Three-dimensional decorative piece and method for producing same

Abstract

The objective of the present invention is to provide a three-dimensional decorative piece, the color of which changes depending on the viewing angle, and a method for producing the same. A three-dimensional decorative piece 10 according to the present invention includes a base material 20 formed from a thermoplastic synthetic resin and has a first color 31 and a second color 32 different from the first color printed alternately in stripes on the surface of the base material, and a large number of protrusions 21, 25 that include at least the first color and the second color are formed on the surface of the base material. The protrusions each have a semi-cylindrical cross-sectional shape and each have a first lateral surface on one side and a second lateral surface that serves as the opposite side, with the apex of the protrusion therebetween. The first lateral surface is the first color, and the second lateral surface can include the second color.

Description

Three-dimensional decorative piece and its manufacturing method

[0001] The present invention relates to a three-dimensional decorative piece whose color changes depending on the viewing angle, and a method for producing the same.

[0002] Three-dimensional decorative pieces such as emblems, appliqués, and stickers are known that use lenticular lenses to change their design depending on the viewing angle. For example, the three-dimensional decorative piece described in Patent Document 1 has a structure in which a stereoscopic design is printed on the underside of a transparent sheet and semi-cylindrical lenticular lenses are arranged on the upper side.

[0003] Patent No. 3038329

[0004] The inventor has developed a three-dimensional decorative piece that retains the texture and feel of a regular emblem, but changes color depending on the angle from which it is viewed.

[0005] An object of the present invention is to provide a three-dimensional decorative piece whose color changes depending on the viewing angle, and a method for producing the same.

[0006] The three-dimensional decorative piece of the present invention is a three-dimensional decorative piece including a base material made of a thermoplastic synthetic resin, and has a first color and a second color different from the first color printed alternately in rows on the surface of the base material, and the surface of the base material is formed with a large number of protrusions including at least the first color and the second color.

[0007] The protrusion may be a semi-cylindrical ridge having a cross section, the ridge having a first side surface on one side of an apex and a second side surface on the opposite side, the first side surface being the first color, and the second side surface including the second color.

[0008] It is preferable that the width w1 of the first color is wider than the width w2 of the second color.

[0009] The protrusions may be protrusions produced by grain embossing.

[0010] It is preferable that a transparent cover layer be formed on the surface of the base material on top of the first color and the second color.

[0011] The substrate may be made of a thermoplastic elastomer, polyvinyl chloride, or polyurethane, and may have a metal vapor deposition layer on the lower surface side.

[0012] It is preferable that one of the first color and the second color is a light color and the other is a dark color.

[0013] The ridges may be linear.

[0014] The ridge may be annular.

[0015] and a mold preparation step of preparing an upper electrode mold having a plurality of recesses on its underside for forming a plurality of protrusions on the surface of the substrate, the upper electrode mold being disposed on the lower electrode such that the cover layer faces upward ... cover layer being disposed on the lower electrode such that the cover layer faces upward, the cover layer being disposed on the lower electrode such that the cover layer faces upward, the cover layer being disposed on the lower electrode such that the cover layer faces upward, the cover layer being disposed on the lower electrode such that the cover layer faces upward, the cover layer being disposed on the lower electrode such that the cover layer faces upward, the cover layer being disposed on the lower electrode such that the cover layer faces upward, the cover layer being disposed on the lower electrode such that the cover layer faces upward, the cover layer being disposed on the cover layer faces upward, the cover layer being disposed on the cover layer faces upward, the cover layer being disposed on the cover layer faces upward, the cover layer being disposed on the cover layer faces upward, the cover layer being disposed on the cover layer faces upward, the cover layer being disposed on the cover layer faces upward, the cover layer being disposed on the cover layer faces upward, the cover layer being disposed on the cover layer faces upward, the cover layer being disposed on the cover

[0016] The color printing step may be a step of printing the second color adjacent to the first color.

[0017] The color printing step can be a step of first printing the first color not only in the areas of the first color but also in the areas of the second color, and then printing the second color in rows on top of the first color.

