Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C59/00—Surface shaping of articles, e.g. embossing; Apparatus therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C59/00—Surface shaping of articles, e.g. embossing; Apparatus therefor
  • B29C59/18—Surface shaping of articles, e.g. embossing; Apparatus therefor by liberation of internal stresses, e.g. plastic memory
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
  • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
  • B41J2/01—Ink jet
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M3/00—Printing processes to produce particular kinds of printed work, e.g. patterns
  • B41M3/06—Veined printings; Fluorescent printings; Stereoscopic images; Imitated patterns, e.g. tissues, textiles

Definitions

• the present invention relates to a three-dimensional pattern printed matter and a method for producing the same.
• Embossing uses an embossing device equipped with an embossing roll having a molding surface with irregularities corresponding to the pattern, and a backup roll positioned opposite the embossing roll.
• the sheet-like substrate is passed between the embossing roll and the backup roll, and the molding surface of the embossing roll is pressed firmly against the surface of the substrate, transferring the irregularities on the molding surface as a pattern to the surface of the substrate (Patent Document 1).
• the irregularities on the molding surface of the embossing roll are transferred to the surface of the substrate, forming a pattern on said surface. If the difference in height between the irregularities is large, the outline of the pattern transferred to the substrate will stand out clearly, while if the difference in height between the irregularities is small, the pattern transferred to the substrate will appear flat. However, it is difficult to reproducibly transfer small letters or patterns onto the substrate with embossing. Furthermore, since it is not possible to transfer irregularities onto the substrate that are deeper or higher than the thickness of the substrate, it is difficult to form clear patterns by embossing on thin substrates.
• the problem that this invention aims to solve is to provide a technology for forming patterns and designs consisting of irregularities of various heights and sizes on the surface of a substrate.
• One aspect of the present invention which has been made to solve the above-mentioned problems, is a method for producing a three-dimensional pattern printed matter having one or more three-dimensional printed portions formed in an island shape on a surface of a flexible sheet-like substrate, the method comprising: a first step of forming a first ink layer having a predetermined planar shape on a surface of the substrate by inkjet printing using a first ultraviolet curable resin ink, and curing at least the surface side of the first ink layer by irradiating the surface side of the first ink layer with ultraviolet light; a second ink layer having the same planar shape as the first ink layer but a smaller area than the first ink layer by inkjet printing a second ultraviolet-curing resin ink on the surface of the first ink layer, and a second step of irradiating ultraviolet light from the surface side of the second ink layer to cure at least the surface side of the second ink layer.
• island-shaped three-dimensional printed portions are formed on the surface of a flexible, sheet-like substrate through a manufacturing process including steps 1 and 2.
• Forming three-dimensional printed portions in an island shape means that each three-dimensional printed portion is large enough to occupy a portion of the substrate's surface. Therefore, when a single three-dimensional printed portion is formed on the surface of the substrate, it naturally covers only a portion of the substrate's surface. Each three-dimensional printed portion needs only to be large enough to occupy a portion of the substrate's surface; when multiple three-dimensional printed portions are formed on the surface of the substrate, the entire substrate surface may be covered by these multiple three-dimensional printed portions.
• the multiple three-dimensional printed portions may be scattered across the entire surface of the substrate, or may be concentrated in a portion of the substrate's surface.
• the appearance of the three-dimensional printed item will vary depending on how the multiple three-dimensional printed portions are arranged, making it possible to manufacture three-dimensional printed items with a wide variety of designs.
• a first ink layer is formed on the surface of a sheet-like substrate by inkjet printing using ultraviolet-curable resin ink, and a second ink layer is then formed on top of that.
• the first and second ultraviolet-curable resin inks used to form the first and second ink layers may be the same or different in color, composition, etc.
• the first and second ultraviolet-curable resin inks may be transparent inks (clear inks) that do not contain colorants.
• the first ink layer and the second ink layer have the same planar shape, and the second ink layer has a smaller area than the first ink layer.
• the first ink layer and the second ink layer may be laminated so that their central positions coincide, or so that their central positions are offset. Even when laminated so that their central positions are offset, it is preferable that the second ink layer be formed on at least the surface of the first ink layer so that it fits within that surface.
