the tank body 1 can be achieved. The surface treatment of the tank body outer surface 1d or the treatment of both surfaces 1c and 1d can be selectively performed.
Therefore, only the inner side or the outer side can be surface-treated according to the required quality of the tank, and the amount of reactive gas to be used can be minimized.
When performing the surface treatment of the tank body side surface 1c, when performing the surface treatment of the tank body outer surface 1d, and when performing the surface treatment of the both surfaces 1c and 1d, each step is different from the one used for the different gas inlets. Since there is no difference in the operation of the tank, the operations are the same. Therefore, the case where the surface treatment of the tank inner surface 1c is performed will be described as a representative.
The chamber 10 is placed on the recess 50b of the drive table 50a as shown in FIG. 1B, and a heating (preheating) heater unit 13 is provided between the recess 50b of the drive table 50a and the chamber 10. ing.
The heater unit may be a hot water unit or an oil knit, or may be a heat retaining type in which a heat retaining material is laid in the chamber, and is not particularly limited.
The chamber 10 is covered with a heat insulating material 17 around each turntable.

The operation of the apparatus will be described with reference to the explanatory diagram of the process shown in FIG.
FIG. 2 illustrates each process performed simultaneously by the apparatus 50 shown in FIG. 1, and the chamber flows in the direction indicated by the arrow in turn as the drive table 50a rotates.
Moreover, the valve | bulb explaining operation | movement of a connection switching part is drawn typically.
The tank body 1 is mounted in the chamber 10 in the tank body mounting step 51.
And it preheats with the heater 13 with which the chamber 10 was equipped at the preheating process 52a, 52b, 52c.
In the preheating step 52c before the evacuation step 53, the tank body is adjusted so that the reactivity between the tank body 1 and the reactive gas is in a temperature range of 50 to 100 ° C., preferably 50 to 80 ° C. Heat evenly.
In the next evacuation step 53, the connection switching unit 40 shown in FIG. 1A is switched to connect the tube 40e and the tube 40k, and the tank inner gas inlet 14 and the vacuum suction device 30 of the chamber 10 in the evacuation step are connected. And connect.
FIG. 3 is an explanatory diagram showing the operation of the connection switching unit 40 by a valve operation.
At this time, the valve 41c shown in FIG. 3 (a) is opened, the tank inner gas inlet 14 and the vacuum suction device 30 are connected, and the hollow portion 1a of the tank body 1 is evacuated.
In this case, the tank outer gas inlet 15 is closed by the connection switching unit 40.
Then, after evacuating the hollow portion 1a, the connection switching unit 40 is switched to close the valve 41c, open the valve 41b, and connect the tube 40e and the tube 40g as shown in FIG. The tank inner gas inlet 14 of the chamber of the drawing step 53 is connected to the tank inner gas inlet of the chamber of the residual gas recovery step 55.
Thus, when connecting a gas inlet with the gas inlet of another chamber, the same kind of gas inlets are connected.
In the hollow portion 1a of the tank body 1 in the residual gas recovery step 55, there is a residual gas of the reactive gas that is injected into the hollow portion 1a in the surface treatment step 54 described later and remains without reacting with the tank body 1.
Therefore, when connected to the gas inlet 14 on the side evacuated in the evacuation step 53, the residual gas in the hollow portion 1a of the tank body 1 in the residual gas recovery step 55 is transferred to the tank hollow portion 1a on the evacuation step 53 side. Be drawn.
Thereby, preliminary surface treatment (residual gas coating) can be performed with the residual gas.

In the next surface treatment step 54, the valve 41d shown in FIG. 3 (a) is opened to connect the tube 40f and the tube 40k in FIG. 14 and the vacuum suction device 30 are connected, and the hollow portion 1a into which the residual gas is injected is evacuated to 70 torr or less by passing through the evacuation step 53.
Next, the connection switching unit 40 is switched, the valve 41d is closed and the valve 41a is opened as shown in FIG. 3B, and the bellows tube 40f and the bellows tube 40j shown in FIG. The in-tank gas inlet 14 of the chamber in the processing step 54 and the gas generator 20 are connected.
Then, a reactive gas such as sulfur trioxide gas or fluorine gas generated by the gas generator 20 is injected into the tank body hollow portion 1a from the tank inner gas injection port, and the surface treatment of the tank body side surface 1c is performed.
The pressure of the reactive gas is preferably about 0.1 atm as the reactive gas partial pressure.
As the surface treatment, a method of sulfonating the surface of the tank body with sulfur trioxide, or a method of halogenation using fluorine (hydrogen fluoride), chlorine, bromine or the like can be considered.
The tank body is kept warm with the heat insulating material at the preheated proper temperature in the preheating steps 52a, 52b, and 52c, so that the reaction efficiency between the reactive gas and the tank body 1 is good. Therefore, the surface treatment can be performed with a small amount of gas used.