[0018] The three-dimensional decorative piece of the present invention can express different colors depending on the viewing angle by varying the ratio of the first color and the second color contained in the protrusions.

[0019] FIG. 1 is a cross-sectional view of a three-dimensional decorative piece according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of a substrate. FIG. 3 is a cross-sectional view of a substrate with a first color printed on the surface. FIG. 4 is a cross-sectional view of a substrate with a second color printed between the first color layers. FIG. 5 is a cross-sectional view of a substrate with UV-curable ink printed on the first and second colors. FIG. 6 is a cross-sectional view showing a printed substrate placed on a lower electrode mold, with an upper electrode mold waiting above the substrate. FIG. 7 is a cross-sectional view showing high-frequency dielectric heating. FIG. 8 is a cross-sectional view of a substrate with the first and second colors printed using different methods. FIG. 9 is a plan view of a substrate with different widths for the first and second colors. FIG. 10 is a cross-sectional view of a three-dimensional decorative piece made from a substrate with different widths for the first and second colors. FIG. 11 is an enlarged photograph of a substrate with the first and second colors printed in the first embodiment. FIG. 12 is an enlarged photograph of a shaped three-dimensional decorative piece in the first embodiment. Figure 13 (a) is an enlarged photograph of the three-dimensional decorative piece of the first embodiment as viewed from the direction of arrow A in Figure 10, and (b) is an enlarged photograph as viewed from the direction of arrow B. Figure 14 is a view of the upper electrode mold on which the grain embossed unevenness is formed, as viewed from the bottom side. Figure 15 is an enlarged photograph of the three-dimensional decorative piece of the second embodiment as viewed from an oblique direction.

[0020] The structure and manufacturing method of one embodiment of the three-dimensional decorative piece 10 of the present invention will be described below with reference to the drawings. Note that the thicknesses of the substrate 20, printed first color 31, printed second color 32, and cover layer 40 shown in each figure are exaggerated.

[0021] <First embodiment> Figure 1 is a cross-sectional view of a three-dimensional decorative piece 10 of the present invention. As shown in the figure, the three-dimensional decorative piece 10 of the present invention is configured such that a plurality of protrusions 21 having a substantially semi-cylindrical cross section are closely arranged as one form of protrusion. The protrusions 21 are shaped so as to bulge out from the surface of a base material 20 in a substantially semi-cylindrical cross section.

[0022] Each protrusion 21 includes a color pair 30 in which a first side surface 22 (the left side surface in the drawing) on ​​one side of the apex is printed in a first color 31, and a second side surface 23 (the right side surface in the drawing) on ​​the opposite side is printed in a second color 32. The first color 31 and the second color 32 are different colors.

[0023] A transparent cover layer 40 is formed on the surface of the first color 31 and the surface of the second color 32. Although the cover layer 40 is shown with each stripe 41 having a uniform thickness in the figure, in reality, it generally maintains a lens-like shape with a slightly thicker center in the width direction, as shown in Figure 5.

[0024] When the three-dimensional decorative piece 10 having the above configuration is viewed from the direction of arrow A in Fig. 1, the first color 31 of the first side surface 22 of the protrusion 21 is visible, and when viewed from the direction of arrow B, the second color 32 of the second side surface 23 of the protrusion 21 is visible. In other words, the color changes depending on the viewing direction.

[0025] The three-dimensional decorative piece 10 of the present invention will now be described together with the structure of each part and the method of manufacturing the same.

