decorative sheet

Abstract

To provide a decorative sheet that can maintain sufficient opacity while keeping the thickness to a minimum. [Solution] The decorative sheet 10 comprises a colored base layer 1 having a thickness of 50 μm or more, a pattern printing layer 2 containing inorganic pigment ink provided on the upper side UP of the colored base layer 1, a clear layer 3 provided on the upper side UP of the pattern printing layer 2, and a top coat layer 4 provided on the upper side UP of the clear layer 3. The thickness of the colored base layer 1 may be less than 70 μm.

Description

Technical Field

[0001] The present invention relates to a decorative sheet.

Background Art

[0002] Conventionally, there are decorative sheets used as surface materials for furniture and building materials for houses. Such decorative sheets often include a base fabric layer and a pattern layer printed on the base fabric layer, and when used as a surface material for building materials for houses, they are bonded to the surface of a wooden base material. In addition, due to the reduction of CO2 emissions and petrochemical products, there is a demand for decorative sheets with a thinner layer thickness.

[0003] As a decorative sheet including a base fabric layer and a pattern layer, there is a decorative sheet described in Patent Document 1. The decorative sheet described in Patent Document 1 has a pattern layer, a first adhesive layer, a polyester resin layer, and a surface protection layer in this order on a thermoplastic resin base sheet (base fabric layer).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in a decorative sheet including a base fabric layer and a pattern layer, when the layer thickness is reduced, the concealment of the decorative sheet decreases, and there is a possibility that the texture and color of the wooden base material bonded to the back surface of the decorative sheet penetrate through the surface of the decorative sheet. When the color of the base material penetrates through the surface of the decorative sheet, there is a risk that the color of the decorative sheet changes depending on the color of the base material.

[0006] In view of the above circumstances, an object of the present invention is to provide a decorative sheet that can have sufficient concealment while suppressing the thickness.

Means for Solving the Problems

[0007] To solve the above problems, this invention proposes the following means. The decorative sheet of the present invention comprises a colored base layer having a thickness of 50 μm or more, a pattern printing layer containing inorganic pigment ink provided on the upper side of the colored base layer, a clear layer provided on the upper side of the pattern printing layer, and a top coat layer provided on the upper side of the clear layer.

[0008] In the decorative sheet described above, the thickness of the colored raw material layer may be less than 70 μm.

[0009] In the above decorative sheet, the opacity value ΔE may be 3.0 or less.

[0010] In the decorative sheet described above, the density of the patterned printing layer may be between 0.3 and 1.4.

[0011] In the decorative sheet described above, the colored base layer may contain a thermoplastic resin. [Effects of the Invention]

[0012] The decorative sheet of the present invention provides a decorative sheet that can have sufficient opacity while suppressing thickness. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic cross-sectional view showing the decorative sheet according to this embodiment. [Modes for carrying out the invention]

[0014] One embodiment of the present invention will be described with reference to the drawings. Figure 1 is a schematic cross-sectional view showing the decorative sheet 10 according to this embodiment.

[0015] In this embodiment, as shown in FIG. 1, the thickness direction of the cosmetic sheet 10 is defined as the "vertical direction V", the side where the top coat layer 4 of the cosmetic sheet 10 is provided is defined as the "upper side UP" in the vertical direction V, and the side opposite to the upper side UP is defined as the "lower side LO" in the vertical direction V.

[0016] The cosmetic sheet 10 includes a coloring original layer 1, a pattern printing layer 2, a clear layer 3, a top coat layer 4, and a primer layer 5.

[0017] The coloring original layer 1 is a layer provided on the upper side UP of the primer layer 5. Details of the primer layer 5 will be described later. As the coloring original layer 1, a thermoplastic resin can be adopted. For example, polyolefin resins such as polyethylene and polypropylene can be adopted as the coloring original layer 1.

[0018] The thickness of the coloring original layer 1 in the vertical direction V is 50 μm or more. The thickness of the coloring original layer 1 is preferably less than 70 μm. More preferably, the thickness of the coloring original layer 1 is 55 μm.

[0019] The pattern printing layer 2 is a layer provided on the upper side UP of the coloring original layer 1. The pattern printing layer 2 is formed, for example, by applying a pattern such as a wood grain, a stone grain, or a sand grain on the upper side UP of the coloring original layer 1.

