JPH07179628A - Method for modifying plastic surface - Google Patents

Abstract

PURPOSE:To improve the rate of surface modification by allowing a dielectric barrier discharge lamp which uses a part or the whole of the enclosure of a radiating space as a radiation outlet to radiate while keeping the thickness of an aq. soln, layer, the shortest radiation passage distance, below a specified value. CONSTITUTION:A sheet 109 of a plastic having C-F bonds (e.g. a polyfluoroethylene) is passed through near the liq. level 23 while the temp. of a radiation outlet in a water tank 21 contg. an aq. soln. 22 of an Al compd. [e.g. Al(OH)3] or a B compd. (e.g. H3BO3) is kept at 250 deg.C or lower with a cooling medium 25. The surface of the sheet thus passing through is modified by exposing it to rays of radiation with wavelengths of 160-200mu emitted from an dielectric barrier discharge lamp 105 sealed with Xe or a gas mainly comprising Xe at as tube wall load of 0.2W/cm<2> while the smallest thickness of the liq. layer, the shortest radiation passage distance, on the top 13 of the radiation outlet of the lamp 105 is kept at 5mum or lower. When the sealed gas is Ar/Cl2 or a Cl compd., the distance is kept at 20mum or lower; when the sealed gas is Ar/F or an F compd., at 2,000mum or lower.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a C-F bond for facilitating painting, printing, adhering of plastics, etc. on the surface of a plastic having a C-F bond. The present invention relates to a method for modifying the surface of a plastic material having the same.

[0002]

2. Description of the Related Art As a method of modifying the surface of plastics, for example, a technique in which a polypropylene resin is brought into contact with an ultraviolet absorbing solvent to irradiate ultraviolet light from a mercury lamp is disclosed in JP-A-64-75079. Done, 19
April 1991, "O plus E, pages 97-102."
It is suggested that the treatment of the fluorine resin should be performed by contacting it with an ammonia compound or a boron compound and irradiating the ultraviolet light of 193 nm emitted from an argon fluorine excimer laser. Recently, a method of irradiating the surface modification of a fluororesin with an aqueous solution of aluminum hydroxide and irradiating it with ultraviolet light having a wavelength of 193 nm from an argon fluorine excimer laser (the 20th anniversary of the Academic Conference of the Laser Society of Japan (13th) Annual Meeting) Conference Proceedings, p. 130), a method of irradiating ultraviolet rays of 172 nm emitted from a dielectric barrier discharge lamp in contact with water for surface modification of polyethylene film (The 54th Annual Meeting of the Japan Society for Applied Physics) Lecture Proceedings No. 1
, Etc. are disclosed, and the surface modification of plastics, which are difficult to paint, print, dye and adhere due to the low activity of the surface, has been actively researched.

In these conventional methods, for example, in the combination of an ultraviolet absorbing organic compound and a mercury lamp described in JP-A-64-75079, it is not possible to sufficiently modify the surface of a fluorine resin, and argon fluorine is used. With the excimer laser, the device is expensive, large, and maintenance is extremely troublesome, and it has not yet been generalized for practical use in the industrial world. In place of the excimer laser, a dielectric barrier discharge excimer lamp whose device is inexpensive, small in size, and easy to handle has recently been developed, and as described above, it has begun to attract attention as a light source for surface modification of plastics.

However, regarding the dielectric barrier discharge excimer lamp, there is an unsolved part regarding the lamp design technology and usage method for surface modification of plastics having a C--F bond whose surface has low activity. Optimal techniques have not been developed for combinations of aluminum compound aqueous solutions and boron compound aqueous solutions.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and its object is to:
(1) A method for efficiently modifying the surface of a fluororesin using a dielectric barrier discharge lamp, (2) a mercury discharge lamp,
By studying an aqueous solution of an aluminum compound, a combination method with an aqueous solution of a boron compound, and the like, CF
A light source for surface modification of plastics having a bond,
It is to find the optimum conditions such as the positional relationship between the light source and the object to be processed, the design of the radiant light extraction part from the lamp, and the tube wall load of the lamp. By this, the surface modification of the plastics having a C—F bond is carried out at a high speed, which makes it suitable for large-scale processing. An object of the present invention is to provide a method capable of inexpensively and rapidly performing surface modification of low activity fluoroplastics.

