Manufacturing method of single layer decorative sheet

Abstract

To provide a single layer decorative sheet which is stuck to a surface of a fixture, face bar or the like in the room and to which touch feeling can be given by applying a resin added with a filler onto the single layer decorative sheet.SOLUTION: A manufacturing method of a single layer decorative sheet 10 in which an original fabric layer 20, a pattern printing layer 21 printed with a pattern, a primer coat layer 22 and a top coat layer 23 are laminated in the order, comprises the steps of: forming a contact pattern by applying an ultraviolet curable resin added with a filler to the surface of the primer coat layer 22 correspondingly to the pattern of the pattern printing layer 21 by using gravure printing; and forming the top coat layer 23 by irradiating the ultraviolet curable resin with the ultraviolet ray and curing the resin. The particle diameter of the filler is 20 to 40 μm. The printing plate when gravure-printing the top coat layer 23 has the line number equal to or greater than 100 lpi. The printing plate has an average value less than 80 of histogram when decomposing the concentration difference of the pattern of the pattern printing layer 21 into 256 gradations on the image data.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a single-layer decorative sheet that is adhered to the surface of interior fittings, facings, etc., and that can be given a tactile feel by applying a resin containing a filler to the single-layer decorative sheet. [Background technology]

[0002] Conventionally, in order to impart a tactile feel to the surface of a decorative sheet with a resin coating, a resin containing particles has been applied using commonly used Poshell platemaking, laser platemaking, or helioplatemaking. Meanwhile, decorative sheets have been known which have a colored layer, a patterned layer, a matte layer, and a surface protective layer provided on a substrate, and in which inorganic particles or synthetic resin particles are contained in the surface protective layer (see paragraph

[0011] and Figure 1 of Patent Document 1). The above-mentioned conventional inorganic particles or synthetic resin particles have an average particle size of 40 μm to 80 μm (see paragraph

[0018] of Patent Document 1).

[0003] Conventionally, a decorative sheet has been known which includes a picture pattern layer formed on a base sheet, a transparent adhesive layer formed on the picture pattern layer, a transparent thermoplastic resin layer having an embossed uneven pattern, a first surface protective layer, and a second surface protective layer partially formed on the first surface protective layer, the second surface protective layer containing a filler consisting of a mixture of filler A having an average particle size of 1.5 to 5 μm and filler B having an average particle size of 8 μm to 20 μm (see paragraphs

[0014] and

[0035] and Figure 1 of Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-077709 [Patent Document 2] Japanese Patent Application Publication No. 2019-209499 Summary of the Invention [Problem to be solved by the invention]

[0005] However, while Porshell and laser platemaking use deep plates to achieve a tactile feel, they require a large amount of coating, making it difficult to express delicate patterns and resulting in high costs. In contrast, Helio platemaking has the advantage of being able to reduce the amount of coating and costs compared to Poshell platemaking and the like. However, while helioplate making can impart a tactile feel by adding filler to the resin, there is a problem in that depending on the plate conditions, there can be a bias in the particle size of the filler transferred to the cells of the plate, and for example, fillers with large particle sizes do not transfer sufficiently, resulting in an unstable tactile feel.

[0006] Therefore, the present invention has been made to solve the above problems, and provides a method for producing a single-layer decorative sheet that can provide a stable feel to the touch. [Means for solving the problem]

[0007] A method for manufacturing a single-layer decorative sheet according to one embodiment of the present invention is a method for manufacturing a single-layer decorative sheet in which a base layer, a pattern-printed layer having a printed pattern, an undercoat layer, and a topcoat layer are laminated in that order, and includes the steps of: applying an ultraviolet-curable resin to which a filler has been added using gravure printing to the surface of the undercoat layer in a manner corresponding to the pattern of the pattern-printed layer, thereby forming a contact pattern; and irradiating the ultraviolet-curable resin with ultraviolet light to harden it and form the topcoat layer, wherein the particle size of the filler is 20 to 40 μm, and the printing plate used for gravure printing the topcoat layer has a line count of 100 lpi or more, and the printing plate has an average histogram value of less than 80 when the shades of the pattern of the pattern-printed layer are decomposed into 256 gradations on image data.