[0020] The pattern printing layer 2 contains inorganic pigment ink. By using inorganic pigment ink in the pattern printing layer 2, the concealability of the cosmetic sheet 10 can be improved as compared with the case of using organic pigment ink. Also, by using inorganic pigment ink in the pattern printing layer 2, the weather resistance of the pattern printing layer 2 can be improved as compared with the case of using organic pigment ink.

[0021] The density (ink density) of the pattern printing layer 2 is preferably 0.3 or more. By setting the density of the pattern printing layer 2 to 0.3 or more, the concealability of the cosmetic sheet 10 can be improved. Also, from the viewpoints of the productivity of the pattern printing layer 2 and the reproducibility of the pattern, the density of the pattern printing layer 2 is preferably 1.4 or less.

[0022] The ink density of the pattern printing layer 2 is measured by, for example, a reflection densitometer. When measuring the ink density of the pattern printing layer 2 with a reflection densitometer, the reflection densitometer captures and measures the amount of light reflected from the surface of the pattern printing layer 2 and reaching the eyes. Also, when most of the light is absorbed on the surface of the pattern printing layer 2 and there is little light reflection, the reflection density (ink density) is measured to be high.

[0023] As a printing method for the pattern printing layer 2, for example, known printing methods such as gravure printing, offset printing, flexographic printing, silk screen printing, or inkjet printing can be adopted.

[0024] The clear layer 3 is a layer provided on the upper side UP of the pattern printing layer 2. As the clear layer 3, a thermoplastic resin can be adopted. As the clear layer 3, for example, polyolefin resins such as polyethylene and polypropylene can be adopted. It is preferable to adopt a transparent or translucent material for the clear layer 3 such that the pattern of the pattern printing layer 2 can be seen through. The clear layer 3 is formed, for example, by extrusion lamination using an extruder.

[0025] In the present embodiment, the surface of the clear layer 3 is embossed, and an uneven shape (emboss) formed by pressing an embossing plate is provided. Note that the surface of the clear layer 3 does not necessarily have to be embossed.

[0026] The top coat layer 4 is a layer provided on the upper side UP of the clear layer 3. As the top coat layer 4, a thermosetting resin, an ultraviolet curable resin, an electron beam curable resin, or a mixture thereof can be adopted. As the top coat layer 4, for example, urethane resins, acrylic resins, etc. can be adopted. It is preferable to adopt a transparent or translucent material for the top coat layer 4 such that the pattern of the pattern printing layer 2 can be seen through the clear layer 3.

[0027] As a method for laminating the topcoat layer 4, known printing methods such as gravure printing, offset printing, flexographic printing, screen printing, or inkjet printing can be employed. Alternatively, the topcoat layer 4 may be laminated using a known coating apparatus.

[0028] The primer layer 5 is a layer provided on the lower LO of the colored base material layer 1. The primer layer 5 can be made of polyester resin, urethane resin, acrylic resin, etc. As a method for laminating the primer layer 5, known printing methods such as gravure printing, offset printing, flexographic printing, screen printing, or inkjet printing, or lamination methods using known coating equipment can be employed.

[0029] The primer layer 5 is a layer that improves the adhesion between the decorative sheet 10 and the substrate to be bonded to the back surface (lower side LO) of the decorative sheet 10 when forming a decorative panel by bonding a substrate such as a wood-based substrate to the back surface (lower side LO) of the decorative sheet 10.

[0030] When a base material such as a wood-based material is laminated to the back of a decorative sheet, if the opacity of the decorative sheet is insufficient, the texture and color of the base material may show through to the surface of the decorative sheet. In such cases, the color of the surface of the decorative sheet may change compared to before the base material was laminated.

[0031] One way to improve the opacity of decorative sheets is to increase the thickness of the colored base layer. However, this could potentially reduce the processability of the decorative sheet and increase CO2 emissions from its manufacture.

