Light irradiation device and light irradiation method

Abstract

To suppress influence of a shadow by a dimming member given to an object to be irradiated in the case of using the dimming member by providing a light irradiation device with the member.SOLUTION: Provided is a light irradiation device 1 comprising an excimer lamp 2 for irradiating an object to be irradiated T conveyed in a predetermined conveyance direction with excimer beam. The excimer lamp 2 is filled with discharge gas for emitting excimer beam. The light irradiation device 1 is equipped with a dimming member 3 which is provided between the excimer lamp 2 and the object to be irradiated T and constituted of a plurality of line members 3a, an extending direction of at least one of the plurality of line members 3a crosses the conveyance direction at an angle larger than 0°, and a member which generates a linear or a mesh-like shadow of the excimer beam is not provided between the discharge gas and the object to be irradiated T.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a light irradiation device and a light irradiation method. [Background technology]

[0002] Patent Document 1 discloses a vacuum ultraviolet light processing apparatus (light irradiation apparatus) that includes a light source that irradiates vacuum ultraviolet light, a stage on which a material to be processed is placed, and a correction member that is arranged between the stage and the light source and corrects the in-plane light intensity distribution of the vacuum ultraviolet light irradiated onto the surface of the material to be processed, and is characterized in that the correction member adjusts the in-plane transmittance so that vacuum ultraviolet light having a uniform light intensity is irradiated onto the material to be processed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-49305 Summary of the Invention [Problem to be solved by the invention]

[0004] The invention of Patent Document 1 aims to uniformly adjust the light intensity distribution of the vacuum ultraviolet light irradiated onto the material to be treated by providing a correction member (hereinafter referred to as "light-reducing member") between the stage on which the material to be treated is placed and the light source, thereby achieving highly uniform treatment of the material to be treated. A mesh-like member or the like is used as the light-reducing member.

[0005] The inventors of the present application have discovered that when a light-attenuating member is provided in a light irradiation device and light is irradiated, the light-attenuating member casts a shadow on the excimer light irradiated onto the object to be irradiated, and this shadow can have a direct, undesirable effect on the object to be irradiated.

[0006] In particular, it has been found that for decorative sheets having a cured UV coating as a surface layer, the shadow of the excimer light caused by the light-reducing member causes significant aesthetic problems.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to suppress the influence of a shadow cast by a light-reducing member on an object to be irradiated when a light-reducing member is provided in a light irradiation device. [Means for solving the problem]

[0008] In order to achieve the above object, the light irradiation device of the present invention includes a light source for irradiating an object to be irradiated transported in a predetermined transport direction with excimer rays, the light source is filled with a discharge gas for emitting the excimer rays, and a dimming element composed of a plurality of linear elements is provided between the light source and the object to be irradiated, the extension direction of at least one of the plurality of linear elements intersects with the transport direction at an angle greater than 0°, and no linear elements that would cast linear or mesh-like shadows of the excimer rays are provided between the discharge gas and the object to be irradiated.

[0009] The light irradiation method of the present invention is a method of irradiating an object with excimer rays using the light irradiation device, wherein the object has a base layer made of resin and a surface layer made of a cured product of UV paint laminated on the base layer, and the gloss of the surface layer at a portion irradiated with the excimer rays becomes lower than that before the irradiation. [Effects of the Invention]

[0010] According to the present invention, when a light irradiation device is used with a light-reducing member provided, it is possible to suppress the influence of the shadow cast by the light-reducing member on an object to be irradiated. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic cross-sectional view showing a light irradiation device according to an embodiment of the present invention. [Figure 2] 10 is a conceptual diagram showing the relationship between a light-reducing member and the conveying direction of an object to be irradiated. FIG. [Figure 3] 3 is a conceptual diagram showing a relationship (θ=45°) between a light-reducing member different from that in FIG. 2 and the conveying direction of the irradiated object. [Figure 4]3 is a conceptual diagram showing a relationship (θ=20°) between a light-reducing member different from that in FIG. 2 and the conveying direction of the irradiated object. [Figure 5] FIG. 2 is a cross-sectional view showing a decorative sheet obtained by curing the surface layer of a resin sheet. [Figure 6] 1 is a photograph showing the surface of the decorative sheet obtained in Example 1, with a scale indicating the length. [Figure 7] 1 is a photograph showing the surface of the decorative sheet obtained in Comparative Example 4, with a scale indicating the length. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail. Note that the present invention is not limited to the following embodiments, and can be appropriately modified and applied within the scope of the present invention.

