Light processing method, light processing device, and light processing system

Abstract

The present invention reduces the amount of inert gas used.　This light processing method involves performing light processing on a surface of an object to be processed by emitting vacuum ultraviolet light onto the object to be processed, the method including emitting the vacuum ultraviolet light so that the vacuum ultraviolet light emitted from a light source passes through a first medium mainly containing air and in contact with the light source and a second medium not containing oxygen gas and in contact with the object to be processed. A light processing system includes: a light processing device including a light source that emits vacuum ultraviolet light, a lamp house surrounding the light source, and an air supply port for causing a space in the lamp house to be filled with a first medium mainly containing air, the light processing device performing light processing on a surface of an object to be processed conveyed along a conveyance path; and an isolation part that includes a second medium, not containing oxygen gas, so as to cover the surface of the object to be processed.

Description

Optical processing method, optical processing device, and optical processing system

[0001] The present invention relates to a light processing method, a light processing device, and a light processing system.

[0002] Protective materials known as decorative materials and decorative sheets have been used to protect articles such as building interior materials (walls, ceilings, floors, etc.), housing equipment and furniture, and vehicle interior and exterior materials. Decorative materials and decorative sheets are required to have design properties in addition to surface properties such as scratch resistance, stain resistance, and weather resistance, as well as physical and mechanical properties required of protective materials, such as processability.

[0003]

[0003] In order to enhance the texture and improve the design of decorative materials and decorative sheets, methods for imparting a matte effect to the surface of the decorative material or decorative sheet are known. For example, an acrylic photocurable or thermosetting resin is applied to the surface of the decorative material or decorative sheet to form a coating film, and ultraviolet light is irradiated to cure and shrink the surface of the coating film, forming fine irregularities, thereby imparting a matte effect.

[0004] As a light irradiation device for irradiating ultraviolet light, for example, a light treatment device for manufacturing semiconductors or liquid crystal elements is known. Patent Document 1 discloses a light treatment device including a vacuum ultraviolet light source that irradiates vacuum ultraviolet light onto the surface of a workpiece transported along a transport path, and a lamp house surrounding the vacuum ultraviolet light source. Since vacuum ultraviolet light is absorbed by oxygen gas, the document describes supplying an inert gas into the lamp house and irradiating the vacuum ultraviolet light in an atmosphere mainly composed of the inert gas.

[0005] JP 2019-018164 A

[0006] In order to irradiate a large-area object to be treated, such as a decorative material or decorative sheet, with vacuum ultraviolet light, a large lamp house is required. When the lamp house is large, a large amount of inert gas is also required to reduce the oxygen concentration inside the lamp house. An object of the present invention is to reduce the amount of inert gas used.

[0007] As a result of extensive research, the inventors have discovered that the surface of a workpiece can be sufficiently phototreated even when irradiated with vacuum ultraviolet light in an atmosphere containing oxygen gas. However, as will be described in detail below, it is necessary to consider oxygen inhibition that occurs on the surface of the resin layer of the workpiece. That is, the phototreatment method disclosed in this specification is a phototreatment method for phototreating the surface of a workpiece by irradiating the workpiece with vacuum ultraviolet light, in which the vacuum ultraviolet light emitted from a light source is irradiated so that the vacuum ultraviolet light reaches the workpiece after passing through a first medium that mainly contains air and is in contact with the light source, and a second medium that is substantially free of oxygen gas and is in contact with the workpiece.

[0008] Because the second medium on the surface of the resin layer of the workpiece is substantially free of oxygen gas, oxygen inhibition does not occur and the curing of the resin is not hindered. Meanwhile, the first medium primarily uses air instead of an inert gas, allowing for a reduction in the amount of inert gas used. In this specification, the term "medium" refers to any medium capable of transmitting light. In other words, unless otherwise specified, "medium" includes a space through which light passes and which is filled with gas molecules, a vacuum space in which almost no gas molecules are present (a vacuum space is naturally a "medium that transmits light energy" because it naturally passes through light), or a liquid or solid that transmits light.

[0009] The object to be processed may be transported along a transport path, and the position of the second medium may be fixed relative to the transported object to be processed. In other words, the object to be processed and the second medium may be transported together. Such a transport method is exemplified in the first and second embodiments in the "Mode for Carrying Out the Invention."

[0010] The second medium may be a light-transmitting solid. The light-transmitting solid may be, for example, quartz glass or a resin such as polyethylene. Such a transport method is exemplified in the second embodiment in the "Description of Embodiments."