[0026] <Substrate Preparation Step> The substrate 20 can be a thermoplastic synthetic resin sheet or film that can be expanded and shaped by high-frequency dielectric heating. Examples of such thermoplastic synthetic resins include, but are not limited to, thermoplastic elastomer, polyvinyl chloride, and polyurethane. As shown in FIG. 2, the substrate 20 can have a metal vapor deposition layer 24 on its underside, where a metal such as aluminum is vapor-deposited. To prevent oxidation and shedding of the metal vapor deposition layer 24, a three-layer structure is preferably formed by providing a resin layer 20a made of the same material as the substrate 20 on the underside of the metal vapor deposition layer 24. Of course, the substrate 20 may also have multiple layers of metal vapor deposition layers 24 and resin layers 20a alternately provided on its underside. The thickness of the substrate 20 is not particularly limited, but the pressure difference between the metal vapor deposition layer 24 and the resin layer 20a is preferably 0.1 mm to 0.8 mm, and more preferably 0.2 mm to 0.5 mm.

[0027] If necessary, the base material 20 may be configured to include a dye transfer prevention film with an adhesive layer interposed on the bottom surface, and a thermoplastic synthetic resin film with another adhesive layer interposed thereon. The transfer prevention film prevents dyes from clothing from transferring to the surface side of the three-dimensional decorative piece 10. An example of a dye transfer prevention film is an ethylene-vinyl alcohol copolymer (EVOH) film.

[0028] The substrate 20 is generally a rectangular sheet before cutting, and can be cut into a desired shape such as a circle, ellipse, or star shape using a die with a cutting blade or the like during shaping by high-frequency dielectric heating as described below in Figures 6 and 7. Of course, the substrate 20 may be cut into the desired shape from the beginning, or the substrate 20 may be cut into the desired shape after shaping.

[0029] 4, a first color 31 and a second color 32 are printed on the surface of the substrate 20. As will be described below, the first color 31 and the second color 32 are different colors, and the printing method is, for example, screen printing. The adjacent first color 31 and second color 32 are referred to as a color pair 30.

[0030] The first color 31 and the second color 32 are printed adjacently in rows (stripe-like). For example, as shown in FIG. 3 , the first color 31 is first printed in rows, and then the second color 32 is printed in rows between the first colors 31, thereby producing the substrate 20 shown in FIG. 4 on which the first color 31 and the second color 32 are printed alternately in rows. Note that the rows of the first color 31 and the second color 32 may be linear rows or circular rings (a form in which the first color 31 and the second color 32 are printed alternately in concentric circles centered on a circle or point). They may also be concentric triangles, rectangles, stars, ellipses, or the like.

[0031] The first color 31 and the second color 32 are different colors. For example, one of the first color 31 and the second color 32 may be a light color and the other may be a dark color. Specific examples of the color combinations include, but are not limited to, those shown in Table 1.

[0032]

[0033] The first color 31 and the second color 32 can be made to express a sharp difference depending on the viewing angle by using opposite or complementary colors on the color wheel.

[0034] As shown in FIG. 4, the first color 31 and the second color 32 are printed with widths w1 and w2, respectively. The sum of the width w1 of the first color 31 and the width w2 of the second color 32 constitutes the width W of the color pair 30. The width W of the color pair 30 is the same as the width W of the recessed streaks 51 of the upper electrode mold 50, which will be described later. The width W (= w1 + w2) is, for example, 0.6 mm to 0.8 mm, preferably 0.7 mm to 0.75 mm. The width w1 of the first color 31 and the width w2 of the second color 32 may be the same, or one may be wider than the other, as shown in FIG. 9, which will be described later. For example, w1:w2 = 0.7:1 to 1.3:1. Note that, if the first color 31 is a light color and the second color 32 is a dark color, as shown in Table 1, making the first color 31, which has a weaker hue, wider can create a more distinct color difference when viewed from different angles.

[0035] The first color 31 and the second color 32 are printed to a thickness of, for example, 10 μm to 30 μm. The thickness of the first color 31 and the second color 32 is preferably 10 μm to 20 μm.

[0036] In addition, when adding a design 33 such as a pattern or letters to the three-dimensional decorative piece 10, a color different from the first color 31 and the second color 32 may be printed partially on the base material 20, as shown in Figures 11 to 13 of the embodiment. In the embodiment, the design 33 is black.

