KR20040085242A - Method and Device of Surface Modification for the Inner Wall of Polymer Container - Google Patents

Abstract

PURPOSE: A method and a device for the surface treatment of the inside of a polymeric container are provided to modify the inner surface for the purpose of improving hydrophilicity, hydrophobicity, adhesive property, biocompatibility and gas barrier property, etc. CONSTITUTION: The method for the surface treatment of inside of a polymeric container comprises the steps of: (a) wrapping a polymeric container(7) with a conductive cover(8); (b) positioning the polymeric container(7) on a sample holder(11) in a vacuum reservoir(1); (c) shielding the polymeric container(7) and the sample holder(11) with an insulation body(10); (d) introducing a plasma source gas selected depending on the particular purpose of surface modification into the vacuum reservoir(1); and (e) discharging the gas to form plasma(6) and applying negative high-voltage pulse to the conductive cover(8) and the holder(11) so as to introduce gas plasma ions into the container at high energy, or introducing ions while generating plasma directly by using a strong electric field caused by high-voltage pulse applied to the holder(11) and ground electrode(9) inserted in the container(7) under high pressure.

Description

Method and device for surface treatment inside polymer container {Method and Device of Surface Modification for the Inner Wall of Polymer Container}

The present invention relates to a method and an apparatus for surface treatment of an interior of a polymer container by plasma ion implantation. More specifically, the present invention relates to a surface treatment method and apparatus for treating an inner surface of a container made of a polymer material by plasma ion implantation to improve an inner surface property of the container.

Polymers are used in various industrial fields because they are light, easy to process, transparent, and have good insulating properties. However, polymers have been limited in their use due to their inherent properties such as lack of hydrophilicity, adhesion, and biocompatibility. In order to solve the shortcomings of the polymer material, various surface treatment methods such as chemical treatment, corona treatment, plasma treatment, and ion implantation treatment have been developed, but there are many problems in treating the inside of the container.

For example, in the case of chemical treatment, it is generally possible to treat the surface, but the surface treatment process by such chemical treatment is cumbersome, and contaminants are generated during the process, which is environmentally harmful. In this case, there is a problem that the treated layer after the treatment is very thin and easily deteriorates with time.

In addition, in the case of the surface treatment of the polymer material by the ion beam, which moves the polymer material or moves the ion beam to treat the surface of the material, the ion beam proceeds in the vertical direction. There is a problem that the container inner wall surface cannot be treated.

The inventors of the present invention, by installing a conductive metal grid on the sample stage to enable plasma ion implantation on the surface of the three-dimensional polymer sample, by modifying the surface of the polymer and hydrophilicity of water on the surface of the polymer, and other materials A method of surface modification of a three-dimensional solid polymer material to improve adhesion and surface conductivity has been disclosed (Korean Patent No. 351516, Japanese Patent No. 3220445, and US Patent No. 6,403,167), but a high voltage is simply applied to the sample stage on which the sample is placed. In addition, in the internal processing of the polymer container, since the polymer container is an insulator which is not electrically conductive, the effect of ion implantation cannot be achieved. This made it difficult to handle the inside of the container.

As described above, the plasma ion implantation technique using plasma and high voltage pulses is a technique capable of achieving surface modification by uniformly injecting ions into the surface of a large-area three-dimensional solid sample, but when treating the inside of the container of the polymer material, Since it is an insulator and only the surface in the vertical direction can be processed, the inside of the container cannot be effectively processed.

Accordingly, an object of the present invention is to modify the inner surface by allowing plasma ion implantation into the inside of the container form made of a polymer, so that the interior surface of the polymer container such as hydrophilicity, hydrophobicity, adhesiveness, biocompatibility, and gas permeation prevention The present invention provides a method and apparatus for improving the characteristics.

1 is a schematic diagram of a plasma ion implantation apparatus according to the present invention for surface modification inside a polymer container.

FIG. 2 shows water contact angles measured at the bottom surface of each container and the inner surface 1.5 cm, 3 cm and 4.2 cm from the container inlet after injection of plasma ions into the PET and LDPE containers in Example 1 of the present invention. Graph showing the results.

Figure 3 is a graph comparing the water contact angle measured after treating the PET container in Example 2 of the present invention by the conventional plasma method and the plasma ion implantation method of the present invention, respectively.

