Decorative sheet

Abstract

To provide a decorative sheet that allows information of a display device to be visible when the display device emits light, can securely conceal the display device when the display device does not emit light, and is suitable for vehicle interior materials requiring high designability.SOLUTION: A decorative sheet has an opaque colored layer. The decorative sheet is constituted by forming a plurality of holes with aperture area of 0.007 to 0.13 mm2 in a thickness direction of the decorative sheet. It is preferable that a fiber fabric substrate is disposed on a rear surface of the opaque colored layer and that total light transmittance of the decorative sheet is 20% or less.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a decorative sheet, and more particularly to a decorative sheet that is disposed so as to cover the surface of a display device.

[0002] 2. Description of the Related Art Decorative panels using decorative sheets as skin materials are used in automobile cabins and the like to give a sense of luxury. Meanwhile, the instrument panel at the driver's seat is equipped with a wide variety of functional parts and display devices, such as gauges such as the speedometer and tachometer, switches for the air conditioner, window opening and closing, door lock, etc., a car navigation system, an external monitor, lighting, etc. Therefore, even if a decorative panel using a decorative sheet as the skin material is adopted, most of the area around the driver's seat is occupied by functional parts and display devices, making it difficult to achieve a sense of luxury.

[0003] An invention is known in which a decorative sheet with adjusted visible light transmittance is attached to a display device so that the display portion is visible when the display device is illuminated and the entire display portion is concealed when the display device is not illuminated, thereby presenting an appearance decorated by the decorative sheet. However, in order to ensure concealment when not emitting light, the color tone of the decorative sheet is limited to black, and when the interior of the vehicle is bright, the decorative sheet cannot completely conceal the display device, allowing it to be seen through (Patent Document 1, etc.). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-144511 A Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention aims to provide a decorative sheet which, when covering a display device, allows information on the display device to be viewed when the display device is emitting light, and reliably conceals the display device when the display device is not emitting light. [Means for solving the problem]

[0006] The inventors conducted intensive research to solve the above problems, and invented a decorative sheet that, by forming a plurality of microscopic holes that are invisible or difficult to see with the naked eye, allows the information on the display device to be seen when the display device is emitting light, and reliably conceals the display device when the display device is not emitting light.

[0007] The present invention relates to the following. (1) A decorative sheet having an opaque colored layer, the opening area of ​​which is 0.007 to 0.13 mm in the thickness direction of the decorative sheet. 2 A decorative sheet having a plurality of holes formed therein. (2) The decorative sheet according to (1), characterized in that a fiber fabric substrate is provided on the back surface of the opaque colored layer. (3) The decorative sheet according to (1) or (2), characterized in that the total light transmittance is 20% or less. (4) The decorative sheet according to (1) or (2), which is used as a skin material for covering a display device. Effect of the Invention

[0008] The present invention can provide a decorative sheet that, by forming a plurality of micropores that are invisible or difficult to see with the naked eye, allows the information on the display device to be visible when the display device is emitting light, and can reliably conceal the display device when the display device is not emitting light. Therefore, it can be ideally used as an interior material for vehicles, where high design quality is required. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic plan view of a decorative sheet according to the present invention; [Diagram 2] 1 is a schematic cross-sectional view of a decorative sheet of the present invention. [Diagram 3] FIG. 2 is a partially enlarged schematic cross-sectional view of the decorative sheet of the present invention. [Figure 4] FIG. 2 is an image diagram showing the outline of a logo designed with holes in a decorative sheet in an embodiment. [Diagram 5] 1 is an image showing the results of the [Clarity] test of Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The decorative sheet of the present invention will be described with reference to Figures 1 to 5. Figures 2 and 3 are cross-sectional views of the decorative sheet cut in the thickness direction. Figure 3 is a partially enlarged view of Figure 2. In this specification, "decoration" refers to a decorative appearance such as leather, woodgrain, geometric, or fabric look. In this specification, the term "display device" is a general term indicating anything that has a light-emitting component, and includes the light-emitting component itself, such as a light.

