Thin glass-laminated printed steel sheet having excellent surface quality and method for manufacturing the same

Abstract

To provide a thin glass-laminated printed steel sheet having surface quality excellent in high hardness, high gloss and high image clarity, and a method for manufacturing the same.SOLUTION: Provided is a thin glass-laminated printed steel sheet comprising: a printed steel sheet including a metal sheet and a printed layer on which a design or pattern having a high resolution of 300 dpi or more is printed on a surface of the metal sheet; an adhesive layer which is formed by curing an ultraviolet curable adhesive solution on the printed steel sheet, has a thickness of 10 to 100 μm, and is transparent; and a flexible thin glass attached by the adhesive layer; where a reference value for color density evaluation (Dmax Comparison) is higher than 1.6 as measured by a spectrophotometer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention provides inkjet printers with high-resolution patterns, images, designs, etc. Thin glass bonding printer in which transparent and flexible thin glass is bonded to a jet-printed metal steel plate. This relates to cemented steel plates. [Background technology]

[0002] Generally, surface-treated steel sheets with printed patterns are used for building exteriors, home appliance exteriors, etc. Such printed steel sheets are used by adjusting the gloss with a clear coating. Design various images and shapes to achieve the desired aesthetic effect of the product or the interior of the building. Used to increase the effect.

[0003] As the quality of life gradually improves, consumers start purchasing home appliances, building materials, etc. In addition to product functionality, the appearance quality and design of the product are also important factors in product selection. In response to these consumer needs, recently, cars painted in one color have become available. By using colored steel plates and ink to create various patterns, we can give the product a beautiful appearance and texture. Printed steel sheets with excellent surface appearance and visual functionality are attracting attention. Plates and printed steel plates are used for fire doors, elevator interiors, and high-end products in line with individuality and luxury. It is widely used in buildings, interiors, home appliances, kitchens, and furniture. Printed steel sheets can be applied with various designs requested by consumers and are high resolution. It is possible to express high-quality designs while maintaining a low cost, so demand for it is gradually increasing. This is a trend.

[0004] Conventionally, printed steel sheets with patterns on them have a transparent coating layer applied over the printed design layer. This transparent coating prevents damage to the printed pattern, and the printed pattern becomes more visible through this transparent coating. However, the current clear coating method for the sheet system Use Luxclean or curtain coating to achieve high gloss in part. However, the thickness of the transparent coating layer is relatively thick, about 50 to 100 μm, and it is hard to apply by heat curing. The evaporation of the solvent causes the surface to become rough, making it difficult to achieve a beautiful surface. Due to the natural flattening process, it takes a long time to harden, which reduces productivity, and it is also very vulnerable to fires. In particular, it is necessary to provide the surface characteristics of high gloss, high hardness, and high image clarity that are similar to glass surfaces, as required by customers. However, the surface is rough and high image clarity cannot be achieved, and it is difficult to achieve high surface hardness, high gloss, etc. The reality is that it has not been possible to achieve the beautiful surface quality of Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been proposed to solve the above-mentioned conventional problems, and is a high-hardness, high-performance Thin glass bonded printed steel sheet with excellent surface quality, gloss and high image clarity, and its manufacturing method to provide.

[0006] The object of the present invention is not limited to the above. Those skilled in the art will be able to understand further problems of the present invention from the overall content of the specification of the present invention. There is no difficulty in understanding. [Means for solving the problem]

[0007] One aspect of the present invention is a metal plate and a metal plate having a design or pattern printed on the surface thereof. A printed steel plate containing a printed layer; formed by curing an ultraviolet-curable adhesive solution on the printed steel plate a transparent adhesive layer having a thickness of 10 to 100 μm; and a film attached by the adhesive layer. Flexible thin glass; Color density evaluation using a spectrophotometer ( Thin glass bonded print with a Dmax (Dmax Comparison) standard value exceeding 1.6 It is a steel plate.

[0008] The thickness of the thin glass sheet may be 0.1 to 2 mm.

[0009] The glossiness of the above thin glass bonded printed steel sheet is 85% or more based on a 60-degree glossmeter. It is possible.

[0010] The image clarity of the above thin glass bonded printed steel sheet is SW 30 or less based on the image clarity measuring instrument. , LW 10 or less.

[0011] The optical properties of the above thin glass-bonded printed steel sheet were evaluated using a spectrophotometer. When the L value of the White Point Comparison exceeds 75 and the maximum saturation (Saturation) for the gamut volume n=1) standard HSL (H: Hue, S: Saturation, L: Lightness When evaluating the HSL comparison value, the reference value is 440,000. It is evaluated based on the absolute value of the gamut volume (Cubic Volume Comparison). When using a 200,000-mg dose, the reference value can be greater than 200,000.

