JP5097014B2 - Painted board - Google Patents

Description

  The present invention relates to a coated plate formed by applying ink-jet coating on the surface of a substrate having an uneven pattern.

  Conventionally, coating on a cement-based exterior plate or the like is generally performed by applying a paint to the surface of a substrate using a spray coater, a roll coater coater, a flow coater coater, or the like. However, with such sprays, roll coats, flow coats, etc., it is difficult to paint a complicated pattern, and it is particularly difficult to paint on a board with irregularities such as bricks on the surface like exterior building boards. Have difficulty. On the other hand, painting is also performed using printing rolls such as letterpress and intaglio, but in this case, the same pattern is repeatedly applied and tends to be a monotonous pattern. When changing the above, it is necessary to replace the printing roll, and it is not possible to paint a different pattern for each substrate.

  Therefore, recently, an inkjet printer is used as a coating machine, and the substrate surface is conveyed by ejecting ink from the coating nozzle head while transporting the substrate by a conveyor and passing under the coating nozzle head of the inkjet type coating machine. It has been proposed to paint.

  In addition, in an inkjet coating machine, painting is performed while controlling the ejection of ink from a number of ejection nozzles provided in the painting nozzle head, so that the ink can be ejected to form an arbitrary pattern on an arbitrary position on the substrate. In particular, the control for ejecting ink from the spray nozzle of the coating nozzle head can be set for each substrate supplied to the ink jet coating machine, so that a different pattern is painted for each substrate. It is also possible.

Further, in the ink jet coating machine, the ink ejected from the coating nozzle head is applied to the surface of the substrate so that it can be applied in a non-contact manner on the surface of the substrate. Therefore, even if there is a complicated uneven pattern on the substrate, it is possible to apply the ink sprayed from the coating nozzle head to the convex part and concave part, respectively, and paint it, and the color pattern pattern synchronized with the concave and convex pattern It becomes easy to perform coating (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 2007-2460

  Here, in the ink jet coating machine, since the droplet size of the ejected ink is determined by the hole diameter of the spray nozzle of the coating nozzle head, the droplet size of the ink ejected from the coating nozzle head is constant. The smaller the ink droplet size, the more the pattern can be formed as an aggregate of many ink dots, so the density difference of the pattern can be expressed clearly, and the gradation is improved and the pattern is expressed. Can be increased.

  However, when inkjet coating is performed on a substrate having convex and concave portions on the surface, the convex portion protrudes from the surface of the substrate, so the distance between the coating nozzle head of the inkjet coating machine and the convex surface is short. Is recessed from the surface of the substrate, the distance between the coating nozzle head and the bottom of the concave portion becomes long, and the distance at which the ink droplets ejected from the coating nozzle head fly at the concave portion. At this time, if the ink droplet size is small, the kinetic energy of the ink droplet ejected from the coating nozzle head is small. Under the influence of conditions, straight running performance is reduced.

  Therefore, when ink-jet coating is applied to a recess where the distance to the coating nozzle head is long and the ink droplets fly long, when ink is applied with a small droplet size, the ink is accurately applied to the target position. It becomes difficult to apply, and there is a problem that the sharpness and reproducibility of the pattern are lowered even if the ink is applied with a small droplet size ink in order to improve the expression of the pattern.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a decorative board capable of obtaining high pattern expression, sharpness, and reproducibility.

  The decorative board according to claim 1 of the present invention is a coated board in which inkjet coating is performed on the surface of the substrate 3 having the convex portions 1 and the concave portions 2 by the ink ejected from the coating nozzle head 5 of the inkjet coating machine 4. The ink droplet size applied to the convex portion 1 is smaller than the ink droplet size applied to the concave portion 2 or smaller than the ink droplet size applied to the concave portion 2. It is characterized by including both of the same droplet size as that applied to the recess 2.