[0013] (Embodiment) -Light irradiation device- The light irradiation device 1 according to this embodiment is intended to enhance the design of the surface of the object T by applying excimer light to the object T being transported in a predetermined transport direction, thereby achieving effects such as matting.

[0014] The irradiated object T is, for example, a plate-shaped or film-shaped object. Specific examples of such irradiated objects T include building materials such as wall materials, fixtures, and building materials, decorative sheets, automobile interior / exterior sheets, and anti-reflection films. The irradiated object T may be a decorative sheet, as described below, configured by laminating a cured product of UV paint on a substrate layer. In addition, the irradiated object T may be one whose surface is cleaned or modified by irradiation with excimer rays.

[0015] As shown in FIG. 1, the light irradiation device 1 includes one or more excimer lamps 2 (light sources) that irradiate the object to be irradiated T with excimer rays from above, a dimming member 3 provided between the excimer lamps 2 and the object to be irradiated T, and a transport means 4 for transporting the object to be irradiated T.

[0016] The shape of the excimer lamp 2 is not limited, but may be, for example, a round rod shape. Fig. 1 shows the cross section of the excimer lamp 2 cut in a direction perpendicular to the longitudinal direction. The excimer lamp 2 contains Ar 2 , Kr 2 , Xe 2 The chamber is filled with a discharge gas such as, for example, 120 to 230 nm. By changing the type of discharge gas, the peak wavelength of the irradiated electromagnetic wave can be changed. Excimer rays are ultraviolet light with a wavelength of, for example, 120 to 230 nm.

[0017] As shown in FIG. 1, the light-reducing member 3 is disposed below the excimer lamp 2 and is supported by a support means (not shown) above the object to be irradiated T at a distance so as not to come into contact with the object to be irradiated T. As shown in FIG. 2, the light-reducing member 3 is composed of a plurality of wire members 3a made of metal. In FIG. 2, these plurality of wire members 3a extend parallel to each other, but this does not necessarily have to be the case. The extending direction of at least one wire member 3a intersects with the transport direction at an angle θ greater than 0°, and preferably at an angle θ of 15° or more.

[0018] If the extending direction of the linear member 3a intersects with the transport direction at an angle θ greater than 0°, the position of the shadow of the excimer beam cast by the light-attenuating member 3 on the surface of the object T changes as the object T is transported. As a result, the entire surface of the object T is irradiated with the excimer beam. As a result, the influence of the shadow cast by the light-attenuating member 3 on the object T can be reduced.

[0019] As shown in Figures 3 and 4, the dimming member 3 may be configured in a mesh-like pattern with a plurality of first line members 3a extending parallel to one another and a plurality of second line members 3b extending parallel to one another and intersecting the first line members 3a at an angle of 90°. Figure 3 shows the case where θ = 45°, and Figure 4 shows the case where θ = 20°. The extending direction of at least one of the first line members 3a and the second line members 3b intersects with the conveying direction at an angle θ greater than 0°, and preferably at an angle θ of 15° to 45°.

[0020] The aperture ratio of the aperture 3c surrounded by the first wire member 3a and the second wire member 3b is preferably 33.0% or more, more preferably 58.4% or more, and even more preferably 60.8% or more. For example, when the wire diameters of the first wire member 3a and the second wire member 3b are the same, the aperture ratio can be calculated by the following formula (1), where d is the wire diameter and a is the distance between adjacent wire members. Open area ratio={a / (a+d)} 2 ×100 (1) Although the openings 3c are square in shape in FIGS. 3 and 4, the present invention is not limited to this, and the openings 3c may be rectangular, parallelogram-shaped, or diamond-shaped.

[0021] The conveying means 4 is not limited as long as it is driven by a driving unit (not shown) such as a motor and can convey the irradiation object T placed on top in the direction (conveying direction) indicated by the arrow in Fig. 1. Such conveying means 4 may be, for example, a stage that moves in the conveying direction, or may be a plurality of rollers.

