Optical Modification Device and Optical Modification Method

Abstract

To provide an optical modification device and an optical modification method which enable formation of a thick surface modified layer at low cost with a simple structure.SOLUTION: An optical processing device includes: a treatment chamber for modifying a surface of workpiece; an ultraviolet light source for irradiating the workpiece in the treatment chamber with ultraviolet light having a dominant light-emission wavelength in a wavelength region of 243 nm or less; and at least one heater for heating the workpiece in the treatment chamber to a temperature higher than a room temperature outside the treatment chamber. An optical modification method conveys workpiece into a treatment chamber, irradiates the workpiece having a temperature higher than a room temperature outside the treatment chamber with ultraviolet light having a dominant light-emission wavelength in a wavelength region of 243 nm or less, and modifies a surface of the workpiece.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an optical modification apparatus and an optical modification method for surface modification of a workpiece.

Background Art

[0002] In recent years, resin glazing using a transparent synthetic resin has attracted attention as an alternative material to silicate glass used for windows of automobiles or construction machines. The transparent synthetic resin used for resin glazing has a high visible light transmittance comparable to that of glass, and exhibits a mass (specific gravity) about half that of silicate glass. Further, the transparent synthetic resin used for resin glazing has characteristics of high moldability, impact resistance, or heat insulation. As a specific material of such a transparent synthetic resin, polycarbonate is exemplified.

[0003] However, the abrasion resistance or weather resistance of a transparent synthetic resin such as polycarbonate is lower than that of silicate glass. Therefore, in order to improve the abrasion resistance and weather resistance of the transparent synthetic resin, a technique of forming a polysiloxane-based hard coat film on the transparent synthetic resin is known.

[0004] Furthermore, a technique for improving such a hard coat film is known. For example, Patent Document 1 discloses a surface modification method in which a hard coat film is irradiated with vacuum ultraviolet light having a main emission wavelength of 172 nm, and then the hard coat film is irradiated with near ultraviolet light such as 222 nm, 248 nm, 308 nm, etc. to form a cured layer mainly composed of silicon dioxide on the surface of the hard coat film.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the surface modification method described in Patent Document 1, in addition to a light source that emits vacuum ultraviolet light, it is necessary to prepare a light source that emits near ultraviolet light, which increases the cost or complexity of the apparatus. Therefore, an object of the present invention is to provide a light modification apparatus and a light modification method that can form a thick surface modification layer with a low cost and a simple structure.

[0007] The light modification apparatus of the present invention includes a processing chamber for modifying the surface of a workpiece, an ultraviolet light source that irradiates the workpiece in the processing chamber with ultraviolet light having a main emission wavelength in a wavelength range of 243 nm or less, and at least one heater that heats the workpiece in the processing chamber to a temperature higher than the room temperature outside the processing chamber.

[0008] The present invention modifies the polymer material on the surface of the workpiece with "ultraviolet light having a main emission wavelength in a wavelength range of 243 nm or less". Although details will be described later, it is presumed that the surface modification by this ultraviolet light is performed by the following mechanism. First, "ultraviolet light having a main emission wavelength in a wavelength range of 243 nm or less" photo-cleaves the atomic bonds of the polymer material on the workpiece surface and photo-decomposes the oxygen molecules contained in the polymer material. Then, the excited oxygen atoms generated by photo-decomposition bond to the photo-cleaved atoms to form a cured layer in which the polymer material is cured.

[0009] As a result of intensive research, the present inventors have obtained the following findings. When the oxygen molecules in the film composed of the polymer material are reduced by photo-decomposition, the oxygen molecules contained in the atmosphere gas in the processing chamber penetrate into the polymer material and diffuse into the interior of the polymer material. At this time, it has been found that when the diffusion rate of oxygen molecules in the polymer material is increased, the oxygen molecules reach deeper into the polymer material, so that the thickness of the cured layer increases. Therefore, in order to increase the diffusion rate of oxygen molecules in the workpiece, the workpiece is heated to a temperature higher than the room temperature (for example, 25°C) outside the processing chamber.