[0012] The thin glass may be alkali-free borosilicate glass, soda-lime glass or tempered glass. It can be glass.

[0013] The printed steel sheet has a base color layer and a primer layer between the metal sheet and the printing layer. It may further include at least one.

[0014] A pretreatment layer may further be included between the metal plate and the primer layer.

[0015] The printed steel plate may be an inkjet printed steel plate.

[0016] The resolution of the printed design or pattern on the printed steel plate is 300 dpi or higher. It is possible.

[0017] Another aspect of the present invention is a metal plate and a metal plate having a design or pattern printed on the surface thereof. preparing a printed steel plate including a printed layer; applying ultraviolet curing to the surface of the prepared printed steel plate; forming an adhesive layer by applying an ultraviolet-curable adhesive solution; A step of attaching a flexible thin glass sheet to a printed steel plate; applying pressure to the flexible thin glass; and irradiating ultraviolet light to the ultraviolet-hardening layer. and curing the cured adhesive solution.

[0018] The thin glass sheet may have a thickness of 0.1 to 2 mm.

[0019] The pressure applied in the step of applying the pressure can be 2 to 10 kgf.

[0020] The thickness of the adhesive layer after curing of the ultraviolet curable adhesive solution may be 10 to 100 μm. do.

[0021] The ultraviolet curable adhesive solution contains a polyester acrylate oligomer with six or more functional groups, Difunctional urethane acrylate oligomer, one or more photocurable monomers, and a photoinitiator may include:

[0022] The resolution of the design or pattern printed on the printing layer must be 300 dpi or higher. can.

[0023] Another aspect of the present invention is a method for coating a printed steel plate with an ultraviolet-curable adhesive solution. Coating means: provided at the rear end of the coating means, for applying thin glass sheets onto the adhesive solution glass attaching means; connected to the glass attaching means, and press-fitting the glass film to adhere it a pressure-bonding means for adhering the ultraviolet light source and the glass film to each other; and a pressure-bonding means provided at the rear end of the pressure-bonding means. A thin plate containing a curing means for curing the ultraviolet curable adhesive solution by irradiating the adhesive with light to form a coating film. This is a manufacturing system for lath-jointed printed steel sheets.

[0024] The manufacturing system for the above thin glass bonded printed steel sheet removes minute bubbles from the frame by decompression. The device may further include a pressure reducing means for removing the gas. [Effects of the Invention]

[0025] The present invention is a method for bonding thin glass sheets having small roughness onto a printed steel plate. It can realize various images on printed steel sheets with high clarity and protect the printing layer. Not only can it be applied, but it also has high hardness, high gloss and high image clarity, which can prevent discoloration and peeling. To provide a thin glass bonded printed steel sheet having excellent surface quality and good optical properties. This has the effect of making it possible to do the following.

[0026] The various yet significant advantages and effects of the present invention are not limited to those described above. This can be more easily understood in the course of describing specific embodiments of the invention. [Brief explanation of the drawings]

[0027] [Figure 1] 1 shows the structure of a thin glass-bonded printed steel sheet according to one aspect of the present invention. [Figure 2] 1 shows various modified examples of a thin glass-bonded printed steel sheet according to one aspect of the present invention. (a) to (c) show modified examples in which a base color layer and / or a primer layer is formed between the metal sheet and the printing layer, and (d) shows a modified example in which a base color layer, a primer layer, and a pretreatment layer are all formed between the metal sheet and the printing layer. [Figure 3] 1 is a scanning electron microscope (SEM) photograph of the surface state of an inkjet-printed steel plate. [Figure 4] 1 shows various embodiments of the adhesive layer, where (a) is a film adhesive, (b) is a heat-curable adhesive, and (c) is an ultraviolet-curable adhesive solution according to the present invention. [Figure 5] 1 is a diagram illustrating a method for manufacturing a thin glass-bonded printed steel sheet according to another aspect of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] Preferred embodiments of the present invention will be described below. However, some embodiments of the present invention may be different. The present invention can be modified into other forms, and the scope of the present invention is not limited to the embodiments described below. Furthermore, the embodiments of the present invention are not intended to be limiting to the scope of the present invention, but are intended to be illustrative and not restrictive. It is provided to explain the concept more completely.

[0029] [Thin glass bonded printed steel sheet] FIG. 1 shows a schematic structure of a thin glass-bonded printed steel sheet according to one aspect of the present invention. Referring to FIG. 1, a thin glass bonded printed steel sheet according to one aspect of the present invention is shown. The device includes a metal plate 11 and a printed layer 12 on the surface of the metal plate, on which a design or pattern is printed. A printed steel plate 1 is formed by curing an ultraviolet curing adhesive solution on the printed steel plate 1; a transparent adhesive layer 2 having a thickness of 10 to 100 μm; and a frame adhered by the adhesive layer 2. It includes a flexible thin glass sheet 3.