[0037] <Cover Layer Formation Step> As shown in FIG. 4 , a color pair 30 consisting of a first color 31 and a second color 32 is printed on the substrate 20. A cover layer 40 is then formed on the substrate 20 (cover layer formation step) as shown in FIG. 5 . The cover layer 40 is, for example, a UV-curable ink. The provision of the cover layer 40 creates a lens effect, further enhancing the color change. The cover layer 40 is printed in stripes on the first color 31 and the second color 32, respectively, as indicated by the reference numeral 41, and then cured by UV irradiation. Screen printing can also be used for the cover layer 40. The width w3 of each stripe 41 on the cover layer 40 may be the same as the widths of the first color w1 and the second color w2. However, as shown in FIG. 5 , it is preferable that the width w3 be wider than w1 and w2, i.e., that each stripe 41 on the cover layer 40 straddles the first color 31 and the second color 32. Making w3 wider than w1 and w2 enhances the lens effect, resulting in a more pronounced color change. For example, the width w3 of the streaks 41 of the cover layer 40 is preferably set such that w3:(w1 or w2) is 1:1 to 1.3:1. The thickness of the cover layer 40 may be set to 0.1 mm to 0.5 mm.

[0038] <Mold preparation step and shaping step> The color pair 30 of the first color 31 and the second color 32 shown in Figure 5, and the substrate 20 with a cover layer 40 printed on each color, are shaped and cut into the desired shape by the electrode pair 50, 55 shown in Figure 6 to form the three-dimensional decorative piece 10 shown in Figure 1.

[0039] In the shaping step, as shown in FIGS. 6 and 7, the substrate 20 is shaped by high-frequency dielectric heating using an upper electrode mold 50 and a lower electrode 55 .

[0040] 6, the upper electrode mold 50 has a shape in which a plurality of recesses 51 are formed on the underside. The recesses 51 have a semi-cylindrical cross section, and a width W that is the same as the width W of the color pair 30 of the first color 31 and the second color 32 on the substrate 20. The recesses 51 are linear when the color pair 30 is arranged linearly, and in the case of a circular or annular shape, the recesses 51 have a shape that follows the shape of the color pair 30.

[0041] The upper electrode mold 50 has a fusion blade 52 formed on the outer periphery of the grooves 51, which fuses the base material 20 into the shape of the three-dimensional decorative piece 10 to be produced. The fusion blade 52 is formed to extend downward beyond the tip of the grooves 51, and for example, when producing a three-dimensional decorative piece 10 with a circular outline, the fusion blade 52 has a shape that connects to a circle.

[0042] Furthermore, when a pattern 33 is to be applied to the three-dimensional decorative piece 10, the upper electrode mold 50 may be provided with an engraved or other concave / convex pattern at a position facing the pattern 33.

[0043] The lower electrode 55 has a flat plate shape.

[0044] The upper electrode mold 50 and the lower electrode 55 are connected to a high-frequency circuit capable of applying a high-frequency voltage.

[0045] 6, in the shaping step, the substrate 20 on which the color pair 30 of the first color 31 and the second color 32 and the cover layer 40 are printed is placed on the lower electrode 55. The upper electrode mold 50 is also arranged so that the recessed stripes 51 face downward and the color pair 30 and the recessed stripes 51 overlap one another vertically.

[0046] In this state, as shown by arrow C in Fig. 6 , the upper electrode mold 50 is brought close to the lower electrode 55 to sandwich the substrate 20. Then, by applying a high-frequency voltage to the upper electrode mold 50 and the lower electrode 55, a high-frequency electric field is generated between the upper electrode mold 50 and the lower electrode 55, and the substrate 20 is subjected to high-frequency dielectric heating.

[0047] As a result, the base material 20 expands along the recessed ribs 51 as shown in Fig. 7, and ribs 21 are formed on the surface. The ribs 21 are located at the center of the color pair 30 of the first color 31 and the second color 32 printed on the surface of the base material 20, i.e., the apex of the ribs 21 is the boundary between the first color 31 and the second color 32. As a result, the first side surface 22 (the left side surface in the drawing) on ​​one side of the apex of the ribs 21 is the first color 31, and the second side surface 23 (the right side surface in the drawing) on ​​the opposite side is the second color 32.

