Decorative sheets and decorative panels

Abstract

To provide decorative sheets and decorative panels that suppress curling and improve surface strength. [Solution] The decorative sheet 10 comprises a base paper 1, a thermoplastic resin layer 2 provided on the upper side UP of the base paper 1, and a pattern layer 4 provided on the upper side UP of the thermoplastic resin layer 2, wherein the thermoplastic resin layer 2 has a thickness of 20% to 80% of the thickness of the base paper 1 and a thickness of 10 μm or more, and contains homopolypropylene resin. The decorative board 100 comprises the decorative sheet 10 and a base material 20 adhered to the lower side LO of the decorative sheet 10.

Description

[Technical Field] 【0001】 This invention relates to decorative sheets and decorative panels. [Background technology] 【0002】 Traditionally, decorative sheets used as surface materials for furniture and building materials for houses often consist of a base paper and a patterned layer laminated on one side of the base paper. The patterned layer provides design appeal to the decorative sheet through its pattern. The patterned layer is formed by printing on one side of the base paper. 【0003】 One example of a decorative sheet comprising a base paper and a pattern layer is the decorative paper described in Patent Document 1. The decorative paper described in Patent Document 1 is a decorative paper in which a thermoplastic resin layer and a pattern layer (pattern layer) are laminated in this order on one side of the base paper. [Prior art documents] [Patent Documents] 【0004】 [Patent Document 1] Japanese Patent Publication No. 2020-75442 [Overview of the Initiative] [Problems that the invention aims to solve] 【0005】 However, decorative sheets, such as the decorative paper described in Patent Document 1, which have a thermoplastic resin layer between the base paper and the pattern layer, may curl when printing the pattern layer due to differences in the thermal shrinkage rates between the base paper and the thermoplastic resin layer. Furthermore, if the strength of the thermoplastic resin layer is insufficient, the surface strength of the decorative sheet will be poor, and when external force is applied to the surface of the decorative sheet, dents may occur on the surface of the decorative sheet, or delamination may occur between the base paper and the thermoplastic resin layer. 【0006】 Based on the above circumstances, the present invention aims to provide decorative sheets and decorative panels that suppress curling and improve surface strength. [Means for solving the problem] 【0007】 To solve the above problems, this invention proposes the following means. The decorative sheet of the present invention comprises a base paper, a thermoplastic resin layer provided on the upper side of the base paper, and a pattern layer provided on the upper side of the thermoplastic resin layer, wherein the thermoplastic resin layer has a thickness of 20% to 80% of the thickness of the base paper and a thickness of 10 μm or more, and contains homopolypropylene resin. 【0008】 The decorative sheet described above may include a base coloring layer containing an isocyanate curing agent, provided between the thermoplastic resin layer and the pattern layer, and the thermoplastic resin layer may be corona treated on the upper surface on which the base coloring layer is provided. 【0009】 The decorative sheet described above may include a matte layer provided on the upper side of the patterned layer, and a surface protection layer provided on the upper side of the matte layer and in a position synchronized with the pattern of the patterned layer, and having a different gloss than the matte layer. The matte layer and the surface protection layer may contain a urethane resin. 【0010】 The decorative panel of the present invention comprises any of the decorative sheets described above and a base material adhered to the underside of the decorative sheet. [Effects of the Invention] 【0011】 The decorative sheet and decorative panel of the present invention can provide a decorative sheet and decorative panel that suppress curling and improve surface strength. [Brief explanation of the drawing] 【0012】 [Figure 1] This is a schematic cross-sectional view showing a decorative panel according to this embodiment. [Modes for carrying out the invention] 【0013】 An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing a decorative board 100 according to the present embodiment. 【0014】 In the present embodiment, as shown in FIG. 1, the thickness direction of the decorative board 100 is defined as the "vertical direction V", the side of the decorative board 100 where the base material 20 is provided is defined as the "lower side LO" in the vertical direction V, and the side opposite to the lower side LO is defined as the "upper side UP" in the vertical direction V. 