JPH07256734A - Method and apparatus for producing resin blow molded article - Google Patents

Abstract

PURPOSE:To simply produce a blow molded article having a membrane having good characteristics provided on the inner surface thereof within a short time. CONSTITUTION:A resin molded article is produced by forming a membrane to the inner surface of a resin molded article obtained by blow molding. After the completion of blow molding, an exhaust means is connected to the mouth part of a mold in succession to the separation of the mold from a blow molding machine without taking out the resin molded article from the mold to evacuate the cavity of the resin molded article and, thereafter, a membrane forming means is introduced into the cavity of the resin molded article to form a membrane on the inner surface of the resin molded article under reduced pressure. The membrane forming means contains a vacuum exhaust pipe 8 having the connection port to a vacuum pump at one end thereof and having an O-ring 35 at the other open end thereof, the gas introducing pipe opened to the interior of the vacuum exhaust pipe and the membrane forming means 38, 39 arranged to the leading end of the arm 37 movable at least in the axial direction of the vacuum exhaust pipe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a resin blow-molded product having a thin film formed on its inner surface, and a thin film forming apparatus suitable for use therein.

[0002]

2. Description of the Related Art A resin blow-molded product is widely used because it is lightweight and has excellent mechanical strength such as toughness. Further, a thin film is formed on its surface to impart functionality. Is used for various purposes. For example, a method of forming a metal film of tin, indium, titanium or the like on the surface of a resin molded product by vapor deposition or sputtering and then subjecting this film to anodic oxidation treatment to impart antistatic properties (JP-A-47-21468). Japanese Patent Laid-Open No. 55-154), a method of forming a stannous oxide film on the inner surface of a resin container by vapor deposition to provide gas barrier properties (JP-A-55-154).
No. 254) is disclosed.

Further, in order to coat the film uniformly and efficiently, a vapor deposition substance is previously deposited on the resistance wire, and the resistance wire is heated to coat the vapor deposition substance on the inner surface of the resin molding ( Japanese Patent Laid-Open No. 58-55563), a method of forming a thin film by defining the incident angle of the thin film raw material vapor at the initial stage of thin film coating with respect to the surface of the resin molded product is 30 to 90 ° (Japanese Patent Laid-Open No. Sho 61-61)
-87864) is also known.

However, in any of the above-mentioned methods, since the manufacturing process of the resin molded product and the thin film coating process are performed in separate steps, the manufacturing time becomes long and the elapsed time until the thin film coating after the resin molded product is manufactured. Since the resin molding is long, the surface of the resin molded product is exposed to the outside air to be contaminated and the adhesion of the thin film is lowered, and the characteristics of the thin film itself are deteriorated.

Therefore, the present invention provides a method for easily producing a blow-molded product in which a thin film having good properties is provided on the inner surface of the blow-molded product in a short time without contamination of the inner surface and a method therefor. It is intended to provide a device for use in.

[0006]

First, the present invention relates to a method for producing a resin blow-molded product having a thin film on the inner surface thereof, the method comprising the steps of: After separating the mold and the blow molding machine, an exhaust means was connected to the mouth of the mold to evacuate the inner space of the resin molded product, and then a thin film forming means was introduced into the inner space of the resin molded product. The present invention provides a method characterized in that a thin film is formed on the inner surface of the resin molded product under reduced pressure.

In the method of the present invention, as the blow molding method, any blow molding method such as an extrusion blow molding method, an injection blow molding method, a cold parison type blow molding method or the like can be used. Blow molding conditions are not particularly limited, and conventional molding conditions can be used. Blow molding can be performed as follows, for example. That is, a resin as a raw material (including a resin composition, the same applies below) is heated and melted to be plasticized. The heating temperature varies depending on the resin used, but is usually 150 ° C to 350 ° C,
Hold at this temperature for a sufficient time to plasticize, typically 3-60 seconds. Here, the resin as a raw material is not particularly limited as long as it is suitable for blow molding, and examples thereof include polyolefins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), and polyarylate. (PAR), polycarbonate (PC), polyether sulfone (PES), etc. can be used.