[0006]

In order to achieve this object, the present invention selects a dielectric barrier discharge lamp as an ultraviolet radiation source, combines a fluorine scavenger in an ultraviolet irradiation process, and combines them as follows. , Set various conditions.

(1) The surface of a plastic having a C—F bond is brought into contact with an aqueous solution of an aluminum compound or an aqueous solution of a boron compound, and the contact portion is filled with xenon or a gas containing xenon as a main component. When irradiating the radiant light from the barrier discharge lamp to modify the surface of the plastics at the contact portion, the lamp configures a part or the whole of the container surrounding the discharge space as the radiant light extraction part, and The shortest radiant light transmission distance of the layer is kept below 5 μm. (2) Dielectric in which the surface of a plastic having a C—F bond is brought into contact with an aqueous solution of an aluminum compound or an aqueous solution of a boron compound, and a gas containing argon and chlorine or a gas containing a chlorine compound is sealed in the contact portion. When irradiating the radiant light from the barrier discharge lamp to modify the surface of the plastics at the contact portion, the lamp configures a part or the whole of the container surrounding the discharge space as the radiant light extraction part, and Minimum radiant ray transmission distance between layers is 2
It is maintained at 0 μm or less. (3) Dielectric in which the surface of a plastic having a C—F bond is brought into contact with an aqueous solution of an aluminum compound or an aqueous solution of a boron compound, and a gas containing argon and fluorine or a gas containing a fluorine compound is sealed in the contact portion. When irradiating the radiant light from the body barrier discharge lamp to modify the surface of the plastics at the contact portion, the lamp configures a part or the whole of the container surrounding the discharge space as the radiant light extraction part, and the aqueous solution. The shortest distance for transmission of radiant light of the layer is maintained at 2000 μm or less.

That is, the feature is the combination of the type of dielectric barrier discharge lamp, the scavenger for fluorine, and the processing conditions.

If a mercury discharge lamp is selected as the ultraviolet radiation source, the following method is preferable. That is, C-F
The surface of the plastic having a bond is brought into contact with an aqueous solution of an aluminum compound or an aqueous solution of a boron compound,
When the contact portion is irradiated with radiant light from a mercury discharge lamp in which mercury is enclosed as a main luminescent material to modify the surface of the plastic of the contact portion, the lamp is a part of a container surrounding the discharge space. Alternatively, the whole is configured as a radiant light extraction part, and the shortest radiant light transmission distance of the aqueous solution layer is 80 μm.
Keep below m.

Here, as will be described later, the dielectric barrier discharge lamp has characteristics which are considerably different from those of the conventional arc discharge lamp and glow discharge lamp, and the inner wall surface area of the container surrounding the discharge space is S (cm ² ). When the electric input is W (Watt), it is advisable to control the lamp so that the value of the wall load W / S is 0.2 or more. Moreover, since the spectral radiation characteristics hardly change even when cooled, at least one of the radiant light extraction part of the container and the part other than the extraction part has a double wall structure,
The temperature of the radiant light extraction portion may be set to 250 ° C. or less by flowing liquid nitrogen into the gap or by making the radiant light extraction portion of the container have a double wall structure and flowing liquid nitrogen into the gap. Cooling water may be used when directly cooling the extraction portion.

The above-mentioned cooling fluid may be used to cool the aqueous solution layer in contact with the plastics. When at least one of the discharge electrodes is in contact with the container, the wall of the container in contact with the electrode is in contact with the container. The temperature of the part is kept below 300 ° C.

[0012]

[Function] The discharge vessel is filled with a discharge gas that forms excimer molecules, and a dielectric barrier discharge (also known as ozonizer discharge or silent discharge. Revised new edition issued by the Institute of Electrical Engineers of Japan (Discharge Handbook), 7th edition, 7th edition, reprinted) (See page 263)
An excimer molecule that forms an excimer molecule by means of which the light emitted from the excimer molecule is extracted, that is, a dielectric barrier discharge lamp, has various characteristics that conventional low-pressure mercury discharge lamps and high-pressure arc discharge lamps do not have. . This lamp itself is known, for example, from Japanese Patent Application Laid-Open No. 2-7353.