[0011] The object to be processed may be transported along a transport path, and the position of the second medium may be fixed relative to the light source. Such a transport method is exemplified in a third embodiment in the "Description of Embodiments."

[0012] The second medium may be an inert gas or a vacuum. Such a transport method is exemplified in the first and third embodiments in the "Description of the Invention."

[0013] The light processing system disclosed in this specification includes a light processing device that includes a light source that emits vacuum ultraviolet light, a lamp house surrounding the light source, and an air supply port that fills the space within the lamp house with a first medium mainly containing air, and that performs light processing on the surface of a workpiece transported along a transport path; and an isolation unit that includes a second medium that is substantially free of oxygen gas and that covers the surface of the workpiece. The isolation unit refers to a mechanism for removing oxygen gas from the surface of the workpiece. In the light processing system described in this paragraph, the isolation unit is an entity independent of the light processing device. The isolation unit is not included in the light processing device. Such a light processing system is exemplified by the light processing system described in the "First Embodiment" and the "Second Embodiment" of the "Form for Carrying Out the Invention."

[0014] In the optical processing system, the second medium may be an inert gas, and the isolation unit may be a housing for filling the inert gas. Such an optical processing system is exemplified as a first embodiment in the "Description of Embodiments."

[0015] The isolating portion may be a light-transmitting solid, and the light-transmitting solid itself may be the second medium. Such a light processing system is exemplified in a second embodiment in the "Description of Embodiments."

[0016] The light treatment device disclosed in this specification is a light treatment device that performs light treatment on the surface of a workpiece transported along a transport path by irradiating the workpiece with vacuum ultraviolet light, and includes: a light source that emits the vacuum ultraviolet light; a lamp house surrounding the light source; an air supply port that fills the space within the lamp house with a first medium mainly containing air; a housing that surrounds the transported workpiece and is fixed in position relative to the lamp house; and an inert gas supply port that fills the space within the housing with a second medium that is substantially free of oxygen gas. The light treatment device described in this paragraph represents a light treatment device that incorporates the isolation unit. Such a light treatment device is exemplified in the third embodiment in the "Form for Carrying Out the Invention."

[0017] It is possible to provide a light processing method, a light processing apparatus, and a light processing system that reduce the amount of inert gas used.

[0018] FIG. 1 is a diagram showing a first embodiment of an optical processing system. FIG. 2 is a diagram showing the state in the vicinity of an object to be processed in a comparative embodiment in which a second medium contains oxygen gas. FIG. 3 is a diagram showing the state in the vicinity of an object to be processed in an embodiment in which the second medium does not substantially contain oxygen gas. FIG. 4 is a diagram showing an embodiment of an isolating unit. FIG. 5 is a diagram showing an embodiment of an isolating unit. FIG. 6 is a diagram showing an embodiment of a member constituting the isolating unit. FIG. 7 is a diagram showing a second embodiment of an optical processing system. FIG. 8 is a diagram showing a third embodiment of an optical processing system. FIG. 9 is a diagram showing a substrate unwound from a roll being coated with a curable resin and irradiated with light.

[0019] Embodiments of the present invention will be described with reference to the drawings. The drawings disclosed in this specification are merely schematic illustrations. In other words, the dimensional ratios in the drawings do not necessarily correspond to the actual dimensional ratios, and the dimensional ratios between the drawings do not necessarily correspond to the actual dimensional ratios or the number of each component shown in the drawings.

[0020] In the following, each drawing will be described with reference to the XYZ coordinate system. In this specification, when a direction is expressed and a distinction is made between positive and negative directions, it is described with a positive or negative sign, such as "+X direction" and "-X direction." When a direction is expressed without distinguishing between positive and negative directions, it is simply described as "X direction." In other words, in this specification, when simply referring to "X direction," it includes both "+X direction" and "-X direction." The same applies to the Y direction and the Z direction. In the embodiment described below, the direction of gravity is the -Z direction, the transport direction in which the workpiece is transported is the -Y direction, and the width direction of the workpiece is the X direction.

[0021] <First embodiment> [Outline of light processing system] Fig. 1 is a diagram showing a first embodiment of a light processing system. The light processing system 100 has a light processing device 10 and an isolation unit 20 that prevents oxygen gas from coming into contact with an object to be processed. The light processing device 10 has a light source 3 that emits vacuum ultraviolet light L1, a lamp house 1 that surrounds the light source 3, and a supply port 8 for a first medium 12. The interior of the lamp house 1 forms a space filled with the first medium 12. The first medium 12 is a gas that mainly contains air.