Next, in the case of extrusion blow molding, for example, a resin is extruded to preform a parison, which is placed in a mold and blown with air to expand it. The compressed air pressure at this time is usually 2 to 7 kg / cm ^{2, although} it varies depending on the desired thickness of the molded product, the type of resin, and the like. Then, the mold is cooled to obtain a resin molded product.

In the method of the present invention, after the blow molding is completed, the mold and the blow molding machine are separated from each other without removing the resin molded product from the mold, and then the exhaust is discharged to the mouth of the mold. The inside of the resin molded product is evacuated by connecting the means. The time required from the separation of the mold and the blow molding machine to the connection of the exhaust means is preferably within 5 minutes. When it is exposed to the outside air for a long time, the inner surface of the resin molded product is contaminated, and the characteristics of the film formed thereon are deteriorated and the adhesion is also reduced. As the exhaust means, for example, a general-purpose vacuum pump such as a rotary pump, an oil diffusion pump, a sorption pump, a sputter ion pump, a sublimation pump, a cryo pump, and a turbo molecular pump can be used. Normally,
Rotary pump and other pumps 1 to reduce exhaust time
A mixture of two or more types is used, and after roughly drawing with a rotary pump, another pump is used to exhaust to a predetermined vacuum degree. The ultimate vacuum is usually 10 ⁻⁴ Torr or less, though it varies depending on the thin film forming means used, the type of thin film, and the like.

The vacuum exhaust is preferably performed by using a vacuum exhaust pipe having a connection port to a vacuum pump at one end and a vacuum holding means such as an O ring at the other open end. At that time, the O-ring is pressure-bonded to the mouth of the mold to seal it, and the connected vacuum pump is operated to evacuate the inside of the resin molded product. Here, the mouth of the mold is a connecting portion with the blow molding machine, and air is often blown into the parison through this portion. The vacuum exhaust pipe is not particularly limited as long as it is a material that can withstand vacuum, and for example, a metal pipe such as stainless steel or aluminum can be used. As the O-ring, a general-purpose O-ring made of, for example, silicone rubber can be used.

After the inner space of the resin molded product is evacuated as described above, a thin film forming means is introduced into the inner space of the resin molded product to form a thin film on the inner surface of the resin molded product. The thin film forming means is not particularly limited as long as it can uniformly form a thin film on the inner surface of the resin molded product, but from the viewpoint of thin film homogeneity, high-speed film forming property, ease of operation, etc., the sputtering method,
It is preferably a means for performing a method selected from plasma CVD method and photo CVD method. The thin film forming means preferably uses a magnetron sputter cathode in the case of the sputtering method, preferably uses a coil to generate active plasma in the case of the plasma CVD method, and in the case of the photo CVD method. In order to effectively generate radicals, it is preferable to use a short wavelength light source having a light intensity peak at 400 nm or less.

The above-mentioned thin film forming means may be introduced into the inside of the resin molded product through the above-mentioned vacuum exhaust pipe, but it is integrated with the vacuum exhaust pipe from the viewpoint of downsizing of the entire apparatus, easiness of operation and the like. Is preferred.

The present invention also provides such an integrated thin film deposition apparatus for carrying out the method described above. That is, a vacuum exhaust pipe having a connection port to a vacuum pump at one end and a vacuum holding means (for example, an O-ring) at the other open end, a gas introduction pipe opening into the vacuum exhaust pipe, and the inside of the vacuum exhaust pipe. There is provided a thin film forming apparatus including the installed thin film forming means, and the thin film forming means is installed at least at the tip of an arm movable in the axial direction of the vacuum exhaust pipe. An example of the apparatus of the present invention for performing the sputtering method will be described with reference to FIGS. 1 and 2. However, the apparatus of the present invention is not limited to the sputtering method, and other film forming methods such as plasma CV may be used.
It also includes cases such as the D method and the photo CVD method.