[0010] Various modes can be considered for the heater that heats the workpiece. Also, the mode of the heater may be one type or a combination of multiple types. As an example of the heater, a heating element may be disposed below the workpiece to heat the workpiece. The heating element may be, for example, a heating wire or a pipe through which a heating fluid flows.

[0011] It is provided with a gas supply port for supplying gas to the processing chamber, At least one of the heaters may be a gas heater that heats the gas. The gas supplied to the processing chamber may be a gas containing oxygen such as air or an inert gas such as nitrogen gas.

[0012] At least one of the heaters may be an infrared light source that irradiates the workpiece with infrared light.

[0013] A sensor for measuring the temperature of the workpiece, And a control unit for controlling the heating energy output from at least one of the heaters based on the temperature of the workpiece measured by the sensor may also be provided.

[0014] The control unit may reduce the heating energy during the lighting of the ultraviolet light source. Since the temperature of the workpiece may rise upon receiving the energy of the ultraviolet light source, even if the heating energy is reduced, the workpiece can be maintained at a state higher than the room temperature outside the processing chamber.

[0015] The optical modification method of the present invention involves carrying the workpiece into the processing chamber, Irradiating the workpiece showing a temperature higher than the room temperature outside the processing chamber with ultraviolet light having a main emission wavelength in the wavelength range of 243 nm or less to modify the surface of the workpiece.

[0016] The workpiece may be heated by at least one of a heating element disposed below the workpiece, a heating gas supplied to the processing chamber heated by a gas heater, and an infrared light source that irradiates the workpiece with infrared light.

[0017] During the lighting of the ultraviolet light source, the heating energy of the heater may be decreased.

[0018] Before carrying the workpiece into the processing chamber, the workpiece may be heated.

[0019] The workpiece may be a laminate including a substrate made of a visible light-transmissive synthetic resin and a polysiloxane-based film.

Advantages of the Invention

[0020] Thereby, it is possible to provide a light modification apparatus and a light modification method that can form a thick surface modification layer with a low cost and a simple structure.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4A

Figure 4B

Figure 5

Embodiments for Carrying Out the Invention

[0022] Each embodiment will be described with reference to the drawings. Note that each drawing disclosed in this specification is merely schematically illustrated. That is, the dimensional ratios on the drawings do not necessarily match the actual dimensional ratios, and the dimensional ratios do not necessarily match even between the drawings.

[0023] In the following, each drawing will be described with reference to the XYZ coordinate system as appropriate. In this specification, when expressing a direction and distinguishing between positive and negative directions, it is described with positive and negative signs such as "+X direction" and "-X direction". When expressing a direction without distinguishing between positive and negative directions, it is simply described as "X direction". That is, in this specification, when simply described as "X direction", both "+X direction" and "-X direction" are included. The same applies to the Y direction and Z direction. The +Z direction is the direction in which gravity acts.

[0024] <First Embodiment> [Overview of the Optical Modification Device] FIG. 1 is a cross-sectional view schematically showing a first embodiment of an optical modification device. The optical modification device 100 includes a processing chamber 2 for modifying the surface of a workpiece 3, an ultraviolet light source 10, a control unit 5, a heater 6 for heating the workpiece 3, and a transfer unit 4. The workpiece 3 is an object whose surface is to be modified in the processing chamber 2, and details will be described later.

[0025] In the present embodiment, the processing chamber 2 is constituted by a lamp house for attaching a plurality of ultraviolet light sources 10 arranged substantially at equal intervals along the transfer direction (X direction in the drawing). In a state where the workpiece 3 is carried into the processing chamber 2, a separation distance is ensured in the Z direction in the drawing between the workpiece 3 and the ultraviolet light source 10. Then, ultraviolet light L1 is emitted from the plurality of ultraviolet light sources 10 attached to the processing chamber 2 which is the lamp house, toward the workpiece 3. By irradiating the workpiece 3 with the ultraviolet light L1, the surface of the workpiece 3 is modified.