[0048] Furthermore, when the fusion cutting blade 52 of the upper electrode mold 50 comes into contact with the lower electrode 55 , the base material 20 is fusion cut into the contour of the three-dimensional decorative piece 10 .

[0049] After high-frequency dielectric heating, the substrate 20 is cooled to fix the shape, and the electrodes 50 and 55 are separated from each other, and the substrate 20 is then removed.

[0050] When the obtained three-dimensional decorative piece 10 is viewed from the direction of arrow A in FIG. 1, the first color 31 of the first side surface 22 of the protrusion 21 is visible, and when viewed from the direction of arrow B, the second color 32 of the second side surface 23 of the protrusion 21 is visible, resulting in a decorative body whose color changes depending on the viewing direction.

[0051] The three-dimensional decorative piece 10 of the present invention has the texture and feel of a normal emblem due to the unevenness of the ridges 21 and the pattern 33, and has a tasteful and luxurious feel as the color changes depending on the viewing angle.

[0052] 2 to 4, in the color printing step, the first color 31 is first printed in rows on the substrate 20, and the second color 32 is printed between the first colors 31, 31. However, as shown in Fig. 8, the first color 31 may be printed over the entire surface of the substrate 20, and the second color 32 may be printed in rows on top of the first color 31. If the interval between the first color 31 and the second color 32 is narrow and it is difficult to print the second color 32 precisely between the first colors 31, 31, the first color 31 and the second color 32 may be printed as shown in Fig. 8.

[0053] FIG. 9 is a plan view of a substrate 20 printed so that the width w1 of the first color 31 is wider than the width w2 of the second color 32. Specifically, w1:w2 = 0.7:1 to 1.3:1. The first color 31 is a lighter color than the second color 32; that is, the first color 31 is a light color in Table 1, and the second color 32 is a dark color. A cover layer 40 (not shown) is formed on the first color 31 and the second color 32. When the substrate 20 is shaped as shown in FIGS. 6 and 7, the three-dimensional decorative piece 10 shown in FIG. 10 is obtained.

[0054] In this three-dimensional decorative piece 10, the width w1 of the first color 31 is wider than the width w2 of the second color 32, so the first side surface 22 to the left of the apex of the protrusion 21 is the first color 31. Therefore, when viewed from direction A, the second color 32 located distally below the apex is invisible. Therefore, the light-colored first color 31 is clearly visible when viewed from direction A. On the other hand, the second side surface 23 to the right of the apex of the protrusion 21 has the first color 31 on the side closest to the apex and the second color 32 below that. Therefore, when viewed from direction B, not only the dark second color 32 but also the light-colored first color 31 is visible. However, when comparing the first color 31 and the second color 32, the dark second color 32 stands out, so it essentially appears as the second color 32. This configuration allows for a clear and distinct color transition between directions A and B.

[0055] In the three-dimensional decorative piece 10 shown in Fig. 1 in which the widths w1 and w2 of the first color 31 and second color 32 are the same, the slightly darker second color 32 may be visible even when viewed from direction A. As a result, the darker second color 32 stands out when viewed from both direction A and direction B, so although the color change can be recognized, it is less distinct than the three-dimensional decorative piece 10 shown in Fig. 10. Therefore, it is preferable to make the lighter (weaker) first color 31 wider than the darker (stronger) second color 32.

[0056] Example 1: A three-dimensional decorative piece 10 was produced using the method described above. Figure 11 is an enlarged photograph of a substrate 20 with a first color 31, a second color 32, and a cover layer 40 printed on its surface (not visible). The substrate 20 is a thermoplastic elastomer sheet with aluminum vapor deposition. Similar to Figure 9, the width w1 of the first color 31 and the second color 32 is wider than the width w2. Specifically, the width w1 of the first color 31 is 0.38 mm, and the width w2 of the second color 32 is 0.35 mm. The w1:w2 ratio is approximately 1.09:1.