The evacuation pipe 8 has one end connected to a vacuum pump and the other open end having an O-ring 35. The vacuum exhaust pipe 8 is used by being connected to the mouth 16 of the mold via an O-ring 35. The vacuum exhaust pipe 8 has a gas introduction pipe opening to the inside thereof, and introduces gas by the gas introduction valves 32 and 33.
The evacuation tube 8 is also optionally equipped with a vacuum release valve 34. From the gas inlet valve, sputter gas (Ar, Kr, X
e) and, if necessary, reaction gases (O ₂ , N ₂ , N ₂
O, etc.) are introduced and the gas pressure is adjusted to the desired level. The pressure during sputtering depends on the type of thin film to be formed, but is usually
It is 1.0 × 10 ^{−4 to} 1.0 × 10 ⁻² Torr. A magnetron sputter cathode (thin film forming means) 38 is installed at the tip of the arm 37, and a target (for example, ITO) is placed thereon.
At the time of forming the film, a powder sintered body 39 of In ₂ O ₃ and SnO ₂ is installed. When carrying out the sputtering method, after moving the cathode 38 by the arm 37 and placing it at a desired position, a negative voltage is applied to the cathode 38 to generate a sputter discharge and the thin film is applied to the inner surface of the resin molded product. Form a film.
In order to form a uniform film on the inner surface of the resin molded product, the cathode 38 can be moved by the arm 37 during the film formation, if necessary. The arm 37 is a vacuum exhaust pipe 8
It is controlled by an arm drive system 36 installed midway, and can be freely moved at least in the axial direction of the vacuum exhaust pipe 8, preferably in the front, rear, left, right, and up and down directions. The arm drive system 36 is connected to a power source 48 by a lead wire 47. The arm 37 is, for example, a magic hand; a hydraulic system is used to expand / contract in the axial direction of the vacuum exhaust pipe 8 and a known means such as being suspended on an orthogonal rail provided in the drive system 36 to move back and forth and left and right. Can be moved. Further, the power supply from the DC power supply 50 to the cathode 38 is performed via the lead wire 42. The applied power varies depending on the shape and size of the cathode used, target type, pressure, gas type, etc., but is usually 0.5 to 15 W / cm
^{Is 2} . During film formation, the cathode 38 and the target 39 can be appropriately cooled by introducing cooling water from the cooling water introducing valve 44.

Plasma CV is used instead of the sputtering method.
When the D method is used, a coil is installed at the tip of the arm 37. As the gas species introduced from the gas introduction valve, instead of the sputtering gas and the above reaction gas, a gas that is a raw material of a film to be formed, for example, a reaction such as SiH ₄ and O ₂ when a SiO ₂ film is formed. Use gas. After applying a high frequency to this coil to generate plasma discharge, the reaction gas is decomposed to generate radicals, and a thin film is formed on the inner surface of the resin molded product by the subsequent reaction. The vacuum degree at this time depends on the type of thin film to be formed,
Usually, it is 1.0 × 10 ^{−4 to} 1.0 × 10 ⁻² torr. The high frequency power applied to the coil varies depending on the type of reaction gas used, the pressure, the number of turns of the coil, the thickness of the coil, etc., but is usually 0.1.
~ 5.0 kw. Also, optical CV is used instead of the sputtering method.
When the D method is used, a short wavelength light source is installed at the tip of the arm 37. As the gas species introduced from the gas introduction valve, instead of the sputtering gas and the above-mentioned reaction gas, a gas which is a raw material of a film to be formed, for example, SiH ₄ and N ₂ O when forming a SiO ₂ film is used. A reaction gas is used. Electric power is supplied to this light source to emit short-wavelength light to decompose the reaction gas and generate radicals, and a subsequent reaction forms a thin film on the inner surface of the resin molded product. The vacuum degree at this time varies depending on the type of thin film to be formed, but is usually 1.0 ×
It is 10 ^{−4 to} 1.0 × 10 ⁻² Torr. The light source used is preferably a short wavelength light source having a light intensity peak at 400 nm or less in order to effectively generate radicals. Such light sources include arc short lamps, low and high pressure mercury lamps, excimer lasers and the like.