[0008] Furthermore, in a method for producing a single-layer decorative sheet according to one aspect of the present invention, a helio printing plate is used as the printing plate in the gravure printing. [Effects of the Invention]

[0009] According to one aspect of the present invention, a method for producing a single-layer decorative sheet that can provide a stable feel to the touch can be provided. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view of a single-layer decorative sheet according to an embodiment of the present invention. [Figure 2] 1A and 1B are cross-sectional views showing an example of plate making according to an embodiment of the present invention, in which FIG. 1A is a helioplate making method and FIG. 1B is a Paushell plate making method. [Figure 3] FIG. 1 is a cross-sectional view showing an example of the present invention in which a primer layer is used.

[0011] Hereinafter, an embodiment of the present invention will be described with reference to FIGS. The drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each layer, etc., differ from the actual ones. Furthermore, the embodiments shown below are merely examples of configurations for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention is not limited to the materials, shapes, structures, etc. of the components described below. The technical idea of ​​the present invention can be modified in various ways within the technical scope defined by the claims.

[0012] (Single layer decorative sheet 10) In Figs. 1 and 3, 10 denotes a single layer decorative sheet, which is to be adhered to the surface of a board substrate 40 such as an interior fitting or surface material. As shown in Figure 1, the single-layer decorative sheet 10 is formed by laminating, in this order, (1) a base layer 20, (2) a pattern printed layer 21, (3) an undercoat layer 22, and (4) a topcoat layer 23. (1) to (4) will be described later. 3, the single-layer decorative sheet 10 has a primer layer 30 formed on the back surface of the raw fabric layer 20, and is bonded to a plate substrate 40 via the primer layer 30. The primer layer 30 may be omitted. Here, the "single-layer decorative sheet 10" refers to a sheet in which a top coat layer 23 is provided on the base fabric layer 20 without providing a transparent resin layer (not shown).

[0013] (Original layer 20) The raw fabric layer 20 is a sheet-like member that serves as the base of the single-layer decorative sheet 10. The raw fabric layer 20 is a pigmented colored polypropylene sheet, and has a thickness of, for example, 50 μm. Although a polypropylene sheet is used as the raw fabric layer 20, the present invention is not limited to this and any thermoplastic resin may be used, such as vinyl chloride resin, acrylic resin, or polyolefin-based polypropylene resin or polyethylene resin. Among these, polyolefin-based resins are preferred in terms of environmental compatibility, processability, and price.

[0014] (Picture printing layer 21) The pattern printed layer 21 is formed on the surface side of the raw fabric layer 20 and is a layer for decorating the surface side of the single-layer decorative sheet 10. The pattern printed layer 21 is formed by printing a pattern, for example, a wood grain pattern, using urethane ink or the like by gravure printing, for example. Here, a wood grain pattern is used as an example of a "pattern," but this is not limited to this, and various patterns similar to those used in conventional decorative sheets can be used, such as a stone grain pattern, an abstract pattern, or a solid color. Although gravure printing and urethane ink are exemplified for the pattern printed layer 21, the printing method and printing ink are not particularly limited, and an ink corresponding to the printing method can be appropriately selected. It is preferable to select the ink taking into consideration adhesion to the resin base fabric layer 20, printability, and weather resistance as a decorative material.

[0015] (Undercoat layer 22) The undercoat layer 22 is formed by applying, for example, urethane resin onto the pattern printed layer 21. The amount of urethane resin applied is usually 3 to 6 g / m 2The reason is that if the amount of coating is too small, other physical properties (stain resistance and scratch resistance) will be reduced. In the example described below, urethane resin is coated on the picture printed layer 21 to a thickness of about 5 μm.

[0016] (Topcoat layer 23) The top coat layer 23 is formed on the undercoat layer 22 and provides functions such as weather resistance, scratch resistance, stain resistance, and design, and in the present invention is a layer provided to provide a tactile feel. The top coat layer 23 is formed by applying an ultraviolet curable resin to which a filler has been added onto the undercoat layer 22 using gravure printing. After application, the coating is cured by irradiating it with ultraviolet light, thereby forming a topcoat layer 23.