[0057] Referring to FIG. 11, vertical stripes are visible, and it can be seen that these stripes are color pairs 30 in which a first color 31 and a second color 32 are printed alternately in rows.

[0058] For this substrate 20, an upper electrode mold 50 is used which has ridges 21 formed thereon with the same width W as the width W of the color pair 30 and which has circular fusion blades 52 on its outer periphery. Note that a concave-convex pattern different from the ridges 21 is engraved on the upper electrode mold 50 in the portion corresponding to the design 33 (not shown).

[0059] Then, as shown in Figure 6, the substrate 20 is placed on the lower electrode 55, and the upper electrode mold 50 is aligned and pressed downward while a high-frequency voltage is applied, causing the substrate 20 to expand and take shape, and then to be cut by the cutting blade 52 to obtain a three-dimensional decorative piece 10 of the desired shape (circular in this example).

[0060] 12 and 13 are enlarged planar photographs of the produced three-dimensional decorative piece 10. In Fig. 13(a), the three-dimensional decorative piece 10 in Fig. 12 is photographed from the direction of arrow A in Fig. 10, and Fig. 13(b) is photographed from the direction of arrow B in Fig. 10.

[0061] 12, for each protrusion 21, a first color 31 can be seen on the first side surface 22 on the left side, and a second color 32 can be seen on the second side surface 23 on the right side. Although the first color 31 can also be seen on the second side surface 23, the second color 32 is so strong that it appears to be essentially the second color 32.

[0062] Comparing Figures 13(a) and (b), which are viewed from different angles, it is difficult to distinguish between the two figures, but the colors clearly differ depending on the viewing angle, creating a sense of contrast. In Figure 13(a), the first color 31 printed on the first side surface 22 on the left side of the ridge 21 is visible, while in Figure 13(b), the second color 32 is primarily visible. In other words, a three-dimensional decorative piece 10 with different colors was obtained depending on the viewing angle. This three-dimensional decorative piece 10 has the texture and feel of a regular emblem due to the unevenness of the ridge 21 and the pattern 33, and the color changes depending on the viewing angle, giving it a tasteful and luxurious feel.

[0063] Second Embodiment In the first embodiment, a plurality of recesses 51 are formed in the upper electrode mold 50 to shape the substrate 20. In this embodiment, shaping is performed using an upper electrode mold 50 having embossed irregularities 53 similar to grains as shown in Fig. 14. Note that the substrate 20 and the like are the same as those in the first embodiment, and therefore description thereof will be omitted.

[0064] FIG. 14 is a schematic diagram of the upper electrode mold 50 as viewed from the bottom. The illustrated upper electrode mold 50 forms a textured surface 53, with the black areas representing convex portions of the sandy embossing and the white areas representing concave portions. The textured surface 53 may be random, or may be formed by creating numerous depressions using a drill or similar tool. In one embodiment, when the depressions are created using a drill, the diameter of the depressions may be 0.2 mm to 0.7 mm and the depth may be 0.1 mm to 0.4 mm. Using the upper electrode mold 50, the substrate 20 is shaped in the same manner as in the first embodiment. This results in a three-dimensional decorative piece 10 having numerous protrusions 25 formed on the substrate 20. The protrusions 25 are a form of projection, and each protrusion 25 includes a first color 31 and a second color 32. In the first embodiment, each protrusion 21 includes the first color 31 and the second color 32 in a regular pattern, but in the second embodiment, since the protrusion is embossed in a sandy pattern, each protrusion 25 includes the first color 31 and the second color 32 in a random width, random direction, and random ratio. Therefore, the three-dimensional decorative piece 10 of the second embodiment is a decorative piece that appears to be a different color when viewed from any direction on the surface side, not just from two directions, A and B, but by changing the angle.