• the flexible sheet-like substrate can be any material that can be printed with UV-curable resin ink, and examples of materials include synthetic leather, natural leather, knitted fabric, woven fabric, synthetic resin, and paper. Furthermore, there is no limit to the thickness of the sheet-like substrate as long as it is flexible, and thin film substrates (films) and flat plate-like substrates (plates) are also included in the category of sheet-like substrates.
• a first ink layer is formed by inkjet printing using a first ultraviolet-curing resin ink on the surface of the substrate, and then ultraviolet light is irradiated onto the surface of the first ink layer.
• the amount of ultraviolet light incident on the surface side of the first ink layer is greater than that on the substrate side, so the polymerization reaction of the first ultraviolet-curing resin ink on the surface side proceeds faster than the polymerization reaction of the first ultraviolet-curing resin ink on the substrate side.
• the surface side is free and unadhered.
• the ultraviolet-curing resin ink on the surface side hardens through the polymerization reaction, resulting in a volume on the surface side that is relatively larger than the volume on the substrate side.
• stress is generated within the first ink layer from the substrate side to the surface side, causing the first ink layer to bend toward the surface, resulting in a raised deformation of the sheet-like substrate.
• the magnitude of the raised deformation of the sheet-like substrate corresponds to the flexibility of the substrate.
• a second ink layer is formed by inkjet printing using a second UV-curable resin ink on the surface of the first ink layer, and then the surface of the second ink layer is irradiated with ultraviolet light.
• the volume of the second ink layer is relatively larger on the surface side than on the substrate side (the first ink layer side). This causes the second ink layer to curve toward the surface, which in turn causes the first ink layer and substrate to rise and deform.
• island-shaped 3D printed areas are formed in the areas of the substrate where the first and second ink layers are formed.
• the 3D printed areas are formed by the first and second ink layers as well as the rising and deforming of these first and second ink layers and the substrate.
• the sheet-like substrate is a flexible substrate such as a vinyl chloride sheet or a synthetic leather sheet
• the curvature of the first and second ink layers toward the surface causes the entire area of the substrate where the first and second ink layers are formed to rise and deform. This results in a relatively clear outline of the 3D printed areas formed on the substrate surface.
• the ink layers that make up the three-dimensional print section are not limited to two layers, the first and second ink layers, but may also be one or more ink layers (hereinafter referred to as the third ink layer) laminated on top of the second ink layer.
• the process of forming the third ink layer (hereinafter referred to as the third process) is similar to the first and second processes described above: after forming the third ink layer, ultraviolet light is irradiated from the surface side to harden at least the surface side of the third ink layer.
• the third process is carried out as follows: of the multi-layer third ink layer, the two layers that overlap one another are formed as follows: a lower third ink layer is formed, ultraviolet light is irradiated from the surface side to harden at least the surface side of the lower third ink layer, and then an upper third ink layer is formed on top of that, ultraviolet light is irradiated from the surface side to harden at least the surface side of the upper third ink layer.
• the intensity of the ultraviolet light irradiated onto each ink layer in steps 1 to 3 is preferably 100% to 50% of the intensity required to cure the ultraviolet-curable resin ink that makes up each ink layer.
• the intensity of the ultraviolet light irradiated onto each ink layer may be the same or different.
• the area of the substrate surface where the 3D printed portion is formed may be colored in a different manner from the other areas.
• the surface of the substrate is colored by inkjet printing using an ultraviolet resin ink containing a colorant, the entire process from forming the 3D printed portion to coloring can be performed by inkjet printing.
• the three-dimensional pattern printed matter of the present invention has a three-dimensional pattern including a first ink layer formed by inkjet printing using a first ultraviolet-curing resin ink on the surface of a flexible sheet-like substrate, and a second ink layer formed by inkjet printing using a second ultraviolet-curing resin ink on the surface of the first ink layer, the second ink layer having the same planar shape as the first ink layer but a smaller area than the first ink layer.
• a three-dimensional printed portion formed on a flexible sheet-like substrate causes the portion of the substrate on which the three-dimensional printed portion is formed to rise and deform, thereby forming a raised three-dimensional printed pattern on the surface of the sheet-like substrate.