[0026] The ultraviolet light source 10 is a light source that emits ultraviolet light L1 whose main emission wavelength is in a wavelength range of 243 nm or less. "Ultraviolet light whose main emission wavelength is in a wavelength range of 243 nm or less" belongs to a wavelength band called vacuum ultraviolet light or deep ultraviolet light.

[0027] In this specification, the "main emission wavelength" refers to the wavelength λi in the wavelength range Z(λi) that exhibits an integrated intensity of 40% or more with respect to the total integrated intensity within the emission spectrum when the wavelength range Z(λ) of ±10 nm with respect to a certain wavelength λ is defined on the emission spectrum. For example, in an excimer lamp in which an emission gas such as Xe is enclosed, in a light source with an extremely narrow half-value width and showing light intensity only at a specific wavelength, usually, the wavelength with the highest relative intensity (main peak wavelength) can be regarded as the main emission wavelength.

[0028] In this embodiment, as the ultraviolet light source 10, a Xe excimer lamp in which an emission gas containing Xe is enclosed is used. The Xe excimer lamp emits excimer light with a main emission wavelength of 172 nm. By changing the material of the emission gas, the main emission wavelength can be made different. For example, in the case of Kr gas, it is 146 nm, in the case of ArBr gas, it is 165 nm, and in the case of ArF gas, it is 193 nm. Note that as long as it is a configuration that emits ultraviolet light with a wavelength showing higher light energy than the bond energies of Si-C bonds and O-O bonds, the ultraviolet light source 10 is not limited to an excimer lamp and may be a solid light source such as an LED, for example. Further, the ultraviolet light source 10 may be a dielectric barrier discharge lamp formed by applying a phosphor to the tube wall of a discharge tube in which the above-exemplified emission gas is enclosed.

[0029] In this embodiment, the transfer unit 4 not only carries the workpiece 3 into and out of the processing chamber 2 while holding the workpiece 3, but also holds the workpiece 3 during surface modification. The transfer unit 4 of this embodiment is composed of a plurality of rollers 41 each connected to a motor M. The motor M is controlled by the control unit 5. The rotation of the rollers 41 is used to carry the workpiece 3 in and out. Note that the transfer unit 4 may be composed of known means other than rollers. Examples of such known means include a belt conveyor and a robot arm.

[0030] The heater 6 heats the workpiece 3 and raises the temperature of the workpiece 3 higher than the room temperature outside the processing chamber 2. The purpose of heating the workpiece 3 is to promote surface modification and increase the thickness of the surface modification layer. The details of the purpose of heating the workpiece 3 and specific examples of the heater 6 will be described later.

[0031] [Workpiece] FIG. 2 is a cross-sectional view schematically showing an example of the workpiece 3. The workpiece 3 is a laminate including a base material 31 made of a visible light-transmissive synthetic resin, a hard coat film 33 used as a protective film for the base material 31, and a primer layer 32 that strengthens the bonding between the base material 31 and the hard coat film 33. Various aspects can be considered for the shape and dimensions of the workpiece 3. The workpiece 3 is, for example, a rectangular plate-like body having a long side of 1500 mm.

[0032] The material of the base material 31 is not particularly limited, but in this embodiment, the material of the base material 31 is polycarbonate. The primer layer 32 between the base material 31 and the hard coat film 33 is a material mainly composed of an acrylic resin. In this embodiment, AS primer manufactured by Topron Co., Ltd. is used as the primer layer 32. Note that the primer layer may not be provided.

[0033] The hard coat film 33 is a polysiloxane-based polymer material in which an organic group is bonded as a side chain to the main chain composed of a siloxane bond. Examples of such a polymer material include a material mainly composed of dimethylpolysiloxane. In this embodiment, AS100 manufactured by Topron Co., Ltd. is used.