[0030] Printed steel plate The printed steel sheet 1 of the thin glass bonded printed steel sheet according to one aspect of the present invention is not particularly limited. Regardless of the type of printed steel sheet, any printed steel sheet that is currently manufactured or commercially available can be suitably applied to the present invention. The printed steel sheet 1 can be used as a metal sheet 11 and a metal plate 21. It may include a print layer 12 on which a design or pattern is printed. Although not required, in one embodiment the resolution of the design or pattern is 300 dpi or higher. It can be high resolution.

[0031] As a non-limiting embodiment, the printed steel plate 1 is an inkjet printed steel plate. It is possible to print designs or patterns via inkjet printing. If printing, full color printing at a high resolution of 300 dpi or higher is required. It is easy to achieve subtle contrast, vibrant saturation, and realistic colors. In addition, when the thin glass sheet 3 is brought into contact with the inkjet printed steel plate according to the present invention, It is possible to achieve a surface appearance similar to that of natural materials, and to obtain beautiful decorative materials. There is an advantage to this.

[0032] As a non-limiting example of a modified example, the printed steel plate 1 is formed by the metal plate 11 and the printing layer 12. A base color layer 4 and / or a primer layer 5 may be included between them. 2(a) to (c) show the structure of the thin glass bonded printed steel plate according to the above modification. The base color layer 4 plays a role in expressing the base color of the printed steel sheet 1. The thickness of the printed layer 12 may be 5 to 30 μm. The primer layer 5 can be formed on the metal plate 1 by plasma treatment. 1 and the base color layer 4, or between the metal plate 11 and the printing layer 12. The thickness of the film can be 1 to 10 μm.

[0033] In another non-limiting modification, a layer of a protective film is formed between the metal plate 11 and the primer layer 5. 2(d) shows a configuration in which a pretreatment layer 6 is further included. The pre-treatment layer 6 provides the basic corrosion resistance of the metal plate 11. It serves to improve adhesion between the metal plate 11 and the primer layer 5, and its thickness is 0 It can be 0.1 to 2 μm.

[0034] adhesive layer On the other hand, a transparent adhesive for bonding with the thin glass sheet 3 is formed on the printed layer 12 of the printed steel sheet 1. An adhesive layer 2 can be formed on the printed steel plate 1, and the adhesive layer 2 is formed by applying an ultraviolet curing agent to the printed steel plate 1. The adhesive solution can be applied and then cured to form the film.

[0035] First, the adhesive layer 2 is preferably formed from an ultraviolet-curable adhesive solution. Generally, when joining glass to building materials, film adhesives or heat-curing adhesives are used. However, as shown in Figure 3, the printed steel plate 1, especially the inkjet printer, Since the printed steel plate has a surface roughness of several to several tens of μm, the film adhesive is applied to the printed steel plate 1. Also, if a thermosetting adhesive is used, it is not possible to obtain beautiful surface clarity and flatness. 4, in more detail, in the case of the film adhesive of FIG. 4(a), the ink The specific surface roughness caused by the droplets is transferred directly to the adhesive film and glass, causing bending. This causes the surface flatness to be poor. In the case of a curable adhesive, a solvent is usually included in the adhesive coating. As shown in the right photo (red circle), these solvents evaporate during the curing heat treatment. The problem is that the adhesive cannot escape and remains in the adhesive coating, which can cause bubbles. Therefore, the surface roughness of the printed steel sheet is not transferred to the glass, and the generation of bubbles is minimized. To minimize this, a liquid adhesive is more suitable than a solid film adhesive, and a thermosetting adhesive is more suitable. Better surface quality characteristics can be obtained when using UV-curable adhesive solutions than do.

[0036] The adhesive layer 2 is made of a material that is transparent to the printed steel plate. Therefore, it is preferable that the adhesive layer 2 has excellent transparency. It is preferable that the transmittance is high, about 85% or more, in the 100 nm wavelength band, and the yellowing index (Ye It is preferable that the lowness index is 2 or less.

[0037] On the other hand, the adhesive layer 2 is preferably formed to a thickness of 10 to 100 μm. If the thickness of the ink-jet printing layer 2 is less than 10 μm, the roughness of the ink-jet printing surface (printing layer) is offset. This can lead to problems with surface quality, i.e., image clarity. However, if the thickness of the adhesive layer 2 exceeds 100 μm, the thickness of the adhesive layer 2 becomes excessively thick, and the color becomes discolored. This can cause problems with current performance and curing efficiency, and requires the use of relatively large amounts of adhesive solution. This can lead to problems such as increased manufacturing costs.