【0015】 The decorative board 100 includes a decorative sheet 10 and a base material 20. The base material 20 is a layer provided on the lower side LO of the decorative board 100. The base material 20 is adhered to the lower side LO of the decorative sheet 10. As the base material 20, particle board or medium density fiberboard (MDF) or the like can be adopted. 【0016】 As the base material 20, a plate-like member made of a metal such as aluminum or stainless steel, or a composite board in which a metal such as aluminum is attached to both sides of a core material made of a resin such as polyethylene may be adopted. 【0017】 The decorative sheet 10 includes a base paper 1, a thermoplastic resin layer 2, an undercoat coloring layer 3, a pattern layer 4, a matte layer 5, and a surface protection layer 6. 【0018】 The base paper 1 is a layer provided on the lower side LO of the decorative sheet 10. The base material 20 is adhered to the lower side LO surface of the base paper 1. As the base paper 1, a thin paper such as paper reinforced paper or printed paper, or a fibrous sheet such as titanium paper can be adopted. 【0019】 The thermoplastic resin layer 2 is a layer provided on the upper side UP of the base paper 1. The thermoplastic resin layer 2 contains a homopolypropylene resin. For example, in the thermoplastic resin layer of a conventional decorative sheet, a polyethylene resin is often used. The thermoplastic resin layer 2 containing a homopolypropylene resin is excellent in rigidity compared with the case where a polyethylene resin is used, so the surface strength of the decorative sheet 【0020】 In addition, since the thermoplastic resin layer 2 containing the homopolypropylene resin is superior in rigidity compared to the case where a polyethylene resin is used, the occurrence of curling of the decorative sheet 10 can be suppressed by including the homopolypropylene resin in the thermoplastic resin layer 2. 【0021】 The thermoplastic resin layer 2 has a thickness of 20% or more and 80% or less, and 10 μm or more, with respect to the thickness of the base paper 1. By setting the thickness of the thermoplastic resin layer 2 to be 20% or more and 10 μm or more with respect to the thickness of the base paper 1, the surface strength of the decorative sheet 10 can be improved. Since the thermoplastic resin layer 2 of the present embodiment contains a homopolypropylene resin and has a thickness of 10 μm or more and 20% or more with respect to the thickness of the base paper 1, sufficient surface strength can be imparted to the decorative sheet 10. 【0022】 In addition, by setting the thickness of the thermoplastic resin layer 2 to 80% or less with respect to the thickness of the base paper 1, the occurrence of curling of the decorative sheet 10 can be suppressed. Since the thermoplastic resin layer 2 of the present embodiment contains a homopolypropylene resin and has a thickness of 80% or less with respect to the thickness of the base paper 1, the occurrence of curling of the decorative sheet 10 can be preferably suppressed. The homopolypropylene resin is excellent in heat resistance and solvent resistance. Therefore, by using the homopolypropylene resin in the thermoplastic resin layer 2, the heat resistance and solvent resistance of the decorative sheet 10 can be improved. 【0023】 As a method for laminating the thermoplastic resin layer 2, a melt extrusion molding method, dry lamination, wet lamination, non-solvent lamination, wax lamination, or the like can be adopted. 【0024】 The upper surface (upper surface 2s) of the thermoplastic resin layer 2 on the upper side UP may be subjected to corona treatment. By subjecting the upper surface 2s of the thermoplastic resin layer 2 to corona treatment to generate polar groups and improve wettability, the adhesion between the thermoplastic resin layer 2 and the base coloring layer 3 can be improved. 【0025】 The base coloring layer 3 is a layer provided on the upper side UP of the thermoplastic resin layer 2. The base coloring layer 3 is formed, for example, on the upper surface 2s of the thermoplastic resin layer 2 by printing. Known printing methods such as gravure printing, offset printing, flexographic printing, silkscreen printing, or inkjet printing can be used to form the base coloring layer 3. 【0026】 For example, a two-component curing urethane resin-based ink with an isocyanate curing agent can be used as the base coloring layer 3. By providing the base coloring layer 3, the opacity of the decorative sheet 10 can be improved, and the texture and color of the substrate 20 can be suppressed from showing through to the surface of the decorative sheet 10. 