[0034] The workpiece 3 is manufactured, for example, as follows. First, the base material 31 is cleaned to remove dust adhering to the surface. The base material 31 is immersed in a primer solution or the primer solution is sprayed onto the base material 31 using a spray gun and then dried at a predetermined temperature for a certain period of time to form the primer layer 32.

[0035] Thereafter, it is immersed in a solution of a polysiloxane-based polymer material or sprayed with a spray gun for coating, and dried at a predetermined temperature for a certain period of time to form the hard coat film 33. The coating of the primer liquid or the hard coat film liquid may be performed by flow coating in addition to the above-described method.

[0036] [Surface modification mechanism] The surface modification mechanism of the workpiece 3 will be described. As described above, the surface of the workpiece 3 is covered with the hard coat film 33 mainly composed of dimethylpolysiloxane. When the surface of the workpiece 3 is irradiated with ultraviolet light (hν) having a main emission wavelength in the wavelength range of 243 nm or less, the chemical reaction shown in the following formula (1) occurs. [Chemical formula]

[0037] This chemical reaction is known to occur by the following mechanism. First, ultraviolet light (hν) causes photo-cleavage of the Si-CH3 bond in the side chain of dimethylpolysiloxane. When ultraviolet light (hν) acts on the main chain of dimethylpolysiloxane, it cleaves the main chain and induces low molecular weightization.

[0038] Simultaneously with the photo-cleavage of dimethylpolysiloxane, ultraviolet light (hν) photo-decomposes O2 contained in the hard coat film 33 to generate excited oxygen (hereinafter referred to as "oxygen radical"). This photo-decomposition is shown in the following formula (2). In formula (2), the oxygen radical is shown as O( 1 D) and O( 3 P). [Chemical formula]

[0039] Then, the generated oxygen radical binds to the photo-cleaved part of the Si-C bond. Thereby, the chemical structure shown on the right side of formula (1) is obtained. Note that "O" in formula (1) 1 / 2" indicates that it is bonded to the adjacent Si as well as the Si shown in formula (1). This chemical reaction is also called vitrification (SiO2 formation). In this way, on the surface of the hard coat film 33, vitrification proceeds by consuming O2 contained in the hard coat film 33. As the vitrification of the surface of the workpiece 3 progresses, it hardens, improving the wear resistance and weather resistance of the workpiece 3.

[0040] Ultraviolet light (hν) needs to contain a wavelength component showing higher light energy than the bond energies of Si-C bonds and O-O bonds. The bond energy of Si-C bonds is about 3.2 eV, which is 388 nm in terms of wavelength. Also, the bond energy of O-O bonds is about 5.1 eV, which is about 243 nm in terms of wavelength. The bond energy of Si-O bonds forming the main chain is about 4.7 eV, which is 264 nm in terms of wavelength. Therefore, to break all these bonds, ultraviolet light (hν) in the wavelength range of 243 nm or less is required.

[0041] FIG. 3 is a schematic diagram showing the progress of vitrification of the hard coat film 33. In this schematic diagram, only oxygen molecules and SiO2 are schematically illustrated, and other molecules and oxygen radicals are not illustrated. As vitrification progresses, the O2 contained in the hard coat film 33 decreases. Since there is not an abundance of O2 in the hard coat film 33, as the workpiece is irradiated with ultraviolet light, the O2 contained in the hard coat film 33 depletes.

[0042] However, the inventors have found that if there is O2 in the atmosphere in contact with the hard coat film 33, even if the O2 contained in the hard coat film 33 decreases, the O2 in the atmosphere penetrates and diffuses into the hard coat film 33, and vitrification proceeds.

[0043] Compared with the region before vitrification, in the vitrified SiO2 region, the diffusion rate of O2 is small. If vitrification progresses too far before O2 diffuses sufficiently, O2 cannot diffuse to the inside of the hard coat film 33, and as a result, vitrification remains near the surface of the hard coat film 33.