[0038] Flexible thin glass A flexible thin glass sheet with a thickness of 0.1 to 2 mm is placed on a transparent adhesive layer 2. The material of the thin glass sheet 3 is not particularly limited, but In one embodiment, alkali-free borosilicate glass, soda-lime glass or refractory glass is used. A vitreous glass can be preferably used.

[0039] The thin glass sheet 3 must be flexible and have a thickness of 0.1 to 1.5 mm. A thin plate of 2 mm is preferable. Flexible plate that can be bent freely. Unlike conventional thick plate glass, the glass 3 is bonded to a printed steel plate (laminatin g), and has the advantage of being not only light but also excellent in light transmittance. Due to its soft properties, it can be rounded even after glass is attached. If the thickness of the thin glass 3 is less than 0.1 mm, it is difficult to handle and the glass may be damaged during bonding. Problems may arise in that the flatness decreases due to bending of the surface or external force. If the thickness of the thin glass 3 exceeds 2 mm, the pressure may not be transmitted properly due to the thickness. , and the weight becomes too heavy and economically unsuitable.

[0040] In particular, the thin glass sheet 3 applied to the present invention is not only in the wavelength range of visible light but also in the In the present invention, the adhesive layer 2 is required to transmit ultraviolet rays and radiation in the following wavelength ranges. The metal plate and the thin glass are bonded together through a bonding agent, and the adhesive layer is cured by passing it through an ultraviolet or radiation curing machine. 2 is hardened.

[0041] The thin glass bonded printed steel sheet according to the present invention having the above-mentioned configuration has a glossiness of 60 degrees. The water flow rate is 85% or more based on the water flow meter, and the image clarity is SW 3 based on the image clarity meter. 0 or less, LW 10 or less. Also, the surface hardness is 9H or more based on pencil hardness. It is possible.

[0042] On the other hand, using a spectrophotometer, 376.76 White point evaluation is an optical characteristic evaluated by measuring light in the range of 730 nm to 730 nm. L value (Lightness, white brightness) when using Point Comparison The color gamut volume rating (HSL Co mparison), HSL (H:Hu) based on maximum saturation (Saturation=1) e, S: Saturation, L: Lightness) values ​​are evaluated based on the criteria The value can exceed 440,000, and the color density rating (Dmax Comparison n) can exceed 1.6, and the absolute value of the gamut volume (Gamut Vol The reference value for ume and Cubic Volume Comparison is 200,00 In particular, the present invention provides a standard value for evaluating color density that is greater than 1.6. In order to satisfy the requirements, the high temperature of the printed steel sheet is used even though the thin glass and adhesive layer are formed. It is characterized by the ability to achieve images with resolution at a life-like level.

[0043] Specifically, the evaluation of the optical properties can be carried out under the following conditions. Although it is not specified, when the optical characteristics are evaluated according to the following conditions, the above criteria are met. If it satisfies the above conditions, it can be determined that the scope of the present invention is met.

[0044] The equipment for optical characterization was 3 x X-rite i1Pro 2 Spectr A photometer is used, specifically a D50M2 UV compensator. tion mode(2 degree Standard Observer by CIE 1931), spectral spacing(3.3nm), spectr al bands(107), spectral start(376.67nm), s Measurement was performed under the specular end (730 nm) condition. ArgyllCMS 2.0.1 is used, specifically, single channel annel step (8), gray axis step (32), sample The measurement was performed under the condition of g color patches (882). As applications, GamutVision, Color ThinkPro, Raw data White point, color gamut volume, color density, and color gamut volume using Direct Analysis The absolute value of was evaluated.

[0045] The thin glass bonded printed steel sheet according to one aspect of the present invention has a high resolution printed steel sheet 1 on it. The thin glass 3 is bonded to the glass, which provides high hardness, high image clarity, stain resistance, and other properties. It is possible to achieve excellent chemical resistance and good interfacial adhesion by using thin glass sheets. At the same time, excellent color can be achieved.

[0046] Hereinafter, a method for manufacturing a thin glass-bonded printed steel sheet according to another aspect of the present invention will be described in detail. will be explained.

[0047] [Method of manufacturing thin glass-bonded printed steel sheets] According to another aspect of the present invention, a method for manufacturing a thin glass-bonded printed steel sheet is provided. A step of preparing a printed steel plate 1 by applying an ultraviolet curing adhesive solution to the surface of the printed steel plate 1. Step 12: Applying a thin film glass to the printed steel plate coated with the ultraviolet curing adhesive solution. Step 3: Applying pressure to the attached thin glass sheet, and removing air bubbles formed between the adhesive solution and the thin glass sheet 3; and irradiating ultraviolet light. and hardening the ultraviolet-curable adhesive solution.