[0022] Note that no member that would cast linear or mesh-like shadows of the excimer rays is provided between the discharge gas of the excimer lamp 2 and the object T to be irradiated. If such a member were provided, the member and the linear members 3a of the dimming member 3 would overlap on the object to be irradiated with the excimer rays, which could result in the formation of moiré fringes. In the light irradiation device 1 according to the present invention, no such member is provided, and therefore no moiré fringes are generated. Specific examples of "members that cast linear or mesh-like shadows" include electrodes made of element wires that may be provided in the excimer lamp 2.

[0023] -Decorative sheet- The decorative sheet 10 produced using the light irradiation device 1 will now be described.

[0024] As shown in FIG. 5, the decorative sheet 10 comprises a base layer 11 and a surface layer 12 provided on a surface 11a of the base layer 11.

[0025] The base layer 11 is formed, for example, of a thermoplastic resin sheet. Examples of such thermoplastic resin sheets include, but are not limited to, polyvinyl chloride sheets, glycol-modified polyethylene terephthalate (PETG) sheets, amorphous crystalline polyester resin (APET) sheets, polyolefin sheets (polyethylene sheets, polypropylene sheets, etc.), acrylonitrile-butadiene-styrene resin (ABS) sheets, and polycarbonate sheets. Examples of the amorphous crystalline polyester resin (APET) sheets used for the base layer 11 include recycled polyethylene terephthalate (RPET) sheets. A glycol-modified polyethylene terephthalate sheet is preferred as a thermoplastic resin sheet because it is easy to process into quadratic curved surfaces and has excellent three-dimensional formability. A glycol-modified polyethylene terephthalate sheet is a type of polyethylene terephthalate. While the glycol component of polyethylene terephthalate is ethylene glycol, this is an amorphous polyester that contains ethylene glycol as well as a diol other than ethylene glycol (1,4-cyclohexanedimethanol) as a glycol component.

[0026] The thermoplastic resin sheet may be a stretched sheet or an unstretched sheet. The thermoplastic resin sheet may contain additives such as colorants, ultraviolet absorbers, light stabilizers, antioxidants, antistatic agents, storage stabilizers, lubricants, and fillers, as needed. From the standpoint of design, the thermoplastic resin sheet is preferably colored.

[0027] The thickness of the base layer 11 is not particularly limited, but is preferably 50 to 800 μm, and more preferably 250 to 500 μm. If the thickness of the base layer 11 is 50 μm or more, the mechanical strength and hiding power can be sufficiently improved. If the thickness of the base layer 11 is 800 μm or less, the three-dimensional formability is more excellent, and flexibility and printability can be easily ensured.

[0028] The surface layer 12 is composed of a cured product of UV paint laminated on the base layer 11. For example, the surface layer 12 is a coating film of UV paint whose main components are urethane acrylate and monofunctional acrylate. This surface layer 12 can be formed by applying paint to the surface 11a of the base layer 11 and curing it, and the surface layer 12 is made of the cured product of the paint. The surface layer 12 is composed of an ultraviolet-cured layer formed on the surface 11a of the base layer 11 and an excimer ray-cured layer formed on the surface of the ultraviolet-cured layer. Furthermore, as shown in FIG. 5, wrinkles are formed on the surface 12a of the surface layer 12 (i.e., the surface opposite to the base layer 11 side).

[0029] The urethane acrylate that forms the surface layer 12 is one having 2 to 10 functionalities, such as phenylglycamicyl ether acrylate hexamethylene diisocyanate urethane prepolymer, pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer, and dipentaerythritol pentaacrylate hexamethylene diisocyanate urethane prepolymer. Also, EBECRYL8402, KRM8452, EBECRYL210, EBECRYL220, EBECRYL4500, EBECRYL230, EBECRLY270, EBECRYL4858, EBECRYL8804, EBECRYL8807, EBECRYL9270, EBECRYL4100, EBECRYL4513, EBECRYL8311, EBECRYL8465, EBECRYL9260, EBECRYL8701, KRM8667, E Commercially available products such as BECRYL4265, EBECRYL4587, EBECRYL4200, EBECRYL8210, EBECRYL1290, EBECRYL5129, EBECRYL8254, EBECRYL8301R, KRM8200, KRM8904, RUA-062NS (a product containing a bifunctional acrylate monomer), U-6LPA, UA-1100H, U-200PA, UA-160TM, and UV-7600B (all product names) can be used. These urethane acrylates may be used alone or in combination of two or more.

