JP2022161929A - Decorative sheet and decorative laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decorative sheet that has excellent adhesion to a substrate and can be made thinner.

SOLUTION: A decorative sheet 3 has a concealing layer 4, a patterned layer 5, a transparent substrate sheet 6 and a surface protective layer 7 which are laminated in this order. The concealing layer 4 contains a primer agent containing a concealing pigment with a refractive index of 2.0 or more and serves as a primer layer for improving adhesion to the substrate 2.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2023,JPO&INPIT

Description

TECHNICAL FIELD The present invention relates to a decorative sheet and a decorative board.

Conventionally, as a decorative sheet, for example, a pattern layer, a transparent resin layer and a surface protective layer are laminated in this order on the surface side of a base resin layer, and a primer layer is provided on the back side of the base resin layer. There is (for example, see Patent Document 1). In the decorative sheet described in Patent Document 1, the adhesion between the decorative sheet and the substrate can be improved by the primer layer on the back side of the base resin layer.
However, although the decorative sheet described in Patent Literature 1 can improve adhesiveness, the thickness of the decorative sheet is increased, resulting in a problem of reduced flexibility of the decorative sheet.

JP 2017-154389 A

SUMMARY OF THE INVENTION It is an object of the present invention to provide a decorative sheet and a decorative board which have excellent adhesiveness to a substrate and which can be made thinner.

In order to solve the above problems, the decorative sheet of one embodiment of the present invention is a decorative sheet in which (a) a concealing layer, a pattern layer, a transparent substrate sheet and a surface protective layer are laminated in this order, b) The masking layer contains a primer containing a masking pigment having a refractive index of 2.0 or more, and functions as a primer layer for enhancing adhesion to the substrate.
A decorative board according to another aspect of the present invention comprises (a) a substrate made of a wood-based material, a metal-based material, or a synthetic resin, and (b) the above-described decorative sheet attached to the substrate. .

According to the present invention, since the masking layer contains a primer agent, the adhesion to the substrate can be improved. Moreover, since the concealing layer functions as a primer layer, it is not necessary to provide a primer layer separately from the concealing layer, and the decorative sheet can be made thinner. Therefore, it is possible to provide a decorative sheet and a decorative board which have excellent adhesiveness to a substrate and which can be made thinner.

1 is a cross-sectional view showing a decorative sheet and a decorative board according to an embodiment of the present invention; FIG. 2 is a cross-sectional view showing a decorative sheet of Comparative Example 2; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION A decorative sheet and a decorative board according to embodiments of the present invention will be described below with reference to the drawings. In the description of the drawings, the same or similar parts are denoted by the same or similar reference numerals, and in the description of the decorative sheet and the decorative board, redundant description of substantially similar configurations and the like will be omitted. In addition, the present invention is not limited to the following embodiments, and modifications such as design changes can be made based on the knowledge of those skilled in the art. included in the range of Each drawing is appropriately exaggerated to facilitate understanding.

(Constitution)
A decorative board 1 according to an embodiment of the present invention includes a substrate 2 and a decorative sheet 3 attached to the substrate 2 via an adhesive (not shown). As the adhesive, for example, a urethane-based or vinyl-acetate-based adhesive suitable for bonding the substrate 2 and the decorative sheet 3 can be used.
(substrate)
The substrate 2 is a plate-like member attached to the back surface 4b side of the concealing layer 4 of the decorative sheet 3 via an adhesive. As the substrate 2, 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 made of a wood-based material, for example, wood veneer, wood plywood, laminated lumber, particle board, medium-density fiberboard, and hard fiberboard can be employed. Further, as the substrate made of a metallic material, for example, a steel plate, a brass plate, an aluminum plate, a duralumin plate, and a stainless steel plate can be adopted. Furthermore, as the substrate made of a synthetic resin material, for example, a vinyl chloride resin plate, an acrylic resin plate, or a polyolefin resin plate (polypropylene resin plate, polyethylene resin plate, etc.) can be adopted.