  According to this invention, the droplet size of the ink applied to the concave portion 2 is larger than the droplet size of the ink applied to the convex portion 1, and the distance from the coating nozzle head 5 is long and the ink liquid is large. When coating the concave portion 2 where the droplets fly long, the straightness of the ink droplet is increased, and the ink can be applied to the exact position of the concave portion 2 to improve the sharpness and reproducibility of the pattern. It can be obtained high. Further, the ink droplet of a small size is applied to the convex portion 1 having a short distance from the coating nozzle head 5 and a short distance from which the ink droplet flies, and the straightness of the ink droplet is a particular problem. Therefore, the expression of the pattern can be enhanced with high gradation by the ink having a small droplet size.

  In the present invention, the droplet size of the ink applied to the convex portion 1 is in the range of 15 to less than 20 pl, and the droplet size of the ink applied to the concave portion 2 is in the range of 20 to 30 pl. It is characterized by being.

  By setting the ink droplet size within this range, it is possible to obtain a higher effect of enhancing the expression, sharpness, and reproducibility of the pattern.

  Further, in the present invention, the inkjet coating machine 4 includes two or more types of coating nozzle heads 5 that eject inks having different droplet sizes for each ink color, and the substrate 3 extends along the direction in which the coating nozzle heads 5 are arranged. Ink jet coating is performed on the surface of the substrate 3 by ejecting ink from each coating nozzle head 5 by conveying and passing the coating nozzle head 5. The substrate 3 is arranged on the side where the substrate 3 is carried into the inkjet coating machine 4 from the coating nozzle head 5 that ejects small-sized ink.

  According to the present invention, ink having a large droplet size is applied to the substrate 3 sent to the inkjet coating machine 4, and then ink having a small droplet size is applied. At the boundary between the area where the large droplet size ink is applied and the area where the small droplet size ink is applied, the small droplet size ink overlaps the large droplet size ink. It is possible to prevent the boundary portion from conspicuously giving a sense of incongruity as in the case where the ink having the large droplet size overlaps the ink having the small size and the ink having the small droplet size is hidden.

  According to the present invention, since the ink droplet size applied to the concave portion 2 is larger than the ink droplet size applied to the convex portion 1, the distance between the coating nozzle head 5 and the ink droplet is long. When coating the concave portion 2 having a long flight distance, the straightness of the ink droplet is increased, so that the ink can be applied to the exact position of the concave portion 2, and the sharpness and reproducibility of the pattern can be improved. In addition, the ink droplets of a small size can be applied to the convex portion 1 having a short distance from the coating nozzle head 5 and a short distance from which the ink droplets fly. The straightness of the liquid droplets is not particularly problematic, and the expression of the pattern can be enhanced with high gradation by using the ink having a small liquid droplet size. As described above, it is possible to perform pattern expression with improved expression in the portion of the convex portion 1 where the pattern is conspicuous, and it is possible to obtain high sharpness and reproducibility of the pattern in the concave portion 2 as a result. It is possible to provide a coated plate on which a pattern is formed with expressiveness, sharpness, and reproducibility.

  Hereinafter, the best mode for carrying out the present invention will be described.

  The substrate 3 can be used regardless of whether it is inorganic such as ceramics or metal, or organic such as resin. The ceramic substrate 3 is used for tiles, outer wall materials, and the like. A concavo-convex pattern is formed on the surface of the substrate 3, and the concavo-convex pattern is composed of, for example, a convex portion 1 and a concave portion 2 as shown in FIG.

A receiving layer 10 is formed on the surface of the substrate 3 as shown in FIG. 1B after sealing with a solvent-based, water-soluble or emulsion-based sealer. The receiving layer 10 is a layer necessary for fixing the ink 6 for inkjet coating formed thereon, and can be formed of a water-based paint. Thus, by forming the receiving layer 10 with a water-based paint, an environmental load can be reduced. As this water-based paint, an acrylic resin paint based on an acrylic emulsion or an acrylic silicon resin paint based on an acrylic silicon emulsion can be used. In the water-based paint, at least one of extender pigments and hygroscopic resins is blended, whereby the fixability of the ink can be improved and the color developability can also be improved. Here, silica, alumina, aluminum hydroxide, barium sulfate, porous silica, diatomaceous earth, etc. can be used as the extender pigment, and vinyl acetate, urethane polymer, acrylic polymer, polyvinyl alcohol, etc. can be used as the hygroscopic resin. Ink-absorbing polymers can be used. The receiving layer 10 can be formed by applying a water-based paint at a coating amount of 30 to 200 g / m ² (wet) on the surface of the substrate 3 using a spray gun, a roll coater, a flow coater, a curtain coater or the like. it can.