In this lamp, when synthetic quartz glass is used as a light-transmitting window member and xenon or a gas containing xenon as a main component is selected as a discharge gas, a wavelength of 1 is obtained.
From wavelength 160nm with a peak of 72nm to wavelength 190
vacuum ultraviolet excimer light having a wavelength of 165 nm to 190 nm can be obtained by selecting a gas containing argon and chlorine or a gas containing a chlorine compound. When a gas containing a compound is selected, the wavelength is 1
Vacuum ultraviolet excimer light having a wavelength of 200 nm is obtained from 80. On the other hand, the absorption wavelength band of an aqueous solution of an aluminum compound or a boron compound is in vacuum ultraviolet light having a wavelength of 200 nm or less, and if the radiant light transmission shortest distance in each solution layer is appropriately selected, the On the surface, C-F bond is cleaved,
The released F is captured by aluminum or boron in the aqueous solution to prevent C—F recombination, and C is bound with other radicals such as O and OH. It is presumed that this makes it possible to change the surface of the plastic having a C—F bond to be hydrophilic.

The dielectric barrier discharge lamp is as described above,
Unlike conventional arc discharge lamps and glow discharge lamps, the spectral radiation characteristics do not change even with strong cooling, so even if the electric input is increased, it can be sufficiently cooled. Even if they are used in close proximity, they have the advantage that they do not cause heat damage to the plastics that are the objects to be irradiated. In particular, in this lamp, the value of the lamp wall load, (electrical input / tube wall area) is 0.2 W
The surface modification speed is remarkably high when the resin is designed to be at least 1 cm ² / cm ² and is used in close proximity to plastics while being sufficiently cooled with liquid nitrogen or water.

In the dielectric barrier discharge lamp, since excimer light generated from the discharge has a small self-absorption, the lamp container is designed to be long in a rod shape or a plate shape, and a discharge current is passed in a direction orthogonal to the longitudinal direction. The emitted light can be taken out from the longitudinal direction. Therefore, it is easy to obtain a strong light beam.

As the vacuum ultraviolet light, light having a wavelength of 185 nm emitted from a mercury discharge lamp can also be used, and a plastic having a C—F bond can be used in consideration of the absorptivity of an aqueous solution of an aluminum compound and an aqueous solution of a boron compound. When used in close proximity, the speed of surface modification is significantly high.
In this case, water is better than liquid nitrogen when cooling is required. Further, when water is used to cool the lamp, the aluminum compound aqueous solution and the boron compound aqueous solution which are in contact with the surface of the plastics are also cooled at the same time to prevent the boiling of the liquid and the temperature rise of the plastics. .

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an illustration of a design example of a dielectric barrier discharge lamp used in the present invention. In the figure, 1 is a flat box-shaped container made of synthetic quartz glass containing 400 ppm by weight of OH. The wall thickness is 1 mm, the size is the internal dimension, vertical direction 20 cm, lateral direction 3 m
m, 30 cm in the depth direction perpendicular to the paper surface. A pair of electrodes 2 and 2 are provided on a pair of large-area outer walls. Therefore, the distance d of the barrier discharge is 3 mm. The electrode is made of an aluminum film having a thickness of 0.3 μm to serve also as a reflection plate, and is covered with an oxidation protection film although omitted from the drawing. In order to effectively use the radiated light from the barrier discharge,
A reflective film 4 with a protective film is provided on the outer wall surface other than the emitted light extraction part 3. The protective film is preferably a ceramic coat. Therefore, when the discharge space 5 is filled with xenon as a discharge gas and electric power is supplied to the pair of electrodes 2 and 2 to cause discharge, the shape of the emitted light from the lamp is about 3 m across.
The beam becomes a slit-shaped beam having a width of m and a width of about 30 cm. As mentioned above, since self-absorption is small, a strong light beam can be obtained.

Reference numeral 6 is a trough-shaped groove provided in the vicinity of the emitted light extraction portion 3 along the depth direction, and a slit 7 is provided at the bottom portion. When the liquid is put into this groove, the liquid drops linearly from the slit 7 along the light beam.