(decorative sheet)
The decorative sheet 3 is formed by laminating a masking layer 4, a pattern layer 5, a transparent substrate sheet 6 and a surface protective layer 7 in this order.
(Hiding layer)
The concealing layer 4 is provided on the backmost surface of the decorative sheet 3, and imparts concealing properties necessary for concealing defects such as unfavorable colors and scratches on the surface of the substrate 2 to which the decorative sheet 3 is attached. It is a layer for As a material for the concealing layer 4, for example, a concealing printing ink or coating agent can be used. As a concealing printing ink or coating agent, for example, a fluid composition obtained by mixing a concealing pigment with a binder resin as a dispersion medium and adjusting the viscosity according to the printing or coating method is adopted. can. The flowable composition is required for the target decorative sheet 3 to have a film in which the concealing pigment is dispersed in the binder resin obtained by printing or coating the concealing printing ink or coating agent. Designed for concealment. A solvent may be added as a solvent or a dispersion medium to the fluid composition, if necessary.

As the concealing pigment, for example, a fine powdery pigment having a refractive index higher than that of the binder resin can be used. Direct transmission of light between the front and back surfaces of the decorative sheet 3 can be prevented by the light scattering effect due to the reflection and refraction of light at the interface due to the refractive index difference between the concealing pigment and the binder resin, thereby improving the concealing property. can be expressed. The refractive index of the concealing pigment is preferably 2.0 or more because the refractive index of general binder resins is around 1.5. Moreover, the particle size of the concealing pigment is preferably in the range of 0.1 μm or more and 1 μm or less from the viewpoint of light (visible light) scattering ability.
As fine powdery pigments, for example, organic pigments and inorganic pigments can be used. In particular, inorganic pigments are preferable from the viewpoint of high refractive index and hiding properties. With inorganic pigments, a relatively thin printing or coating film can sufficiently achieve a very high level of hiding power required by the application of the decorative sheet 3 . Inorganic pigments are excellent in light resistance (fastness against fading) and chemical resistance in addition to the aforementioned hiding properties, and are therefore very suitable from the standpoint of durability and fastness.

Coloring pigments of inorganic pigments include, for example, yellow lead, yellow iron oxide, cadmium yellow, titanium yellow, barium yellow, aureolin, molybdate orange, cadmium red, red iron oxide, red lead, cinnabar, mars violet, manganese violet, cobalt Violet, cobalt blue, cerulean blue, ultramarine blue, Prussian blue, emerald green, chrome vermillion, chromium oxide, viridian, iron black, carbon black and the like can be used. Examples of inorganic white pigments include titanium oxide (titanium white, titanium white), zinc oxide (zinc white), basic lead carbonate (lead white), basic lead sulfate, zinc sulfide, lithopone, titanox, and the like. can be used. In particular, since it is excellent in hiding power and light resistance and is suitable for the decorative sheet 3 in terms of color tone in terms of design, the coloring pigments of inorganic pigments include iron oxide pigments such as red iron oxide, yellow iron oxide, and iron black, and inorganic pigments. A titanium oxide-based pigment is preferable as the white pigment of the pigment. That is, it preferably contains at least one of an iron oxide-based pigment and a titanium oxide-based pigment.

As the red iron oxide, for example, a red pigment made of ferric oxide Fe ₂ O ₃ (also known as hematite) and having an average particle size of about 0.2 to 0.6 μm can be used. Anchor FR-110G manufactured by Nihon Bengara Co., Ltd., EP-20D manufactured by Nippon Bengara Co., Ltd., Ferro Color NF-150-P manufactured by Nippon Fellow Co., Ltd., NAT manufactured by Tetsubara Co., Ltd., SR-580 manufactured by Tone Sangyo Co., Ltd., Toda Color 120ED manufactured by Toda Kogyo Co., Ltd., Commercially available products such as Morishita Red Cloisonne manufactured by Morishita Bengara can be used. Further, the yellow iron oxide is, for example, a yellow pigment made of iron hydroxide oxide γ-FeO (OH) (also known as lepidocrocite) or a hydrate thereof, and has an average particle size of about 0.3 to 0.8 μm. For example, Toho Pigment Anchor FY-766, Morishita Yellow MTY-10, Nippon Bengara NYB-40, Toda Kogyo Toda Color Y-1, Tone Sangyo Co., Ltd. Commercial products such as YP-100SB manufactured by Toyo Color Co., Ltd., Toshiki Synthetic Iron Yellow manufactured by Toyo Color Co., Ltd., and Sicotrans Yellow L 1916 manufactured by BASF can be used. Furthermore, as the iron black, for example, a black pigment made of triiron tetroxide Fe ₃ O ₄ (also known as magnetite) having an average particle size of about 0.5 μm can be used. Commercially available products such as Morishita Black MTB-10, TB-50SB manufactured by Tone Sangyo Co., Ltd., Toda Color KN-320 manufactured by Toda Kogyo Co., Ltd., and Toshiki Synthetic Iron Black manufactured by Toyo Color Co., Ltd. can be used. A wide range of color tones from yellow to ocher, brown, and black can be obtained by blending and using iron oxide pigments such as red iron oxide, yellow iron oxide, and iron black in appropriate combinations.