[0030] Examples of the monofunctional acrylate that forms the surface layer 12 include ethyl carbitol acrylate, methoxyethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, β-(meth)acryloyloxyethyl hydrogen phthalate, β-(meth)acryloyloxyethyl hydrogen succinate, nonylphenoxyethyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, phenoxyethyl (meth)acrylate, and phenoxypolyethylene glycol (meth)acrylate. Ethylene glycol (meth)acrylate, butoxy polyethylene glycol (meth)acrylate, alkyl (meth)acrylate, cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-(meth)acryloyloxyethyl-2-hydroxyethyl Phthalic acid, 3-acryloyloxyglycerin mono(meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxy-1-(meth)acryloxy-3-(meth)acryloxypropane, polypropylene glycol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, poly-ε-caprolactone mono(meth)acrylate, dialkylaminoethyl (meth)acrylate, glycidyl (meth)acrylate, mono[2-(meth)acryloyloxyethyl]acidphos phosphate, trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 2,2,3,4,4,4-hexafluorobutyl (meth)acrylate, perfluorooctylethyl (meth)acrylate, dicyclopentenyloxyalkyl (meth)acrylate, dicyclopentenyl (meth)acrylate, tricyclodecanyl (meth)acrylate, tricyclodecanyloxyethyl (meth)acrylate, and isobornyloxyethyl (meth)acrylate. These monofunctional acrylates may be used alone or in combination of two or more.

[0031] The compounding ratio of urethane acrylate to monofunctional acrylate in the surface layer 12 is not particularly limited as long as it does not impair the characteristics of the decorative sheet 10, but a mass ratio of urethane acrylate:monofunctional acrylate of 10:90 to 90:10 is preferred. This is because, due to the low fluidity of urethane acrylate, a high mass ratio of urethane acrylate makes it difficult for wrinkles to form on the surface 12a of the surface layer 12, making it difficult to achieve the low gloss provided by the matte effect. Furthermore, due to the low reactivity of monofunctional acrylate, a high mass ratio of monofunctional acrylate makes it difficult for the paint to harden.

[0032] The thickness of the surface layer 12 is not particularly limited, but is preferably 1 to 45 μm, and more preferably 1 to 10 μm. If the thickness of the surface layer 12 is less than 1 μm, the coating film area that can move during excimer beam irradiation is reduced, making it less likely to wrinkle and resulting in a low gloss due to the matte effect. If the thickness of the surface layer 12 is greater than 45 μm, the tactile sensation is further reduced and the hardness increases, which may result in a decrease in moldability. If the thickness of the surface layer 12 is greater than 10 μm, the surface roughness Sa of the surface layer 12 increases, improving fingerprint resistance but potentially reducing tactile sensation. The term "surface roughness Sa" used here refers to the "three-dimensional surface texture parameter (three-dimensional arithmetic mean roughness)" defined in ISO 25178. The "standard deviation σ of surface roughness Sa" refers to the spread of the surface roughness Sa (variation in surface roughness Sa).

[0033] The coating material for forming the surface layer 12 may contain components other than the urethane acrylate and the monofunctional acrylate. Examples of such components include a photopolymerization initiator, a weathering agent, a colorant, an ultraviolet absorber, a light stabilizer, an antioxidant, an antistatic agent, a storage stabilizer, a plasticizer, a lubricant, and a filler.

[0034] Examples of the photopolymerization initiator that can be used include alkylphenone-based, acylphosphine oxide-based, and cationic initiators. Examples of the weather resistance agent that can be used include ultraviolet absorbers and light stabilizers.

[0035] -Light irradiation method- In the light irradiation method according to the embodiment, an object to be irradiated T is irradiated with excimer light using the light irradiation device 1. Specifically, the object to be irradiated T is prepared and placed on the conveying means 4 of the light irradiation device 1. A light-reducing member 3 is disposed between the excimer lamp 2 and the object to be irradiated T so that at least one of the multiple linear members 3a is not parallel to the conveying direction.

[0036] Next, the object to be irradiated T is irradiated with excimer rays emitted from the excimer lamp 2 while being transported in the transport direction by the transport means 4 .