FIG. 2 is an explanatory view of a method for surface modification of plastics using the above dielectric barrier discharge lamp. In the figure, reference numeral 100 is a dielectric barrier discharge lamp, and a polytetrafluoroethylene sheet 101 is fed in the direction of the arrow in the vicinity of the front pole of the radiant light extraction portion with a gap 102. An aqueous solution of aluminum hydroxide is dropped from the groove 6 and passes through the gap 102 together with the sheet 101. In this case, the electric input to the lamp 100 is 400 W,
When the traveling speed is 6 mm / min, the sheet having a contact angle with water of 120 degrees initially becomes 30 degrees. When the electric input is 700 W, the traveling speed is 10 mm / min and the contact angle is 30 degrees. In this case, the thickness of the layer of the aqueous solution is preferably 5 μm or less, so that the thickness of this layer can be adjusted by adjusting the distance of the gap 102. If it is larger than 5 μm, the surface cannot be practically modified. For the gap 102, a platinum foil spread on the order of several μm was used as a gauge.

FIG. 3 is an explanatory view of another design example of the dielectric barrier discharge lamp used in the present invention. In the figure, the four walls surrounding the discharge space 5 are composed of double walls 81 and 82, and the other pair of facing walls have the same structure. A stepped or spiral partition 9 is provided so that liquid nitrogen, which is a fluid, flows in a spiral shape. The upper surface of the lamp 103 is covered with the upper surface member 10, and the power supply line 11 is drawn out. The lower surface of the lamp 103 is the radiant light extraction part 3, but the central part 1
2 has a convex lens shape so that the emitted light can be condensed, and the liquid flowing from the groove 6 is easily transmitted to the apex (top line) 13 of the central portion 12. To collect light,
Even if the central portion is formed in a concave lens shape, the apex (top line) can be formed at the peripheral edge. The size of the discharge space 5 is the same as that of the lamp 100 shown in FIG. 1, and the inner dimension is 20 cm in the vertical direction, 3 mm in the lateral direction, and 30 cm in the depth direction perpendicular to the paper surface. Therefore, the shape of the emitted light is a linear beam as described above.

The discharge space 5 of the lamp 103 is filled with equimolar amounts of argon and chlorine, filled with 600 torr of neon as a buffer gas, and lit at 400 W. The liquid to be injected into the groove 6 was an aqueous solution of boric acid, which was brought into contact with the polytetrafluoroethylene sheet and surface-modified as in the method shown in FIG. At this time, the lamp 103 and the seat 101
The gap 102 between and is the distance between the apex (top line) 13 and the sheet 101, and the boric acid aqueous solution partially descends from the slit 7 and partly reaches the apex (top line). In this case, when the traveling speed of the sheet 101 is 2 mm / min, the contact angle with water can be reduced to 30 degrees. When the layer thickness of the boric acid aqueous solution exceeds 20 μm, almost no surface modification effect is observed. The lamp 103
Then, the four sides of the lamp except the upper surface and the lower surface are cooled with liquid nitrogen, and the temperature of the wall 81 to which the electrode 2 is attached is 10
The temperature can be maintained at 0 ° C. or lower, and the spectral emission characteristics from the lamp do not change even if such low temperature control is performed.
Rather, when the temperature exceeds 300 ° C., the radiation intensity from the lamp decreases.

Further, in the above embodiment, the radiated light extraction section 3 is used.
Since the temperature can be cooled to 100 ° C. or lower, the heating of the boric acid aqueous solution and the sheet can be suppressed even if the gap 102 is extremely small.

The discharge space 5 of the above dielectric barrier discharge lamp 103 is filled with argon and fluorine and neon as a buffer gas, and 10 ° C. water as a cooling fluid is flowed through the space 14. The object to be treated is a fluororesin sheet, and the groove 6
When an aqueous solution of boric acid is supplied to the surface for surface modification, the running angle is 11 mm and the contact angle of the sheet with water is 11 mm.
It can be 0 to 30 degrees. In this case, when the thickness of the layer of the aqueous solution exceeds 2000 μm, the surface modification effect cannot be obtained, and therefore the thickness value is set to 2000 μm or less.