As the titanium oxide pigment, for example, a white pigment composed of titanium dioxide TiO ₂ and having an average particle size of about 0.1 to 0.5 μm can be used. Commercially available products such as JR manufactured by Co., Ltd., FR-41 manufactured by Furukawa Mining Co., Ltd., and CR-50 manufactured by Ishihara Sangyo Co., Ltd. can be used. Titanium oxide-based pigments include anatase type (also known as anatase) and rutile type (also known as rutile), with refractive indices of 2.45 to 2.55 and 2.61 to 2.90, respectively. The rutile type is preferable because it has a higher refractive index and therefore has excellent masking properties, and is also excellent in chemical stability and light resistance.
These inorganic pigments (iron oxide-based pigments and titanium oxide-based pigments) have the effect of improving the adhesion to the picture pattern layer 5 due to the anchoring effect, in addition to the effects of imparting the concealing properties and coloring described above.

In addition to the iron oxide-based pigment and titanium oxide-based pigment described in detail above, the concealing layer 4 may contain other pigments (for example, concealing or non-concealing inorganic pigments or organic pigments) for the purpose of adjusting the color tone. ) may be used in small amounts. However, it is essential to use iron oxide pigments and titanium oxide pigments as main components, and the amount of other pigments used is preferably 20% by mass or less with respect to the total pigments. In addition, as a pigment to be used in combination, it is preferable to select a pigment having high light resistance. Among inorganic pigments, cobalt blue and carbon black are more preferable, and among organic pigments, phthalocyanine pigments such as phthalocyanine blue are more preferable. . Extender pigments such as silica, calcium carbonate and barium sulfate may also be used in combination, if necessary.

From the standpoint of concealing properties, the larger the amount of the concealing inorganic pigment to be added, the more advantageous. In order to keep the balance, the range of 300 parts by mass or more and 600 parts by mass or less with respect to 100 parts by mass of the binder resin is preferable. Similarly, the thicker the concealing layer 4 is, the more advantageous it is from the standpoint of concealing properties. In order to balance with the above, it is preferable to set the thickness in the range of 3 μm or more and 20 μm or less.

Further, as the binder resin, for example, a primer agent, which is a resin having excellent adhesion to the adhesive used for bonding the decorative sheet 3 and the substrate 2, can be used. Various primers such as urethane, acrylic, ethylene-vinyl acetate copolymer, and vinyl chloride-vinyl acetate copolymer can be used as the primer. Select and use one suitable for the adhesive from among these. By using a primer agent, the adhesion between the masking layer 4 and the substrate 2 can be improved, and the masking layer 4 can function as a primer layer for enhancing the adhesion to the substrate 2 . Powders such as silica, alumina, calcium carbonate, and barium sulfate may be added to the primer agent. By adding these powders, it is possible to roughen the surface of the concealing layer 4, prevent blocking during winding storage of the decorative sheet 3, and improve the adhesiveness with the adhesive due to the anchoring effect. You can also try to

Solvents for dissolving or dispersing the concealing pigment and the binder resin include petroleum organic solvents such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, methylcyclohexane, ethyl acetate, Ester-based organic solvents such as butyl acetate, 2-methoxyethyl acetate, and 2-ethoxyethyl acetate, alcohol-based organic solvents such as methyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol, isobutyl alcohol, ethylene glycol, and propylene glycol , acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and other ketone organic solvents; diethyl ether, dioxane, tetrahydrofuran, and other ether organic solvents; dichloromethane, carbon tetrachloride, trichlorethylene, tetrachlorethylene, and other chlorine organic solvents. , inorganic solvents such as water, or mixed solvents thereof can be used.

