Decorative sheet, its manufacturing method and decorative board using same

Abstract

To provide a decorative sheet capable of preventing weather resistance deterioration of a colored ink layer, a method for manufacturing the same, and a decorative board using the same.SOLUTION: There is provided a decorative sheet, comprising: a base material 11; a colored ink layer 12 formed by directly applying a mixed solution containing a coloring ink and 20 pts.wt. or more and 50 pts.wt. or less of titanium oxide based on 100 pts.wt. of the coloring ink to a surface of the base material 11; and a surface protective layer 13 directly applied to the surface of the colored ink layer 12 to protect the surface. Thickness of the colored ink layer 12 may be 3 μm or more and 10 μm or less, the base material 11 is a thermoplastic resin, and embossing may be formed on the surface of the base material between the same and the colored ink layer 12, and a primer layer may be formed on a back surface of the base material 11 to increase adhesion to the base material to be attached to the back surface.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a decorative sheet capable of preventing deterioration of the weather resistance of a colored ink layer, a manufacturing method thereof, and a decorative board using the same. [Background technology]

[0002] Conventionally, a colored ink layer is formed on the surface of a substrate, and a surface protective layer is further formed on the surface of the colored ink layer to protect the colored ink layer. However, when the coating of the surface protective layer had minor pinholes such as holes, the colored ink layer was exposed to direct light and moisture, causing embrittlement and a decrease in cohesive strength of the colored ink layer, resulting in significant deterioration.

[0003] Further, polyolefin-based decorative sheets in which a transparent resin coating layer is laminated on a picture design layer have been conventionally known (see paragraph

[0020] and FIG. 2 of Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2000-211079 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in contrast to conventional surface protective layers, a thermoplastic transparent PP layer can be laminated on the surface of the colored ink layer to prevent deterioration of the colored ink layer, but this creates the problem of high costs in areas where it is used and in the market for monochrome sheets. In addition, in order to apply the surface protective layer without any gaps such as pinholes, a smoothing roll can be used; however, smoothing rolls pose productivity issues as they can cause the resin to accumulate or become streaked, making it impossible to apply the layer completely without any gaps.

[0006] On the other hand, in the ink of Patent Document 1, a colored solid print layer is formed under the picture pattern layer, and 20 parts by weight of titanium oxide is added to the colored solid print layer per 100 parts by weight of the ink resin (see paragraph

[0025] and Figure 2 of Patent Document 1). However, the colored solid print layer in Patent Document 1 is located above the primer layer, i.e., between the primer layer and the picture pattern layer, and is intended to ensure long-term stability of adhesion by preventing harmful light from reaching the area where the primer is located (paragraph 1 of Patent Document 1:

[0007] , and FIG. 2). In this sense, the invention of Patent Document 1 aims to address the problem of weather resistance deterioration of the colored ink layer, whereas the invention of the present invention aims to address a different problem. Therefore, in order to solve the above problems, one aspect of the present invention aims to provide a decorative sheet that can prevent weather deterioration of a colored ink layer, a manufacturing method thereof, and a decorative board using the same. [Means for solving the problem]

[0007] A decorative sheet according to one embodiment of the present invention is characterized in that it comprises a substrate, a colored ink layer formed by directly applying a mixed liquid containing a colored ink and 20 parts by weight or more and 50 parts by weight or less of titanium oxide per 100 parts by weight of the colored ink to the surface of the substrate, and a surface protection layer formed by directly applying a mixed liquid to the surface of the colored ink layer to protect the surface. In addition, the decorative sheet according to one embodiment of the present invention is characterized in that the colored ink layer has a thickness of 3 μm or more and 10 μm or less.

[0008] A decorative sheet according to one aspect of the present invention is characterized in that the substrate is made of a thermoplastic resin, and an embossment is formed between the surface and the colored ink layer. The decorative sheet according to one aspect of the present invention is characterized in that a primer layer is formed on the back surface of the base material in order to enhance adhesion to a substrate to be attached to the back surface. The decorative sheet according to one embodiment of the present invention is characterized in that the surface protective layer is made of any one of three resins: a thermosetting resin, an ultraviolet-curable resin, or an electron beam-curable resin, or a mixture of two or more of the three resins.

[0009] A method for producing a decorative sheet according to one embodiment of the present invention is characterized in that a mixed liquid containing a colored ink and 20 parts by weight or more of titanium oxide per 100 parts by weight of the colored ink is directly applied to the surface of a substrate to form a colored ink layer, and a surface protection layer for protecting the surface is directly formed on the surface of the colored ink layer. A decorative board according to one aspect of the present invention is characterized by comprising a substrate and a decorative sheet attached to the substrate via a primer layer. Effect of the Invention

[0010] According to one aspect of the present invention, it is possible to provide a decorative sheet capable of preventing deterioration of the weather resistance of a colored ink layer, a manufacturing method thereof, and a decorative board using the same. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view of a decorative sheet according to a first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] (Decorative sheet 10) In FIG. 1, 10 denotes a decorative sheet according to the first embodiment, which is for interior use and is primarily monochrome and has a white color. Although a single color has been exemplified, the present invention is not limited to this and multiple colors may be used. Also, although a white-based color has been exemplified as a single color, other colors may be used.