[0011] The decorative sheet of the present invention has an opaque colored layer, and the opening area in the thickness direction of the decorative sheet is 0.007 to 0.13 mm 2 A plurality of holes are formed. Opening area is 0.007mm 2 With a hole of this size, the light emitted from the display device can pass through and the information on the display device can be seen. 2 Holes of the following sizes are difficult to see from close range, and it is extremely difficult for the human eye to distinguish between the holes and other parts at a distance of 50 cm from the holes. Therefore, for example, when a display device installed on the instrument panel of a vehicle is covered with the decorative sheet of the present invention, when the display device is not emitting light, passengers cannot see the display device provided on the back side of the decorative sheet, nor the holes formed in the decorative sheet. Therefore, the vehicle interior becomes a space with a high-class feel and excellent design. On the other hand, when the display device emits light, the light passes through the holes formed in the decorative sheet, allowing occupants to confirm the information on the display device without impeding the original function of the display device. Considering the visibility of the hole, the concealment when the display device is not emitting light, and the clarity of the information on the display device when the display device is emitting light, the opening area of ​​the hole is 0.017 to 0.05 mm 2 It is preferable that:

[0012] The holes can be formed by a conventionally known means such as drilling, discharge, or laser irradiation. The shape of the hole is not particularly limited, and any shape such as a circle, an ellipse, a polygon, etc. can be selected, but from the viewpoint of the abrasion resistance of the decorative sheet, a shape without corners such as a circle, an ellipse, etc. When the hole is a circle, the hole diameter φ is 0.1 to 0.4 mm, preferably 0.15 to 0.25 mm.

[0013] The holes may be arranged regularly or randomly, and may be provided over the entire surface of the decorative sheet or may be provided partially.

[0014] The opening area of ​​the hole does not need to be constant in the thickness direction, and the maximum opening area is 0.007 to 0.13 mm. 2 For example, the cross section of the hole may be trapezoidal or conical. With this configuration, it is possible to provide a decorative sheet that allows the information on the display device to be viewed when the display device is emitting light, and can reliably conceal the display device when the display device is not emitting light.

[0015] The holes are not necessarily limited to through holes. For example, the effect of the present invention can be obtained even in a case where the transparency of the front side of the decorative sheet is increased and non-through holes are formed from the back side, or the transparency of the back side of the decorative sheet is increased and non-through holes are formed from the front side. Considering the clarity of the light emitted from the display device, through holes are preferable.

[0016] The distance between adjacent holes is not limited, but is preferably 0.1 mm or more. If the distance is less than 0.1 mm, there is a concern that the mechanical strength of the decorative sheet, such as abrasion resistance and tensile strength, may decrease.

[0017] [Opaque colored layer] The decorative sheet of the present invention has an opaque colored layer. The opaque colored layer is added with a pigment to color the decorative sheet opaquely. The amount of pigment added is not particularly limited, but is preferably 0.5 to 30 parts by mass with respect to 100 parts by mass of the synthetic resin forming the opaque colored layer.

[0018] The synthetic resin constituting the opaque colored layer may be any resin that can be used in ordinary decorative sheets, but polyurethane resins and polyvinyl chloride resins are preferred.

[0019] Specific examples of the polyurethane resin include polyester polyurethane resin, polyether polyurethane resin, polycaprolactone polyurethane resin, polyester / polyether copolymer polyurethane resin, polyamino acid / polyurethane copolymer resin, and non-yellowing polycarbonate polyurethane resin obtained by reacting a polycarbonate diol component with a non-yellowing diisocyanate component and a low molecular chain extender, etc. In addition, polyvinyl chloride resin, synthetic rubber, etc. may be mixed with the polyurethane resin as long as the physical properties as a decorative sheet are not impaired.

[0020] As the vinyl chloride resin, specifically, polyvinyl chloride, a copolymer of a vinyl chloride monomer with another monomer copolymerizable therewith, or a blend of these resins can be used. Examples of other monomers copolymerizable with the vinyl chloride monomer include ethylene, propylene, vinyl acetate, vinylidene chloride, acrylic acid, acrylic acid esters, methacrylic acid, methacrylic acid esters, maleic acid, and acrylonitrile fumarate.