[0032] On the other hand, reducing the thickness of the colored base layer 1 can reduce CO2 emissions from manufacturing the decorative sheet 10. For example, if decorative sheet 10 is produced in 12,000 m lots with a yield of 97.7% and the density of the patterned printing layer 2 is 1.4, reducing the thickness of the colored base layer 1 by 15 μm will reduce CO2 emissions from approximately 1,120 kg-CO2eq before the change to 1,040 kg-CO2eq after the change, resulting in a 7.2% reduction in emissions compared to the current method.

[0033] For example, the thickness of the colored base layer in conventional decorative sheets is about 70 μm. If the thickness of the colored base layer in conventional decorative sheets is reduced by 15 μm to 55 μm, the CO2 emissions would be approximately 1,120 kg-CO2eq. However, if the thickness of the colored base layer is 70 μm, the emissions would be 1,040 kg-CO2eq, resulting in a 7.2% reduction in emissions compared to the current level.

[0034] However, reducing the thickness of the colored base layer reduces the opacity of the decorative sheet. As mentioned above, if the opacity of the decorative sheet is insufficient, the texture and color of the substrate laminated to the back of the decorative sheet may show through to the surface of the decorative sheet, potentially changing the color of the surface of the decorative sheet.

[0035] Furthermore, conventional decorative sheets often use organic pigment inks in the pattern printing layer. As described above, the decorative sheet 10 of this embodiment uses inorganic pigment inks in the pattern printing layer 2, thereby improving the opacity of the decorative sheet 10 compared to the case where organic pigment inks are used. Therefore, even if the thickness of the colored base layer 1 of the decorative sheet 10 of this embodiment is thinner than the thickness of the colored base layer of conventional decorative sheets, sufficient opacity can be maintained.

[0036] The opacity value ΔE of a decorative sheet 10 with sufficient opacity is, for example, 3.0 or less. The opacity value ΔE is a value that indicates the color difference between the surface of the decorative sheet 10 with the white opacity test paper placed on the back side of the decorative sheet 10 (white background) and the surface of the decorative sheet 10 with the black opacity test paper placed on the back side of the decorative sheet 10 (black background).

[0037] The opacity test paper is a test paper used in the opacity test defined by JIS K 5600. Furthermore, the color difference on the surface of the decorative sheet 10 is measured using a colorimeter with a D65 light source.

[0038] By setting the opacity value ΔE of the decorative sheet 10 to 3.0 or less, sufficient opacity can be provided to the decorative sheet 10. Even when a substrate is laminated to the back surface of the decorative sheet 10, the texture and color of the substrate can be suppressed from showing through to the surface of the decorative sheet 10, and the color of the decorative sheet 10 can be suppressed.

[0039] The decorative sheet 10 of this embodiment improves opacity by using inorganic pigment ink in the pattern printing layer 2, so that it can have sufficient opacity even when the thickness of the colored base layer 1 is about 55 μm. In other words, by using inorganic pigment ink in the pattern printing layer 2, it is possible to realize a decorative sheet 10 with sufficient opacity while suppressing the thickness of the colored base layer 1. Furthermore, the decorative sheet 10 of this embodiment has sufficient opacity even when the thickness of the colored base layer 1 is 50 μm.

[0040] The decorative sheet 10 of this embodiment comprises a colored base layer 1 having a thickness of 50 μm or more, a pattern printing layer 2 containing inorganic pigment ink provided on the upper side UP of the colored base layer 1, a clear layer 3 provided on the upper side UP of the pattern printing layer 2, and a top coat layer 4 provided on the upper side UP of the clear layer 3.

[0041] As described above, by using inorganic pigment ink in the pattern printing layer 2, the decorative sheet 10 can have sufficient opacity while suppressing the thickness of the colored base layer 1. Furthermore, by suppressing the thickness of the colored base layer 1, the thickness of the decorative sheet 10 can be suppressed.

[0042] As a result, it is possible to provide a decorative sheet 10 that can suppress thickness while having sufficient concealment.

[0043] Although one embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like that do not depart from the spirit of the present invention are also included. Furthermore, the components shown in the above-described embodiment and the following modifications can be combined as appropriate.

[0044] (Variation 1) In the above embodiment, the decorative sheet 10 includes a primer layer 5, but the form of the decorative sheet 10 is not limited thereto. The decorative sheet does not need to include a primer layer 5.