[0022] In this specification, the term "first medium 12 primarily containing air" includes a case in which 50 vol% or more of the gas components constituting the "first medium 12" is air. Conversely, less than 50 vol% of the gas in the first medium 12 may be other gases. The other gas may be an inert gas such as nitrogen. Air contains approximately 21 vol% oxygen gas and approximately 79 vol% inert gas (including approximately 78 vol% nitrogen and approximately 1 vol% argon). Therefore, the higher the concentration of inert gas mixed with the air in the first medium 12, the lower the oxygen concentration in the first medium 12 from approximately 21 vol%. The higher the concentration of inert gas in the first medium 12, the less the vacuum ultraviolet light L1 is absorbed by the first medium 12. However, as long as the vacuum ultraviolet light L1 reaches the workpiece 5 at a level sufficient to enable phototreatment by the workpiece 5, the presence of oxygen gas in the first medium 12 is not a problem. Rather, from the viewpoint that an increase in the amount of inert gas used results in an increase in costs, it is preferable to mix as little inert gas as possible into the first medium 12. It is preferable that 70 vol % or more of the first medium 12 is air, and it is preferable that 90 vol % or more of the first medium 12 is air.

[0023] In this embodiment, the supply port 8 ejects the first medium 12 along a plane (XY plane) including the transport direction of the belt 4, which will be described later, but the first medium 12 may also be ejected toward the belt 4. Note that although the supply port 8 is provided in this embodiment, the supply port 8 need not be provided.

[0024] The isolating section 20, which prevents oxygen gas from coming into contact with the object to be treated, is disposed between the belt 4 and the lamp house 1 so as to be placed on the belt 4. The lamp house 1 transports the isolating section 20, and there is a gap between the lamp house 1 and the isolating section 20 so that the isolating section 20 can be transported on the belt 4. The belt 4 is supported by a plurality of guide rollers 33. The belt 4 is moved in the -Y direction by a drive unit (not shown). The isolating section 20 moves in the -Y direction together with the belt 4.

[0025] The isolation unit 20 includes a housing 21 surrounding the workpiece 5, a light-transmitting unit 23 disposed at the opening of the housing 21, and a second medium 22 sealed inside by the housing 21 and the light-transmitting unit 23. The second medium 22 is a gas that covers the surface of the workpiece 5 and is a gas that is substantially free of oxygen gas. In this specification, the oxygen concentration in the second medium 22 that is substantially free of oxygen gas is 1 vol% or less. However, the oxygen concentration in the second medium is preferably, for example, 0.5 vol% or less, and more preferably 0.1 vol% or less. In this embodiment, the second medium 22 is an inert gas. In this embodiment, nitrogen gas is used as the inert gas, but an inert gas other than nitrogen gas may also be used. The inert gas is filled by replacing the air in the housing 21. The second medium 22 may also be a vacuum. That is, the gas in the housing 21 may be sucked out to create a reduced-pressure space inside the housing 21. By creating a vacuum (reduced pressure space) inside the housing 21, the oxygen concentration can be reduced.

[0026] The light transmitting portion 23 itself is a third medium that transmits the vacuum ultraviolet light L1. The purpose of the light transmitting portion 23 is to isolate the first medium 12 from the second medium 22. It is preferable to select a material for the light transmitting portion 23 that has a small amount of attenuation for the vacuum ultraviolet light L1 so that the vacuum ultraviolet light L1 reaches the workpiece 5 without attenuation as much as possible. The light transmitting portion 23, which is also the third medium, can be made of, for example, quartz glass or a resin such as polyethylene.

[0027] The isolation unit 20 is a component of the optical processing system 100 together with the optical processing device 10, but the object 5 is not a component of the optical processing system 100. The isolation unit 20 will be described in detail later.