Various additives such as a dispersant, a plasticizer, a surfactant, a tackifier, an adhesion aid, a drying agent, a curing agent, a curing accelerator, or a curing retardant are appropriately added to the concealing layer 4 as necessary. You may
As a method for forming the concealing layer 4, known printing methods and coating methods can be used. For example, gravure printing, offset printing, screen printing, relief printing, flexographic printing, electrostatic printing, inkjet Various printing methods such as printing method and electrophotography method, gravure coating method, roll coating method, dip coating method, air knife coating method, knife coating method, comma coating method, die coating method, lip coating method, kiss coating method, rod Various coating methods such as a coating method, a spray coating method, a flow coating method, and the like can be employed.

(Pattern layer)
The picture pattern layer 5 is provided on the surface 4a side of the masking layer 4, and is a layer formed by printing or coating a picture for imparting a design to the decorative sheet 3. FIG. The constituent material and formation method of the pattern layer 5 are not particularly limited, and various pattern forming materials and pattern forming methods that have been applied to the pattern layer 5 of the known decorative sheet 3 can be used. For example, various printing inks and printing methods similar to those for the concealing layer 4 described above can be applied. However, if sufficient concealment is ensured by the concealing layer 4, the printing ink constituting the pattern layer 5 is not required to have a particularly remarkable concealing property. may be

Accordingly, the pigments to be used are not particularly limited to inorganic pigments, and organic pigments may be used as long as the decorative sheet 3 satisfies requirements such as sufficient light resistance and durability. For example, organic pigments such as azo pigments, lake pigments, anthraquinone pigments, phthalocyanine pigments, isoindolinone pigments and dioxazine pigments can be used. Moreover, a pigment obtained by combining two or more selected from these organic pigments and the various inorganic pigments described above can also be used.
The pattern layer 5 may be formed by the same printing method as that for the masking layer 4. For example, a hand drawing method, a suminagashi method, a photography method, a laser beam or electron beam drawing method, a partial vapor deposition method of metal or the like, or the like may be used. An etching method or the like, or a combination of these methods can also be employed.
The type of pattern of the pattern layer 5 is not particularly limited, and any pattern can be used according to the application of the decorative sheet 3 . For example, wood grain patterns, cork patterns, stone grain patterns, abstract patterns, etc., which are widely used in the field of conventional decorative sheets 3, can be used. Further, for example, for the purpose of simple coloring or color adjustment, a single solid color may be employed.

(Transparent substrate sheet)
The transparent substrate sheet 6 is provided on the surface 5a side of the picture pattern layer 5, and is a layer for protecting the picture pattern layer 5 and imparting good surface physical properties such as abrasion resistance and solvent resistance. As the material of the transparent substrate sheet 6, for example, a resin having high transparency is preferable, but any resin having transparency at least to the extent that the picture pattern layer 5 can be seen through may be used, as long as it is translucent or colored. It may be a transparent resin. For example, in the conventional decorative sheet 3 having a multilayer structure, the same type of resin as the resin used as the transparent resin layer on the surface side can be appropriately used, and it may be a thermoplastic resin or a thermosetting resin. It may be a curable resin such as a curable resin or an ionizing radiation curable resin. The transparent substrate sheet 6 may be a multi-layer laminate composed of layers of a plurality of types of resin. However, considering environmental issues, it is preferable to use a non-halogen resin.