【0027】 The pattern layer 4 is a layer provided above the base coloring layer 3, and is formed by printing a pattern such as wood grain, stone pattern, or sand pattern. Known printing methods such as gravure printing, offset printing, flexographic printing, screen printing, or inkjet printing can be used to form the pattern layer 4. Known printing inks suitable for the chosen printing method can be used for the pattern layer 4. 【0028】 The matte layer 5 is a layer provided above the pattern layer 4. It is preferable to use a material for the matte layer 5 that is transparent or semi-transparent enough to allow the pattern of the pattern layer 4 to be seen through. For example, a urethane resin can be used as the material for the matte layer 5. 【0029】 As a method for forming the matte layer 5, known printing methods such as gravure printing, offset printing, flexographic printing, screen printing, or inkjet printing can be employed. Alternatively, the matte layer 5 may be formed using a known coating apparatus. 【0030】 The surface protection layer 6 is a layer provided above the matte layer 5. It is desirable that the surface protection layer 6 be made of a material that is transparent or semi-transparent enough to allow the pattern of the design layer 4 to be seen through the matte layer 5. For example, a urethane resin can be used as the material for the surface protection layer 6. 【0031】 As a method for forming the surface protective layer 6, known printing methods such as gravure printing, offset printing, flexographic printing, screen printing, or inkjet printing can be employed. Alternatively, the surface protective layer 6 may be formed using a known coating apparatus. 【0032】 When a thermosetting resin having a urethane bond is used for the matte layer 5 and the surface protective layer 6, the hardness may be inferior compared to, for example, when an ultraviolet-curing resin is used. The decorative sheet 10 of this embodiment includes a thermoplastic resin layer 2 containing homopolypropylene resin, with a thickness of 20% or more of the thickness of the base paper 1 and 10 μm or more. Therefore, even when the matte layer 5 and the surface protective layer 6 are formed of a thermosetting resin, sufficient surface strength can be achieved. 【0033】 Preferably, the matte layer 5 and the surface protection layer 6 have different gloss levels. One method for creating a difference in gloss between the matte layer 5 and the surface protection layer 6 is to add a matting agent to the matte layer 5. By adding a matting agent to the matte layer 5, the gloss level of the matte layer 5 can be made lower than that of the surface protection layer 6. 【0034】 Furthermore, different amounts of matting agents may be added to the matting layer 5 and the surface protective layer 6 to the extent that a difference in gloss between the matting layer 5 and the surface protective layer 6 can be created. The difference in gloss between the matting layer 5 and the surface protective layer 6 can be used to create a visually three-dimensional effect by utilizing an optical illusion. A gloss resin having a sufficiently high gloss compared to the matting layer 5 may be used for the surface protective layer 6. 【0035】 Preferably, the surface protection layer 6 is formed in a position that is synchronized with the pattern of the pattern layer 4. For example, if the pattern layer 4 has a wood grain pattern, forming the surface protection layer 6 in a position that is synchronized with the pore portion of the wood grain pattern will give the pore portion a visually three-dimensional effect due to the difference in gloss between the matte layer 5 and the surface protection layer 6, thereby providing decorative sheets 10 and decorative panels 100 with a wood grain pattern that is closer to the appearance of natural wood. 【0036】 The decorative sheet 10 of this embodiment comprises a base paper 1, a thermoplastic resin layer 2 provided on the upper side UP of the base paper 1, and a pattern layer 4 provided on the upper side UP of the thermoplastic resin layer 2. The thermoplastic resin layer 2 has a thickness of 20% to 80% of the thickness of the base paper 1 and a thickness of 10 μm or more, and contains homopolypropylene resin. The decorative panel 100 of this embodiment comprises the decorative sheet 10 and a base material 20 adhered to the lower side LO of the decorative sheet 10. 【0037】 The decorative sheet 10 and decorative panel 100 of this embodiment can provide decorative sheets 10 and decorative panels 100 that suppress curling and improve surface strength. Furthermore, by including homopolypropylene resin in the thermoplastic resin layer 2, the heat resistance and solvent resistance of the decorative sheet 10 and decorative panel 100 can be improved. 