[0045] If the adhesion between the decorative sheet and the substrate to which the decorative sheet is bonded is sufficient even without the primer layer 5, the decorative sheet does not need to have the primer layer 5.

[0046] The present invention will be described in detail with reference to the following examples. The present invention is not limited to the following examples.

[0047] (Example 1) A 70 μm thick colored base layer 1 made of thermoplastic resin was prepared. The opacity value ΔE was measured while varying the thickness of the colored base layer 1 while keeping the pigment concentration constant. The results showed that the opacity value ΔE decreased by 0.09 when the thickness of the colored base layer 1 was reduced to 1 μm.

[0048] A pattern was printed onto the upper side (UP) of the colored base material layer 1 using gravure printing to form the patterned printing layer 2. In this layer, an inorganic pigment ink was used. The inorganic pigment ink was color-matched by mixing ochre, brown, and cyan. The color of the inorganic pigment ink was primarily determined by the iron oxide pigment contained in the ink. The density of the patterned printing layer 2 was set to 1.4. The ink thickness of the patterned printing layer 2 was 2 μm.

[0049] A clear layer 3 was laminated to the upper side UP of the patterned printing layer 2 using an extruder, and the upper surface of the clear layer 3 was embossed. A primer layer 5 was laminated to the lower side LO of the colored base layer 1, and then a topcoat layer 4 was laminated to the upper side UP of the clear layer 3 to obtain the decorative sheet 10 of Example 1.

[0050] (Example 2) The decorative sheet 10 of Example 2 was obtained by the same method as in Example 1, except that the density of the pattern printing layer 2 was set to 1.0.

[0051] (Example 3) The decorative sheet 10 of Example 3 was obtained by the same method as in Example 1, except that the density of the pattern printing layer 2 was set to 0.3.

[0052] (Example 4) The decorative sheet 10 of Example 4 was obtained by the same method as in Example 1, except that the thickness of the colored raw material layer 1 was set to 63 μm.

[0053] (Example 5) The decorative sheet 10 of Example 5 was obtained by the same method as in Example 1, except that the thickness of the colored base layer 1 was 63 μm and the density of the patterned printing layer 2 was 1.0.

[0054] (Example 6) The decorative sheet 10 of Example 6 was obtained by the same method as in Example 1, except that the thickness of the colored base layer 1 was 63 μm and the density of the patterned printing layer 2 was 0.3.

[0055] (Example 7) The decorative sheet 10 of Example 7 was obtained by the same method as in Example 1, except that the thickness of the colored raw material layer 1 was set to 60 μm.

[0056] (Example 8) The decorative sheet 10 of Example 8 was obtained by the same method as in Example 1, except that the thickness of the colored base layer 1 was 60 μm and the density of the patterned printing layer 2 was 1.0.

[0057] (Example 9) The decorative sheet 10 of Example 9 was obtained by the same method as in Example 1, except that the thickness of the colored base layer 1 was 60 μm and the density of the patterned printing layer 2 was 0.3.

[0058] (Example 10) The decorative sheet 10 of Example 10 was obtained by the same method as in Example 1, except that the thickness of the colored raw material layer 1 was set to 55 μm.

[0059] (Example 11) The decorative sheet 10 of Example 11 was obtained by the same method as in Example 1, except that the thickness of the colored base layer 1 was 55 μm and the density of the patterned printing layer 2 was 1.0.

[0060] (Example 12) The decorative sheet 10 of Example 12 was obtained by the same method as in Example 1, except that the thickness of the colored base layer 1 was 55 μm and the density of the patterned printing layer 2 was 0.3.

[0061] (Example 13) The decorative sheet 10 of Example 13 was obtained by the same method as in Example 1, except that the thickness of the colored raw material layer 1 was set to 50 μm.

[0062] (Example 14) The decorative sheet 10 of Example 14 was obtained by the same method as in Example 1, except that the thickness of the colored base layer 1 was 50 μm and the density of the patterned printing layer 2 was 1.0.

[0063] (Example 15) The decorative sheet 10 of Example 15 was obtained by the same method as in Example 1, except that the thickness of the colored base layer 1 was 50 μm and the density of the patterned printing layer 2 was 0.3.