[0021] When the opaque colored layer is made of polyvinyl chloride resin, a plasticizer is blended together with the polyvinyl chloride resin in order to more effectively exhibit flexibility similar to that of natural leather. Examples of the plasticizer include general phthalate ester plasticizers such as dioctyl phthalate (DOP), diisononyl phthalate (DINP), butyl benzyl phthalate (BBP), diisodecyl phthalate (DIDP), and diundecyl phthalate (DUP); general fatty acid ester plasticizers such as dioctyl adipate (DOA), dioctyl sebacate (DOS), and dioctyl azelaate (DOZ); polymer plasticizers such as trioctyl trimellitate plasticizers and adipic acid polyester plasticizers such as polypropylene adipate; sebacic acid plasticizers; and phosphate ester plasticizers such as tricresyl phosphate (TCP), trixylenyl phosphate (TXP), tris(isopropylphenyl)phosphate, tributyl phosphate, triethyl phosphate, triphenyl phosphate, and triethylphenyl phosphate.

[0022] In addition to the above, the opaque colored layer may contain various additives such as a filler, a dispersant, an antifoaming agent, a matting agent, and a lubricant.

[0023] A fiber fabric substrate is preferably provided on the back surface of the opaque colored layer. The decorative sheet of the present invention is used to cover a display device, thereby exhibiting concealment when the display device is not emitting light and visibility when the display device is emitting light. When covering a display device with a decorative sheet, it is necessary to make the sheet conform to the curved surface and unevenness of the display device. In this case, the decorative sheet is stretched, and there is a concern that the opening area of ​​the holes may be expanded or the shape of the holes may become distorted. This makes the holes more visible, impairing the design. By providing a fiber fabric substrate on the back surface of the opaque colored layer, the stretching of the decorative sheet is suppressed, and problems such as an increase in the opening area of ​​the holes or irregular shapes of the holes can be eliminated. In order to ensure mechanical strength, it is also preferable that a fiber fabric substrate is provided on the back surface of the opaque colored layer.

[0024] [Textile fabric base material] The fabric constituting the fiber fabric substrate is not particularly limited, and may be any fabric using fibers, such as knitted fabric, woven fabric, nonwoven fabric, etc. The fibers forming the fiber fabric substrate are not particularly limited, and may be synthetic fibers, natural fibers, etc. Examples of the synthetic fiber material include, but are not limited to, polyester, polyamide, acrylic, nylon, etc. Examples of the natural fiber material include, but are not limited to, cotton, linen, rayon, etc. The thickness of the fiber fabric substrate is not particularly limited, but considering the mechanical strength and texture of the decorative sheet, the thickness is preferably 100 μm or more and 2000 μm or less, and more preferably 500 μm or more and 1200 μm or less. The basis weight of the fiber fabric substrate is also not particularly limited, but considering the mechanical strength and texture of the decorative sheet, similarly to the thickness, the basis weight is preferably 10 g / m or more and 10 g / m or less. 2 More than 500g / m 2 It is preferable that the thickness is less than 100 g / m 2 More than 400g / m 2 It is more preferable that:

[0025] The decorative sheet and the fiber fabric substrate are joined via an adhesive layer. The adhesive layer is preferably formed by soaking a part of the composition constituting the adhesive layer into the fiber fabric substrate described below. Since the decorative sheet of the present invention can prevent fluffing of the fiber fabric substrate from the holes by soaking a part of the composition constituting the adhesive layer into the fiber fabric substrate in the thickness direction of the decorative sheet, light emitted by the display device can be clearly viewed without blurring.

[0026] Since the decorative sheet of the present invention needs to have a concealing property when the display device is not emitting light, it is preferable that the thickness of the opaque colored resin layer is large. On the other hand, if the thickness of the opaque colored layer is large, the weight of the decorative sheet increases. In order to suppress the increase in weight and increase the thickness, it is preferable to form a foamed adhesive layer by foaming the adhesive layer, or to provide a foamed layer between the opaque colored layer and the adhesive layer. Means for forming a foamed layer include physical foaming by mechanical stirring, chemical foaming by adding a foaming agent, and pseudo-foaming by adding hollow fine particles. The foaming ratio of the foamed adhesive layer and the foamed layer is preferably 1.3 to 2.0 times, which ensures the mechanical strength of the decorative sheet while providing an effect of increasing the thickness and reducing the weight.