  A coated plate can be obtained by ink-jet coating the surface of the receiving layer 10 provided on the substrate 3 with water-based ink. As shown in FIG. 3, the inkjet coating apparatus for inkjet coating includes a coating nozzle head 5 provided with an ejection nozzle 11, an ink supply tank 12 that supplies ink to the ejection nozzle 11 of the coating nozzle head 5, and coating. The ink jet coating machine 4 is provided with a coating control system 13 that controls the ejection of ink from the ejection nozzles 11 of the nozzle head 5, and a transport conveyor 14 that transports the substrate 3. The conveyor 14 is disposed below the inkjet coating machine 4, and the substrate 3 is led out from the position directly under the inkjet coating machine 4 and the inkjet coating machine 4 from the front position where the substrate 3 is introduced into the inkjet coating machine 4. It is arranged over the rear position.

  The coating nozzle head 5 is provided at the lower end of the ink jet coating machine 4 and is formed as a long line head in a direction perpendicular to the feeding direction of the substrate 3 and is arranged so as to cross the conveyor 14. is there. A number of spray nozzles 11 are provided on the lower surface of the coating nozzle head 5 along the longitudinal direction thereof. In the present embodiment, the coating nozzle head 5 is formed of four types of coating nozzle heads 5y, 5c, 5m, and 5k that eject inks of yellow, cyan, magenta, and black, and performs painting by full-color printing. I can do it. Similarly, the ink supply tank 12 is also composed of four types. The ink supply tank 12y for supplying yellow ink is applied to the coating nozzle head 5y, and the ink supply tank 12c for supplying cyan ink is applied to the coating nozzle head 5c. The ink supply tank 12m for supplying magenta ink is connected to the coating nozzle head 5m, and the ink supply tank 12k for supplying black ink is connected to the coating nozzle head 5k. The coating nozzle heads 5y, 5c, 5m, and 5k are arranged along the transport direction of the substrate 3.

Moreover, the inkjet coating machine 4 used in the present invention includes a plurality of coating nozzle heads 5 corresponding to the droplet sizes to be ejected so that ink can be ejected with different droplet sizes. For example, when ink is ejected in two types of droplet sizes, it is provided with two types of coating nozzle heads 5, and the coating nozzle heads 5y, 5c, and 5m that eject ink of four types of colors as described above. , in the case of using 5k is painted nozzle head for ejecting the large ink droplet size _{5y 1, 5c 1, 5m 1} , 5k 1 and, paint nozzle head for ejecting a small ink drop size _5y 2, 5c ₂ , 5m ₂ , 5k ₂ .

  The painting control system 13 is composed of various CPUs, ROMs, RAMs, and the like, and includes a painting data creation unit, a painting control unit, an injection nozzle control unit, and the like. The paint data creation unit inputs and stores the image data of the color pattern obtained by scanning the original image with a scanner or the like, and the paint control unit stores the image data of the color pattern corresponding to the substrate 3 to be painted. It is taken out from the paint data creation unit and outputs a control signal to the spray nozzle control unit based on the image data of the color pattern. The spray nozzle control unit is connected to each spray nozzle 11 of the coating nozzle heads 5y, 5c, 5m, and 5k, and controls each spray nozzle 11 based on a control signal input from the spray nozzle control unit. . Each ejection nozzle 11 is controlled to be ejected by, for example, a piezo control system or a system in which a photothermal conversion element is irradiated with a laser, and the ejection nozzle controller controls each ejection nozzle 11. Thus, the spraying and stopping of each ink of yellow, cyan, magenta, and black can be individually controlled to perform painting by full color printing corresponding to the color pattern.