[0037] The illuminance of the excimer rays emitted from the excimer lamp 2 is not particularly limited, but when this method is applied to the manufacturing method of a decorative sheet described later, the illuminance is set to 11 mW / cm from the viewpoint of reducing the stripes caused by the shadow of the light-reducing member 3 that appear on the surface of the decorative sheet 10. 2 More than 15mW / cm is preferable. 2 From the same viewpoint, the cumulative light amount is preferably 9 mJ / cm. 2 Less than 7mJ / cm is preferred 2 The following is more preferred:

[0038] -Decorative sheet manufacturing method- A method for producing the decorative sheet 10 using the light irradiation method will now be described.

[0039] When manufacturing the decorative sheet 10, first, a base layer 11 made of, for example, the thermoplastic resin sheet is prepared. This thermoplastic resin sheet may be a commercially available one, or may be one manufactured by a known manufacturing method such as a calendar method or an extrusion molding method.

[0040] Next, a UV paint is applied to the surface 11a of the base layer 11 to form a coating film. A preferred UV paint is, for example, a paint containing a solvent to which a urethane acrylate, a monofunctional acrylate, and a photopolymerization initiator have been added. For example, when using a urethane acrylate containing a bifunctional acrylate monomer, such as the aforementioned RUA-062NS, the use of the monofunctional acrylate can be omitted.

[0041] The coating method is not particularly limited, and examples thereof include cast coating, die coating, gravure coating, roll knife coating, reverse roll coating, roll coating, and comma coating.

[0042] Next, the coating film formed on the surface 11a of the base layer 11 is irradiated with excimer rays (for example, wavelength 120 to 230 nm). This causes curing only on the outermost surface of the coating film, which will become the surface layer 12, to form the excimer ray-cured layer. During this process, non-uniformity occurs between the surface and interior of the coating film, and coating components migrate from unreacted areas inside the coating film to the surface, forming wrinkles on the surface of the coating film. As a result, it becomes possible to achieve a low gloss (low glossiness) in the surface layer 12.

[0043] Next, the coating is cured by irradiating it with ultraviolet light (e.g., 350 to 450 nm) that has a longer wavelength than excimer light, thereby forming an ultraviolet-cured layer. That is, a surface layer 12 is formed, which is composed of an ultraviolet-cured layer formed on the surface 11a of the base layer 11 and an excimer light-cured layer formed on the surface of the ultraviolet-cured layer. In this way, as shown in FIG. 5, uniform irregularities are formed across the entire surface 12a of the surface layer 12. As a result, a decorative sheet 10 is produced that has an improved appearance due to the uniformly formed irregularities, while maintaining the low gloss achieved by excimer light irradiation.

[0044] It should be noted that even if the coating film is irradiated with excimer light having a short peak wavelength (within the range of 120 to 230 nm) instead of the ultraviolet light (350 to 450 nm), the coating film will not be completely cured.

[0045] The matte effect of the wrinkles causes the gloss level of the surface 12a of the surface layer 12 to be 5 or less, making it possible to achieve low gloss in the decorative sheet 10. The "gloss level" referred to here is an index of low gloss, and is the 60° gloss level measured according to a method in accordance with JIS Z 8741:1997.

[0046] From the viewpoint of further improving the low gloss and enhancing the designability, the gloss level is preferably 4 or less, and more preferably 3 or less.

[0047] As explained above, in the decorative sheet 10, the glossiness of the portion of the surface layer 12 that is irradiated with excimer light becomes lower than before irradiation. Therefore, when the above-mentioned light irradiation method is used to manufacture the decorative sheet 10, if the effect of the shadow of the excimer light cast by the light-reducing member 3 on the surface of the decorative sheet 10 is not suppressed, there will be a large difference in appearance between the portion that is not affected by the shadow and has a reduced glossiness, and the portion that is affected by the shadow and has not a reduced glossiness. In this way, the shadow cast by the light-reducing member 3 causes significant aesthetic problems in the manufactured decorative sheet 10.

[0048] In this regard, in the light irradiation device 1, the influence of the shadow of the excimer light caused by the light-reducing member 3 is suppressed, so that a decorative sheet 10 that presents no aesthetic problems can be produced.