As thermosetting resins, for example, melamine-based resins, phenol-based resins, urea-based resins, epoxy-based resins, unsaturated polyester-based resins, diallyl phthalate-based resins, urethane-based resins, and aminoalkyd-based resins can be used. As the ionizing radiation-curable resin, for example, a resin that is cured by irradiation with ultraviolet rays, electron beams, or the like, such as an acrylate-based resin, a urethane acrylate-based resin, an ester acrylate-based resin, or an epoxy acrylate-based resin, can be used.

The thickness of the transparent substrate sheet 6 is more advantageous from the standpoint of surface physical properties such as abrasion resistance and solvent resistance, weather resistance, and design properties such as coating feeling, depth, and emboss depth. 3, the softness and flexibility, and bending workability such as V-cutting, etc., may be deteriorated. For example, when a curable resin is used, the thickness is limited to 20 μm or less, preferably 3 μm or more and 10 μm or less, from the viewpoint of flexibility. Further, for example, when a thermoplastic resin is used, it is possible to provide a thicker layer, and the range is 20 μm or more and 120 μm or less. Therefore, thermoplastic resins are advantageous in terms of abrasion resistance, design, etc., and are also advantageous in terms of manufacturing processes, such as the need for hardening treatment and easy quality stability.

The method for forming the transparent substrate sheet 6 is not particularly limited, and a sheet forming method that has been applied to known transparent substrate sheets can be used. For example, a method of applying a coating agent obtained by dissolving or dispersing the constituent resin of the transparent base sheet 6 in an appropriate solvent, followed by drying and solidifying, and an uncured resin composition that becomes the constituent resin of the transparent base sheet 6 after curing. A method of cross-linking and curing after coating, and a method of applying an adhesive such as a dry laminate adhesive, a heat-sensitive adhesive, a pressure-sensitive adhesive, or an ionizing radiation-curable adhesive to a transparent base sheet 6 that has been formed into a film or sheet in advance. It is possible to employ a method of adhering via a bonding agent, or a method of directly adhering by a means such as thermocompression bonding or ultrasonic welding without an adhesive agent. Among these methods, a method that matches the characteristics of the constituent resin is selected and used.

(Uneven pattern)
A surface 6a of the transparent substrate sheet 6 may be provided with a desired uneven pattern 8, if necessary. The type of pattern of the uneven pattern 8 is not particularly limited, and any pattern can be used according to the application of the decorative sheet 3 . For example, various patterns widely used in the field of conventional decorative sheets 3, such as wood grain (in particular, vessel pattern), stone grain, Japanese paper, texture, and geometric patterns, can be employed. . Further, for example, a simple matt finish, grainy finish, hairline finish, suede finish, and the like can be used. By synchronizing the pattern of these uneven patterns 8 with the pattern of the pattern layer 5, it is possible to further improve the design. However, if there is no need to further improve the design, it may be out of sync with the pattern of the pattern layer 5 . Moreover, it may include both a pattern synchronized with the pattern of the pattern layer 5 and a pattern not synchronized.

Moreover, the method of forming the uneven pattern 8 is not particularly limited, and a known method of forming the uneven pattern 8 of the decorative sheet 3 can be used. For example, a mechanical embossing method using a metal embossing plate can be employed. In addition, the timing of forming the uneven pattern 8 is not particularly limited, either before lamination with the surface protective layer 7, at the same time as lamination, or after lamination. The uneven pattern 8 of the same or different pattern can be applied a plurality of times at a plurality of times selected from. If necessary, the recessed portions of the uneven pattern 8 may be filled with a coloring agent by a method such as a wiping method. By filling the colorant, it is possible to obtain the decorative sheet 3 having a color pattern in harmony with the uneven pattern 8 on the surface and having an excellent design.