[0064] In this way, using inorganic pigment ink in the pattern printing layer 2, decorative sheets 10 of Examples 1-15 were obtained in which the densities of the pattern printing layer 2 were 1.4, 1.0, and 0.3, respectively, and the thickness of the colored base layer 1 was 70 μm, 63 μm, 60 μm, 55 μm, and 50 μm, respectively.

[0065] (Comparative Example 1) A decorative sheet of Comparative Example 1 was obtained by the same method as in Example 1, except that an organic pigment ink was used for the pattern printing layer. The organic pigment ink was mixed with yellow, red, and blue to achieve the same color as the inorganic pigment inks of Examples 1-15. The color of the organic pigment ink is determined by the organic compounds contained in the organic pigment ink as pigments.

[0066] (Comparative Example 2) A decorative sheet for Comparative Example 2 was obtained using the same method as for Comparative Example 1, except that the density of the patterned printing layer was set to 1.0.

[0067] (Comparative Example 3) A decorative sheet for Comparative Example 3 was obtained using the same method as for Comparative Example 1, except that the density of the patterned printing layer was set to 0.3.

[0068] (Comparative Example 4) A decorative sheet of Comparative Example 4 was obtained using the same method as in Comparative Example 1, except that the thickness of the colored raw material layer was set to 63 μm.

[0069] (Comparative Example 5) A decorative sheet for Comparative Example 5 was obtained using the same method as for Comparative Example 1, except that the thickness of the colored base layer was 63 μm and the density of the patterned printing layer was 1.0.

[0070] (Comparative Example 6) A decorative sheet for Comparative Example 6 was obtained using the same method as for Comparative Example 1, except that the thickness of the colored base layer was 63 μm and the density of the patterned printing layer was 0.3.

[0071] (Comparative Example 7) A decorative sheet of Comparative Example 7 was obtained using the same method as in Comparative Example 1, except that the thickness of the colored raw material layer was set to 60 μm.

[0072] (Comparative Example 8) A decorative sheet for Comparative Example 8 was obtained using the same method as for Comparative Example 1, except that the thickness of the colored base layer was 60 μm and the density of the patterned printing layer was 1.0.

[0073] (Comparative Example 9) A decorative sheet for Comparative Example 9 was obtained using the same method as for Comparative Example 1, except that the thickness of the colored base layer was 60 μm and the density of the patterned printing layer was 0.3.

[0074] (Comparative Example 10) A decorative sheet of Comparative Example 10 was obtained by the same method as in Comparative Example 1, except that the thickness of the colored raw material layer was set to 55 μm.

[0075] (Comparative Example 11) A decorative sheet for Comparative Example 11 was obtained using the same method as for Comparative Example 1, except that the thickness of the colored base layer was 55 μm and the density of the patterned printing layer was 1.0.

[0076] (Comparative Example 12) A decorative sheet for Comparative Example 12 was obtained using the same method as for Comparative Example 1, except that the thickness of the colored base layer was 55 μm and the density of the patterned printing layer was 0.3.

[0077] In this way, by using organic pigment inks in the patterned printing layer, we obtained decorative sheets of Comparative Examples 1-12, in which the density of the patterned printing layer was 1.4, 1.0, and 0.3, respectively, and the thickness of the colored base layer was 70 μm, 63 μm, 60 μm, and 55 μm, respectively.

[0078] In addition, the pigment concentration of the colored base layer was the same in the decorative sheets of Examples 1-15 and Comparative Examples 1-12. That is, in the above-mentioned examples and comparative examples, only the thickness was changed while the pigment concentration of the colored base layer remained unchanged.

[0079] (Experiment 1) Color difference measurement tests were performed on the decorative sheets of Examples 1-15 and Comparative Examples 1-12. In the color difference measurement tests, the color difference (opacity value ΔE) between the decorative sheet with a white background and the decorative sheet with a black background was measured using the method described in the above embodiments.

[0080] (Experiment 2) A color difference evaluation test was conducted on the decorative sheets of Example 4-15 and Comparative Example 4-12. In the color difference evaluation test, a sensory evaluation was performed focusing on the color difference of the decorative sheets against a white background and a black background, using the opacity test paper described in the above embodiment.