[0028] [Reducing the Amount of Inert Gas Used] FIGS. 2A and 2B are diagrams illustrating the state of the workpiece 5 and its vicinity irradiated with vacuum ultraviolet light L1. In FIG. 2A, the second medium 22 near the workpiece 5 contains oxygen gas (i.e., the comparative embodiment in this specification). In FIG. 2B, the second medium 22 near the workpiece 5 does not substantially contain oxygen gas (i.e., the embodiment in this specification). In both FIGS. 2A and 2B, the workpiece 5 has a substrate 5b coated with curable resin 5a. Then, vacuum ultraviolet light L1 is irradiated onto the curable resin 5a. As described above, when vacuum ultraviolet light L1 passes through a space containing oxygen gas, some of the vacuum ultraviolet light is absorbed by the oxygen gas, but the remainder reaches the workpiece 5.

[0029] The vacuum ultraviolet light L1 penetrates the curable resin 5a. Multiple photochemical reactions occur in parallel in the curable resin 5a. An example of a photochemical reaction will be described. The curable resin 5a includes a resin precursor (in this embodiment, a monomer or oligomer having an acrylic group, or both a monomer and an oligomer), a photopolymerization initiator, and a solvent. First, a photochemical reaction involving the photopolymerization initiator occurs. The photopolymerization initiator absorbs the vacuum ultraviolet light L1, and an initiation reaction occurs in which highly active radicals are generated from the photopolymerization initiator. The radicals cleave double bonds contained in the resin precursor (monomer or oligomer; hereinafter, "monomer or oligomer" will be referred to as "monomer, etc.") in the curable resin 5a. This generates highly active monomers, etc. The highly active monomers, etc. polymerize with other monomers, etc., extending the polymer chain and generating new radicals in a chain reaction. This reaction is called a propagation reaction. In the propagation reaction, when a termination reaction occurs in which no new radicals are generated even when monomers or the like are bonded, the series of polymerization reactions stops. In this way, in the curable resin 5a, a chain reaction of polymerization reactions of the curable resin 5a occurs. Note that photochemical reactions involving a photopolymerization initiator can also occur with light having an intensity in a wavelength other than the vacuum ultraviolet region.

[0030] Secondly, a photochemical reaction not involving a photopolymerization initiator also occurs. When the resin precursor absorbs the vacuum ultraviolet light L1, the resin precursor is directly cleaved, generating radicals of the resin precursor. This causes polymerization to proceed. Thus, there are multiple mechanisms for the photochemical reaction that occurs when the vacuum ultraviolet light L1 penetrates the curable resin 5a.

[0031] In FIG. 2A, oxygen molecules penetrate the surface of the curable resin 5a. Even if the photopolymerization initiator or resin precursor absorbs vacuum ultraviolet light L1 and generates highly active radicals, the generated radicals are used to radicalize oxygen molecules present in the vicinity. The radicalized oxygen molecules then stop the polymerization reaction of the polymer during the propagation reaction. As a result, the polymerization reaction of the curable resin 5a does not proceed in the surface layer where the oxygen molecules penetrate (the region 5i hatched with diagonal lines in FIG. 2A). This is sometimes referred to as "oxygen inhibition" in this specification.

[0032] 2B, the second medium 22 near the workpiece 5 does not contain oxygen gas, so oxygen inhibition does not occur, and the polymerization reaction proceeds even in the surface layer of the curable resin 5a. Therefore, in FIG. 2B, there is no region 5i into which oxygen molecules can penetrate. In the surface layer, contraction accompanying the polymerization reaction of the curable resin 5a creates fine irregularities on the surface that scatter visible light, imparting a matte effect.

[0033] 2A and 2B, in order to prevent oxygen inhibition, the second medium 22 that comes into contact with the workpiece 5 must be substantially free of oxygen gas. As for the first medium 12 that does not come into contact with the workpiece 5, the polymerization reaction of the curable resin 5a proceeds even if the vacuum ultraviolet light L1 has a reduced light intensity due to absorption by the oxygen gas contained in the first medium 12. Therefore, the first medium 12 that does not come into contact with the workpiece 5 may contain oxygen gas, particularly air, which requires almost no cost.

[0034] In FIG. 2B , the vacuum ultraviolet light L1 is used to advance the polymerization reaction of the curable resin 5a in the surface layer of the curable resin 5a. However, even if the polymerization reaction is advanced by the vacuum ultraviolet light L1, the curable resin 5a is not completely cured to the depths. Therefore, in order to harden the curable resin 5a, light other than the vacuum ultraviolet light L1 or heat is applied to advance the hardening process of the unhardened curable resin 5a. After the processing by the optical processing system 100 is completed, the coating film is hardened by applying light, heat, or other energy rays using an apparatus separate from the optical processing system 100. Note that the optical processing system 100 may also have a mechanism for hardening the entire coating film (e.g., a light source for photo-hardening the coating film, a heater for thermal hardening, or other energy ray generator).