(Surface protective layer)
The surface protective layer 7 is provided on the surface 6a side of the transparent substrate sheet 6 and is a layer for imparting even better surface physical properties to the surface of the decorative sheet 3 . The material of the surface protective layer 7 is not particularly limited, and a known topcoat agent that has been applied to the surface protective layer 7 of the decorative sheet 3 can be used. The topcoat agent must have transparency such that at least the base of the surface protective layer 7 (the pattern of the patterned layer 5 and the color of the concealing layer 4) can be seen through. In addition, in order to provide the surface physical properties such as abrasion resistance, scratch resistance, solvent resistance, stain resistance, etc. required by the use of the decorative sheet 3, the decorative sheet 3 may be composed of a material containing a curable resin as a main component. preferable. In particular, when the transparent substrate sheet 6 is made of a thermoplastic resin, it is preferable to apply the surface protective layer 7 made of a curable resin. Examples of topcoat agents include thermosetting resins such as melamine resins, phenolic resins, urea resins, epoxy resins, aminoalkyd resins, urethane resins, polyester resins, silicone resins, and acrylic resins. An ionizing radiation curable resin such as a resin can be used. In addition, various additives such as luster modifiers, lubricants, antistatic agents, anti-condensing agents, antibacterial agents, and antifungal agents may be added to the topcoat agent, if necessary.

A method for forming the surface protective layer 7 is not particularly limited, either, and a known coating method can be used. For example, gravure coating, roll coating, dip coating, air knife coating, knife coating, comma coating, die coating, lip coating, kiss coating, rod coating, spray coating, flow coating, etc. can be adopted.
If the adhesion between the transparent substrate sheet 6 and the surface protective layer 7 is insufficient, the surface of the transparent substrate sheet 6 may be treated, for example, by corona treatment, prior to forming the surface protective layer 7 by coating. Adhesion between the transparent base sheet 6 and the surface protective layer 7 can be improved by surface treatment such as ozone treatment, plasma treatment, ionizing radiation treatment, dichromic acid treatment, anchoring or primer treatment.

(Effect of this embodiment)
The invention according to this embodiment has the following effects.
(1) The decorative sheet 3 according to the present embodiment is a decorative sheet 3 in which a concealing layer 4, a pattern layer 5, a transparent substrate sheet 6, and a surface protective layer 7 are laminated in this order. The concealing layer 4 contains a primer containing a concealing pigment, and functions as a primer layer for enhancing adhesion to the substrate 2 . Therefore, since the masking layer 4 contains the primer agent, the adhesiveness to the substrate 2 can be improved. Further, since the concealing layer 4 functions as a primer layer, it is not necessary to provide a primer layer separately from the concealing layer 4, and the decorative sheet 3 can be made thinner. Therefore, it is possible to provide the decorative sheet 3 which has excellent adhesiveness to the substrate 2 and which can be made thinner.
In addition, by forming the concealing layer 4 by printing with a printing ink made of a primer agent containing a concealing pigment or by coating with a coating agent, the concealing layer 4 can be formed simply by changing the concealing pigment of the printing ink or coating agent. 4 colors can be changed. Therefore, for example, unlike the method of forming the concealing layer 4 by the compositional thickness reduction of the concealing layer 4, in order to realize the concealing layer 4 of various colors, the compositional thickness reduction of the concealing layer 4 of various colors is prepared. you don't have to.

(2) In the decorative sheet 3 according to this embodiment, the concealing pigment contains an inorganic pigment. Therefore, it is possible to provide the decorative sheet 3 excellent in concealability, weather resistance, and chemical resistance.
(3) In the decorative sheet 3 according to this embodiment, the inorganic pigment contains at least one of an iron oxide-based pigment and a titanium oxide-based pigment. Therefore, it is excellent in concealability and weather resistance, and can be imparted with a design suitable for the decorative sheet 3 in terms of color tone.
(4) In the decorative sheet 3 according to this embodiment, the transparent base sheet 6 has a thickness of 20 μm or more and 120 μm or less, and the concealing layer 4 has a thickness of 3 μm or more and 20 μm or less. Therefore, it is possible to provide the decorative sheet 3 having excellent softness and flexibility in addition to surface physical properties and weather resistance.

(5) In the decorative sheet 3 according to this embodiment, the transparent base sheet 6 is made of a colored transparent resin. Therefore, it is possible to provide the decorative sheet 3 with excellent design.
(6) In the decorative sheet 3 according to this embodiment, the surface 6a of the transparent base material sheet 6 is provided with the uneven pattern 8. As shown in FIG. Therefore, it is possible to provide the decorative sheet 3 with excellent design.
(7) The decorative board 1 according to this embodiment includes a substrate 2 made of a wood-based material, a metal-based material, or a synthetic resin, and a decorative sheet 3 attached to the substrate 2 . Therefore, it is possible to provide the decorative board 1 which has excellent adhesiveness to the decorative sheet 3 and which can be made thinner.

