TWI883550B - Decorative sheet and resin-impregnated decorative plate - Google Patents

Abstract

The present disclosure provides a decorative sheet used for a production of a resin-impregnated decorative plate, the decorative sheet comprising: a porous substrate; a white solid layer placed on an entire surface of one surface of the porous substrate, and including a white pigment; a pictorial pattern layer placed partially on the white solid layer, on an opposite side surface to the porous substrate; and a releasing layer placed in a pattern on the pictorial pattern layer, on an opposite side surface to the white solid layer, wherein the white solid layer includes a white blank region not covered with the pictorial pattern layer; an L ^*value at the white blank region is 93.0 or more; and an ash included in the decorative sheet is 20.0% by mass or more and 40.0% by mass or less.

Description

Decorative sheets and resin impregnated decorative boards

The present invention relates to a decorative sheet for manufacturing a resin-impregnated decorative board and a resin-impregnated decorative board.

Previously, resin-impregnated decorative boards were known, which were obtained by impregnating a pre-dried material (uncured resin) such as melamine resin into a porous substrate and then curing the pre-dried resin. Resin-impregnated decorative boards are used for walls, furniture, floors, etc. in residences, shops, public facilities, etc. In particular, there is a high demand for designs with a white base tone like marble, and a white substrate is usually used when expressing a white design.

Melamine decorative boards showing a glossy matte design are known. For example, Patent Document 1 discloses a decorative board having a release layer on a part of the surface of a porous substrate, a thermosetting resin layer on the remaining area of the surface of the porous substrate without the release layer, and the thermosetting resin is impregnated into the porous substrate to be cured, the porous substrate is a fiber substrate, and the height difference between the thermosetting resin layer and the release layer is 5 μm or more.

[Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 6716877

The method described in Patent Document 1 describes that the surface of the decorative board can present a bright glossy matte design by presenting a glossy design feeling through the thermosetting resin layer and presenting a matte design feeling through the release layer, or presenting a matte design feeling through the thermosetting resin layer and presenting a glossy design feeling through the release layer. It is expected that by applying this method to a white porous substrate, a white resin-impregnated decorative board with a glossy matte design that could not be presented in previous products can be provided.

However, white porous substrates such as titanium paper generally contain white pigments such as titanium oxide, so there are many gaps between papers, and the ink of the release layer responsible for the expression of the glossy matte design will penetrate into the porous substrate, making it difficult to express the glossy matte design. On the other hand, in the porous substrate that can fully exert the function of the release layer, the content of white pigment is insufficient, and the white design cannot be expressed. Therefore, in the previous decorative sheets for the manufacture of resin-impregnated decorative boards, it is difficult to obtain a resin-impregnated decorative board that can express a white design and stably express a glossy matte design.

The present invention is completed in view of the above-mentioned problems, and its main purpose is to provide a decorative sheet material of a resin-impregnated decorative board that can express a white design and stably express a glossy matte design.

The present invention provides a decorative sheet material for manufacturing a resin-impregnated decorative board, and the decorative sheet material has: a porous substrate; a white coating layer, which is disposed on the entire surface of one side of the porous substrate and contains a white pigment; a pattern layer, which is partially disposed on the surface of the white coating layer opposite to the porous substrate; and a release layer, which is disposed on the surface of the pattern layer opposite to the white coating layer and has a pattern shape; the white coating layer has a white area not covered by the pattern layer, and the L* value in the white area is 93.0 or more, and the ash content contained in the decorative sheet is 20.0 mass% or more and 40.0 mass% or less.

In addition, the present invention provides a resin impregnated decorative board, which comprises: the decorative sheet; a core substrate arranged in a manner opposite to the porous substrate in the decorative sheet; and a hardened resin layer arranged in the white area and containing a hardened product of the hardening resin Y; the core substrate and the porous substrate contain the hardened product of the hardening resin Y, and when the L* value in the white area is measured through the hardened resin layer, the L* value is 88.0 or more.

In the present invention, the effect of providing a decorative sheet of a resin-impregnated decorative board capable of expressing a white design and stably expressing a glossy matte design is exerted.