[0035] [Details of Light Processing Device] Returning to FIG. 1 , the details of the light processing device 10 of this embodiment will be described. The light processing device 10 of this embodiment includes exhaust chambers 11 upstream and downstream of the lamp house 1. Each exhaust chamber 11 includes an exhaust port 13. When vacuum ultraviolet light L1 is emitted in an oxygen-containing environment, some of the vacuum ultraviolet light L1 generates oxygen radicals from oxygen molecules, and these radicals combine with other oxygen molecules to generate ozone. The ozone leaks out through the gap between the lamp house 1 and the conveyor (belt) 4. Ozone poses a risk of harming the body and damaging surrounding equipment. Therefore, the exhaust chamber 11 collects ozone and prevents it from leaking out of the light processing device 10. The exhaust chamber 11 may be located either upstream or downstream, or the exhaust chamber 11 may be absent.

[0036] The light source 3 will now be described. The light source 3 irradiates the surface of the workpiece 5 being transported with ultraviolet light L1. The vacuum ultraviolet light L1 emitted by the light source 3 is ultraviolet light having light belonging to a wavelength band of at least 205 nm or less. As used herein, "light belonging to a wavelength band of at least 205 nm or less" refers to light that exhibits an emission intensity at least at 205 nm or less in the emission spectrum of the light source 3. Examples of such light include: (1) light that exhibits intensity over a broad wavelength band and exhibits an emission spectrum in which the peak emission wavelength showing the maximum intensity is 205 nm or less; (2) light that exhibits an emission spectrum in which multiple maximum intensities (multiple peaks) are present and any of the multiple peaks is within the wavelength range of 205 nm or less; and (3) light in which light at 205 nm or less exhibits an integrated intensity of at least 30% or more of the total integrated intensity in the emission spectrum.

[0037] In this embodiment, the light source 3 is a xenon excimer lamp that emits light with a peak emission wavelength of 172 nm, which indicates maximum intensity. The light source 3 may be a discharge lamp filled with a gas other than xenon gas. While the light treatment device 10 shown in FIG. 1 includes only one light source 3, it may include multiple light sources 3. The multiple light sources may be arranged side by side in the X direction, or the light sources 3 may be arranged side by side in both the X and Y directions. Each light source 3 may be composed of one or multiple small light sources. The small light sources may be semiconductor solid-state light sources such as LEDs. The illuminance of the workpiece 5 may be changed by moving the light source 3 closer to or further away from the belt 4. The illuminance may also be changed by placing a desired neutral density filter on the light source 3. Although FIG. 1 includes only one lamp house 1, multiple lamp houses 1 may be included. As shown in the modified examples in this paragraph, the light treatment device 10 described in this embodiment is merely an example.

[0038] [Details of Isolation Unit] Details of the isolation unit 20 of this embodiment will be described with reference to Figures 3A, 3B, and 3C. Figure 3A is a cross-sectional view of the isolation unit 20 in the YZ plane. Figure 3B is a cross-sectional view of the isolation unit 20 in the YZ plane, showing each component of the isolation unit 20 separated from one another. Figure 3C is a top view of the isolation unit 20, showing only the first portion 21a and the workpiece 5 placed on the first portion 21a.

[0039] The isolation unit 20 includes a housing 21 surrounding the workpiece 5, a light-transmitting unit 23 disposed in an opening of the housing 21, and a second medium 22 sealed inside by the housing 21 and the light-transmitting unit 23. As shown in Fig. 3A, the housing 21 is composed of a first portion 21a, a second portion 21b stacked on the first portion 21a, and a third portion 21c stacked on the second portion 21b.

[0040] The first portion 21a, the second portion 21b, and the third portion 21c each have a screw hole, and the stacked portions 21a to 21c are fixed together by inserting a screw 24 into the screw hole and tightening the screw 24. The fixing method is only one example. As another example, the first portion 21a and the second portion 21b, or the second portion 21b and the third portion 21c, may be detachably fixed together using a hinge and a fastener.

[0041] The first portion 21a has a bottom region on which the workpiece 5 is placed. The second portion 21b and the third portion 21c are both frame-shaped members having large openings through which light passes. The light-transmitting portion 23 is large enough to cover the openings of the frame-shaped members. The light-transmitting portion 23 is fixed by having the edge of the light-transmitting portion 23 sandwiched between the second portion 21b and the third portion 21c.