[0081] The evaluation criteria consisted of four levels, with anything other than a failing grade considered a pass. ◎(Excellent): There is absolutely no noticeable color difference between the white and black backgrounds. 〇 (Good): There is almost no noticeable color difference between the white and black backgrounds. △(Fair): There's a slight color difference between the white and black backgrounds, but it's not bothersome. × (Poor): The color difference between the white and black backgrounds is clearly noticeable.

[0082] (Experimental results) The results of Experiment 1-2 are shown in Table 1-2. Table 1-2 shows the thickness of the colored base material layer and the density of the patterned printing layer for Example 1-15 and Comparative Example 1-12. Example 1-15, shown in Table 1, uses inorganic pigment ink for the patterned printing layer 2, while Comparative Example 1-12, shown in Table 2, uses organic pigment ink for the patterned printing layer.

[0083] Furthermore, Table 1-2 does not show the color difference evaluation results for Experiment 2 for Example 1-3 and Comparative Example 1-3. Example 1-3 and Comparative Example 1-3 have a colored base layer thickness of 70 μm, equivalent to that of conventional decorative sheets, and sufficient opacity can be achieved with this thickness. Therefore, Example 1-3 and Comparative Example 1-3 are listed in Table 1-2 as Reference Example 1-6, respectively.

[0084] As shown in Table 1, the decorative sheets 10 of Examples 4-15, which used inorganic pigment ink in the patterned printing layer 2, showed good results in Experiment 2. The decorative sheets 10 of Example 4-5, in which the thickness of the colored base layer 1 was 63 μm and the density of the patterned printing layer 2 was 1.0 or higher, showed particularly good results in Experiment 2.

[0085] In Experiment 2, the decorative sheet 10 of Example 6, in which the thickness of the colored base layer 1 was 63 μm and the density of the patterned printing layer 2 was 0.3, and the decorative sheet 10 of Examples 7-12, in which the thickness of the colored base layer 1 was 55 μm or more and less than 63 μm, showed good results, although they were inferior to those of Examples 4-5.

[0086] In Examples 13-15, the decorative sheet 10, which had a colored base layer 1 with a thickness of 50 μm, showed good results in Experiment 2, although it was inferior to that of Examples 6-12.

[0087] In Example 4-15, which showed good results in Experiment 2, the opacity value ΔE of the decorative sheet 10 measured in Experiment 1 was 3.0 or less.

[0088] As shown in Table 2, the decorative sheet of Comparative Example 4-12, which used organic pigment ink in the patterned printing layer, failed Experiment 2. In Comparative Example 4-12, which failed Experiment 2, the opacity value ΔE of the decorative sheet measured in Experiment 1 was greater than 3.0.

[0089] As shown in Table 1, even when the decorative sheet 10 has a colored base layer 1 with a thickness of 55 μm, which is 15 μm less than the 70 μm thickness of the colored base layer used in conventional decorative sheets, it can have excellent opacity by using inorganic pigment ink in the pattern printing layer 2. Furthermore, a decorative sheet 10 using inorganic pigment ink in the pattern printing layer 2 can have sufficient opacity even when the thickness of the colored base layer 1 is 50 μm.

[0090] [Table 1]

[0091] [Table 2] [Explanation of Symbols]

[0092] 10 Decorative sheets 1 Colored original fabric layer 2 pattern printing layers 3 Clear Layer 4. Top coat layer V vertical direction UP upper side LO (lower side)

Claims

1. A colored raw material layer with a thickness of 50 μm or more, A pattern printing layer containing inorganic pigment ink is provided above the aforementioned colored base layer, The clear layer provided on the upper side of the patterned printed layer, The top coat layer provided on the upper side of the clear layer, Equipped with, Decorative sheet.

2. The thickness of the aforementioned colored raw material layer is less than 70 μm. The decorative sheet according to claim 1.

3. The concealment value ΔE is 3.0 or less. The decorative sheet according to claim 1 or claim 2.

4. The density of the patterned printing layer is 0.3 to 1.

4. The decorative sheet according to claim 3.

5. The aforementioned colored raw material layer contains a thermoplastic resin. The decorative sheet according to claim 4.

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