1: Porous substrate

2: White coating layer

3: Pattern layer

4: Release layer

10: Decorative sheets

20: Core substrate

30: Thermosetting resin layer

30': Thermosetting resin layer

31': Hardened resin layer

32: Hardening the resin layer

40: Release membrane

51:Container

51': 1st layer

52: Cover

52': 2nd layer

53:Metal plate

54: Unimpregnated melamine resin

100: Resin impregnated decorative board

α: Area

O1: 1st opening

O2: Second opening

O1: Outer edge

O2: Outer edge

S: Sample

U: Unhardened material

X: White area

Figure 1 is a schematic cross-sectional view illustrating the decorative sheet of the present invention.

Figure 2 is a schematic cross-sectional view illustrating the resin-impregnated decorative board of the present invention.

Figure 3 (a) to (e) are schematic cross-sectional views illustrating a method for manufacturing a resin-impregnated decorative board using the decorative sheet of the present invention.

Figure 4 (a) to (c) are schematic diagrams of the container and lid used in the impregnation evaluation in the embodiment.

Figure 5 (a) to (e) are diagrams for explaining the impregnation evaluation method in the embodiment.

Figure 6 (a) to (h) are schematic top views of the white coating layer of the present invention.

The following describes the implementation method with reference to the drawings, etc. However, the present invention can be implemented in a variety of different forms and is not limited to the description of the implementation method illustrated below. In addition, in order to make the description clearer, the drawings show the width, thickness, and shape of each part in a schematic manner compared to the actual form, but it is ultimately an example and is not interpreted in a limiting manner.

In this specification, when other components are arranged on a certain component, if it is simply expressed as "on..." or "below...", unless otherwise specified, the following two situations are included: the other components are arranged directly above or directly below in a manner of contact with a certain component; and the other components are arranged above or below a certain component with another component interposed therebetween. In addition, in this specification, when other components are arranged on the surface of a certain component, if it is simply expressed as "on...", unless otherwise specified, the following two situations are included: the other components are arranged directly above or directly below in a manner of contact with a certain component; and the other components are arranged above or below a certain component with another component interposed therebetween.

A. Decorative sheets

The decorative sheet of the present invention will be described in detail below. FIG. 1 is a schematic cross-sectional view illustrating the decorative sheet of the present invention. The decorative sheet 10 shown in FIG. 1 has: a porous substrate 1; a white coating layer 2, which is disposed on the entire surface of one side of the porous substrate 1 and contains a white pigment; a pattern layer 3, which is partially disposed on the surface of the white coating layer 2 opposite to the porous substrate 1; and a release layer 4, which is disposed on the surface of the pattern layer 3 opposite to the white coating layer 2 and has a pattern shape. In the present invention, the white coating layer 2 has a white area X that is not covered by the pattern layer 3, and the L* value in the white area X is 93.0 or more. In addition, the ash content in the decorative sheet 10 is greater than 20.0 mass % and less than 40.0 mass %.

As described above, it is difficult to obtain a resin-impregnated decorative sheet that can express a white design and a glossy matte design in the previous resin-impregnated decorative sheet manufacturing. The inventors of the present case have found that when visually observing the resin-impregnated decorative sheet, if the L* value in the L*a*b* color system is above a specified value, a white feeling can be obtained. In addition, the curable resin impregnated in the decorative sheet (melamine resin, phenol resin, diallyl phthalate resin, polyester resin, etc.) is mostly colored or translucent, which may hinder the whiteness of the decorative sheet. Therefore, it was found that in order to ensure sufficient white design properties in decorative panels, decorative sheets need to ensure higher white design properties (L* value).

If it is general decorative paper, you can also consider the method of coating the entire surface of the substrate with white ink to obtain a white design, but the decorative sheet used to make resin-impregnated decorative boards is usually not coated with ink on the entire surface to ensure the resin impregnation of the porous substrate.

The decorative sheet of the present invention is prepared by having a white coating layer on the entire surface of one side of the porous substrate within the range of the resin impregnation of the porous substrate, and the ash content is above a specified ratio, and the L* value of the white area X of the white coating layer 2 not covered by the pattern layer 3 can be set to a specified value or above. Therefore, by using the decorative sheet of the present invention, a resin-impregnated decorative board showing a white design can be obtained.