• FIG. 1A is a diagram showing a schematic configuration of a three-dimensional pattern printed matter according to an embodiment of the present invention
• FIG. 1B is a diagram showing a schematic configuration of a comparative example.
• FIG. 2 is an explanatory diagram of the first step of the method for producing a three-dimensional pattern printed matter according to an embodiment of the present invention.
• FIG. 10 is an explanatory diagram of a second step in the method for producing a three-dimensional pattern printed matter according to an embodiment of the present invention.
• Schematic diagram of specimens e to i used in Test 2 Schematic diagram of laminates L-1, J-1, K-1, and N-1 used in Test 2. Photographs showing examples of the production of three-dimensional pattern printed materials.
• Fig. 1(a) shows a schematic configuration of a three-dimensional pattern printed matter according to this embodiment.
• the three-dimensional pattern printed matter 1 includes a flexible sheet-like substrate 2 and an island-shaped three-dimensional printed portion 3 including a plurality of ink layers 30 formed on the surface 21 of the substrate 2.
• Fig. 1(a) shows an example in which a single three-dimensional printed portion 3 is formed on the surface of the substrate 2, but multiple ink layers 30 may also be formed on the surface of the substrate 2. All of the ink layers 30 constituting the three-dimensional printed portion 3 are formed by printing with a predetermined ultraviolet-curable resin ink using an inkjet printer.
• the three-dimensional printed portion 3 is formed on the surface 21 of the substrate 2, causing the region of the substrate 2 where the three-dimensional printed portion 3 is formed to be raised and deformed along with the three-dimensional printed portion 3. Therefore, the height of the top of the portion of the substrate 2 where the three-dimensional printed portion 3 is formed (i.e., the height of the three-dimensional printed portion 3) is the sum of the thickness h1 of the multiple ink layers 30 and the raised height h2.
• the comparative printed matter 1A in which multiple ink layers 30 are simply formed on the surface 21 of the substrate 2 (i.e., no raised deformation occurs), as shown in FIG.
• the height of the three-dimensional printed portion 3A is the same as the thickness h1 of the multiple ink layers 30. In comparison, the height of the three-dimensional printed portion 30 in the three-dimensional pattern printed matter 1 of this embodiment is greater by the raised height. Furthermore, while the top surface of the three-dimensional printed portion 3A in the printed matter 1A is flat, the top surface of the three-dimensional printed portion 3 in the three-dimensional pattern printed matter 1 is curved, allowing for a more varied three-dimensional pattern to be formed compared to the printed matter 1A.
• multiple ink layers 30 (hereinafter referred to as the first ink layer 31, the second ink layer 32, etc. from the bottom up) are formed in sequence on the surface of the sheet-like substrate 2 by inkjet printing using ultraviolet-curable resin ink. This forms a laminate in which multiple ink layers are stacked.
• the first ink layer 31 is formed by inkjet printing the first ultraviolet-curable resin ink on the surface 21 of the substrate 2 ( Figure 2(a)). Then, ultraviolet light is irradiated onto the surface of the first ink layer 31. Because the amount of ultraviolet light incident on the surface side of the first ink layer 31 is greater than on the substrate 2 side, the polymerization reaction of the first ultraviolet-curable resin ink on the surface side proceeds relatively faster than the polymerization reaction of the first ultraviolet-curable resin ink on the substrate 2 side.
• the substrate 2 side of the first ink layer 31 is adhered to the substrate 2, while the surface side is not adhered to anything and is in a free state, the polymerization reaction of the ultraviolet-curable resin ink on the surface side proceeds in various directions.
• the volume of the first ink layer 31 on the surface side is relatively larger than that on the substrate 2 side, generating stress within the ink layer on the surface side from the substrate side to the surface side.
• the second ink layer 32 is formed by inkjet printing a second UV-curable resin ink on the curved surface of the first ink layer 31 ( Figure 3(a)).
• the surface of the second ink layer 32 is then irradiated with UV light.
• the polymerization reaction of the UV-curable resin ink in the second ink layer 32 proceeds relatively faster on the surface side than on the substrate 2 side (first ink layer 31 side).