[0042] The first part 21a and the second part 21b each have a sealing member 25. This allows the interior of the housing 21 to be airtight when the housing 21 is assembled from the first part 21a, the second part 21b, and the third part 21c.

[0043] As shown in FIG. 3C , the first portion 21a includes a supply pipe 26 that supplies the second medium 22 into the isolation unit 20 and an exhaust pipe 27 that exhausts the gas G2 from the isolation unit 20. By injecting the second medium 22 into the housing 21 assembled from the supply pipe 26 and exhausting the gas G2 from the inside through the exhaust pipe 27, the isolation unit 20 is obtained in which the second medium 22 that is substantially free of oxygen gas is arranged to contact the workpiece 5. The isolation unit 20 of this embodiment has a configuration in which the position of the second medium 22 is fixed with respect to the workpiece 5 being transported. In this embodiment, once the second medium 22 is filled, no additional inert gas is required until the workpiece 5 is replaced, thereby reducing the amount of inert gas used.

[0044] [Belt] In this embodiment, the belt 4 is sheet-shaped and supported by guide rollers 33. The width of the belt 4 in the X direction is larger than the width of the workpiece 5 in the X direction. The width of the belt 4 in the X direction is preferably 500 mm or more and 560 mm or less. The belt 4 is one embodiment of a conveying body, and the conveying body is not limited to this.

[0045] [Workpiece to be processed] Examples of the workpiece 5 to be processed in the optical processing system 100 include a decorative material or a decorative sheet. The workpiece 5 includes a substrate 5b and a film of a curable resin 5a formed by coating on the surface of the substrate 5b. Other materials may also be used as the workpiece 5. The effect of reducing the amount of inert gas used is most pronounced when the workpiece 5 is long and large.

[0046] Second Embodiment A second embodiment of the optical processing system will be described with reference to Fig. 4. The following description will focus on features that differ from the first embodiment. Points not described in the second embodiment can be implemented in the same way as the first embodiment. The same applies to the third and subsequent embodiments described below.

[0047] The optical processing system 200 includes an optical processing device 10 and an isolation unit 20. The optical processing device 10 has the same configuration as in the first embodiment, but the isolation unit 20 of this embodiment includes a workpiece 5 and a light-transmitting solid layered in contact with the workpiece 5. The light-transmitting solid layered in contact with the workpiece 5 itself serves as a second medium 22. The light-transmitting solid is also a material that substantially does not contain oxygen gas. For example, quartz glass or resin (e.g., a plastic material such as polyethylene) can be used as the light-transmitting solid. In this embodiment, an inert gas is not required as the second medium, allowing for a significant reduction in the amount of inert gas. The workpiece 5 and the light-transmitting solid (second medium 22) are transported simultaneously. As in the first embodiment, the isolation unit 20 of this embodiment has a configuration in which the position of the second medium 22 is fixed relative to the workpiece 5 being transported.

[0048] Third Embodiment A third embodiment of the light processing system will be described with reference to FIG. 5A . The light processing system 300 of this embodiment includes a light processing device 50 incorporating an isolation unit, but does not include an isolation unit independent of the light processing device 50 as in the first and second embodiments. The light processing device 50 has a second housing 51 that surrounds the light irradiation area of ​​the transported workpiece 5. The second housing 51 is a hollow box with an opening facing the belt 4 (−Z direction). The second housing 51 has a light transmitting portion 23 that transmits vacuum ultraviolet light L1. The position of the second housing 51 relative to the lamp house 1 is fixed. In other words, even if the belt 4 and the workpiece 5 move, the second housing 51 does not move.

[0049] The second housing 51 has a supply port 52 for the second medium 22 inside the box. The supply port 52 sprays the second medium 22 along a plane (XY plane) including the conveying direction of the belt 4. This fills the inside of the second housing 51 with the second medium, and oxygen gas is expelled from the inside. The workpiece 5 being conveyed inside the second housing 51 comes into contact with the second medium 22. Because the second housing 51 has an opening, the second medium 22 needs to be continuously replaced, but because the volume of the internal space of the second housing 51 is smaller than the volume of the internal space of the lamp house 1, the amount of gas used for the second medium 22 can be reduced.