After the thin film is formed, gas introduction and power supply are stopped, the thin film forming means is returned to a predetermined position by retracting the arm, and then the vacuum release valve 34 is opened to bring the inside of the resin molded product to atmospheric pressure. return. As a result, the O-ring that has been crimped to the mouth of the mold is released, so that the vacuum exhaust pipe 8 is removed from the mold and the resin molded product is taken out.

The above-mentioned thin film forming apparatus is preferably installed on a moving carriage so that a thin film can be formed continuously immediately after the completion of blow molding.

[0018]

The present invention will be described in more detail by the following examples. Examples 1 to 4 Using a blow molding machine shown as C in FIG. 1, a propylene resin composition (manufactured by Tonen Chemical Co., Ltd., E200) as a raw material resin is used.
Blow molding was carried out using T). I.e. the hopper
The raw material resin is charged from 21 and heated to 210 ° C in the cylinder 19 to melt it, and kneaded with the screw 20 (rotation speed 70 rp).
m) while pushing out to the front breaker plate 22 part. After moving the blow molding machine with the moving carriage 24 so that the die 23 was directly above the blow molding die 15, the breaker plate 22 was opened and 45 g of the molten resin was extruded into the die 23 to form a parison. Next, the parison was installed in the blow molding die 15, and 5 kg / cm was supplied from the air injection port 17.
Compressed air ( ²⁾ was blown for 10 seconds to mold a bottle having a volume of 500 ml in a mold.

After the blow molding is completed, the blow molding machine located directly above the blow molding die 15 is removed by the moving carriage 24, and the resin molding (bottle) is continuously present in the die,
By moving the moving carriage 1 and operating the lifting carriage 2 up and down,
An O-ring at one end of the vacuum exhaust pipe 8 in the thin film forming apparatus (portion A) was crimped to the mouth 16 of the mold, and the rotary pump was operated to roughly draw the inside of the bottle to 0.1 torr.
It took about 1 minute from the removal of the blow molding machine at the mouth of the mold to the mounting of the O-ring. Next, the turbo molecular pump 4 was operated, and the inside of the bottle was further evacuated to 1 × 10 ⁻⁴ Torr or less.

Next, the magnetron sputter cathode 38 provided at the tip of the arm 37 and the target (In ₂
A powder sintered body of O ₃ and SnO ₂ , a weight ratio of 90:10) 39 was introduced into the bottle by extending the arm 37.

Ar gas (100 SCCM) from the gas introduction valve 32,
O ₂ (0.5SCCM) was introduced from the gas introduction valve 33, and the gas pressure was 4.0
It was set to × 10 ^-3 torr. Further, the cooling water introduction valve 44 and the cooling water discharge valve 45 are opened to open the cathode 38 and the target 39.
Cooling was started, and then a power of 3.0 W / cm ² was supplied to the target 39 from the DC power source for sputtering 50 to generate spatter discharge, and an ITO film was formed on the inner surface of the bottle. The film thickness was 1500 Å.

After the film formation was completed, power supply, gas introduction and cathode cooling were stopped, the arm was retracted, and the magnetron sputter cathode was returned to its original position in the vacuum exhaust pipe. Then, the vacuum release valve was opened to return the inside of the bottle to atmospheric pressure.

After the vacuum exhaust pipe 8 was separated from the mold 15 and the thin film forming apparatus was moved by the moving carriage 1, the mold 15 was opened and the molded product was taken out.

The bottom plate portion of the bottle molded product having the ITO film formed on the inner surface thus obtained was cut out, the resistivity was measured by the four-terminal method, and the adhesive force of the film was evaluated by a tape peeling test. In the tape peeling test, 100 squares of 1 mm square were prepared, and cellophane tape was attached and peeled off to measure the number of remaining squares. The same sample was tested 10 times and evaluated by the average value. The results are shown in Table 1. Comparative Examples 1 to 4 In the same manner as in Examples 1 to 4, except that the time from the removal of the blow molding machine at the mouth of the mold to the mounting of the O-ring took 10 minutes instead of 1 minute. An ITO thin film having a thickness of 1500 angstrom was formed on the inner surface of the blow-molded bottle.