• the volume of the second ink layer 32 is relatively larger on the surface side than on the substrate 2 side. This causes the second ink layer 32 to curve toward the surface, and the first ink layer 31 and substrate 2 rise and deform accordingly, so that the height h6 of the three-dimensionally printed portion becomes larger than the height h5 before the rise ( Figure 3(b)).
• the second ink layer 32 has a smaller area than the first ink layer 31 and a larger radius of curvature (smaller curvature) than the first ink layer, theoretically the amount of protrusion caused by the second ink layer 32 will be smaller than the amount of protrusion caused by the first ink layer 31.
• Test 1 we investigated the relationship between the amount of UV light irradiated onto an ink layer formed on a flexible sheet-like substrate and the degree of curing. Specifically, we formed one ink layer of the same shape and area (specifically, a circular ink layer with a diameter of 3.5 cm) on the surface of the substrate by inkjet printing using a UV-curable resin ink, and irradiated each with different amounts of UV light.
• the substrate, ultraviolet curable resin ink, and inkjet printer used in the test are as follows:
• Base material Synthetic leather sheet (product name: PVC-8000) manufactured by Masuda Co., Ltd.
• This synthetic leather is a flexible synthetic leather sheet with a thickness of 1.2 mm, consisting of a base fabric made of a 1-way knit blend of 65% polyester and 35% rayon, and a surface layer made of 100% polyvinyl chloride (PVC).
• UV-curable resin ink LUS-120 ink manufactured by Mimaki Engineering Co., Ltd.
• Inkjet printing machine A flatbed UV printer "JFX-200-2513EX" (Mimaki Engineering Co., Ltd.) was used.
• the changes in the shape of the substrate were then observed immediately after UV light was irradiated onto the ink layer (when printing was completed), and 48 hours and 72 hours after UV light irradiation began. 48 hours after UV light irradiation began corresponds to the time it takes for the polymerization reaction of the polymerizable components contained in the UV-curing resin ink to be nearly complete.
• test specimen a and test specimen b upon completion of printing, and the ink layer on both specimens cured to form a cured coating.
• the coating surface of test specimen b was slightly more tacky than that of test specimen a.
• test specimen b had a stronger odor than test specimen a.
• the odor disappeared as curing progressed it was determined that the curing reaction of test specimen b was insufficient.
• the stickiness of test specimen b had disappeared, but the odor of test specimen b had not diminished compared to test specimen a, both at 48 and 78 hours.
• the cured coating film caused deformation of the substrate, and in both cases the degree to which the substrate bulged due to the cured coating film increased in proportion to the time elapsed since printing was completed.
• the bulging deformation of the substrate had almost completely stopped after 24 hours
• the bulging deformation of the substrate had almost completely stopped after 72 hours. Because the bulging deformation of the substrate had been occurring for a longer period of time, the degree of bulging after 72 hours was greater for test specimen b than for test specimen a.
• specimen c based on the surface condition and odor of specimen c and specimen d, it was clear that both were in an uncured state upon completion of printing.
• specimen c With specimen c, numerous bubbles appeared on the surface of the ink layer within approximately five minutes of printing being completed. These bubbles expanded over time, and after approximately 12 hours, they combined and burst. After approximately 24 hours, a sponge-like component of the ink layer naturally peeled off.
• Specimen d also showed the same generation of bubbles as specimen c, but the majority of the ink layer was not cured, and no noticeable changes in appearance were observed either approximately one hour after printing was completed or 72 hours later.
• the mechanical action exerted on the substrate by the cured coating is the difference in volume change between the surface and substrate sides as the ink layer hardens; specifically, the stress caused by the relative expansion of the volume of the ink layer on the surface side compared to the ink layer on the substrate side; and that the rate at which this volume change progresses varies depending on the amount of UV light irradiated onto the ink layer.
• Test 2 was conducted to verify the change in the protrusion of the substrate depending on the number of layers in the laminate when the 3D printed portion is made of a laminate of multiple ink layers.
• the substrate used was the same as the substrate (synthetic leather sheet) used in Test 1.
• UV-curable resin ink was used to inkjet print the surface of the substrate, forming ink layers of the following shapes with thicknesses of 30 to 40 ⁇ m, and each ink layer was then irradiated with UV light at 100% intensity for 10 minutes to form a cured coating.