A reforming test was conducted on various lamps including the above-mentioned lamp, and it was found that there was a correlation between the tube wall load of the lamp and the reforming rate. A practical reaction rate was obtained when W / S ≧ 0.2. In any of the above embodiments, the discharge space 5
Since the inner surface area surrounding the is 1200 cm ² , they are, for example, 400 W, 700 W, 240 W to 10 W.
When turned on with an electric power of 00W, the lamp wall load (W
The value of / S) is 0.2 or more, and the predetermined radiant light can be efficiently obtained without largely depending on the type of the enclosed gas. Further, the temperature rise of the lamp and the like can be sufficiently controlled by cooling.

FIG. 4 is an explanatory diagram of a design example of the low-pressure mercury lamp 104 used in the present invention. In the figure, reference numeral 15 is a quartz glass tubular valve, and a pair of electrodes 16 and 1
The distance between 6 is 20 cm. The discharge space 17 was filled with 4 Torr of argon for starting the lamp and 1 mg of mercury per 1 cm ^{3 of the} internal volume of the bulb, and the current was 2.8 A and about 10
It is designed to light up with 0 W power consumption. The lamp 104 emits ultraviolet light having a wavelength of 185 nm and a wavelength of 254 nm. As shown in FIG. 5, this lamp 104 is attached to a polytetrafluoroethylene sheet 101 with a gap 10 therebetween.
The sheet 101 is irradiated by the lamp 104 while supplying the aqueous solution of aluminum hydroxide to the sheet 101 from the upstream side of the traveling of the sheet from the upstream side of the traveling of the sheet from the linear nozzle 18 parallel to the valve axis of the lamp. . In this case, since the gap 102 is kept at 10 μm, the thickness of the aluminum hydroxide aqueous solution layer is also 10 μm. In this state, when the traveling speed of the sheet was maintained at 4 mm / min for surface modification, the contact angle of the sheet 101 with water was changed from 120 degrees to 30 degrees. If the thickness of the layer exceeds 80 μm, the modifying effect is remarkably inferior, so 80 μm or less is preferable. Conventionally,
It was said that surface modification of polytetrafluoroethylene could not be done by irradiation with a low-pressure mercury lamp, but it is possible to modify the surface by contacting it with a layer of an aqueous solution of aluminum hydroxide as described above. It was found that, instead of the aqueous solution of aluminum hydroxide, an aqueous solution of boric acid has the same effect.

FIG. 6 is an explanatory diagram of another embodiment of the present invention. In the figure, the dielectric barrier discharge lamp 105 is
Although the discharge space 5 has the same size and shape as the lamp of FIG. 1, it does not have the groove 6 and does not have a structure for cooling the entire lamp. However, only the radiation light extraction part 3 can be cooled by the cooling liquid sprayed from the cooling fluid nozzles 26 from both sides. In the discharge space 5,
Argon, fluorine and neon are filled, and the synchrotron radiation extraction part 3
Is placed very close to the fluororesin-based sheet that is the object to be treated. If the cooling liquid is an aqueous solution of boric acid, the cooling fluid of the radiant light extraction part 3 can also serve as the scavenger aqueous solution 19, and the thickness of the liquid layer can be substantially determined by the distance of the gap 102. it can. It can be seen that with this sheet, a contact angle with water of 110 degrees can be reduced to 20 degrees, and a surface modification effect can be obtained.

FIG. 7 is an explanatory view of another embodiment of the present invention. In the figure, the size and shape of the discharge space 5 of the dielectric barrier discharge lamp 107 are the same as those of the lamp shown in FIG. 1, but the filling gas is argon and chlorine. Synchrotron radiation part 3
Has a double structure, and liquid nitrogen or its vaporized nitrogen gas can be passed through the hollow portion 20. As a result, the temperature rise of the radiant light extraction part 3 and its surroundings is suppressed, and the gap 10 formed between the radiated light extraction part 3 and the fluororesin sheet 108 is formed.
A scavenger fluid satisfying 2 such as an aqueous solution of an aluminum compound can be sufficiently cooled. It can be seen that in this sheet, the contact angle with water of 110 degrees can be reduced to 10 degrees, and the surface modification effect can be obtained.