[0017] Here, examples of the "ultraviolet curable resin" that can be used include (meth)acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, epoxy resins, and polycarbonate resins. Although an ultraviolet-curable resin is exemplified as the resin to which the filler is added, the present invention is not limited to this, and an ionizing radiation-curable resin other than an ultraviolet-curable resin, a thermosetting resin, or a mixture thereof can also be used. Here, "ionizing radiation" refers to electromagnetic waves and charged particle beams that can crosslink the organic resin that constitutes the top coat layer 23 directly or indirectly via activation of a reaction initiator, and ultraviolet rays or electron beams are usually used.

[0018] (filler) As the filler, a highly transparent acrylic resin bead made of synthetic resin, or a surface-treated inorganic filler such as silica glass beads can be used. Resin beads made of synthetic resin are preferred as the filler. The particle size of the filler is, for example, 20 to 40 μm. If the particle size is less than 20 μm, the feel to the touch will be weak, and if it exceeds 40 μm, the particle size will be too large, the filler will not transfer sufficiently, and the feel to the touch will not be stable.

[0019] (gravure printing) The ultraviolet curable resin was applied by gravure printing. Further, the helioplate making method shown in Fig. 2(a) is used for the gravure printing. Note that Figs. 1 and 3 show the top coat layer 23 in a schematic manner. Although the helioplate making has been exemplified as the plate making method for gravure printing, it is not limited to this, and the Poshell plate making method shown in FIG. 1(b) may also be used. Helio printing set the number of lines to 100 lpi or more. If the number of lines is less than 100 lpi, it is difficult to express delicate patterns, and if the number of lines is more than 100 lpi, the texture becomes weaker.

[0020] Furthermore, Helio Platemaking set the average value of the histogram (hereinafter referred to as the "histogram average value") when the shading of the pattern of the pattern printing layer 21 is resolved into 256 gradations (0 to 255) on the image data to less than 80. Here, setting it to less than 80 means that the amount of filler added to the ultraviolet curable resin is shifted toward the high density range. 1 and 3, the top coat layer 23 is shown schematically. When the histogram average value exceeds 80, the texture tends to weaken.

[0021] (Method of manufacturing single-layer decorative sheet 10) The single-layer decorative sheet 10 having the above-described configuration is manufactured as follows. The first step is to form a pattern printed layer 21 by printing a wood grain pattern on the surface of the raw fabric layer 20 using urethane ink or the like, for example, by gravure printing. The second step is to apply a base urethane resin onto the pattern printed layer 21 to a thickness of about 5 μm, thereby forming the base coat layer 22 . The third step is to apply a UV-curable resin containing filler to the surface of the undercoat layer 22 using gravure printing in a manner that corresponds to the pattern of the pattern printing layer 21, thereby forming a contact pattern. The fourth step is to irradiate the ultraviolet curable resin with ultraviolet light to cure it, thereby forming the topcoat layer 23 .

[0022] (Features and Effects of the Embodiments Based on the Present Invention) The features of the embodiment of the present invention are as follows. (First feature) The first feature is a method for manufacturing a single-layer decorative sheet 10 in which an original layer 20, a pattern-printed layer 21 having a pattern printed thereon, an undercoat layer 22, and a topcoat layer 23 are laminated in that order, and includes the steps of applying an ultraviolet-curable resin to which a filler has been added using gravure printing to the surface of the undercoat layer 22 in a manner that corresponds to the pattern of the pattern-printed layer 21, thereby forming a contact pattern, and irradiating the ultraviolet-curable resin with ultraviolet light to harden it and form the topcoat layer 23, wherein the particle size of the filler is 20 to 40 μm, and the printing plate used for gravure printing the topcoat layer 23 has a line count of 100 lpi or more and a histogram average value of less than 80. (Effect of the first feature) According to the first characteristic, it is possible to provide a method for producing a single-layer decorative sheet that prevents unevenness in the particle size of the filler transferred to the cells of the plate and provides a stable feel to the touch.