• the ink layers (cured coatings) of each shape were designated Test Specimens e to i.
• Test piece e 10mm diameter circle
• Test piece f 12mm diameter circle
• Test piece g 14mm diameter circle
• Test piece h 16mm diameter circle Test piece i: 18mm diameter circle
• each of the test specimens e to i was formed in a line on the surface of a single substrate 2, and when the number of stacked ink layers was set to 1, 3, and 6, the appearance was observed, and the following results were obtained.
• Layer count 1 No bulging due to substrate deformation was observed in any of the test specimens, and only an increase in thickness due to the volume of the cured coating was observed
• Layer count 3 Bulging due to substrate deformation was observed in all of the test specimens. The height of the bulge due to substrate deformation (the length equivalent to h1 + h2 in Figure 1), excluding the thickness of the cured coating, was approximately 0.3 mm in all of the test specimens, and no difference in bulge height was observed between the test specimens.
• Test piece e approx. 0.5 mm Test piece f: approx. 0.5 mm Test piece g: approx. 0.7 mm Test piece h: approx. 1.0 mm Test piece i: approx. 1.2 mm
• Laminates L-1, J-1, K-1, and N-1 were formed by stacking several of the test specimens e to i in order of largest area.
• Laminates L-1, J-1, K-1, and N-1 were formed by repeatedly forming an ink layer using inkjet printing with ultraviolet-curing resin ink and then curing it.
• laminate L-1 is composed of five types of laminates stacked on substrate 2, in the order of test specimens i, h, g, f, and e, with their centers aligned.
• the substrate 2 on which this laminate L-1 was formed had a raised area where laminate L-1 was formed, with a maximum height of approximately 0.9 mm.
• the lower part of Figure 5(a) is a cross-sectional view of region L-2 of substrate 2 where laminate L-1 was formed. As can be seen from this figure, substrate L-2 in the laminate-formed area had been deformed into an embossed shape, forming gentle staircases at roughly the same rate starting from the boundary lines of each ink layer.
• a laminate of nine layers in total, consisting of three layers of test pieces g + h + i (hereinafter referred to as laminate J-1, see the upper part of Figure 5(b)).
• a laminate of nine layers in total, consisting of three layers of test pieces e + f + i (hereinafter referred to as laminate K-1, see the upper part of Figure 5(c)).
• laminate J-1 A laminate of nine layers in total, consisting of three layers of test pieces e + f + i
• laminate K-1 see the upper part of Figure 5(c)
• Figure 5(d) shows an example in which a three-dimensional printed portion (laminate) is formed on a substrate by stacking multiple circular ink layers with their centers offset from one another.
• protrusions with irregular cross sections other than conical shapes are obtained (see N-1 and N-2 in Figure 5(d)).
• Figure 6 shows an example of a three-dimensional pattern printed product in which a three-dimensional printed portion is formed on a synthetic leather sheet by inkjet printing using ultraviolet-curable resin ink, and the surface is colored.
• This synthetic leather sheet is the same as that used in Test 1.
• Figure 6(b) is an enlarged photograph of a portion of Figure 6(a)
• Figure 6(c) is a photograph of the back surface of the substrate.
• Figure 6(c) shows that the substrate has been deformed to a convex shape on the surface side.
• an ink layer is formed on the surface of the 3D printed area by inkjet printing using ultraviolet-curable resin ink, which is then cured to form a coating film and then colored.
• the cured coating film made from the ink layer is formed as protrusions and convex patterns on the surface of the 3D printed area, thereby decorating the surface of the 3D printed area and allowing for the production of 3D patterned printed items with even greater design and decorativeness.

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• Health & Medical Sciences (AREA)
• Engineering & Computer Science (AREA)
• General Health & Medical Sciences (AREA)
• Textile Engineering (AREA)
• Vascular Medicine (AREA)
• Ink Jet Recording Methods And Recording Media Thereof (AREA)

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Citations (6)

• 2024
  • 2024-12-17 WO PCT/JP2024/044591 patent/WO2025229782A1/ja active Pending
  • 2024-12-17 JP JP2026503650A patent/JPWO2025229782A1/ja active Pending

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