FIG. 8 is an explanatory view of another embodiment of the present invention. In the figure, 21 is a water tank containing an aqueous solution 22, in which the dielectric barrier discharge lamp 105 is
The apex (top line) 13 of the emitted light extraction part 3 is located above. Between the liquid surface 23 and the apex (top line) 13 11
At the same time, 1 becomes the thickness of the liquid layer, and at the same time, forms the shortest distance for radiated light transmission. The plastic sheet 109 passes near the liquid surface 23 via the four rollers 24, and the gap 110 should be substantially zero. In this state, if the lamp 105 is turned on and the surface modification treatment work of the sheet 109 is continued, the temperature of the liquid 22 rises, so the cooling means 25 is provided. As a result, both the liquid and the lamp can be cooled, and the radiant light transmission shortest distance of the liquid layer can be easily determined only by changing the height of the lamp.

The structures and cooling methods of the lamps used in the description of the above embodiments, the method for supplying the aqueous solution for capturing fluorine, that is, the aqueous solution for the scavenger, and the method for determining the radiant light transmission shortest distance of the aqueous solution layer are as described above. Obviously, various methods other than the examples can be adopted.

[0030]

As can be understood from the above description of the embodiments, the present invention provides a dielectric barrier discharge lamp that emits vacuum ultraviolet light having a wavelength of 160 nm to 200 nm.
Select a lamp that emits excimer light emitted from a xenon excimer, an argon chlorine excimer, or an argon fluorine excimer, or select vacuum ultraviolet light having a wavelength of 185 nm emitted from a low pressure mercury lamp, while
As the scavenger aqueous solution, an aqueous solution of a boron compound or an aqueous solution of an aluminum compound having an absorption band in a wavelength range of about 200 nm or less is selected, and both are combined,
The surface of plastics having a C—F bond, which could not be conventionally surface-modified, is modified, or the processing speed is remarkably fast.

As described above, in the dielectric barrier discharge lamp, the radiant intensity decreases as the temperature of the discharge gas and the radiant light extraction portion rises, but the spectral radiative characteristics do not change even if the cooling is sufficiently performed. It has the advantage that it can be cooled very close to the object to be treated and the lamp itself can be cooled, as well as the aqueous solution and the object to be treated. Heat damage to the plastics can be made smaller than with conventional arc discharge lamps. it can. Since this cooling is possible enough, the electric input to the lamp can be 10 W / cm ² or more, while
The temperature of the wall of the lamp provided with the electrodes can be kept at 300 ° C. or lower and the temperature of the radiant light extraction part can be kept at 250 ° C. or lower. Can perform surface modification work on plastics.

Since the vacuum ultraviolet light emitted from each lamp is not completely the same, the radiant light transmission shortest distance of the aqueous solution layer was experimentally determined according to each lamp, and the optimum conditions for practical use were found. Therefore, it is possible to provide a surface modification method that is significantly faster than the conventional surface modification treatment speed of plastics having a C—F bond.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a design example of a dielectric barrier discharge lamp used in the present invention.

FIG. 2 is an explanatory diagram of a surface modification method of a plastic sheet.

FIG. 3 is an explanatory view of another design example of the dielectric barrier discharge lamp used in the present invention.

FIG. 4 is an explanatory diagram of a design example of a low pressure mercury lamp used in the present invention.

FIG. 5 is an explanatory diagram of another embodiment of the present invention.

FIG. 6 is an explanatory diagram of another embodiment of the present invention.

FIG. 7 is an explanatory diagram of another embodiment of the present invention.

FIG. 8 is an explanatory diagram of another embodiment of the present invention.