[0050] 5B shows a case in which the substrate 5b is in sheet form, such as a decorative sheet. The sheet-like substrate 5b is unwound from an unwinding roll 55, and a curable resin 5a is applied to one side of the unwound substrate 5b by a coater 53 to form the workpiece 5. The applied curable resin 5a is irradiated with vacuum ultraviolet light L1 from a light treatment device 50, and the cured workpiece 5 is wound up to obtain a take-up roll 56. A guide roller 33 supports the sheet-like substrate 5b. In this case, the belt 4 as a conveyor is not necessarily required. The conveyor may be a drive unit that rotates the unwinding roll 55 and the take-up roll 56.

[0051] Although several embodiments of the optical processing device have been described above, the present invention is not limited to the above-described embodiments, and various modifications or improvements can be made to the above-described embodiments, or the embodiments can be combined, within the scope of the spirit of the present invention.

[0052] Although the above-described optical processing system (100, 200, 300) includes a single optical processing device (10, 50), multiple optical processing devices (10, 50) may be arranged in the transport direction (Y direction). The above-described optical processing devices (100, 200, 300) are shown as emitting ultraviolet light L1 in the same direction as the direction of gravity (-Z direction), but the direction of emission of ultraviolet light L1 may be different from the direction of gravity. For example, ultraviolet light may be emitted horizontally onto a transport body transported in the direction of gravity.

[0053] The object 5 to be treated by the light treatment device of this embodiment may be something other than a decorative material or decorative sheet. Among vacuum ultraviolet light, ultraviolet light of various wavelengths is used depending on the purpose. The light treatment device and light treatment system of this embodiment may be used for purposes other than imparting a matte effect.

[0054] DESCRIPTION OF SYMBOLS 1: Lamp house 3: Light source 4: Belt 5: Object to be treated 5a: Curable resin 5b: Substrate 8: Supply port 10, 50: Light treatment device 11: Exhaust chamber 12: First medium 13: Exhaust port 20: Isolation section 21: Housing 21a: First part (of housing) 21b: Second part (of housing) 21c: Third part (of housing) 22: Second medium 23: Light transmitting section 24: Screw 25: Sealing member 26: Supply pipe 27: Discharge pipe 33: Guide roller 51: Second housing 52: Supply port 53: Coater 55: Unwinding roll 56: Winding roll 100, 200, 300: Light treatment system L1: Vacuum ultraviolet light

Claims

1. An optical processing method for optically processing the surface of an object to be processed by irradiating the object with vacuum ultraviolet light, characterized in that the vacuum ultraviolet light emitted from a light source is irradiated so that the vacuum ultraviolet light reaches the object to be processed after passing through a first medium that mainly contains air and is in contact with the light source, and a second medium that is substantially free of oxygen gas and is in contact with the object to be processed.

2. The optical processing method according to claim 1, wherein the object to be processed is transported along a transport path, and the position of the second medium is fixed relative to the transported object to be processed.

3. The light processing method according to claim 2, wherein the second medium is a light-transmitting solid.

4. The optical processing method according to claim 1, wherein the object to be processed is transported along a transport path, and the position of the second medium is fixed relative to the light source.

5. The optical processing method according to claim 2 or 4, wherein the second medium is an inert gas or a vacuum.

6. An optical processing system comprising: an optical processing device comprising a light source that emits vacuum ultraviolet light, a lamp house surrounding the light source, and an air supply port that fills the space within the lamp house with a first medium mainly containing air, and that optically processes the surface of an object to be processed that is transported along a transport path; and an isolation unit that comprises a second medium that does not substantially contain oxygen gas so as to cover the surface of the object to be processed.

7. The optical processing system according to claim 6, wherein the second medium is an inert gas, and the isolation section is a housing for filling the inert gas.

8. The light processing system according to claim 6, wherein the isolating portion is a light-transmitting solid, and the light-transmitting solid itself is the second medium.

9. An optical treatment device that optically treats the surface of an object to be treated by irradiating the object with vacuum ultraviolet light as the object is transported along a transport path, the optical treatment device comprising: a light source that emits the vacuum ultraviolet light; a lamp house surrounding the light source; an air supply port that fills the space within the lamp house with a first medium that mainly contains air; a second housing that surrounds the light irradiation area of ​​the object to be treated as it is transported and whose position relative to the lamp house is fixed; and an inert gas supply port that fills the space within the housing with a second medium that is substantially free of oxygen gas.

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