After the surface treatment step 54 is finished, it is injected into the tank body hollow portion 1a in the surface treatment step 54 as shown in FIG. There is residual gas left without.
As described above, after the inside of the tank gas inlet 14 of the chamber in the evacuation step 53 is evacuated as described above, the connection switching unit is switched and the valve 41c is closed as shown in FIG. Then, the valve 41b is opened, and the surface treatment in the residual gas recovery process 55 is finished, and the tank body 2 is sent to the hollow part 1a of the tank body 1 in the evacuation process 53 that has been evacuated.
In this way, the remaining gas remaining without reacting with the tank body 1 in the surface treatment step 54 is sent to the tank body 1 before the surface treatment step 54 for preliminary surface treatment. The reaction rate of the body with the resin increases.
Accordingly, the gas barrier property of the tank body can be increased, the amount of the reactive gas to be exhausted can be reduced, and the life of the removal filter for removing the reactive gas can be extended.
The chamber after the residual gas is sent is connected to the vacuum suction device 30 by switching the connection switching unit 40, purged inside, and the tank body (resin fuel tank product) 2 that has been surface-treated in the tank body removal step 56 Take out.

In order to confirm the effect of the preliminary heating of the tank body, the gas barrier property between the tank body subjected to the processing method for adding the gas barrier property according to the present invention and the tank body subjected to the conventional processing technique as an example of a gasoline fuel tank A comparative experiment was conducted.
FIG. 4 shows the experimental results.
As the tank body, a molded product (capacity: about 2 L) obtained by blow molding high density polyethylene (manufactured by Asahi Kasei Chemicals Corporation, Suntec B470) was used.
The temperature of the tank body for performing the surface treatment with the reactive gas was preheated in the case of the treatment to which the present invention was applied, and the temperature was set to 50 ° C. (Example 1).
On the other hand, the temperature of the tank body to which the conventional processing method was applied was room temperature (Comparative Example 2).
Each tank body is accommodated in a chamber, the inside of the chamber (reactor) is depressurized to 1 mmHg, and then a mixed gas of sulfur trioxide and nitrogen is injected until the inside of the chamber reaches 700 mmHg. In the case of Example 1, the tank body was left in the chamber for 1 hour, and in the case of the conventional treatment method, 4 hours.
The mixed gas was 50 torr sulfur and 650 torr nitrogen in Example 1 of the present invention, and 140 torr sulfur and 560 torr nitrogen in Comparative Example 2 of the prior art.
An experiment was also conducted as Comparative Example 1 for a tank body that was not treated with sulfur trioxide.
In the experiment, a regular tank of commercially available regular gasoline was put in a tank (2 L), the fuel filler port was sealed with a fuel-impermeable cap, and then left at 40 ± 2 ° C., then the gas was reduced by the weight reduction method. The amount of permeation was measured.
In the experimental results shown in FIG. 4, the gas permeation amount is shorter in the permeation amount in Example 1 of the present invention, which is a quarter of that in Comparative Example 2 of the prior art, and the amount of sulfur trioxide is also small. Regardless, the result was an excellent result of 8.5 g / m ² / day, which was less than the transmission amount of Comparative Example 2 of 9.0 g / m ² / day.
Moreover, even if the amount of nitrogen is reduced as in Example 2 where sulfur trioxide is 50 torr and nitrogen is 50 torr, the permeation amount is as small as 7.0 g / m ² / day. The amount tends to be small.

The explanatory view of the gas barrier property addition processing device of the resin fuel tank concerning the present invention is shown. Explanatory drawing of the process of a gas barrier property addition processing apparatus is shown. Explanatory drawing of a vacuum drawing process, this surface treatment process, and a residual gas collection | recovery process is shown. The comparative experiment result of the gas barrier property when the tank body is preheated and when it is not preheated is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resin tank body 1a before gas barrier property addition process Hollow part 1b of tank body 1c Tank body side 1d Tank side surface 1d Tank body outer surface 1e Tank recessed part 2 Resin tank body after gas barrier property addition process (resin fuel tank product) )
10a, 10b, 10c, 10d, 10e chamber 10f, 10g, 10h chamber 11 chamber lid 12 chamber body 12a chamber body projection 13 heating (preheating) heater unit 14 tank inner gas inlet 14a tank inside Gas inlet outer port 14b Tank inner gas inlet inner port 15 Tank outer gas inlet 16 Empty portion 17 Heat insulating material 18 Seal member 19 Mounting bracket 20 Gas generator (gas injector)
30 Vacuum suction device 31 Detoxification filter (removal filter)
40 Connection switching units 40a, 40b, 40c, 40d, 40e, 40f Connection pipes 40g, 40h, 40i, 40j, 40k Connection pipe 50 Surface treatment device 50a Rotary drive table 50b Rotary drive table recess 51 Tank body attaching process 52a, 52b, 52c Preheating process 53 Vacuuming process 54 Main surface treatment process 55 Residual gas recovery process 56 Tank body extraction process

Claims (1)

It has a plurality of chambers each containing a resin tank, and the inside of the chamber is decompressed in order to decompress the inside or / and outside of the tank before or after the step of preheating the tank and the step of preheating the tank. A step of performing a gas barrier surface treatment on the decompressed chamber earlier and connecting the chamber in which the residual gas exists, thereby sending the residual gas into the chamber and performing a preliminary surface treatment. And a step of depressurizing the inside of the chamber into which the residual gas has been sent in and then injecting a reactive gas anew .

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