[Explanation of symbols]

 1 Container 2 Electrode 3 Synchrotron Radiation Extraction Part 4 Reflective Film 5 Discharge Space 6 Groove 7 Slit 9 Partition 18 Nozzle 21 Water Tank 23 Liquid Level 24 Roller 25 Cooling Means

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takeo Matsushima 1194 Sado, Bessho-cho, Himeji-shi, Hyogo Ushio Electric Co., Ltd. (72) Inventor Shinichi Iso, 1194, Sado, Bessho-cho, Himeji-shi, Hyogo Usio Electric Co., Ltd. Within

Claims (14)

[Claims] 1. A dielectric barrier in which the surface of a plastic having a C—F bond is brought into contact with an aqueous solution of an aluminum compound or an aqueous solution of a boron compound, and xenon or a gas containing xenon as a main component is sealed in the contact portion. When irradiating the radiant light from the discharge lamp to modify the surface of the plastics at the contact portion, the lamp configures a part or the whole of the container surrounding the discharge space as the radiant light extraction part, and a layer of the aqueous solution. The method for modifying the surface of plastics, characterized in that the shortest distance for transmitting radiant light is maintained at 5 μm or less. 2. The surface of a plastic having a C—F bond is brought into contact with an aqueous solution of an aluminum compound or an aqueous solution of a boron compound, and a gas containing argon and chlorine or a gas containing a chlorine compound is sealed in the contact portion. When radiating light emitted from the dielectric barrier discharge lamp to modify the surface of the plastics at the contact portion, the lamp configures a part or all of the container surrounding the discharge space as a radiant light extraction part, A method for modifying the surface of plastics, characterized in that the radiant light transmission shortest distance of the aqueous solution layer is maintained at 20 μm or less. 3. The surface of a plastic having a C—F bond is brought into contact with an aqueous solution of an aluminum compound or an aqueous solution of a boron compound, and a gas containing argon and fluorine or a gas containing a fluorine compound is sealed in the contact portion. When irradiating the radiant light from the dielectric barrier discharge lamp to modify the surface of the plastics at the contact portion, the lamp configures a part or all of the container surrounding the discharge space as the radiant light extraction part. A method for modifying the surface of plastics, characterized in that the radiant light transmission shortest distance of the aqueous solution layer is maintained at 2000 μm or less. 4. A radiated light from a mercury discharge lamp in which the surface of a plastic having a C—F bond is brought into contact with an aqueous solution of an aluminum compound or an aqueous solution of a boron compound, and mercury is enclosed in the contact portion as a main luminescent material. When the surface of the plastics in the contact area is modified by irradiating with, the lamp configures a part or the whole of the container surrounding the discharge space as a radiant light extraction part, and the radiant light transmitting shortest of the aqueous solution layer is formed. A plastics surface modification method, characterized in that the distance is maintained at 80 μm or less. 5. The plastics surface modification method according to claim 1, wherein the emitted light is extracted from a direction significantly different from the direction of the current flowing in the container. 6. When the inner wall surface area of the container surrounding the discharge space is S (cm ² ) and the electric input is W (watt), W /
The plastics surface modification method according to any one of claims 1 to 3, wherein the lamp is controlled and lit so that the value of S is 0.2 W / cm ² or more. 7. The plastics surface modification method according to claim 1, wherein the radiant light extraction part or its vicinity is cooled with a cooling fluid having a temperature of about room temperature or lower. 8. The plastics surface modification method according to claim 1, wherein the container surrounding the discharge space is cooled with a cooling fluid having a temperature of about room temperature or lower. 9. The plastics according to claim 7, wherein the cooling fluid is in contact with the container or the radiant light extraction part, and the layer of the aqueous solution in contact with the plastics is also cooled. Surface modification method. 10. The plastics surface modification method according to claim 7, wherein the cooling fluid is an aqueous solution in contact with the surface of the plastics. 11. The container according to claim 1, wherein at least one of the synchrotron radiation extraction portion and the portion other than the extraction portion has a double wall structure, and liquid nitrogen or vaporized nitrogen gas thereof is caused to flow in the gap. 4. The plastic surface modification method according to item 3. 12. The radiant light extraction portion of the container has a double wall structure, and cooling water is caused to flow through the gap.
4. The plastics surface modification method according to claim 3. 13. The plastics surface modification method according to claim 11, wherein the temperature of the radiant light extraction part is maintained at 250 ° C. or lower. 14. A pair of discharge electrodes is provided, and when at least one of the electrodes is in contact with the container, the temperature of the container wall portion in contact with the electrode is maintained at 300 ° C. or lower. The plastics surface modification method according to claim 11 or 12.