Figure 4 is a graph showing the water contact angle according to the frequency, treatment time and post-treatment atmospheric exposure time in Example 3 of the present invention.

Figure 5 compares the results of measuring the adhesion of each of the PET and LDPE containers not plasma-treated, the PET and LDPE containers conventionally plasma-treated and the PET and LDPE containers treated with plasma ion implantation according to the present invention. graph.

<Description of the code for the main part of the drawing>

1 .: vacuum chamber 2 .: vacuum pump

3 .: RF power supply 4 .: Matching network

5 .: Antenna 6 .: Plasma

7 .: Polymer container 8 .: Conductive cover

9 .: grounded electrode 10 .: insulator

11 .: sample stand 12 .: high voltage pulse generator

13 .: Gas introduction device 14 .: Vacuum chamber ground

The present inventors have diligently studied to solve the above-mentioned problems. As a result, when the vessel surrounded by the conductive material is placed on the sample stage and a negative high voltage pulse is applied to the sample stage, ions are extracted from the plasma and accelerated perpendicularly to the inner wall of the vessel. The inner surface of the polymer container is modified by the ions injected uniformly into the polymer container and injected with constant energy, thereby improving the hydrophilicity or hydrophobicity, adhesion, biocompatibility, and gas permeability of the polymer container. It has been found that the present invention has been achieved.

Hereinafter, with reference to the accompanying Figure 1 which is a schematic diagram of a plasma ion implantation apparatus according to the present invention, the present invention is not limited thereto.

The present invention

(a) surrounding the polymeric container 7 with a conductive cover 8,

(b) placing the polymer container 7 on the sample stage 11 in the vacuum chamber 1,

(c) covering the polymer container 7 and the sample bed 11 with the insulator 10,

(d) introducing a selected plasma source gas into the vacuum chamber 1 according to the desired surface modification,

(e) after discharging the gas to form a plasma 6, a negative high voltage pulse is applied to the conductive cover 8 and the sample stage 11 to inject gas plasma ions into the polymer container at high energy; Or simultaneously implanting ions while generating a plasma directly by using a strong electric field caused by a high voltage pulse applied to the grounded electrode 9 and the sample stage 11 installed in the polymer container 7 at a high pressure.

It provides a method of treating the inner surface of the polymer container comprising a.

The present invention also provides a vacuum chamber (1) grounded to electrical ground; Vacuum pump 2; A gas introduction device 13 for introducing a plasma source gas into the vacuum chamber 1; An antenna 5 for generating a plasma 6 using the introduced gas; Vacuum chamber ground 14; Power supplies such as RF power supply 3 and matching network 4; A conductive cover 8 surrounding the polymer container 7 to which a negative high voltage pulse is applied to accelerate the plasma ions for ion implantation; A sample table 11 for supporting a conductive cover; An insulator 10 for protecting the polymer container 7 and the outer portion of the sample stage 11; Grounded electrode 9; And a high voltage pulse generator 12 for generating the required high voltage pulses.

Polymer materials that can be surface modified according to the method of the present invention include polystyrenes, polyethylene terephthalates, polyethylenes, polypropylenes, polyacrylates, polymethyl methacrylates, polyhydroxyethyl methacrylates, Synthetic resins such as polyvinyl chlorides, polyethylene naphthalates, polycarbonates, silicones, and the like, but are not limited thereto.

Oxygen, nitrogen, hydrogen, carbon monoxide, carbon dioxide, ammonia, etc. may be used as a plasma source of the reactive gas for forming hydrophilic functional groups on the inner surface of the polymer container, and methane, CF ₄ , C ₂ F ₆ , C ₃ F _8, or a mixed gas thereof may be used. Argon, neon, helium, krypton, xenon, and the like may be used as the plasma source of the inert gas for improving the adhesion by forming chemical radicals on the inner surface, but is not limited thereto.

In addition, the plasma of the injected gas may be generated by a power supply such as an antenna (5), a matching network (4) and an RF power device (3) in the vacuum chamber (1), or a general plasma generator such as filament may be used. Alternatively, ion implantation may be simultaneously performed while generating a plasma directly by using a strong electric field caused by a high voltage pulse applied to the grounded electrode 9 and the sample stage 11 installed in the container at a high pressure, but is not limited thereto. It is not.