Furthermore, the decorative sheet of the present invention can suppress the ink of the release layer responsible for expressing the glossy matte design from penetrating into the porous substrate by keeping the ash content below a specified ratio, so that the glossy matte design can be expressed stably.

1. Composition of decorative sheets (1)L* value

The decorative sheet of the present invention has a white area where the white coating layer is not covered by the pattern layer, and the L* value of the L*a*b* color system in the white area is 93.0 or more. If it is such a decorative sheet, a resin-impregnated decorative board capable of expressing a white design can be manufactured as described below. The above L* value is more preferably 94.5 or more, and particularly preferably 95.0 or more. If it is such a decorative sheet, even if the L* value decreases during the manufacturing process of the resin-impregnated decorative board, a resin-impregnated decorative board capable of expressing a white design can be manufactured. On the other hand, the above L* value is, for example, 97.0 or less, and can be 96.0 or less.

"L*a*b* color system" refers to the color system standardized by CIE (International Commission on Illumination) and adopted in JIS Z 8781-4:2013. In the L*a*b* color system, brightness is expressed by L* value, and chromaticity, which represents hue and chroma, is expressed by a* value and b* value. L* value actually represents whiteness, and the closer to 100, the higher the whiteness, and the closer to 0, the lower the whiteness.

The L* value of the L*a*b* colorimetric system of the white area is the average value of the values measured at 5 locations on the surface of the white area using CM-3700A manufactured by Konica Minolta. In addition, the primary color measurement area is a circle with a diameter of 25.4mm (area 506.71mm2).

As shown in FIG1 , the white area X refers to the area of the white coating layer 2 that is not covered by the pattern layer 3, and more specifically, refers to the area that is not covered by the pattern layer 3 and the release layer 4. Furthermore, it can also be assumed that when viewed from the thickness direction, a portion of the release layer 4 protrudes from the area where the pattern layer 3 is arranged. In this case, the area covered by the colorless and transparent release layer 4 and not covered by the pattern layer 3 can also be called the white area.

(2) Ash content

In the present invention, the ash content in the decorative sheet is 20.0 mass % or more, preferably 22.0 mass % or more. The above ash content ratio is similar to the content of inorganic substances such as white pigments in the decorative sheet, which is mainly a porous substrate. If the ash content is too little, even if a white coating layer containing white pigment is configured, the white design cannot be expressed. On the other hand, the above ash content is 40.0 mass % or less, preferably 30.0 mass % or less. If the ash content is too much, the glossy matte design cannot be stably expressed.

The ash content in the present invention is the value measured by the following measurement method and measurement conditions.

<Measurement method>

Cut out about 5 mg of the test sample from the decorative sheet. Use the following thermogravimetric/differential thermal analysis device to raise the temperature from room temperature to 30°C at a rate of 10°C/min under the following conditions, and keep it at 30°C for 15 minutes. Then, raise the temperature to 120°C at a rate of 10°C/min, and keep it at 120°C for 30 minutes. Then, raise the temperature to 600°C at a rate of 10°C/min, and keep it at 600°C for 30 minutes. In this way, the test sample is ashed.

<Measurement equipment and mechanical conditions>

．Device: DTG-60A (TG-DTA)

．Ambient gas: air

． Gas flow rate: 175[ml/min]

． Initial mass: about 5mg (cut out decorative sheet)

． Heating program

Room temperature→heat up (10℃/min)→30℃, keep for 15min→heat up (10℃/min)→120℃, keep for 30min→heat up (10℃/min)→600℃, keep for 30min→end

The ash content in the present invention is as shown in the following calculation formula, which is the value expressed as a percentage of the sample mass after being kept at 600°C for 30 minutes relative to the sample mass after being kept at 120°C for 30 minutes in the above-mentioned temperature rise program.

<Calculation formula>

Ash content (%) = (mass of sample after being kept at 600℃ for 30 minutes [mg]/mass of sample after being kept at 120℃ for 30 minutes [mg]) × 100

2. Components of decorative sheets

The decorative sheet of the present invention has at least a porous substrate, a white coating layer, a pattern layer and a release layer.