[0049] -Other embodiments- The decorative sheet 10 is not limited to the one described in detail above, but may be any sheet in which at least a portion of the surface layer 12 is hardened by irradiation with excimer rays, and the gloss of the portion of the surface layer 12 irradiated with excimer rays is lower than before irradiation. [Example]

[0050] -Conditions- The conditions for Example 1 are described below. First, a decorative sheet was produced as described in the above embodiment. That is, a polyvinyl chloride sheet having a thickness of 350 μm was prepared as a substrate layer, and a coating material formulated as described below was applied to the surface of this substrate layer using a bar coater and dried at 60° C. for 30 seconds, resulting in a film thickness of about 6 μm after drying. The paint was prepared by blending 37% by weight of urethane acrylate (manufactured by Mitsubishi Chemical Corporation, product name "UV-7620EA"), 24.1% by weight of tetrahydrofurfuryl acrylate as a monofunctional acrylate (manufactured by Kyoeisha Chemical Co., Ltd., product name "Light Acrylate THF-A"), 0.4% by weight of acryloyl group-containing modified polydimethylsiloxane (manufactured by BYK Japan Co., Ltd., product name: BYK-UV3505), 1.4% by weight of an alkylphenone photopolymerization initiator (manufactured by IGM Resins BV, product name "Omnirad1173"), and 37% by weight of methyl ethyl ketone as a solvent, so that the solids concentration was 50% by weight.

[0051] The substrate layer coated with this paint was used as the object to be irradiated, and the surface was irradiated with excimer light using a light irradiation device. The excimer lamp and transport means of the light irradiation device were a "172 nm air-cooled excimer irradiation device" (model: MEIRA-MS-1-A4-H) manufactured by MDCOM. The discharge gas filled in the excimer lamp was Xe 2 (Peak wavelength of excimer light: 172 nm) was used.

[0052] The light-reducing member used was a linear member that intersected with each other to form a substantially square-shaped aperture as shown in Figures 3 and 4. The excimer beam irradiation was carried out in a nitrogen atmosphere with an oxygen concentration of 1000 ppm or less. Other conditions for the excimer beam irradiation were set to the values ​​shown in Table 1, including the wire diameter of the light-reducing member (linear member), the aperture ratio, the angle θ with respect to the conveying direction, and the illuminance and integrated light amount of the irradiation. The aperture ratio was calculated using the above formula (1).

[0053] The illuminance and the integrated amount of light were adjusted by appropriately changing the voltage of the excimer lamp, the distance between the excimer lamp and the object to be irradiated, and the transport speed.

[0054] Next, the coating film was irradiated with ultraviolet light (dominant wavelength: 365 nm) using an ultraviolet irradiation device (4 kW ultraviolet curing high-pressure mercury lamp (H04-L41) manufactured by Eye Graphics Co., Ltd.) to photo-cure the coating film, thereby forming a surface layer on the surface of the substrate layer and producing a decorative sheet. The ultraviolet irradiation distance was 15 cm, the conveyor transport speed was 0.75 m / min, and the cumulative light dose was 200 mJ / cm. 2 It was decided.

[0055] [Table 1]

[0056] Examples 2 to 24 and Comparative Examples 1 to 8 were carried out in the same manner as Example 1, except that the irradiation conditions of the excimer beam were changed as shown in Tables 1 to 6. The difference between Examples 1 to 24 and Comparative Examples 1 to 8, as can be seen from Tables 1 to 6, is that in Examples 1 to 24 the light-attenuating member was positioned so that the angle θ was greater than 0°, whereas in Comparative Examples 1 to 8 the light-attenuating member was positioned so that the angle θ was 0°.

[0057] [Table 2]

[0058] [Table 3]

[0059] [Table 4]

[0060] [Table 5]

[0061] [Table 6]

[0062] -evaluation- The surfaces of the decorative sheets obtained in Examples 1 to 24 and Comparative Examples 1 to 8 were visually inspected and rated on a three-point scale: 3 if stripes remained on the decorative sheet surface due to the influence of the shadow of the dimming member, 2 if the stripes were improved (lightened), and 1 if the stripes were further improved (almost completely disappeared). The evaluation results are shown in Tables 1 to 6.