[0048] Preparation of printed steel plate and adhesive layer formation stage First, a metal plate 11 and a printed steel plate 1 on which various high-resolution designs are printed are prepared. A transparent ultraviolet-curing adhesive solution is applied onto the printed steel plate 1. The adhesive solution is applied using a coating device such as a separate roll coater or slot knife. It can be applied manually by the operator using equipment such as a brush or spray gun. However, the present invention is not limited to this, and the adhesive solution may be applied uniformly to the entire printed steel plate. Any conventional known means can be used as long as it can be applied uniformly. do.

[0049] The ultraviolet-curable adhesive solution is an adhesive that is cured by ultraviolet light and has adhesive strength. The adhesive solution can be preferably applied to the present invention. In a non-limiting embodiment, the ultraviolet curable adhesive solution may be 6 Polyester acrylate oligomers with 2 or more functional groups, urethane acrylate oligomers with 2 or more functional groups The polymer may include one or more photocurable monomers, a photoinitiator, and other additives. Examples of the photocurable monomers are TMPTA, THFA, PETA, and IBOA. Examples of the photoinitiator include 2-hydroxy-2-methyl-1-ph enyl-propane, oxy-phenyl-acetic acid 2-[2 oxo-2phenyl-acetoxy-ethoxy]-ethyl ester In addition, examples of the other additives include phosphoric acid ac rylate(acid value 250), polyether siloxan may contain fluoroalkyl compounds and fluoroalkyl compounds. Cut.

[0050] The ultraviolet-curable adhesive solution must be applied uniformly over the entire surface of the printed steel plate 1 . For this reason, it is preferable to apply the coating to the entire surface of the printed steel plate with a uniform thickness, and It is more preferable to apply a constant amount of adhesive solution at regular intervals. Then, the adhesive solution is printed by the pressure through the step of attaching and pressing the thin glass sheet 3. It spreads and disperses evenly over the entire area of ​​the steel plate, minimizing waste of adhesive solution.

[0051] In addition, when applying the ultraviolet curing adhesive solution, the printed steel plate 1 is supported. In the case of a coiled steel sheet, it is preferable that the roll or bed is configured such that It is preferable to provide a roll made of rubber or metal, and in the case of a sheet material, a roll made of plastic is used. A bed made of steel, metal, or wood is provided to support the entire surface of the sheet material. It is preferable that the ultraviolet curing adhesive melting agent be formed on such a roll or bed. When applying a liquid, it can be applied more easily and uniformly.

[0052] Thin glass attachment and pressure application step After applying an ultraviolet curing adhesive solution onto the printed steel plate 1, a 0.1 to 2 mm thick adhesive is applied on top of it. Then, a thin flexible glass sheet 3 is attached. After the adhesive is attached, a pressure of 2 to 10 kgf is applied to the thin glass sheet 3 to press the adhesive. By applying an appropriate pressure to the glass 3, the thickness of the adhesive layer 2 can be adjusted appropriately. In addition, bubbles formed in the ultraviolet curing adhesive solution and the thin glass sheet 3 can be easily removed. can be done.

[0053] When the pressure applied to the thin glass sheet 3 is less than 2 kgf, the pressure decreases and the adhesive layer remains at the adhesive interface. Air bubbles may be trapped or pressure may not be transmitted completely, resulting in a gap between the thin glass and the adhesive layer. On the other hand, if the pressure exceeds 10 kgf, The thickness of adhesive layer 2 is reduced due to high pressure, and the rough surface of the printing layer is adhered, resulting in poor image clarity. This can cause adhesive solution to leak out and contaminate the device. The pressure is preferably controlled to 2 to 10 kgf.

[0054] The method of applying pressure is not limited to the present invention as long as it is a conventionally used glass pressing method. As a non-limiting example, the printed steel plate 1 may be provided with a plurality of The paper is pressed by the roll press method, which applies pressure using a paper roll (pressing roll) placed on the paper. In addition, as a non-limiting example, thin glass can be attached and pressure can be applied. The adhesion mechanism and the pressure bonding mechanism used in the step of A roll press including a slip sheet roll and a thin plate provided above the roll press. a glass drawing mechanism; and a thin glass sheet 3 and a printed steel sheet 1 on which an adhesive layer 2 is formed. and a supporting member for maintaining the thin glass sheet 3 in a flat state. can be done.