The conductive cover (8) surrounding the sample vessel is constructed so that the separation distance from the outer surface of the polymer vessel is less than 5 mm so that ions can be efficiently and uniformly injected into the vessel inner surface from the plasma generated in the vessel. The cover is mainly made of thin stainless steel barrel or aluminum foil, but other conductive materials may be used.

According to the present invention, the high voltage pulse applied to the conductive cover 8 and the sample stage 11 is -100 V to -20 kV, the voltage at pulse-off is 0 V to -1 kV, and the pulse width is 1 kV to 50 kV. The pulse frequency is 10 Hz to 10 kHz. If the voltage of the high voltage pulse is less than -100 V, it is almost similar to the plasma effect, and if it is more than -20 kV, the surface of the polymer container is damaged and the plasma sheath is superimposed to degrade the surface characteristics. In addition, when the pulse width is less than 1 mW, the plasma ion implantation effect is hardly observed, and when the pulse width is 50 mW or more, the pulse is long and exhibits the characteristics of direct current (DC).

According to the method of the present invention, since the energy of the ions perpendicularly incident on the inner surface of the sample by the conductive cover is much higher than the ion energy of the polymer surface modification method using the conventional plasma, the surface modification effect is excellent and the surface is modified to the deeper layer below the surface. It is possible to effectively prevent surface degradation over time after the treatment.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples.

<Example>

Water contact angle and adhesive force in the following Examples were carried out according to the following measuring method.

How to measure water contact angle

The water contact angle measuring device (manufactured by Remhart Co., Ltd.) was measured using the static cecidrop method.

How to measure adhesion

The adhesion test was measured using a 90 degree peel tester (manufactured by Sangyo). The unit is gf (grams of force).

<Example 1>

Cylindrical polyethylene terephthalate (PET) containers 1 mm thick (50 mm in diameter and 50 mm in height) and 1.5 mm thick LDLD containers (70 mm in diameter and 45 mm in height) are placed in stainless steel cans, respectively. Was surrounded by metal and placed on a sample bed in a plasma ion implantation device having a vacuum degree of 10 ^-5 Torr in a vacuum chamber, and then the container and the sample bed were protected with Pyrex.

Oxygen gas was supplied into the apparatus at a flow rate of 5 sccm and plasma was generated in a vacuum chamber using RF waves with a frequency of 13.56 MHz and an output of 100 W. At this time, the ion implantation conditions were -5 kV pulse voltage applied to the sample stage and the container cover, -80 V voltage at the pulse-off, pulse width was 5 kHz and pulse frequency was 2 kHz. After generating the oxygen plasma in this manner, each of the PET and LDPE container samples was treated for 3 minutes.

After the samples treated in the vessel were exposed to air for 1 hour, the water contact angles were measured at the bottom surface of each sample, 1.5 cm, 3 cm, and 4.2 cm from the container inlet, and the results are shown in FIG. 2.

From the results, it was found that the water contact angle of the inner surface of the sample subjected to plasma ion injection was significantly reduced compared to the water contact angle of the inner surface of the untreated container. In particular, in the case of PET containers, the water contact angle was reduced to less than 10 degrees, indicating that the inside of the container was effectively surface treated.

<Example 2>

A cylindrical PET container (50 mm in diameter, 110 mm in height) having a thickness of 1 mm was placed in a stainless steel barrel, surrounded by metal and placed on a sample table in a vacuum chamber, under the same conditions as in Example 1 using oxygen gas. Treatment was by plasma ion implantation.

After 3 minutes of surface treatment, the sample was exposed to air for 1 hour, and the water contact angles of the inner and bottom surfaces 2 cm, 4 cm, 6 cm, and 8 cm away from the container entrance, and the inside of the container treated with the conventional plasma method. The water contact angle of is shown in FIG.

The water contact angle inside the vessel implanted with plasma ion showed a very low value, which showed superior hydrophilicity improvement compared to the surface treatment by the conventional plasma, and it was found that the inside of the vessel was uniformly treated by showing a constant water contact angle depending on the position.