【0038】 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. 【0039】 (Variation 1) In the above embodiment, the decorative sheet 10 includes a base colored layer 3, but the form of the decorative sheet is not limited thereto. The decorative sheet does not need to include a base colored layer 3. 【0040】 The base coloring layer 3 is a layer that provides base coloring to the pattern layer 4 and opacity to prevent the color and texture of the thermoplastic resin layer 2, base paper 1, and substrate 20 from showing through to the surface of the decorative sheet 10. 【0041】 If sufficient base coloring and opacity can be achieved without providing the base coloring layer 3, the decorative sheet does not need to have the base coloring layer 3. If the decorative sheet does not have the base coloring layer 3, the pattern layer is provided on the upper surface of the thermoplastic resin layer. 【0042】 The present invention will be described in detail with reference to the following examples. The present invention is not limited to the following examples. 【0043】 (Example 1) As base paper 1, thickness 26 μm (basis weight 25 g / m²). 2 A reinforced paper was prepared. A thermoplastic resin layer 2 was formed on the upper surface of the base paper 1 by melt extrusion molding to a thickness of 16 μm using homopolypropylene resin (homo PP). The upper surface 2s of the thermoplastic resin layer 2 was subjected to corona treatment. In Example 1, the thickness of the thermoplastic resin layer 2 is 62% of the thickness of the base paper 1. 【0044】 A base colored layer 3 was formed by gravure printing a urethane ink (PCNT manufactured by Toyo Ink Co., Ltd.) with an isocyanate curing agent added to the upper surface 2s of a corona-treated thermoplastic resin layer 2. 【0045】 A urethane ink (PCNT manufactured by Toyo Ink Co., Ltd.) was printed on the upper surface of the base colored layer 3 to form a patterned layer 4 with a wood grain design. 【0046】 A urethane-based resin was applied as a matte layer 5 to the upper surface of the patterned layer 4. A urethane-based gloss resin was applied as a surface protection layer 6 to the upper surface of the matte layer 5. The surface protection layer 6 was applied using a die that was synchronized with the wood grain in the patterned layer 4. 【0047】 After applying the surface protective layer 6, the matte layer 5 and the surface protective layer 6 were cured at 60°C for 96 hours to allow the curing agent added to them to react, thereby curing the matte layer 5 and the surface protective layer 6. In this way, the decorative sheet 10 of Example 1 was obtained. 【0048】 (Example 2) Base paper 1: Thickness 31 μm (Basis weight 30 g / m²) 2 The decorative sheet 10 of Example 2 was obtained by the same method as in Example 1, except that the inter-paper reinforcement paper was used. In Example 1, the thickness of the thermoplastic resin layer 2 was 52% of the thickness of the base paper 1. 【0049】 (Comparative Example 1) The base paper has a thickness of 35 μm (basis weight 35 g / m²). 2 A decorative sheet for Comparative Example 1 was obtained in the same manner as in Example 1, except that a reinforcing paper was used and the thickness of the thermoplastic resin layer was set to 30 μm. In Comparative Example 1, the thickness of the thermoplastic resin layer was 86% of the thickness of the base paper. 【0050】 (Comparative Example 2) The base paper has a thickness of 31 μm (basis weight 30 g / m²). 2 A decorative sheet for Comparative Example 2 was obtained in the same manner as in Example 1, except that a paper-reinforced inter-paper material was used and a random polypropylene resin (random PP) was used for the thermoplastic resin layer. In Comparative Example 2, the thickness of the thermoplastic resin layer was 52% of the thickness of the base paper. 【0051】 (Comparative Example 3) The base paper has a thickness of 31 μm (basis weight 30 g / m²). 2 A decorative sheet for Comparative Example 3 was obtained in the same manner as in Example 1, except that a reinforced paper was used and a block polypropylene resin (block PP) was used for the thermoplastic resin layer. In Comparative Example 3, the thickness of the thermoplastic resin layer was 52% of the thickness of the base paper. 【0052】 (Comparative Example 4) The base paper has a thickness of 31 μm (basis weight 30 g / m²). 2 A decorative sheet for Comparative Example 4 was obtained in the same manner as in Example 1, except that a reinforcing paper was used and the thickness of the thermoplastic resin layer was set to 8 μm. In Comparative Example 4, the thickness of the thermoplastic resin layer was 26% of the thickness of the base paper. 【0053】 (Comparative Example 5) The base paper has a thickness of 55 μm (basis weight 50 g / m²). 