[0023] (Second feature) The second feature is that helioplate making is used in gravure printing. (Effect of the second feature) According to the second feature, by using helio-plate making, the amount of coating can be reduced, leading to cost savings. In addition, according to the second feature, by specifying the particle size, number of lines, and histogram average value of the filler, a stable feel can be obtained. [Example]

[0024] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to the following examples in any way. (Example) In the examples, single-layer decorative sheets with a textured feel were produced using the following materials and procedures. A 50 μm thick pigmented colored polypropylene sheet was used as the printing base layer, and a wood grain pattern was printed by gravure printing using urethane ink (manufactured by Toyo Ink Co., Ltd.) to form a picture print layer. On the picture print layer, a urethane resin (urethane resin manufactured by DIC Graphics) was applied to a thickness of about 5 μm as an undercoat layer. Furthermore, a topcoat layer was formed by adding filler (particle size 20-40 μm) to an ultraviolet-curable resin (urethane acrylate resin manufactured by DIC Graphics) and applying it using a helioplate making machine. The topcoat layer was then cured by irradiating it with ultraviolet light using a metal halide lamp, producing the decorative sheet according to the example. The Helio printing used at this time had a line count of 100 lpi and a histogram average value of 63.

[0025] (Comparative Example 1) In Comparative Example 1, a decorative sheet according to Comparative Example 1 was produced using the same materials and procedures as in the Examples, except that the screen frequency was 100 lpi and the histogram average value was 89. (Comparative Example 2) In Comparative Example 2, a decorative sheet according to Comparative Example 2 was produced using the same materials and procedures as in Example, except that the screen frequency was 100 lpi and the histogram average value was 107.

[0026] (Evaluation method and criteria) The decorative sheets described in Example, Comparative Example 1 and Comparative Example 2 were evaluated by the following methods. 1. Surface roughness measurement For "surface roughness measurement," the surface roughness of each decorative sheet of Example, Comparative Example 1, and Comparative Example 2 was measured, and the surface roughness Rmax (μm), which is the maximum height difference between the irregularities of the top coat layer, was determined. 2. Tactile evaluation The tactile evaluation was carried out by comparing the feel of the surface of the decorative sheets of Example, Comparative Example 1 and Comparative Example 2, and rating them on the following three levels. (1) "〇": Feels tactile, (2) "△": Feels tactile but weak, "×": "No feel" to "Almost no feel" 3. Verdict The evaluation was made such that if the feel to the touch was "good", it was marked as "good" and the sample was deemed "passed." When the feel was "Δ" or "×", the evaluation was "×" and the product was deemed "failed".

[0027] (Evaluation results) The results are shown in Table 1.

[0028] [Table 1]

[0029] Of the Example, Comparative Example 1, and Comparative Example 2, only the Example was judged to be "passed." The samples of Comparative Example 1 and Comparative Example 2 were judged as "failed." Regarding the histogram average value of the pattern density, when it is "63" or less as in the example, the "touch feel" is appropriate, and when it is "89" or more as in the comparative example 1, it can be assumed that it is inappropriate. Furthermore, when comparing the surface roughness Rmax between the Example and Comparative Example 1, the values ​​are relatively far apart, so it was thought that if the histogram average value is less than "80", it could be inferred that "there is a feeling of touch." [Explanation of symbols]

[0030] 10 Single layer decorative sheet 20 Original layer 21 Picture printing layer 22 Primer coat layer 23 Topcoat layer 30 primer layer 40 Plate base material

Claims

1. A method for producing a single-layer decorative sheet in which a base layer, a pattern printed layer having a printed pattern, an undercoat layer, and a topcoat layer are laminated in this order, a step of applying an ultraviolet curable resin containing a filler to the surface of the undercoat coating layer by gravure printing in a manner corresponding to the pattern of the pattern printing layer to form a contact pattern; and a step of irradiating the ultraviolet curable resin with ultraviolet light to cure it and form the top coat layer, In the single-layer decorative sheet, the base fabric layer and the picture print layer are in contact with each other without providing a transparent resin layer on the base fabric layer, The particle size of the filler is 20 to 40 μm, A method for manufacturing a single-layer decorative sheet, characterized in that the printing plate used for gravure printing the top coat layer has a line count of 100 lpi, and at the same time, the printing plate has a histogram average value of less than 80 when the shades of the pattern of the pattern printing layer are decomposed into 256 gradations on image data.

2. 2. The method for producing a single-layer decorative sheet according to claim 1, wherein the printing plate used in the gravure printing is a helioprinting plate.

3. 3. The method for producing a single-layer decorative sheet according to claim 1, wherein the undercoat layer is formed of a urethane resin.

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