<Example 3>

A 200 mm output RF plasma was placed in a vacuum vessel in which 10 ^-3 torr of oxygen gas was injected after placing a cylindrical PET container (50 mm in diameter and 110 mm in height) with a thickness of 1 mm and surrounding the outside of the container with aluminum foil. After applying the high voltage of -5 kV at 5 ㎲ pulse width and 1 kHz and 2 kHz frequency to the sample wrapped aluminum and the sample stage, it was treated with plasma ion implantation for 5 minutes and 3 minutes respectively, and then 2cm, 4cm, 6cm , Water contact angle was measured according to the exposure time of the inner surface and the bottom surface to the air 8cm away. Figure 4 shows a graph comparing water contact angles showing surface hydrophilicity in order by position at 2 cm, 4 cm, 6 cm, 8 cm and bottom.

The inner wall of the vessel treated for 5 minutes at 1 kHz frequency showed better hydrophilicity, and there was no difference between the positions of the inner surface of the vessel, indicating that the vessel was uniformly treated. It also showed stability against deterioration.

<Example 4>

Cylindrical polyethylene terephthalate (PET) containers 1 mm thick (50 mm in diameter and 50 mm in height) and 1.5 mm thick LDLD containers (70 mm in diameter and 45 mm in height) are placed in stainless steel barrels, respectively. Was surrounded by metal and placed on a sample bed in a vacuum chamber, and then treated with plasma ion implantation under the same conditions as in Example 1 using argon and nitrogen gas.

After exposing the sample treated with plasma ion implantation for 3 minutes to air for 1 hour, the adhesive force with the tape was measured on the inner surface 3 cm away from the inlet of the container, and is shown in FIG. 5 together with the adhesive force inside the vessel treated with the conventional plasma method. It was. Compared to the adhesion of the inner surface of the untreated container, the adhesion of the inner surface of the sample subjected to plasma ion implantation was greatly increased, and more effective when argon was used as the plasma source.

The adhesion inside the vessel implanted with the plasma ion was greater than the adhesion of the sample treated by the conventional plasma method, and the surface adhesion within the vessel treated by the present invention was further improved.

When the inside of the polymer container is treated with the conductive cover according to the method of the present invention, even if the polymer container is an insulating material, plasma ions of the gas contained in the container are accelerated by the voltage applied to the conductive cover and injected vertically to the inner surface of the container. Therefore, the surface properties including hydrophobicity or hydrophilicity, adhesion, biocompatibility, and gas permeation resistance are improved, and the layer to be modified is deep so that the deterioration of the properties is much less. Therefore, the present invention is very effective in changing the surface properties inside the polymer container.

Claims (5)

(a) surrounding the polymeric container with a conductive cover, (b) placing the polymer container on the sample stage in the vacuum chamber, (c) screening the polymer container and sample bed with insulators, (d) introducing a selected plasma source gas into the vacuum chamber in accordance with the desired surface modification, and (e) after discharging the gas to form a plasma, a negative high voltage pulse is applied to the conductive cover and the sample stage to inject gas plasma ions into the polymer container at high energy, or is inserted into the polymer container at a high pressure. And simultaneously implanting ions while generating a plasma using a strong electric field caused by a high voltage pulse applied to the grounded electrode and the sample stage. The method of claim 1, wherein in step (a) the polymer container is surrounded by the conductive cover such that the inner surface of the conductive cover is in close contact with a distance of less than 5 mm from the outer surface of the polymer container. The method of claim 1, wherein the plasma source gas is oxygen, nitrogen, hydrogen, argon, neon, helium, krypton, xenon, carbon monoxide, carbon dioxide, ammonia, methane, CF ₄ , C ₂ F ₆ , C ₃ F ₈ and mixtures thereof And gas selected from the group consisting of gases. The high voltage pulse applied to the container and the sample stage is a pulse voltage of -100 V to -20 kV, a voltage at pulse-off of 0 V to -1 kV, a pulse width of 1 Hz to 50 Hz, and a pulse frequency 10 Hz to 10 kHz. Vacuum chamber grounded to cell ground; A vacuum pump; A gas introduction device for introducing a plasma source gas into the vacuum chamber; An antenna for generating a plasma using the introduced gas; Vacuum grounding; Power supply; A conductive cover surrounding a sample to which a negative high voltage pulse is applied for accelerating plasma ions for ion implantation; A sample stage for supporting the conductive cover; An insulator protecting the sample and the outer portion of the sample stage; Grounded electrodes; And a high voltage pulse generator for generating the required high voltage pulses.