[0055] The interleaving roll is preferably made of a rubber material, and the printed steel sheet and the thin plate When pressing the lath layer, the interleaf roll can be moved in the length direction of the base material (steel plate). It is preferable that the pressure bonding is carried out while the material is being moved using a conveyor belt. The paper roll adjusts the thickness of the adhesive layer applied to the printed steel plate by controlling the height and pressure of the roll. The pressure regulator may include a lift actuator and a pressure regulator to allow the pressure regulator to be adjusted. The members are provided at the widthwise ends of the thin glass sheet to keep the thin glass sheet flat. The above-mentioned members may be, but are not limited to, conveyor belts and rollers. However, any means capable of keeping the transparent thin glass flat is acceptable. It is available for use.

[0056] Curing the adhesive layer After this, the pressed thin glass bonded printed steel sheet is passed through an ultraviolet curing machine to be cured by ultraviolet light. By hardening the curable adhesive solution, a coating film with a thickness of 10 to 100 μm can be formed. At this time, the ultraviolet light irradiated can be in the wavelength range of 300 to 400 nm. However, the present invention is not limited to this, and an ultraviolet curable adhesive solution can also be cured. Any conventionally known means can be applied without any restrictions as long as it is possible.

[0057] Furthermore, during UV curing, a pressure reducing device or other pressure reducing means is used to remove fine air bubbles from the frame. It can also be removed.

[0058] [Printed steel sheet thin glass bonding system] According to another aspect of the present invention, a thin glass bonding system for a printed steel plate is provided. a coating means for coating the ultraviolet curing adhesive solution onto the substrate; a glass adhering means provided at the rear end for adhering a thin glass sheet onto the adhesive solution; A pressing device that connects to the step and presses the glass film to adhere the adhesive means to the glass film. a step provided at the rear end of the pressure bonding means, which irradiates ultraviolet light to harden the ultraviolet-hardening adhesive solution; The coating film may be formed by applying a pressure to the frame portion. A vacuum means for removing micro-bubbles may be included. [Example]

[0059] The present invention will be described in more detail below with reference to examples. However, the following examples are not intended to be limiting of the scope of the present invention. The following description is provided for illustrative purposes only and is not intended to limit the scope of the present invention. It should be noted that the scope of the present invention is not limited to the scope of the claims. This is because the matter is determined by the matters stated and the matters that can be reasonably inferred from them.

[0060] (Example) First, as an example of the invention, a urethane acrylate UV-curable coating housed in a coater fan After dipping the coating roll in the coating solution, a high-resolution pattern (resolution: 1200 dpi) was printed on the inkjet printed steel plate, and a transparent adhesive solution was applied to a thickness of 30 After applying a coating of 40 μm, a thin glass sheet with a thickness of 400 μm and a light transmittance of 90% or more is placed on top of it. After this, the film was pressed with a pressure roll at 3 kg / f to coat the film. After the adhesive solution and the film are adhered together, they are passed through an ultraviolet curing machine to harden the adhesive solution. The glass-bonded steel sheets were then bonded together to produce glass-bonded steel sheets.

[0061] On the other hand, as Comparative Example 1, an inkjet print with a high-resolution pattern printed with a thickness of 1 mm was used. A high-gloss transparent coating liquid was applied to the steel plate, and a coating film was formed by heat curing. As Comparative Example 2, a transparent adhesive solution was applied to a similar inkjet printed steel plate in a thickness of 30 to 40 mm. After applying it to a thickness of 0μm, attach a 5mm thick tempered glass with a light transmittance of 90% or more, and then It was produced by passing it through a radiation curing machine and curing it.

[0062] [Glossiness, image clarity, hardness evaluation] The products manufactured in the above-mentioned examples and comparative examples were measured for gloss and Image clarity and hardness were tested and the results are shown in Table 1 below.

[0063] -Gloss measurement Measurement angle 60° using a gloss meter (BYK-Gardner) The gloss level is a relative value based on the glass reflectance of 100. showed.

[0064] -Image clarity measurement Image clarity was measured using an image clarity measuring device (Wavescan, BYK-Gardner). The surface of a 1cm x 10cm test piece was irradiated with light at a 20° angle and 3750 points were scanned. The degree of unevenness and clarity of the coating film are graded from 0 (good) to 100 (bad). The measurement range is 0.1 to 1.2 mm for short waves (SW) and Measurements were divided into 1.2-12 mm long wave (LW) and 1.2-12 mm long wave (LW).

[0065] In Table 1 below, when the measured image clarity values ​​are SW 20 or less and LW 5 or less, they are marked with ◎, SW 21-30 or less, LW 6-15 or less: ○, SW 31-40 or less, LW 16- Cases of 20 are marked with △, and cases of SW 41 or more and LW 21 or more are marked with ×.