Using the obtained bottle, the resistivity was measured and the adhesion was evaluated in the same manner as in Examples 1 to 4. The results are also shown in Table 1. Comparative Examples 5 to 8 The same operations as in Examples 1 to 4 except that the time from the removal of the blow molding machine at the mouth of the mold to the mounting of the O-ring took 30 minutes instead of 1 minute. An ITO thin film having a thickness of 1500 angstrom was formed on the inner surface of the blow-molded bottle.

Using the obtained bottle, the resistivity was measured and the adhesion was evaluated in the same manner as in Examples 1 to 4. The results are also shown in Table 1.

[0027]

[Table 1]

From the results shown in Table 1, in each of the comparative examples, after the blow molding was completed, the resin molding was exposed to the outside air for a long time before the mold was evacuated, so that the inner surface of the resin molding was contaminated. It can be seen that the characteristics of the formed thin film are deteriorated (that is, the resistivity of the ITO film is high).

[0029]

According to the present invention, a film having good characteristics can be formed on the inner surface of a resin molded product obtained by blow molding with good adhesion. Moreover, the manufacturing time can be significantly reduced as compared with the conventional case.

[Brief description of drawings]

1 is a schematic diagram of an apparatus for carrying out the method of the invention.

2 is a partially enlarged view of the apparatus shown in FIG.

[Explanation of symbols]

 A: Thin film forming equipment part B: Mold part C: Blow molding machine part 1, 24: Moving carriage 2: Lifting carriage 3: Rotary pump 4: Turbo molecular pump 5-7: Vacuum valve 8: Vacuum exhaust pipe 15: Blow Mold 16: Mold mouth 17: Air inlet (compressed air inlet) 18: Band heater 19: Cylinder 20: Screw 21: Hopper 22: Breaker plate 23: Die 32, 33: Gas inlet valve 34: Vacuum release valve 35: O-ring 36: Arm drive system for moving thin film forming means 37: Arm for moving thin film forming means 38: Magnetron sputter cathode 39: Target 40: Cooling water introduction pipe 41: Cooling water discharge pipes 42, 49 : Sputtering lead wire 43: Insulator 44: Cooling water introduction valve 45: Cooling water discharge valve 46: Current introduction terminal 47: Thin film forming means moving arm drive system lead wire 48: Thin film forming means moving arm drive Use working power supply 50: DC sputter power source

Claims (6)

[Claims] 1. A method for producing a resin blow-molded product having a thin film on its inner surface, wherein after the blow molding is completed, the mold and the blow-molding machine are continuously separated without removing the resin molded product from the mold. ,
An exhaust means is connected to the mouth of the mold to evacuate the inside of the resin molded product to vacuum, and then a thin film forming means is introduced into the inside of the resin molded product to form a thin film on the inner surface of the resin molded product under reduced pressure. Forming a film. 2. The method according to claim 1, wherein the time required from the separation of the mold and the blow molding machine to the connection of the exhaust means is within 5 minutes. 3. Vacuum exhaust is performed by using a vacuum exhaust pipe having a connection port to a vacuum pump at one end and an O ring at the other open end, and the O ring is crimped to the mouth of the mold. 3. The method according to claim 1 or 2, wherein the inside of the resin molded product is evacuated by operating a vacuum pump which is sealed and connected. 4. The method according to claim 1, wherein the thin film forming means is a means for performing a method selected from a sputtering method, a plasma CVD method and an optical CVD method. 5. The thin film forming means is a magnetron sputter cathode when performing a sputtering method, a coil when performing a plasma CVD method, or an optical CV.
The method according to claim 4, which is a short wavelength light source having a light intensity peak at 400 nm or less when the method D is performed. 6. A vacuum exhaust pipe having a connection to a vacuum pump at one end and a vacuum holding means at the other open end, a gas introduction pipe opening into the vacuum exhaust pipe, and the inside of the vacuum exhaust pipe. 2. A thin film forming means, wherein the thin film forming means is installed at least at the tip of an arm movable in the axial direction of the vacuum exhaust pipe.
A thin film forming apparatus used in the described method.