[0065] <Second Example> Figure 15 is an enlarged photograph of a three-dimensional decorative piece 10 formed by using the upper electrode mold 50 with the sand-embossed texture 53 of Figure 14 on the substrate 20 described in Figures 9 and 11 (however, the first color 31 has a width w1 of 0.2 mm, and the second color 32 has a width w2 of 0.28 mm). As can be seen from the figure, many protrusions 25 are formed on the three-dimensional decorative piece 10. When this three-dimensional decorative piece 10 is viewed from various angles, the color changes in a captivating way.

[0066] The above description is for the purpose of explaining the present invention, and should not be construed as limiting the invention described in the claims or narrowing its scope. Furthermore, the configuration of each part of the present invention is not limited to the above embodiment, and various modifications are possible within the technical scope described in the claims.

[0067] REFERENCE SIGNS LIST 10 Three-dimensional decorative piece 20 Base material 21 Protrusion (protrusion) 22 First side surface 23 Second side surface 24 Metal vapor deposition layer 25 Protrusion (protrusion) 30 Color pair 31 First color 32 Second color 33 Design 40 Cover layer 50 Upper electrode mold 51 Concave rib 52 Fusing blade 55 Lower electrode

Claims

1. A three-dimensional decorative piece comprising a substrate made of a thermoplastic synthetic resin, the surface of the substrate having a first color and a second color different from the first color printed alternately in rows, and the surface of the substrate having a large number of protrusions formed thereon that include at least the first color and the second color.

2. The three-dimensional decorative piece according to claim 1, wherein the protrusion is a semi-cylindrical ridge having a first side surface on one side of an apex and a second side surface on the opposite side, the first side surface being the first color, and the second side surface being the second color.

3. The three-dimensional decorative piece according to claim 2, wherein the width w1 of the first color is wider than the width w2 of the second color.

4. The three-dimensional decorative piece according to claim 1, wherein the protrusion is a protrusion produced by sand-grain embossing.

5. A three-dimensional decorative piece according to any one of claims 1 to 4, wherein a transparent cover layer is formed on the surface of the base material on top of the first color and the second color.

6. The three-dimensional decorative piece according to claim 5, wherein the base material is a thermoplastic elastomer, polyvinyl chloride, or polyurethane, and has a metal vapor deposition layer on the underside.

7. A three-dimensional decorative piece according to any one of claims 1 to 4, wherein one of the first color and the second color is a light color and the other is a dark color.

8. The three-dimensional decorative piece according to claim 2, wherein the protrusions are linear.

9. The three-dimensional decorative piece according to claim 2, wherein the protrusion is annular.

10. A method for producing a three-dimensional decorative piece, comprising: a substrate preparation step of preparing a substrate made of thermoplastic synthetic resin having a flat surface; a color printing step of printing a first color and a second color different from the first color in multiple closely spaced alternating rows of the same width on the surface of the substrate in a planar view, thereby forming color pairs consisting of adjacent rows of the first color and the second color; a cover layer formation step of printing ultraviolet-curable ink in stripes on the first color and the second color of the substrate, irradiating the ultraviolet-curable ink with ultraviolet light, and curing the ultraviolet-curable ink to form a cover layer; a mold preparation step of preparing an upper electrode mold having a number of recesses on its underside for forming a number of protrusions on the surface of the substrate, and a flat lower electrode; and a shaping step of placing the substrate on the lower electrode with the cover layer facing up, bringing the upper electrode mold close to the lower electrode from above the substrate to sandwich the substrate, and expanding the substrate along the recesses by high-frequency dielectric heating, thereby forming protrusions on the surface by continuously oscillating high-frequency waves between the upper electrode mold and the lower electrode.

11. The method for producing a three-dimensional decorative piece according to claim 10, wherein the color printing step prints the second color adjacent to the first color.

12. The method for producing a three-dimensional decorative piece according to claim 10, wherein the color printing step first prints the first color not only in the areas of the first color but also in the areas of the second color, and then prints the second color in a row on top of the first color.

Images