[0013] The decorative sheet 10 is formed from the following layers: The following (1) to (4) will be discussed later. (1) Base material 11 (2) Colored ink layer 12 (3) Surface protective layer 13 (4) Primer layer 14 The layers of the decorative sheet 10 are not limited to the four layers (1) to (4) described above. For example, although not shown, the back side of the base material 11 may be fixed to a substrate via a primer layer 14 to form a five-layer decorative plate.

[0014] (Base material 11) The substrate 11 is a sheet containing a thermoplastic resin. The thermoplastic resin may be a polyester resin. Specifically, polyethylene terephthalate, polybutylene terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene naphthalate, polylactic acid, or the like may be used.

[0015] Further, although not shown, the front surface side of the base material 11 has an embossed portion, for example, a matte embossed portion. The embossing is provided as necessary to impart a three-dimensional design to the surface side of the substrate 11. The embossing is not limited to a matte finish, and any uneven shape can be used, such as a wood grain duct shape, a stone grain shape, a cloth grain shape, an abstract pattern shape, a Japanese paper shape, a suede shape, a leather shape, a sand grain shape, a hairline shape, a group of parallel straight lines, a group of parallel curved lines, or a combination thereof. In addition, as a method for forming the embossing, for example, a doubling embossing method, an extrusion lamination simultaneous embossing method, etc., which are performed before, after, or simultaneously with lamination of a thermoplastic resin layer on the surface of the substrate 11, can be used.

[0016] (Colored ink layer 12) The colored ink layer 12 is formed by directly applying a mixture containing a colored ink and 20 parts by weight or more of titanium oxide to 100 parts by weight of the colored ink onto the front surface side of the substrate 11 . The amount of titanium oxide blended is preferably 20 parts by weight or more and 50 parts by weight or less, and more preferably 25 parts by weight or more. The thickness of the colored ink layer 12 is preferably, for example, from 3 μm to 10 μm, and in actual use, it is preferably from 5 μm to 7 μm.

[0017] Titanium oxide includes, for example, titanium dioxide TiO 2 A white pigment consisting of the above and having an average particle size of about 0.1 to 0.5 μm can be used, and examples of commercially available products that can be used include KR-310 manufactured by Titan Kogyo Co., Ltd., JR manufactured by Teikoku Kako Co., Ltd., FR-41 manufactured by Furukawa Mining Co., Ltd., and CR-50 manufactured by Ishihara Sangyo Co., Ltd. Titanium oxide includes anatase type (also known as anatase) and rutile type (also known as rutile), which have refractive indices of 2.45 to 2.55 and 2.61 to 2.90, respectively, and the rutile type is preferred because it has a higher refractive index, is excellent in hiding power, and is also excellent in chemical stability and light resistance. Furthermore, in addition to the above-mentioned effects of imparting hiding power and coloring, titanium oxide also has the effect of improving adhesion to the substrate 11 due to its anchoring effect.

[0018] As for materials other than titanium oxide, opaque inks such as carbon black can also be expected to be effective, but since single-color sheets tend to be whitish in color, titanium oxide was selected. In addition, the colored ink layer 12 is assumed to be a single color (ivory), and if the base material 11 has, for example, a matte embossing, it is thought that unless a large amount of ink is applied and the titanium oxide is highly loaded, unevenness will become noticeable, making it even more difficult to apply patterns.

[0019] In addition to the titanium oxide pigments described above, the colored ink layer 12 may contain a small amount of other pigments (for example, opaque or non-opaque inorganic or organic pigments) for the purpose of adjusting the color tone. However, it is essential that the titanium oxide pigment is the main component, and the amount of other pigments used is preferably 20 mass % or less based on the total amount of pigments. In addition, it is preferable to select a pigment with high light resistance as the combined pigment, and among inorganic pigments, cobalt blue and carbon black are more preferable, and among organic pigments, phthalocyanine pigments such as phthalocyanine blue are more preferable. In addition, extender pigments such as silica, calcium carbonate, barium sulfate, etc. can also be used as necessary.