[0066] -Hardness measurement Hardness is evaluated based on the pencil hardness test. The pencil hardness is measured using an automatic Mitsubishi simple pencil hardness tester. Measurements were made using a thermometer (Qmesys, QM450A). The pencil lead specified in 02 is applied to the surface of the steel plate with a load of approximately 1 kgf and the surface is pulled while being pressed. Hardness was measured by scratching and damage evaluation.

[0067] [Evaluation of contamination resistance, chemical resistance, and processability] Stain resistance is measured by drawing a line on the surface of the manufactured product with a board marker and then erasing it. The evaluation was based on whether or not any traces remained. If no traces were left and the surface was completely erased, it was rated as ◎. If only a slight trace remained, it was marked with △, and if it did not disappear, it was marked with ×.

[0068] Chemical resistance was measured by dropping a 95% acetone solution onto the surface of the manufactured product with a 2cm drop. After the cap was placed on the container and left for 2 hours, the acetone solution on the surface was wiped off with a cloth. ◎ indicates that there is no damage, △ indicates that only a part of the coating is damaged, and the entire coating is swollen or peeled off. When the finger was released, it was displayed as "x".

[0069] In addition, the invention example and the comparative example were subjected to rounding to evaluate the workability, and When five products are processed as a standard, all five of the five products have no defects or damage on their surfaces. ◎ indicates that the image is in good condition, ○ indicates that 4 out of 5 images are in good condition, and 2-3 out of 5 images are in good condition. The case where the result was good was indicated by △, and the case where one or less out of five sheets was good was indicated by ×.

[0070] [Optical property evaluation] Meanwhile, a spectrophotometer was used to compare the color realization characteristics of the invention example and the comparative example. After printing 882 sample colors using a colorimeter, The white point and color gamut volume are measured using the following evaluation method. The absolute values ​​of color density and color gamut volume were evaluated, and the results are shown in Table 1 below.

[0071] -White Point Comparison White point evaluation is an index showing the brightness of white, and is based on an L value (Lightness) of over 75. If it was over, it was marked with ◎, and if it was between 50 and 75, it was marked with ○.

[0072] -Gamut Volume (HSL Comparison) The outline of the entire sunlight area indicates the color space area that each medium can reproduce. As an index, the maximum saturation (Saturation = 1) is used as the standard for HSL (H: Hue, S: When evaluating the (Saturation, L: Lightness) values, the actual color reproduction is If the standard value is over 440,000, it is marked as ◎, and if it is between 350,000 and 440,000, it is marked as ◎. Cases where there is a difference are indicated by ○, and cases where there is less than 350,000 are indicated by △.

[0073] -Color density evaluation (Dmax Comparison) In color density, as in blackness or chroma This indicates the percentage of saturated state. If the standard value is over 1.6, it is marked with ◎, and if it is between 1.3 and 1.6, it is marked with ☐. When it was less than 1.3, it was indicated as ○, and when it was less than 1.3, it was indicated as △.

[0074] - Absolute value of gamut volume (Gamut Volume, Cubic Volume Com parison) As an index showing the perceptible color space area in the color region, it is evaluated based on the absolute value of the color gamut volume. When evaluated, if the standard value is over 300,000, it is marked as ◎, and if it is between 200,000 and 300, it is marked as ◎. If it is less than 1,000, it is indicated as ○, and if it is less than 200,000, it is indicated as △.

[0075] [Table 1]

[0076] As can be seen from Table 1 above, the present invention can be applied to a development device having a flat thin glass attached to its surface. The clear glass has excellent gloss and clarity, and is also excellent in hardness and processability. However, in the case of Comparative Example 1, the optical properties and processability are good. However, there were limitations to the gloss and image clarity that could be achieved due to the solvent evaporation of the heat-curing system. The hardness was lower than that of the invention example and comparative example 2 in which glass was bonded, and the contamination resistance and chemical resistance were inferior. In addition, in the case of Comparative Example 2, since glass was bonded, the glossiness, image clarity, hardness, and stain resistance were improved. The properties of the adhesive and chemical resistance were superior to those of the present invention, but the thickness of the bonded glass was too large. Thickness, optical property evaluation of color reproduction such as white point, color gamut volume, color density, absolute value of color gamut volume It was confirmed that the value was worse in all respects than that of the present invention, and the processability was also worse.