  When inkjet coating is performed on the surface of the substrate 3 by the inkjet coating apparatus formed as described above, the substrate 3 is introduced onto the transport conveyor 14 with the surface having the uneven pattern formed thereon, and the substrate 3 is transported to the transport conveyor 14. And pass under the coating nozzle heads 5y, 5c, 5m, and 5k of the inkjet coating machine 4 in order. The substrate 3 is coated on the surface of the substrate 3 by spraying ink droplets from the coating nozzle heads 5y, 5c, 5m, and 5k while feeding the substrate 3 on the transport conveyor 14 in this way. It is something that can be done.

  The substrate 3 coated in this way is sent to the terminal end of the conveyor 14 and is carried out to the next clear coating process. In the clear coating process, a clear coating is applied and the clear layer 16 is overcoated as shown in FIG. 1 (b) in order to protect the ink 6 applied by inkjet coating. And water-based emulsion paints and solvent-based paints based on acrylic silicon can be used.

Here, when the ink droplets are ejected from the coating nozzle heads 5y, 5c, 5m and 5k and applied to the surface of the substrate 3 as described above, the coating nozzle heads 5y, 5c, 5m and 5k are coated. Large ink droplets ejected from the nozzle heads 5y ₁ , 5c ₁ , 5m ₁ , 5k ₁ are applied to the surface of the recess 2 and ejected from the coating nozzle heads 5y ₂ , 5c ₂ , 5m ₂ , 5k _2. small ink Ruekishizuku size as coated on surfaces of the projections 1, paint nozzle head _5y 1 painting control system _13, 5c _1, 5 m 1, 5k ₁ or paint nozzle head _5y 2, _5c 2, 5m ₂ and 5k ₂ are controlled. For example, depending on the height of the unevenness of the surface of the substrate 3 in advance by creating image data is divided into two or three stages, paint nozzle head _5y 1 painting control system 13 on the basis of _this, 5c _1, 5 m 1, 5k ₁ and paint nozzle head _{5y 2,} 5c _2, which controls the 5m _2, 5k 2. When the inclined surface 18 is between the convex portion 1 and the concave portion 2, for example, ink having a small droplet size is applied above the middle step portion of the inclined surface 18, and below the middle step portion of the inclined surface 18. Ink with a small droplet size is applied. FIG. 1 schematically shows a state where ink 6 a having a small droplet size is applied to the convex portion 1 and ink 6 b having a large droplet size is applied to the concave portion 2.

Since the coating nozzle head 5 provided on the lower surface of the inkjet coating machine 4 as described above is disposed to face the surface of the substrate 3, the projection 1 protruding from the surface of the substrate 3 and the coating nozzle head 5. Is short, but the distance between the concave portion 2 recessed from the surface of the substrate 3 and the coating nozzle head 5 is long, and ink droplets ejected from the coating nozzle head 5 at the concave portion 3. The distance that will fly increases. In this way, the distance at which the ink droplets fly at the concave portion 3 becomes long. However, as described above, the ink having a large droplet size is applied to the concave portion 2 from the coating nozzle heads 5y ₁ , 5c ₁ , 5m ₁ , 5k _1. Since 6b is ejected, the kinetic energy of the ink 6b having a large droplet is large, and the straightness of the ink flight is high. For this reason, even if it is influenced by the atmospheric conditions of the coating, the straight running performance is not impaired during the flight, and the straight flight is made to a predetermined portion of the recess 2 and is applied at an accurate position. . As described above, the ink 6b can be applied to an accurate portion of the recess 2, and the sharpness and reproducibility of the pattern can be obtained.

On the other hand, ink 6a having a small droplet size is ejected from the coating nozzle heads 5y ₂ , 5c ₂ , 5m ₂ , and 5k ₂ to the convex portion 1, but the distance between the convex portion 1 and the coating nozzle head 5 is short. Since the distance at which the ink droplets fly at the convex portion 1 is short, the ink droplets reach the surface of the convex portion 1 in a short time, and the ink is applied to the exact portion of the convex portion 1. Can do. Since the droplet size of the ink 6a is small in this way, a pattern can be formed as an aggregate of many ink dots as shown in FIG. 1A, and the density difference of the pattern can be clearly expressed. It is possible to improve the expression of the pattern by improving the gradation.