EXAMPLES Examples and comparative examples according to embodiments of the present invention will be described below. In addition, the present invention is not limited to the following examples.
(Example 1)
In Example 1, as shown in FIG. 1, a decorative sheet 3 was prepared by laminating a concealing layer 4, a pattern layer 5, a transparent substrate sheet 6 and a surface protective layer 7 in this order. First, as the transparent substrate sheet 6, an unstretched polypropylene resin film having a thickness of 60 μm was prepared. Subsequently, the transparent substrate sheet 6 was subjected to a corona treatment so that the wettability index of the surface 6a of the transparent substrate sheet 6 was 38 dyn/cm or more. Subsequently, the surface protective layer 7 was formed by coating the surface 6a side of the transparent substrate sheet 6 with a two-liquid curable urethane topcoat agent containing an antibacterial agent. A gravure coating method was used as the coating method. In addition, the coating amount of the two-liquid curing type urethane-based top coating agent after drying was set to 5 g/m ² or more and 7 g/m ² or less.

Subsequently, a pattern layer 5 was formed by printing a pattern of wood on the back surface 6b side of the transparent substrate sheet 6 with a general urethane-based gravure printing ink for building materials. A gravure printing method was used as the printing method. Subsequently, a small amount of carbon black, cobalt blue, and phthalocyanine blue were mixed mainly with concealing inorganic pigments (iron oxide-based brown, iron oxide-based ocher, and titanium oxide-based white) on the back surface 5b side of the pattern layer 5. A concealing layer 4 was formed by printing with a urethane resin-based ink containing a total of 2 g/m ² of a pigment composition and having a primer effect. A gravure printing method was used as the printing method.

(Example 2)
In Example 2, hiding organic pigments (azo and condensed polycyclic) were used instead of hiding inorganic pigments. A decorative sheet 3 was produced using the same materials and procedures as in Example 1 except for the above.
(Example 3)
In Example 3, the thickness of the transparent substrate sheet 6 was set to 15 μm. A decorative sheet 3 was produced using the same materials and procedures as in Example 1 except for the above.
(Example 4)
In Example 4, the thickness of the transparent substrate sheet 6 was set to 25 μm. A decorative sheet 3 was produced using the same materials and procedures as in Example 1 except for the above.

(Example 5)
In Example 5, the thickness of the transparent substrate sheet 6 was set to 115 μm. A decorative sheet 3 was produced using the same materials and procedures as in Example 1 except for the above.
(Example 6)
In Example 6, the thickness of the transparent substrate sheet 6 was set to 125 μm. A decorative sheet 3 was produced using the same materials and procedures as in Example 1 except for the above.
(Example 7)
In Example 7, the thickness of the masking layer 4 was set to 2 μm. A decorative sheet 3 was produced using the same materials and procedures as in Example 1 except for the above.

(Example 8)
In Example 8, the thickness of the masking layer 4 was set to 4 μm. A decorative sheet 3 was produced using the same materials and procedures as in Example 1 except for the above.
(Example 9)
In Example 9, the thickness of the masking layer 4 was set to 18 μm. A decorative sheet 3 was produced using the same materials and procedures as in Example 1 except for the above.
(Example 10)
In Example 10, the thickness of the masking layer 4 was set to 22 μm. A decorative sheet 3 was produced using the same materials and procedures as in Example 1 except for the above.