2 A decorative sheet for Comparative Example 5 was obtained in the same manner as in Example 1, except that a paper-reinforced inter-paper material was used and the thickness of the thermoplastic resin layer was set to 10 μm. In Comparative Example 5, the thickness of the thermoplastic resin layer was 18% of the thickness of the base paper. 【0054】 (Comparative Example 6) As the base paper, a paper interlayer reinforcing paper with a thickness of 31 μm (basis weight 30 g / m 2 ) was used, and a decorative sheet of Comparative Example 6 was obtained in the same manner as in Example 1, except that a thermoplastic resin layer with a thickness of 16 μm was formed by melt extrusion molding using low-density polyethylene (LDPE). In Comparative Example 6, the thickness of the thermoplastic resin layer was 52% of the thickness of the base paper. 【0055】 (Comparative Example 7) As the base paper, a paper interlayer reinforcing paper with a thickness of 31 μm (basis weight 30 g / m 2 ) was used, and a decorative sheet of Comparative Example 7 was obtained in the same manner as in Example 1, except that a thermoplastic resin layer with a thickness of 16 μm was formed by melt extrusion molding using medium-density polyethylene (MDPE). In Comparative Example 7, the thickness of the thermoplastic resin layer was 52% of the thickness of the base paper. 【0056】 (Comparative Example 8) As the base paper, a paper interlayer reinforcing paper with a thickness of 31 μm (basis weight 30 g / m 2 ) was used, and a decorative sheet of Comparative Example 8 was obtained in the same manner as in Example 1, except that a thermoplastic resin layer with a thickness of 16 μm was formed by melt extrusion molding using high-density polyethylene (HDPE). In Comparative Example 8, the thickness of the thermoplastic resin layer was 52% of the thickness of the base paper. 【0057】 (Experiment 1) A pencil hardness test was carried out on the decorative sheets of Examples 1-2 and Comparative Examples 1-8. In the pencil hardness test, a test conforming to JIS K 5600 was carried out. 【0058】 Specifically, a decorative board was created by bonding a decorative sheet to a base material such as MDF using a vinyl acetate adhesive or the like, and a pencil mounted on a test device was moved at a speed of 1 mm / s so that the core was placed on the surface of the decorative board. At this time, a pencil with the tip of the core flattened was used. In the pencil used for the pencil hardness test, the tip of the core is the part that contacts the surface of the decorative board. 【0059】 <00002In the pencil hardness test, tests were conducted using pencils with lead hardness levels of 2B, B, HB, F, H, 2H, and 3H. The surface hardness was evaluated by checking the indentation on the surface of the decorative laminate. Specifically, the hardness of the pencil lead used in the test was increased sequentially from 2B to 3H, and the hardness was evaluated by checking the hardness of the lead that delaminated between the base paper and the thermoplastic resin layer, and the hardness of the lead that created an indentation on the surface of the decorative laminate. 【0060】 The evaluation criteria consisted of two levels, with a circle (〇) indicating a passing grade. ○ (Good): The hardness of the lead where delamination occurred is HB or higher, and the hardness of the lead where dents occurred is H or higher. × (Poor): The hardness of the lead where delamination occurred is less than HB, and the hardness of the lead where denting occurred is less than H. 【0061】 (Experiment 2) A curling performance evaluation test was conducted on the decorative sheets of Example 1-2 and Comparative Example 1-8. In the curling performance evaluation test, the decorative sheets were cut into 10 cm squares and left to stand for two days. The height from the central plane to the tips of each of the four corners was measured, and the average of the measured heights was calculated for evaluation. The height from the central plane to the tips of the four corners refers to the vertical distance. 【0062】 The evaluation criteria consisted of three levels, with "×" indicating failure. ◎(Excellent): The calculated average value is less than 3cm. ○ (Good): The calculated average value is between 3cm and 5cm. × (Poor): The calculated average value is 5 cm or more. 【0063】 (Experimental results) The results of Experiment 1-2 are shown in Table 1. Table 1 shows the ratio of the thickness of the thermoplastic resin layer to the thickness of the base paper, as well as the thickness and material of the thermoplastic resin layer, for the decorative sheets of Example 1-2 and Comparative Example 1-8. Table 1 also shows the hardness of the core that peeled, the hardness of the core that dented, and the evaluation results for Experiment 1. 