[0027] [Surface treatment layer] The decorative sheet of the present invention may have a surface treatment layer provided on the opaque colored layer. The surface treatment layer is provided for the purpose of making the decorative sheet glossy / matte, imparting abrasion resistance, imparting a tactile feel, imparting antifouling properties, etc. The surface treatment layer can be provided by coating the surface of the skin layer with a coating liquid in which a polyurethane resin is dispersed in an organic solvent or water, for example.

[0028] A primer layer may be provided between the surface treatment layer and the synthetic resin layer in order to improve adhesion between them. The surface treatment layer and the primer layer may contain known additives such as pigments, antioxidants, ultraviolet absorbers, catalysts, inorganic fine particles such as silica, and organic fillers.

[0029] The decorative sheet of the present invention preferably has a total light transmittance of 20% or less. Here, the total light transmittance refers to the total light transmittance of the portion of the decorative sheet where no holes are formed, and is measured in accordance with JIS K7375. If the total light transmittance is 20% or less, when the display device emits light, light is less likely to transmit through the areas where no holes are formed, and only the areas with holes become clear, resulting in a good appearance. For example, if the entire or outline of a logo or mark is formed using holes in the decorative sheet, when light is emitted from the backside, only the holes will transmit light, while areas other than the holes will be restricted from transmitting light, making the logo or mark stand out clearly, resulting in a highly aesthetic skin material (see Figure 5). The closer the total light transmittance is to 0%, the better the above effects are exhibited, so the total light transmittance is more preferably 2% or less.

[0030] The decorative sheet of the present invention has been described above. The decorative sheet of the present invention can be used for various purposes, but is particularly suitable as a skin material for vehicle interiors that require design, particularly for instrument panels. EXAMPLES

[0031] The present invention will be described in detail below with reference to examples. The present invention is not limited to these examples, and various applications are possible within the scope of the technical concept of the present invention.

[0032] Example 1 A vinyl chloride paste for the surface layer (vinyl chloride product name: PSH24, manufactured by Kaneka Corporation) containing black pigment (5 parts by mass per 100 parts by mass of vinyl chloride paste) and plasticizer was applied onto release paper to a dry thickness of 200 μm, and heated at a temperature of 180°C for 2 minutes to gel (resinify), forming an opaque colored layer. Next, a vinyl chloride paste (vinyl chloride product name: PQHPN, manufactured by Shin-Daiichi Vinyl Co., Ltd.) containing a foaming agent, black pigment (0.5 parts by mass per 100 parts by mass of vinyl chloride paste) and a plasticizer was applied to a dry thickness of 200 μm, and heated at a temperature of 200° C. for 2 minutes to cause gelation (resinification) and foaming, forming a foam layer. Next, a vinyl chloride paste containing a plasticizer for the adhesive layer (vinyl chloride manufactured by Shin-Daiichi Vinyl Co., Ltd., product name: PQHPN) was applied at a rate of 100 g / m 2 Immediately after application, a knitted fabric was attached and heated at 180°C for 2 minutes to cause gelation (resinification), after which the release paper was peeled off to obtain a decorative sheet. The obtained decorative sheet was subjected to a drilling process from the front side to form multiple through holes with the outline of the logo shown in Figure 4. The opening area of ​​the through holes was 0.017 mm 2 The distance between each circular hole and the adjacent hole was 1.0 mm. The total light transmittance of the decorative sheet before drilling was 0.01%. The total light transmittance was measured in accordance with JISL7375 using a haze meter (manufactured by Suga Test Instruments Co., Ltd., product name "HZ-V3").

[0033] Example 2 The through hole has an opening area of ​​0.05 mm 2 A decorative sheet was obtained in the same manner as in Example 1, except that the shape was changed to a circular shape.

[0034] Example 3 The through hole has an opening area of ​​0.007 mm 2 A decorative sheet was obtained in the same manner as in Example 1, except that the shape was changed to a circular shape.

[0035] Example 4 The through hole has an opening area of ​​0.13 mm 2 A decorative sheet was obtained in the same manner as in Example 1, except that the shape was changed to a circular shape.