[0044] Therefore, it is necessary to allow O2 in the atmosphere in contact with the hard coat film 33 to diffuse inward without delaying the progress of vitrification. Therefore, the temperature of the work 3 is raised to improve the diffusion rate of O2 in the vitrified SiO2 region in the hard coat film 33. As a result, O2 can be diffused to the inside of the hard coat film 33 while following the progress of vitrification. As a result, the thickness of the vitrified surface modification layer can be increased.

[0045] [Temperature of the work and thickness of the surface modification layer] The relationship between the temperature of the SiO2 layer and the diffusion coefficient of O2 in the SiO2 layer was determined by simulation. FIG. 4A is a graph plotting the temperature of the SiO2 layer (unit: ° C) on the horizontal axis and the diffusion coefficient of O2 in the SiO2 layer (unit: cm 2 s -1 ) on the vertical axis. From FIG. 4A, it can be seen that the diffusion coefficient of O2 increases as the temperature rises. From this graph, for example, it can be seen that the diffusion coefficient of O2 in the SiO2 layer when the temperature of the work 3 is 75 ° C reaches 1500 times that of the diffusion coefficient of O2 in the SiO2 layer when the temperature of the work 3 is 25 ° C.

[0046] FIG. 4B shows the experimental results of subjecting three works 3 with different temperatures to the above-described surface modification by ultraviolet light and determining the thickness (unit: nm) of the surface modification layer mainly composed of SiO2 by XPS. In all samples, all experimental conditions other than the temperature of the work 3 are unified. For example, the O2 concentration in the processing chamber 2 is 0.1%, the irradiation distance is 50 mm, and the integrated light quantity is 3000 mJ / cm 2 is unified. From FIG. 4B, it can be seen that the thickness of the surface modification layer mainly composed of SiO2 increases almost linearly with respect to the temperature of the work 3. Therefore, from FIGS. 4A and 4B, it can be seen that increasing the temperature of the work 3 improves the diffusion rate of O2 in the SiO2 layer contained in the work 3 and increases the thickness of the surface modification layer.

[0047] As described above, the hard coat film 33 is heated until it reaches a temperature higher than the room temperature (e.g., 25°C) outside the processing chamber 2. The temperature of the workpiece 3 preferably increases as the temperature rises, as the thickness of the surface modification layer increases. However, the upper limit temperature of heating should be set to a temperature at which the hard coat film 33 does not crack or burn, for example, 100°C.

[0048] [Heater] Returning to FIG. 1, the details of the heater 6 will be described. The heater 6 of this embodiment is composed of a plurality of heating elements 61 disposed below the workpiece 3. Each heating element 61 is disposed between the rollers 41 of the conveying unit 4 to uniformly heat the workpiece 3. Each heating element 61 has a heating wire built therein. Further, a temperature sensor (not shown) for measuring the temperature of the workpiece 3 is disposed in the processing chamber 2. The control unit 5 controls the heating energy output from the heating element 61 so that the temperature of the workpiece 3 remains within a desired range based on the temperature of the workpiece 3 measured by the temperature sensor.

[0049] As a modification, the heating element 61 may not have a heating wire built therein and may have a pipe for flowing a heating fluid built therein. Further, before the workpiece 3 is carried into the processing chamber 2 of the light modification device 100, the workpiece 3 may be heated using another heater outside the processing chamber 2 and carried into the inside of the processing chamber 2 before the heated workpiece 3 cools down to room temperature. In such a case, the heater 6 is not essential for the light modification device 100. If the heating time of the workpiece 3 in the light modification device 100 becomes unnecessary or the heating time of the workpiece 3 becomes shorter, the tact time of the light modification device 100 can be shortened.

[0050] [Processing Chamber] The details of the processing chamber 2 will be described. The lamp house constituting the processing chamber 2 includes a plurality of lamp units 20 arranged in the X direction, and a plurality of ultraviolet light sources 10 spaced apart in the X direction are configured to be attached within each lamp unit 20. However, all the ultraviolet light sources 10 mounted in the processing chamber 2 may be configured to be attached as one lamp unit 20. Each ultraviolet light source 10 has a shape extending in a direction different from the X direction (here, the Y direction). Also, hereinafter, the +Z direction will be described as vertically downward, but the present invention is not limited to the orientation in which the optical modification device 100 is installed.