[0020] (Surface protective layer 13) The surface protective layer 13 is provided on the surface side of the colored ink layer 12, and is a layer for protecting the colored ink layer 12 and imparting good surface properties such as abrasion resistance, solvent resistance, etc. As a material for the surface protective layer 13, for example, a resin having high transparency is preferable, but any resin having transparency at least to the extent that the embossment of the substrate 11 can be seen through the colored ink layer 12 may be used, and to that extent, a translucent or colored transparent resin may be used.

[0021] (Primer layer 14) The primer layer 14 is applied as necessary in order to improve adhesion with an adhesive used to bond the base material 11 to a substrate (not shown) to which the base material 11 is attached. For example, when the substrate is made of a wood-based material, a vinyl acetate emulsion adhesive, a two-component curing urethane adhesive, or the like is used as the adhesive, and therefore it is desirable to design the primer layer 14 with a resin that matches these adhesives. For example, urethane, acrylic, ethylene-vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer, polyester, or the like can be used. In particular, a two-component curing urethane primer made by blending polyester polyol with polyisocyanate is preferable. In addition, the addition of inorganic powders such as silica, barium sulfate, and calcium carbonate is effective in preventing blocking during storage in a roll and improving adhesive strength by the anchoring effect.

[0022] (Manufacturing method) The decorative sheet 10 having the above-mentioned configuration is provided in the following order. (1) Primer layer 14 (2) Base material 11 (3) Colored ink layer 12 (4) Surface protective layer 13

[0023] (Effects of the first embodiment) The effects of the first embodiment are as follows. First, according to the first embodiment, by containing 20 to 50 parts by weight of titanium oxide in the colored ink layer 12, as described below, ink peeling can be suppressed in a Cellophane Tape (registered trademark) adhesion test after a weather resistance test, and embrittlement and loss of adhesion due to weather resistance deterioration can be prevented. Secondly, according to the first embodiment, it is possible to manufacture the product at low cost without providing a thermoplastic transparent PP layer on the surface side of the colored ink layer 12. Thirdly, according to the first embodiment, when the base material 11 has an embossed texture such as a matte finish, it is difficult to apply the colored ink evenly, which can result in unevenness. However, the inclusion of titanium oxide provides hiding power, making the unevenness less noticeable.

[0024] (Decorative board) Although not shown, a decorative board according to a second embodiment will be described. The decorative plate is formed by attaching a substrate (not shown) to the back side of the primer layer 14 of the decorative sheet 10 having the above-mentioned structure. The substrate is a plate-like member attached via an adhesive. For example, a substrate made of a wood-based material, a metal-based material, or a synthetic resin material can be used as the substrate. For example, a wooden veneer, a wood plywood, a laminated lumber, a particle board, a medium density fiberboard, or a hard fiberboard can be used as the substrate made of a wood-based material. For example, a steel plate, a brass plate, an aluminum plate, a duralumin plate, or a stainless steel plate can be used as the substrate made of a metal-based material. For example, a polyvinyl chloride resin plate, an acrylic resin plate, or a polyolefin-based resin plate (such as a polypropylene resin plate or a polyethylene resin plate) can be used as the substrate made of a synthetic resin material. EXAMPLES

[0025] Below, examples 1 and 2 of the wood base material according to the first embodiment of the present invention, and comparative examples 1 and 2 are described. Note that the present invention is not limited to the following examples 1 and 2.

[0026] Example 1 In Example 1, a decorative sheet was produced using the following materials and procedures. A pigmented random polypropylene sheet (manufactured by RIKEN TECHNOS CORPORATION) with a thickness of 100 μm and an embossing depth of 25 μm was used as the substrate, and a monochrome (ivory) colored ink layer was formed by gravure printing using urethane ink (Lamistar manufactured by Toyo Ink Mfg. Co., Ltd.). The urethane ink contains 20 parts by weight of titanium oxide. The colored ink layer was formed to have a thickness of 5 to 7 μm. Furthermore, a thermosetting resin (urethane acrylate resin manufactured by DIC Graphics) was applied to a thickness of 5 μm to form a surface protective layer.

[0027] Example 2 Example 2 is the same as Example 1, except that the titanium oxide in the urethane ink was 50 parts by weight. Example 3 Example 3 is the same as Example 1, except that the titanium oxide in the urethane ink was 25 parts by weight.

[0028] Example 4 In Example 4, the titanium oxide of the urethane ink was 25 parts by weight, and the colored ink layer was formed to a thickness of 3 μm, and the rest was the same as Example 1. Example 5 In Example 5, the titanium oxide of the urethane ink was 25 parts by weight, and the colored ink layer was formed to a thickness of 10 μm, and the rest was the same as Example 1.