  As described above, by applying the ink 6b having a large droplet size at the portion of the concave portion 2 where the ink droplets fly long, it is possible to obtain high definition and reproducibility of the pattern as well as the ink. By applying the ink 6a having a small droplet size on the convex portion 1 where the droplets fly, the gradation can be improved and the expression of the pattern can be enhanced. And the convex part 1 which protrudes on the surface of the board | substrate 3 will be especially conspicuous, but since the pattern expression which improved the expressibility can be expressed in the part of the convex part 1 where this pattern is conspicuous, the pattern as the whole coating board It can improve the expressiveness.

  Next, a test for setting a preferable range of the ink droplet size to be applied to the convex portion 1 and the ink droplet size to be applied to the concave portion 2 will be described. Here, when ink is applied to the substrate 3, the ink permeates the receiving layer 10, and thus the ink droplet size cannot be defined as the diameter of the ink when applied to the substrate 3. Therefore, in the present invention, the droplet size is defined by the volume (pl: picoliter) of the droplet ejected from the coating nozzle head 5.

  In the test, a substrate 3 having a flat surface is used, the distance from the spray nozzle 11 of the coating nozzle head 5 to the surface of the substrate 3 is changed, and the droplet size of the ink ejected from the coating nozzle head 5 is changed. This was carried out by applying inkjet coating on the surface of the substrate 3. In addition, as an ink jet coating machine, an ink jet printer manufactured by Mastermind and Musashi Engineering is used, an aqueous pigment ink manufactured by Matsushita Electric Works, Ltd. is used as an ink, and a receiving layer 10 is formed of an acrylic emulsion paint made by Matsushita Electric Works, Ltd. did.

(Test 1)
The distance from the coating nozzle head 5 to the substrate 3 was set to 5 mm, and the droplet size ejected from the coating nozzle head 5 was changed in the range of 15 to 20 pl, and ink jet coating was performed on the surface of the substrate 3.

(Test 2)
The distance from the coating nozzle head 5 to the substrate 3 was set to 10 mm, and the droplet size ejected from the coating nozzle head 5 was changed in the range of 15 to 20 pl, and ink jet coating was performed on the surface of the substrate 3.

(Test 3)
The distance from the coating nozzle head 5 to the substrate 3 was set to 15 mm, and the droplet size ejected from the coating nozzle head 5 was changed in the range of 15 to 20 pl, and ink jet coating was performed on the surface of the substrate 3.

(Test 4)
The distance from the coating nozzle head 5 to the substrate 3 was set to 20 mm, and the droplet size ejected from the coating nozzle head 5 was changed in the range of 15 to 20 pl, and ink jet coating was performed on the surface of the substrate 3.

(Test 5)
The distance from the coating nozzle head 5 to the substrate 3 was set to 10 mm, and the droplet size ejected from the coating nozzle head 5 was changed in the range of 20 to 30 pl.

(Test 6)
The distance from the coating nozzle head 5 to the substrate 3 was set to 15 mm, and the droplet size ejected from the coating nozzle head 5 was changed in the range of 20 to 30 pl, and ink jet coating was performed on the surface of the substrate 3.

(Test 7)
The distance from the coating nozzle head 5 to the substrate 3 was set to 20 mm, and the droplet size ejected from the coating nozzle head 5 was changed in the range of 20 to 30 pl.

(Test 8)
The distance from the coating nozzle head 5 to the substrate 3 was set to 15 mm, and the droplet size ejected from the coating nozzle head 5 was changed in the range of 15 to 30 pl.

(Test 9)
The distance from the coating nozzle head 5 to the substrate 3 was set to 10 mm, the droplet size ejected from the coating nozzle head 5 was set to 13 pl, and ink jet coating was performed on the surface of the substrate 3.

(Test 10)
The distance from the coating nozzle head 5 to the substrate 3 was set to 20 mm, the droplet size ejected from the coating nozzle head 5 was set to 32 pl, and ink jet coating was performed on the surface of the substrate 3.

  About the coating board coated by said tests 1-10, the distinctive density | concentration and (DELTA) L value (lightness) of the gradation of a coating were evaluated.