[0077] Although the present invention has been described with reference to the embodiments, it is understood by those skilled in the art that The present invention is not limited to the above and is not intended to be limiting unless it is expressly stated otherwise. It will be understood that various modifications and variations of the invention are possible. [Explanation of symbols]

[0078] 1 Printed steel plate 11 Metal plate 12 printing layer 2 Adhesive layer 3 Thin glass 4 Base color layer 5 Primer layer 6 Pretreatment Layer

Claims

1. A printed steel sheet comprising a metal sheet and a printed layer on which a design or pattern is printed on the surface of the metal sheet; A transparent adhesive layer having a thickness of 10 to 100 μm is formed on the printed steel sheet by curing an ultraviolet-curable adhesive solution; and Includes flexible thin glass sheets attached by the aforementioned adhesive layer; Thin glass-bonded printed steel sheet with a color density evaluation (Dmax Comparison) exceeding 1.6 using a spectrophotometer.

2. The thin glass bonded printed steel sheet according to Claim 1, wherein the thickness of the flexible thin glass is 0.1 to 2 mm.

3. The thin glass bonded printed steel sheet according to Claim 1, wherein the gloss of the thin glass bonded printed steel sheet is 85% or more based on a 60-degree gloss meter.

4. The thin glass bonded printed steel sheet according to Claim 1, wherein the image quality of the thin glass bonded printed steel sheet is SW 30 or less and LW 10 or less, based on an image quality measuring instrument.

5. When optical properties are evaluated using a spectrophotometer, The White Point Comparison (L value) is over 75. The thin glass-bonded printed steel sheet according to claim 1, wherein when evaluating the HSL (H: Hue, S: Saturation, L: Lightness) value based on maximum saturation (Saturation = 1) relative to the color gamut volume (HSL Comparison), the reference value exceeds 440,000, and when evaluating based on the absolute value of the color gamut volume (Cubic Volume Comparison), the reference value exceeds 200,000.

6. The thin glass bonded printed steel sheet according to claim 1, wherein the flexible thin glass sheet is alkali-free borosilicate glass, soda-lime glass, or tempered glass.

7. The thin glass bonded printed steel sheet according to claim 1, wherein the printed steel sheet further comprises at least one of a base color layer and a primer layer between the metal sheet and the printing layer.

8. The thin glass bonded printed steel sheet according to claim 7, further comprising a pretreatment layer between the metal sheet and the primer layer.

9. The thin glass bonded printed steel sheet according to claim 1, wherein the printed steel sheet is an inkjet printed steel sheet.

10. The thin glass bonded printed steel sheet according to claim 1, wherein the resolution of the design or pattern printed on the printing layer is 300 dpi or more.

11. A method for manufacturing a thin glass bonded printed steel sheet, A step of preparing a printed steel sheet, which includes a metal sheet and a printed layer on which a design or pattern is printed on the surface of the metal sheet; This step involves applying an ultraviolet-curing adhesive solution to the surface of the prepared printed steel sheet to form an adhesive layer; The step of attaching a flexible glass sheet to a printed steel sheet coated with the aforementioned ultraviolet-curing adhesive solution; The step of applying pressure to the attached flexible thin glass sheet; and A step of curing the UV-curable adhesive solution by irradiating it with ultraviolet light; A method for manufacturing thin glass-bonded printed steel sheets, including the method described above.

12. The method for manufacturing a thin glass bonded printed steel sheet according to claim 11, wherein the thickness of the flexible thin glass is 0.1 to 2 mm.

13. The method for manufacturing a thin glass bonded printed steel sheet according to claim 11, wherein the pressure is 2 to 10 kgf.

14. The method for manufacturing a thin glass bonded printed steel sheet according to claim 11, wherein the thickness of the adhesive layer after curing of the ultraviolet-curable adhesive solution is 10 to 100 μm.

15. The method for producing a thin glass-bonded printed steel sheet according to claim 11, wherein the ultraviolet-curable adhesive solution comprises a polyester acrylate oligomer with hexafunctional groups or more, a urethane acrylate oligomer with two functional groups, one or more photocurable monomers, and a photoinitiator.

16. The method for manufacturing a thin glass bonded printed steel sheet according to claim 11, wherein the resolution of the design or pattern printed on the printing layer is 300 dpi or more.

17. A coating means for coating a printed steel sheet with an ultraviolet-curing adhesive solution; A glass adhesion means provided at the rear end of the coating means for adhering a flexible thin glass sheet onto the adhesive solution; A pressing means connected to the glass attachment means, which presses the flexible thin glass sheet against the adhesive means to bring the flexible thin glass sheet into close contact with the adhesive means; and A curing means provided at the rear end of the crimping means, which cures the ultraviolet-curable adhesive solution by irradiating it with ultraviolet light to form a coating film; A manufacturing system for thin glass-bonded printed steel sheets, including the glass-bonded printed steel sheet.

18. The manufacturing system for thin glass bonded printed steel sheet according to claim 17, further comprising a depressurization means for removing microbubbles in the frame portion by depressurization.

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