[0029] Comparative Example 1 Comparative Example 1 is the same as Example 1, except that the content of titanium oxide was 15 parts by weight. Comparative Example 2 Comparative Example 2 is the same as Example 1, except that the content of titanium oxide was 55 parts by weight. Comparative Example 3 In Comparative Example 3, the content of titanium oxide was 25 parts by weight, and the colored ink layer was formed to a thickness of 2 μm, and the rest was the same as Example 1.

[0030] (Evaluation method and criteria) The physical properties of the decorative sheet were evaluated based on the following two points: (1) adhesion after SWOM 2000 hours and (2) unevenness evaluation. (After SWOM2000h) The method for evaluating adhesion after 2000 hours of SWOM was to subject the decorative sheets described in Examples 1 and 2 and Comparative Examples 1 and 2 to a sunshine weatherometer test, and after 2,000 hours had passed, they were removed from the test machine, cellophane tape was adhered to the coated portion, and this was then forcefully peeled off in a 45° direction, and the presence and amount of agglomerates of ink and surface protective layer on the cellophane tape side were observed. The evaluation criteria for adhesion after SWOM2000h were three-level, "○", "△", and "×", with "○" being a pass and "△" and "×" being failing.

[0031] (Unevenness evaluation) The unevenness evaluation was performed by visually judging the state of unevenness in the colored ink layer. The evaluation criteria for unevenness were four levels: "◎", "○", "△", and "×". "◎" and "○" were considered pass, while "△" and "×" were considered fail.

[0032] (Evaluation Results) The evaluation results of the decorative sheets are as shown in Table 1 below.

[0033] [Table 1]

[0034] Comparative Example 1 In Comparative Example 1, since the content of titanium oxide was small, the weather resistance of the ink binder deteriorated, and the evaluation after SWOM 2000 hours was "△", which was a failure. As a result, it was inferred that because titanium oxide is an inorganic substance, the higher the content, the less likely weather deterioration will occur. In addition, in Comparative Example 1, when printing on the matte embossed surface of the base material, it was difficult to apply a coating of a uniform thickness to the unevenness, and slight unevenness in film thickness resulted in uneven color tone, resulting in an unevenness evaluation of "△" and thus failure. As a result, it was inferred that if the content of opaque titanium oxide is high, even if there are unevenness in the film thickness, it will not be visible as unevenness in color tone.

[0035] Comparative Example 2 In Comparative Example 2, the ink binder was less affected by weather deterioration due to the high titanium oxide content, but the cohesive force was inherently weak due to the high titanium oxide content, and the adhesion after 2000 hours of SWOM was evaluated as "x", indicating failure. Comparative Example 3 In Comparative Example 3, the unevenness evaluation was rated as "△" and it was unacceptable. As a result, it was presumed that the thickness of the colored ink layer was too thin.

[0036] (Examples 1 to 5) In Examples 1 to 5, both of the physical property evaluations were "passed." As a result, it was estimated that the suitable range of the titanium oxide content is from 20 parts by weight to 50 parts by weight. In particular, in Examples 2 and 3, there was no unevenness in film thickness or color tone, and it was estimated that a titanium oxide content of 25 parts by weight or more and 50 parts by weight or less is desirable. [Explanation of symbols]

[0037] 10 Decorative Sheet 11 Base material 12 Colored ink layer 13 Surface protective layer 14 Primer layer

Claims

1. A substrate; a colored ink layer formed by directly applying a mixed liquid containing a colored ink and titanium oxide in an amount of 20 parts by weight or more and 50 parts by weight or less relative to 100 parts by weight of the colored ink onto a surface of the substrate; a surface protection layer formed by applying directly onto the surface of the colored ink layer to protect the surface; A decorative sheet characterized in that the thickness of the colored ink layer is 3 μm or more and 10 μm or less.

2. The substrate is It is a thermoplastic resin, 2. The decorative sheet according to claim 1, wherein an embossment is formed on the surface between the surface and the colored ink layer.

3. The back surface of the substrate is 3. The decorative sheet according to claim 1, further comprising a primer layer formed on the back surface thereof for improving adhesion to a substrate to be attached thereto.

4. The surface protective layer is The decorative sheet according to any one of claims 1 to 3, characterized in that it is made of one of three resins, namely, a thermosetting resin, an ultraviolet-curable resin, or an electron beam-curable resin, or a mixture of two or more of the three resins.

5. A mixed liquid containing a color ink and 20 parts by weight or more and 50 parts by weight or less of titanium oxide per 100 parts by weight of the color ink is directly applied to the surface of the substrate to form a color ink layer; forming a surface protective layer directly on the surface of the colored ink layer to protect the surface; A method for producing a decorative sheet, characterized in that the thickness of the colored ink layer is 3 μm or more and 10 μm or less.

6. A substrate; A decorative board comprising: the decorative sheet according to any one of claims 1 to 4, attached to the substrate via a primer layer.

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