  The gradation of paint is evaluated by changing the gradation by changing the printing density with black ink, and distinguishing the gradation change when painting is performed by increasing the density by 1% with reference to the black ink density of 50%. This was done by visually judging the possible density difference. It can be evaluated that the gradation change is clearer as the density difference is smaller. The ink density indicates what percentage of the nozzles of the coating nozzle head the ink is ejected from. When the ink is ejected from all the nozzles, the ink density is 100%. When ejected, the ink density is set to 50%.

  The ΔL value was evaluated by printing at a black ink density of 50% and measuring the lightness difference ΔL with a color difference meter (“CR400” manufactured by Konica Minolta, Inc.) based on Test 1. It can be evaluated that the smaller the ΔL value, the ink has landed and painted as set.

  Table 1 shows the evaluation results of the gradation of painting and the ΔL value. In the case of the paint appearance, “◯” indicates that the gradation distinguishable density is 10% or less and the ΔL value is 2 or less, and the gradation distinguishable density exceeds 10% or the ΔL value exceeds 2. Was evaluated as “C” when the gradation distinguishable density exceeded 10% and the ΔL value exceeded 2.

  Tests 1, 2, 5, and 9 in which the distance from the coating nozzle head 5 to the substrate 3 is 5 to 10 mm correspond to the case where the convex portion 1 is coated when the substrate 3 has an uneven pattern. Tests 3, 4, 6, 7, 8, and 10 in which the distance from the coating nozzle head 5 to the substrate 3 is 15 to 20 mm correspond to the case where the concave portion 2 is coated when the substrate 3 has an uneven pattern.

  As seen in the evaluation of the coating appearance in Table 1, in Tests 1, 2, 5, and 9 corresponding to the case where the convex portion 1 is coated, the coating appearance is poor with a droplet size of 13 pl as in Test 9. However, tests 1 and 2 show good results with a droplet size of 15 to 20 pl, and the droplet size of the ink applied to the convex portion 1 is in the range of 15 to 20 pl (15 pl or more and less than 20 pl). Is preferred.

  On the other hand, in tests 3, 4, 6, 7, 8, and 10 corresponding to the case where the coating is applied to the recess 2, the coating appearance is poor with a droplet size of 15 to 20 pl as in test 4 and 32 pl as in test 10. However, tests 6 and 7 show good results with a droplet size of 20 to 30 pl, and test 8 with a droplet size of 15 to 30 pl. The droplet size of the ink applied to the recess 2 is 20 to 30 pl (20 pl or more). , Less than 30 pl) is preferred.

  Further, as seen in Test 5 corresponding to the case where the convex portion 1 is coated, even if the convex portion 1 is coated with a droplet size of 20 to 30 pl, a good coating appearance can be obtained. Therefore, the droplet size of the ink applied to the convex portion 1 is not only small as 15 to 20 pl as described above, but also can be used in combination with a droplet size equivalent to the droplet size applied to the concave portion 2. Is. FIG. 2 schematically shows a state in which the ink 6a having a small droplet size and the ink 6b having a large droplet size are mixedly applied to the convex portion 1.

Here, the coating nozzle heads 5y ₁ , 5c ₁ , 5m ₁ , 5k ₁ for ejecting ink having a large droplet size to the ink jet coating machine 4 and the coating nozzle heads 5y ₂ , 5c ₂ for ejecting ink having a small droplet size. , 5m ₂ , 5k ₂ are arranged in a line along the feed direction of the substrate 3, and in the embodiment shown in FIG. 3, the coating nozzle head 5y that ejects ink having a large droplet size is used. _The substrate 3 is carried into the inkjet coating machine 4 from the coating nozzle heads 5y ₂ , 5c ₂ , 5m ₂ , and 5k ₂ that eject the ink having a small droplet size from ₁ , 5c ₁ , 5m ₁ , and 5k _1. It is arranged on the side, that is, on the rear side in the feed direction of the substrate 4. When arranged in this manner, _first , ink having a large droplet size ejected from the coating nozzle heads 5y ₁ , 5c ₁ , 5m ₁ , and 5k ₁ is applied to the substrate 3, and is then applied with ink having a large dot diameter. Ink with a small droplet size ejected from the coating nozzle heads 5y ₂ , 5c ₂ , 5m ₂ , and 5k ₂ is applied to the substrate 3 and is applied with ink having a small dot diameter.