[0051] The processing chamber 2 has an open end 21 at one end in the X direction. In the present embodiment, the processing chamber 2 includes a shutter 22 capable of closing the open end 21. By moving the position of the shutter 22, the open end 21 is opened, and a state in which the workpiece 3 can be carried into the processing chamber 2 is realized.

[0052] In the present embodiment, the processing chamber 2 has a closed end 23 at the other end in the X direction. That is, in the processing chamber 2, the end opposite to the open end 21 is closed. For this reason, the workpiece 3 is not conveyed to a position on the +X side of the closed end 23, or in other words, the workpiece 3 is not carried out of the processing chamber 2 in the +X side direction.

[0053] [Gas supply port] In the present embodiment, the processing chamber 2 has a gas supply port 71 disposed corresponding to the lamp unit 20. The gas supply port 71 is connected to a processing gas supply source 70A and an inert gas supply source 70B. Then, a processing gas and an inert gas used for processing can be supplied into the processing chamber 2 at a desired ratio from the gas supply port 71. A mixing unit (not shown) for mixing the processing gas and the inert gas may be disposed between the gas supply port 71, the processing gas supply source 70A, and the inert gas supply source 70B.

[0054] The processing gas is a gas containing oxygen, such as air. In this embodiment, the processing gas is CDA (clean dry air). Thereby, O2 for diffusion into the protective film can be supplied. Note that the processing chamber 2 is usually filled with air, and since the O2 for diffusion into the protective film exists around the workpiece 3, if the O2 in the processing chamber is sufficient, it is not necessary to supply the processing gas.

[0055] The inert gas is, for example, nitrogen gas. When the light emitted by the ultraviolet light source 10 is easily absorbed by the gas containing oxygen and hardly absorbed by the inert gas, the inert gas is supplied into the processing chamber 2. Thereby, the oxygen concentration in the processing chamber 2 can be reduced as a whole, the attenuation of the light emitted by the ultraviolet light source 10 can be suppressed, and light of a predetermined intensity can reach the workpiece 3.

[0056] The processing chamber 2 is provided with an exhaust port 72 disposed corresponding to the lamp unit 20. In FIG. 1, the case where the exhaust port 72 is in an open state is illustrated, but the exhaust port 72 may be configured to enable opening and closing control.

[0057] The processing chamber 2 has an oxygen concentration measurement port 74 near the exhaust port 72. By connecting an oxygen concentration meter 73 to the oxygen concentration measurement port 74, the oxygen concentration in the processing chamber 2 can be measured. The measurement result of the oxygen concentration meter 73 is sent to the control unit 5, and the control unit 5 can control the supply amount of the processing gas and the supply amount of the inert gas based on the measurement result.

[0058] Specifically, for example, when the measurement result of the oxygen concentration meter 73 is higher than the specified range, the supply amount of the processing gas is decreased or the supply amount of the inert gas is increased. When the measurement result of the oxygen concentration meter 73 is lower than the specified range, the supply amount of the processing gas is increased or the supply amount of the inert gas is decreased. By maintaining the oxygen concentration within the specified range, the attenuation of the ultraviolet light emitted by the ultraviolet light source 10 can be suppressed, and while allowing light of a predetermined intensity to reach the workpiece 3, the amount of oxygen entering the workpiece 3 can be ensured.

[0059] [Modification Example of Light Modifying Device] In the above example, the workpiece 3 is surface-modified on the roller 41 which is the conveying unit 4. As a modification, the optical modification device 100 may have a table for placing the workpiece 3 inside the processing chamber 2 separately from the conveying unit. And, any conveying unit may be a mechanism for loading the workpiece 3 onto the table from outside the processing chamber 2 or unloading the workpiece 3 from the table to outside the processing chamber 2.