(Comparative example 1)
In Comparative Example 1, the masking layer 4 was omitted. A decorative sheet 3 was produced using the same materials and procedures as in Example 1 except for the above.
(Comparative example 2)
In Comparative Example 2, as shown in FIG. 2, a decorative sheet 3 was prepared by laminating an easy-adhesion layer 12, a colored base sheet 11, a pattern layer 10 and a surface protective layer 9 in this order. First, as the colored base sheet 11, an unstretched polypropylene resin film having a thickness of 60 μmm was prepared. As the unstretched polypropylene resin film, a total of 2 g / m ² was used. Subsequently, the colored base sheet 11 was subjected to a corona treatment to set the wettability index of the surface 11a of the colored base sheet 11 to 38 dyn/cm or more. Subsequently, a wood grain pattern was printed on the surface 11a side of the colored base sheet 11 with a general urethane-based gravure printing ink for building materials to form a pattern layer 10 . A gravure printing method was used as the printing method.

Subsequently, the surface protective layer 9 was formed by coating the surface 10a side of the pattern layer 10 with a two-liquid curable urethane topcoat agent containing an antibacterial agent. A gravure coating method was used as the coating method. The coating amount of the two-liquid curing type urethane-based top coating agent after drying was set to 5 g/m ² or more and 7 g/m ² or less. Subsequently, the easy-adhesion layer 12 was formed on the back surface 11b side of the colored base sheet 11 by printing by applying a mixture of a urethane-based resin, a vinyl chloride resin, and a cellulose resin. A gravure printing method was used as the printing method.
(performance evaluation)
The following performance evaluation tests were performed on the decorative sheets 3 of Examples 1 to 10 and Comparative Examples 1 and 2.
(1) Concealability
In the test of concealability, a gray scale for concealability was adhered to the back surface of the decorative sheet 3, and the degree of transparency was evaluated. The standards shown in Table 1 were used as the criteria for the degree of concealability.

(2) Adhesion In the adhesion test, the decorative sheet 3 was adhered to the MDF substrate via a water-based adhesive. Then, in an atmosphere of 60 [° C.], after cutting the decorative plate to a width of 25 [mm], one end was peeled off from the base material, the decorative sheet 3 at the tip was peeled off, and a weight of 500 [g] was applied. I put it. Further, the peeled decorative sheet 3 was left for 1 hour while being pulled in the 90[°] direction with a load of 500[g], and the peel length (peeling distance) between the MDF base material and the decorative sheet 3 was measured. did.
(3) Flexibility (flexibility)
In the flexibility test, V-cut processing was performed and the state of surface cracks and the like when the decorative plate 1 was bent at 90 degrees was evaluated. The criteria shown in Table 2 were used for judging the degree of flexibility.

(4) Embossed design In the embossed design test, the cross section of the decorative sheet 3 was observed with a microscope to measure the depth of the emboss.
(Test results)
Table 3 shows the performance evaluation test results (numerical values).

As shown in Table 3, the decorative sheets 3 of Examples 1 to 10 were graded "grade 3" or higher for concealability, flexibility and embossed design. In addition, the measured value of adhesion was "1 mm" or less.
On the other hand, in the decorative sheet 3 of Comparative Examples 1 and 2, the grades of concealability, flexibility and embossed design were "second grade" or lower. In addition, the measured value of adhesion was "4 mm" or more.
From the above results, it is clear that the decorative sheets 3 of Examples 1 to 10 are excellent in concealability, flexibility, embossed design and adhesion (adhesiveness) and can be thinned.

DESCRIPTION OF SYMBOLS 1... Decorative board 2... Substrate 3... Decorative sheet 4... Concealing layer 4a... Front side 4b... Back side 5... Pattern layer 5a... Front side 5b... Back side 6... Transparent substrate sheet 6a... Front surface 6b Back surface 7 Protective surface layer 8 Concavo-convex pattern

Claims (3)

A decorative sheet comprising a concealing layer, a picture pattern layer, a transparent substrate sheet and a surface protective layer laminated in this order,
The decorative sheet, wherein the concealing layer contains a primer agent containing a concealing pigment having a refractive index of 2.0 or more, and functions as a primer layer for enhancing adhesion to a substrate. 2. The decorative sheet according to claim 1, wherein the particle size of said concealing pigment is 0.1 [mu]m or more and 1 [mu]m or less. a substrate made of a wood-based material, a metal-based material, or a synthetic resin;
A decorative board comprising: the decorative sheet according to claim 1 or 2 attached to the substrate.

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