  As shown in the boundary between the convex portion 1 and the concave portion 2, a region where a small droplet size ink is ejected and a small dot diameter ink is applied, and a large droplet size ink is ejected and a large dot diameter ink is applied. At the boundary with the area to be applied, the small dot diameter ink and the large dot diameter ink overlap, but at this time, contrary to the above, the small droplet size is ejected first and the small dot size is ejected. After applying ink with a large diameter, if ink with a large dot diameter is applied by ejecting ink with a large droplet size, the ink with a large dot diameter overlaps with the ink with a small dot diameter. The ink with the dot diameter is covered with the ink with the large dot diameter. Accordingly, in this case, only large dot ink appears at the boundary, and the boundary appears unnaturally and stands out.

  On the other hand, as described above, ink with a large droplet size is first ejected and ink with a large dot diameter is applied, and then ink with a small droplet size is ejected and ink with a small dot diameter is applied. Then, at the boundary between the area where the small dot diameter ink is applied and the area where the large dot diameter ink is applied, the small dot diameter ink is placed on the large dot diameter ink. Both large dot diameter ink and small dot diameter ink appear. Therefore, ink with a large dot diameter and ink with a small dot diameter are mixed in the boundary, and the boundary is not unnaturally conspicuous.

In the embodiment of FIG. 3, coating nozzle heads with different droplet sizes to be ejected are arranged side by side as a set for each color, and a coating nozzle head having a large droplet size in each set It arrange | positions to the carrying-in side of the board | substrate 4 rather than a small coating nozzle head. Specifically, coating nozzle heads 5y ₁ and 5y ₂ , coating nozzle heads 5c ₁ and 5c ₂ , coating nozzle heads 5m ₁ and 5m ₂ , coating nozzles from the carry-in side of the substrate 4 along the transport direction of the substrate 3 The heads 5k ₁ and 5k ₂ are arranged in this order. Needless to say, the arrangement of the coating nozzle heads is not limited to that shown in FIG. 3, and the coating nozzle heads 5y ₁ , 5c ₁ , 5m ₁ , 5k ₁ for ejecting ink having a large droplet size are arranged in succession. Subsequently, the coating nozzle heads 5y ₂ , 5c ₂ , 5m ₂ , and 5k ₂ for ejecting ink having a small droplet size may be continuously arranged.

BRIEF DESCRIPTION OF THE DRAWINGS An example of embodiment of this invention is shown, (a) is a partial schematic plan view, (b) is a partial sectional view. It is a partial schematic plan view which shows an example of other embodiment of this invention. It is the schematic which shows an inkjet coating apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Convex part 2 Concave part 3 Board | substrate 4 Inkjet coating machine 5 Coating nozzle head 6 Ink 6a Ink with small droplet size 6b Ink with large droplet size

Claims (2)

A coating plate in which ink jet coating is performed on the surface of a substrate having a convex portion and a concave portion by ink ejected from a coating nozzle head of an ink jet coating machine, and the droplet size of the ink applied to the convex portion is a concave portion. Including those that are smaller than the ink droplet size applied to the recess, or smaller than the ink droplet size applied to the recess and those equivalent to the ink droplet size applied to the recess Oh it is,
The inkjet coating machine includes two or more types of coating nozzle heads that eject inks having different droplet sizes for each color of the ink, and conveys and passes the substrate along the direction in which the coating nozzle heads are arranged. Ink is applied to the surface of the substrate by ejecting ink from each painting nozzle head. The painting nozzle head that ejects ink with a large droplet size is more than the painting nozzle head that ejects ink with a small droplet size. , painted plates, characterized that you have been placed on the side of the substrate is carried into the ink-jet sprayer.   The ink droplet size applied to the convex portion is in a range of 15 pl or more and less than 20 pl, and the ink droplet size applied to the concave portion is in a range of 20 pl or more and 30 pl or less. Item 2. A coated plate according to item 1.

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