[0060] Note that the workpiece 3 may be held by a workpiece holder (not shown), and the workpiece 3 may be loaded into the processing chamber 2 by being conveyed together with the workpiece holder by the conveying unit 4.

[0061] The processing chamber 2 may also be provided with another open end at the end which is the closed end 23. That is, the processing chamber 2 may be provided with one open end at each of both ends in the X direction. When using one open end at each of both ends, for example, the workpiece 3 may be alternately loaded and unloaded from different open ends, or one open end may be used only for loading the workpiece 3 and the other open end may be used only for unloading the workpiece 3.

[0062] [Optical Modification Method] The optical modification method will be described. Open the shutter 22 of the processing chamber 2, use the conveying unit 4 to load the workpiece 3 into the processing chamber 2, and close the shutter 22. The workpiece 3 loaded into the processing chamber 2 is immediately heated using the heater 6 (heating element 61). When the workpiece 3 reaches a predetermined temperature, the ultraviolet light source 10 emits ultraviolet light to perform surface modification of the workpiece 3.

[0063] When irradiating the workpiece 3 with the ultraviolet light L1, the workpiece 3 may be heated by receiving the energy of the ultraviolet light L1. Therefore, during irradiation of the workpiece 3 with the ultraviolet light, heating of the workpiece 3 by the heater 6 may be stopped, or the heating energy output from the heater 6 may be decreased compared to before irradiation with the ultraviolet light. Even if the heating energy is decreased, the workpiece 3 can maintain a state higher than room temperature.

[0064] When the surface modification is completed, turn off the ultraviolet light source 10, open the shutter 22 of the processing chamber 2, and use the transfer unit 4 to carry out the workpiece 3 from the processing chamber 2. Next, if there is a workpiece to be processed next, carry the workpiece into the processing chamber 2 and close the shutter 22.

[0065] <Second Embodiment> FIG. 5 is a cross-sectional view schematically showing a second embodiment of the optical modification apparatus. Matters other than those described below can be implemented in the same manner as in the first embodiment.

[0066] In addition to the heating element 61, the optical modification apparatus 200 of this embodiment has added heaters of two types. One is a mode in which heated gas is blown from the gas supply port 71 toward the surface of the workpiece 3. In this embodiment, the gas supply port 71 is connected to the processing gas supply source 70A via the gas heater 67A and is connected to the inert gas supply source 70B via the gas heater 67B. The gas heaters (67A, 67B) are connected to the control unit 5 and are controlled so that each gas reaches a desired temperature. By blowing the heated gas onto the workpiece 3, the temperature of the workpiece 3 is raised.

[0067] The optical modification apparatus 200 of this embodiment controls the heating of both the processing gas and the inert gas, but either the processing gas or the inert gas may be controlled for heating. Regarding the method of heating the gas, the gas may be heated in some gas heating chamber, or the gas may be heated by heating the gas supply pipe connected to the gas supply port 71.

[0068] Another mode of the heater is two infrared light sources 68. The infrared light sources 68 are connected to the control unit 5 via a power supply unit (not shown), the infrared light sources 68 emit infrared light L2 of a predetermined light amount toward the workpiece 3, and the temperature of the workpiece 3 is raised. Generally, the infrared light source 68 has a simpler structure and lower cost than a near-ultraviolet light source. When the infrared light from the infrared light source 68 passes through the processing chamber 23, the infrared light source 68 may be arranged outside the processing chamber.

[0069] The heater disclosed in the optical modification device 200 has three types of heaters: a heating element 61, gas heaters (67A, 67B), and an infrared light source 68. However, the optical modification device does not necessarily have to be equipped with all three types of heaters. It is preferable to selectively provide the three types of heaters. Also, as described above, when the workpiece 3 that is already in a temperature-rising state is carried in, the optical modification device does not necessarily have to be equipped with a heater.