【0064】 In Example 1, the decorative sheet 10, in which homopolypropylene resin was used as the material for the thermoplastic resin layer 2, and the thickness of the thermoplastic resin layer 2 was 62% of the thickness of the base paper 1 and 10 μm or more, showed good results in Experiments 1-2. 【0065】 In Example 2, the decorative sheet 10, which used homopolypropylene resin for the thermoplastic resin layer 2 and had a thickness of 52% of the thickness of the base paper 1 and 10 μm or more, showed good results in Experiments 1-2. 【0066】 Comparative Example 1, a decorative sheet in which homopolypropylene resin was used as the material for the thermoplastic resin layer, and the thickness of the thermoplastic resin layer was 86% of the thickness of the base paper and 10 μm or more, failed Experiment 2. 【0067】 Comparative Example 2, a decorative sheet in which random polypropylene resin was used as the material for the thermoplastic resin layer, and the thickness of the thermoplastic resin layer was 52% of the thickness of the base paper and 10 μm or more, failed Experiment 1. 【0068】 Comparative Example 3, a decorative sheet in which block polypropylene resin was used as the material for the thermoplastic resin layer, and the thickness of the thermoplastic resin layer was 52% of the thickness of the base paper and 10 μm or more, failed Experiment 1. 【0069】 Comparative Example 4, a decorative sheet in which homopolypropylene resin was used as the material for the thermoplastic resin layer, and the thickness of the thermoplastic resin layer was 26% of the thickness of the base paper and less than 10 μm, failed Experiment 1. 【0070】 Comparative Example 5, a decorative sheet in which homopolypropylene resin was used as the material for the thermoplastic resin layer, and the thickness of the thermoplastic resin layer was 18% of the thickness of the base paper and 10 μm or more, failed Experiment 1. 【0071】 Comparative Example 6, a decorative sheet in which low-density polyethylene resin was used as the material for the thermoplastic resin layer, and the thickness of the thermoplastic resin layer was 52% of the thickness of the base paper and 10 μm or more, failed in Experiment 1 and Experiment 2. 【0072】 Comparative Example 7, a decorative sheet in which a medium-density polyethylene resin was used as the material for the thermoplastic resin layer, and the thickness of the thermoplastic resin layer was 52% of the thickness of the base paper and 10 μm or more, failed in Experiment 1 and Experiment 2. 【0073】 Comparative Example 8, a decorative sheet in which high-density polyethylene resin was used as the material for the thermoplastic resin layer, and the thickness of the thermoplastic resin layer was 52% of the thickness of the base paper and 10 μm or more, failed in Experiment 1 and Experiment 2. 【0074】 As shown in Table 1, a decorative sheet 10 comprising a thermoplastic resin layer 2 containing homopolypropylene resin, having a thickness of 10 μm or more and being between 20% and 80% of the thickness of the base paper 1, exhibits excellent surface strength and can suppress the occurrence of curling. 【0075】 [Table 1] [Explanation of symbols] 【0076】 100 decorative panels 10 Decorative sheets 1 Base paper 2 Thermoplastic resin layer 2s Top surface of thermoplastic resin layer 3. Base coloring layer 4 Pattern Layers 5. Matte layer 6 Surface protective layer 20 Base material V vertical direction UP upper side LO (lower side)

Claims

[Claim 1] The original paper and A thermoplastic resin layer provided on the upper side of the base paper, A pattern layer provided on the upper side of the thermoplastic resin layer, Equipped with, The thermoplastic resin layer is Having a thickness of 20% to 80% of the thickness of the base paper, and a thickness of 10 μm or more. Contains homopolypropylene resin, Decorative sheet. [Claim 2] A base coloring layer containing an isocyanate curing agent is provided between the thermoplastic resin layer and the pattern layer, The thermoplastic resin layer is subjected to corona treatment on the upper surface on which the base coloring layer is provided. The decorative sheet according to claim 1. [Claim 3] A matte layer provided on the upper side of the patterned layer, A surface protective layer is provided above the matte layer and at a position synchronized with the pattern of the patterned layer, and having a gloss different from that of the matte layer. Equipped with, The matte layer and the surface protective layer include a urethane resin. The decorative sheet according to claim 2. [Claim 4] A decorative sheet according to any one of claims 1 to 3, A base material is adhered to the lower side of the decorative sheet, Equipped with, Decorative panel.

Images