[0063] First, comparing Examples 1 to 24 in which the angle θ was set to 15°, 20°, 30° or 45° with Comparative Examples 1 to 8 in which the angle θ was set to 0°, the evaluation results were 1 or 2 for Examples 1 to 24, while the evaluation results were 3 for Comparative Examples 1 to 8. This shows that the extension direction of the linear members of the dimming member is not parallel to the conveyance direction (θ>0°), so that the stripes caused by the influence of the shadow of the dimming member tend to disappear.

[0064] A photograph of the surface of the decorative sheet obtained in Example 1 is shown in Figure 6, and a photograph of the surface of the decorative sheet obtained in Comparative Example 4 is shown in Figure 7. As can be seen from Figures 6 and 7, stripes spaced about 1 mm apart were observed on the surface of the decorative sheet obtained in Comparative Example 4, while no stripes were observed on the surface of the decorative sheet obtained in Example 1.

[0065] Next, when comparing Examples 1 to 16, in which the aperture ratio of the dimming member is 58.4%, the integrated light amount is 9 mJ / cm 2 The evaluation results for Examples 1, 2, 7, and 8 below were all 1, meaning that stripes were barely visible on the surface of the decorative sheet. This is presumably because, when the cumulative light dose of the excimer rays is small, the curing reaction on the outermost surface does not proceed too much even when irradiated with the excimer rays, and the difference between the area not irradiated with the excimer rays, which is caused by the influence of the shadow of the light-reducing member, is less noticeable. However, in Examples 13 and 14, the cumulative light dose was 25 mJ / cm 2Although the irradiance of the excimer light was as high as 15 mW / cm in Examples 13 and 14, the evaluation results were all 1, and almost no stripes were visible on the surface of the decorative sheet. The reason for this is unclear, but in Examples 13 and 14, the irradiance of the excimer light was 15 mW / cm 2 It is believed that the influence of the shadow of the light-reducing member was reduced because the illuminance of the excimer beam was large.

[0066] Focusing on Examples 17 to 22, in which the aperture rate of the dimming member was 60.8% or more, the evaluation result was 1 in all cases regardless of illuminance and integrated light amount, and stripes on the surface of the decorative sheet were barely visible. It can be said that a larger aperture rate of the dimming member can reduce the influence of the shadow of the dimming member. Focusing on Examples 23 to 24, in which the aperture rate of the dimming member was 33.0%, the evaluation result was 2, which shows that at least the stripes on the surface of the decorative sheet were improved. [Industrial Applicability]

[0067] The present invention is useful as a light irradiation device and a light irradiation method. [Explanation of symbols]

[0068] 1 Light irradiation device 2 Excimer lamp 3. Light-reducing material 3a Wire member (first wire member) 3b Second wire member 3c Opening part 4. Means of transportation 10 Decorative Sheet 11 Base material layer 11a Surface of base layer 12 Surface layer 12a Surface of the surface layer T Irradiated object

Claims

1. A light irradiation device including a light source for irradiating an object to be irradiated, which is transported in a predetermined transport direction, with an excimer beam, the light source is filled with a discharge gas for emitting the excimer beam; a light-reducing member configured by a plurality of linear members and provided between the light source and the object to be irradiated; an extending direction of at least one of the plurality of linear members intersects with the conveying direction at an angle greater than 0°; A light irradiation device in which no member that would cause a linear or mesh-like shadow of the excimer light is provided between the discharge gas and the object to be irradiated.

2. The light irradiation device according to claim 1, The plurality of wire members are a plurality of first line members extending in parallel; a plurality of second line members extending in parallel, the second line members intersecting the plurality of first line members at a 90° angle; Including, a light irradiation device, wherein at least one of the extending direction of the first line member and the extending direction of the second line member intersects with the transport direction at an angle of 15° to 45°.

3. A light irradiation method for irradiating an object with excimer light using the light irradiation device according to claim 1 or 2, comprising: The object to be irradiated is a resin base layer; a surface layer formed of a cured product of a UV coating material laminated on the base layer; wherein the gloss of the surface layer at the portion irradiated with the excimer beam becomes lower than that before the irradiation.

4. A light irradiation method for irradiating an object with excimer light using the light irradiation device according to claim 1 or 2, comprising: The illuminance of the excimer beam emitted from the light source is 11 mW / cm ２ This is the light irradiation method.

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