[0036] Example 5 A decorative sheet was obtained in the same manner as in Example 1, except that the amount of the black pigment added was reduced from 5 parts by mass to 0.2 parts by mass. The total light transmittance of the decorative sheet before drilling was 20.7%. The total light transmittance was measured in accordance with JISL7375 using a haze meter (manufactured by Suga Test Instruments Co., Ltd., product name "HZ-V3").

[0037] Comparative Example 1 A decorative sheet was obtained in the same manner as in Example 1, except that no through holes were formed.

[0038] Comparative Example 2 A decorative sheet was obtained in the same manner as in Example 1, except that no pigment was added and the opaque colored layer was a colorless and transparent layer instead of an opaque colored layer.

[0039] Comparative Example 3 The through hole has an opening area of ​​0.004 mm 2 A decorative sheet was obtained in the same manner as in Example 1, except that the shape was changed to a circular shape.

[0040] Comparative Example 4 The through hole has an opening area of ​​0.5 mm 2 A decorative sheet was obtained in the same manner as in Example 1, except that the shape was changed to a circular shape.

[0041] The following evaluations were carried out on the decorative sheets obtained in Examples 1 to 5 and Comparative Examples 1 to 4. The evaluation results are shown in Table 1.

[0042] [Hole visibility] The appearance of the resulting decorative sheet was visually observed and evaluated according to the following criteria. ○: No holes visible when observed from a distance of 10 cm △: The holes are visible when observed from a distance of 10 cm, but not visible when observed from a distance of 50 cm. ×: Holes visible from a distance of 50 cm

[0043] A test panel was created by embedding a 1,700 lumen LED light with a light-emitting surface outer diameter of φ190mm (light-emitting part: φ105mm) in the center of a resin board 300mm long and 300mm wide. The resin board and the embedded LED light were created so that they were flush with each other. The test plate was covered with each decorative sheet, and the "concealment ability", "transparency", and "shape" were evaluated according to the following criteria. Note that the "shape" was only tested for Example 1 and Example 5.

[0044] [Concealment] With the LED light turned off, the test panel was visually observed from a distance of 10 cm and 50 cm. The test was performed at 13:00 on a sunny day, without direct sunlight. ○: The appearance of the LED light part and the other parts is the same at both distances of 10 cm and 50 cm. △: At a distance of 50 cm, there is no difference in appearance between the LED light part and the other parts, but at a distance of 10 cm, the LED light part appears slightly brighter than the other parts. ×: The LED light appears slightly brighter than the rest of the area at both 10cm and 50cm distances

[0045] [Transparency] With the LED light turned on, the test plate was visually observed from a distance of 10 cm and a distance of 50 cm. ○: The light from the LED light was visible from both a distance of 10 cm and a distance of 50 cm △: The light from the LED light part was felt at a distance of 10 cm, but the light from the LED light part was not felt at a distance of 50 cm. ×: The light from the LED light was not visible at a distance of 10 cm or 50 cm.

[0046] [Clarity] The test plates using the decorative sheets of Examples 1 and 5 were visually observed from a distance of 30 cm with the LED light turned on. 〇: The outline of the logo can be clearly seen △: The outline of the logo can be seen, but the boundary between the hole and the non-hole portion appears blurred. FIG. 5 shows images of the test plate using the decorative sheet of Example 1 when the LED light is off and when the LED light is on.

[0047] [Table 1]

[0048] From the results of the Examples and Comparative Examples, it is evident that the decorative sheet of the present invention enables information on a display device to be viewed when the display device is emitting light, and can reliably conceal the display device when the display device is not emitting light. [Explanation of symbols]

[0049] 10...opaque colored layer 20...Foam layer 30...adhesive layer 40... Textile fabric base material 50...hole 100··Decorative sheet

Claims

1. A decorative sheet having an opaque colored layer, The opening area in the thickness direction of the decorative sheet is 0.007 to 0.13 mm ２ A decorative sheet having a plurality of holes formed therein.

2. 2. The decorative sheet according to claim 1, further comprising a fiber fabric substrate provided on the back surface of the opaque colored layer.

3. 3. The decorative sheet according to claim 1, wherein the decorative sheet has a total light transmittance of 20% or less.

4. 3. The decorative sheet according to claim 1, which is used as a skin material for covering a display device.

Images