[0070] Two embodiments and modification examples have been described above. However, the present invention is not limited to the above-described embodiments and modification examples at all, and various changes or improvements can be made to the above-described embodiments without departing from the spirit of the present invention. Also, the embodiments may be combined.

[0071] For example, the above-described processing chamber 2 is a lamp house and is provided with an ultraviolet light source 10 inside the processing chamber 2. However, an ultraviolet light source may be arranged outside the processing chamber 2, and the workpiece 3 arranged inside the processing chamber 2 may be modified by the ultraviolet light source.

Explanation of Reference Numerals

[0072] 2: Processing chamber 3: Workpiece 4: Conveying unit 5: Control unit 6: Heater 10: Ultraviolet light source 20: Lamp unit 21: Open end 22: Shutter 23: Closed end 31: Substrate 32: Primer layer 33: Hard coat film 41: Roller 61: Heating element 67A,67B: Gas heaters 68: Infrared light source 70A: Processing gas supply source 70B: Inert gas supply source 71: Gas supply port 72: Exhaust port 73: Oxygen concentration meter 74: Oxygen concentration measurement port 100, 200: Light reforming device L1: Ultraviolet light L2: Infrared light M: Motor

Claims

1. A processing chamber for modifying the surface of a workpiece, an ultraviolet light source that irradiates the workpiece in the processing chamber with ultraviolet light having a main emission wavelength in a wavelength range of 243 nm or less, a gas supply port that supplies a processing gas containing oxygen and an inert gas to the processing chamber, an oxygen concentration measurement port capable of measuring the oxygen concentration in the processing chamber, at least one heater that heats the workpiece in the processing chamber to a temperature higher than the room temperature outside the processing chamber, a control unit that controls the supply amount of the processing gas and the supply amount of the inert gas and sends the measurement result from an oxygen concentration meter connected to the oxygen concentration measurement port, comprising: at least one of the heaters is a gas heater that heats the gas, the control unit is characterized in that it controls the heating of at least one of the processing gas and the inert gas, an optical modification device.

2. The optical modification device according to claim 1, wherein at least one of the heaters has a heating element disposed below the workpiece.

3. The optical modification device according to claim 1 or 2, further comprising a gas supply port for supplying gas to the processing chamber.

4. The optical modification device according to claim 1 or 2, wherein at least one of the heaters is an infrared light source that irradiates the workpiece with infrared light.

5. a sensor for measuring the temperature of the workpiece, a control unit that controls the heating energy output from at least one of the heaters based on the temperature of the workpiece measured by the sensor, the optical modification device according to claim 1 or 2.

6. The optical modification device according to claim 5, wherein the control unit reduces the heating energy during lighting of the ultraviolet light source.

7. Carry the workpiece into the processing chamber, Irradiate the workpiece having a temperature higher than the room temperature outside the processing chamber with ultraviolet light having a main emission wavelength in a wavelength range of 243 nm or less to modify the surface of the workpiece, Supply a processing gas containing oxygen and an inert gas to the processing chamber, Measure the oxygen concentration in the processing chamber, and control at least one of the supply amount of the processing gas and the supply amount of the inert gas based on the measured oxygen concentration, An optical modification method characterized by controlling the heating of at least one of the processing gas and the inert gas to heat the workpiece in the processing chamber to a temperature higher than the room temperature outside the processing chamber.

8. The optical modification method according to claim 7, wherein the workpiece is additionally heated by at least one of a heating element disposed below the workpiece and an infrared light source that irradiates the workpiece with infrared light.

9. The optical modification method according to claim 8, wherein during lighting of the ultraviolet light source, heating energy of a heater that additionally heats the workpiece is decreased.

10. The optical modification method according to any one of claims 7 to 9, wherein the workpiece is heated before being carried into the processing chamber.

11. The optical modification method according to any one of claims 7 to 9, wherein the workpiece is a laminate including a base material made of a visible light-transmissive synthetic resin and a polysiloxane-based film.

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