(1) Release layer

Regarding the release layer in the present invention, at least a part is arranged on the surface of the pattern layer opposite to the white coating layer and has a pattern shape. In the manufacturing step of the resin-impregnated decorative board described later, the release layer has a release property to the hardened resin layer between the release layer and the release film. By having such a release property, for example, in the resin-impregnated decorative board 100 shown in FIG. 3(e) manufactured using the decorative sheet in the present invention, the hardened resin layer 32 is given a glossy design sense, and the release layer 4 is given a matte design sense to express a vivid glossy matte design sense.

Furthermore, the release layer is preferably arranged in the same style as the pattern of the pattern layer. "Same style" means that the shapes and positions of the two patterns as objects are roughly the same. Specifically, the shape and position of the pattern of the release layer and the pattern of at least a part of the pattern constituting the pattern layer are consistent to the extent that the sense of reality and high-end feeling are not damaged. By arranging the pattern of the release layer in the same style as the pattern of the pattern layer, a higher quality can be obtained.

The release layer contains a resin component. The resin component is typically a hardened product (cross-linked structure) of a hardening resin. Furthermore, in the present invention, the hardening resin in the release layer is sometimes referred to as hardening resin X. On the other hand, the resin component may be a thermoplastic resin. Among them, the release layer preferably contains a hardened product of a hardening resin. The reason is that a release layer with good wear resistance can be obtained. In addition, because the release layer contains a hardened product of a hardening resin, the release property to the hardening resin layer is good.

Examples of the curable resin X include ionizing radiation curable resins and thermosetting resins. Examples of the ionizing radiation curable resin include electron beam curable resins and ultraviolet curable resins.

Ionizing radiation curable resins (ionizing radiation curable compounds) are not limited as long as they are materials that undergo crosslinking polymerization reactions by irradiation with ionizing radiation and are converted into three-dimensional polymer structures. Examples of ionizing radiation curable resins include prepolymers, oligomers, and monomers that have polymerizable unsaturated bonds or epoxy groups in their molecules that can be crosslinked by irradiation with ionizing radiation. In the present invention, only one type of ionizing radiation curable resin may be used, or two or more types may be used. Among them, it is preferred to use at least one type of multifunctional monomer and oligomer as the ionizing radiation curable resin.

Examples of ionizing radiation curable resins include (meth)acrylate resins such as urethane (meth)acrylate, ester (meth)acrylate, and epoxy (meth)acrylate; silicone resins such as siloxane; ester resins; and epoxy resins. (Meth)acrylate resins refer to acrylate resins or methacrylate resins.

The weight average molecular weight of the ionizing radiation curable resin is, for example, 500 to 80,000, or 1,000 to 50,000. The weight average molecular weight is a value measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.

As the ionizing radiation curable resin, it is preferred to contain at least a multifunctional monomer or oligomer having a weight average molecular weight of 500 or more. Examples of such multifunctional monomers or oligomers include: (Meth)acrylate resins such as dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, urethane (meth)acrylate, ester (meth)acrylate, and epoxy (meth)acrylate.

On the other hand, examples of thermosetting resins include unsaturated ester resins, urethane resins (including two-component curing polyurethane), epoxy resins, aminoalkyd resins, phenol resins, urea resins, diallyl phthalate resins, melamine resins, guanamine resins, melamine urea co-condensation resins, silicone resins, and siloxane resins.

The release layer may contain a matte agent. Examples of matte agents include inorganic particles and synthetic resin particles. Examples of inorganic particles include silicon oxide, aluminum oxide, calcium carbonate, magnesium carbonate, calcium sulfate, barium sulfate, and kaolin. Examples of synthetic resin particles include acrylic beads, urethane beads, nylon beads, silicone beads, silicone rubber beads, polycarbonate beads, and polyolefin waxes (e.g., polypropylene wax and polyethylene wax).

The average particle size of the matte agent is, for example, 0.3 μm to 10 μm, 0.5 μm to 7 μm, or 1 μm to 5 μm. The average particle size is D50 based on the volume-based standard particle size distribution measured by laser diffraction scattering. The content of the matte agent relative to 100 parts by mass of the resin component of the release layer is, for example, 5 parts by mass to 40 parts by mass, or 10 parts by mass to 35 parts by mass.

The release layer may also contain a release agent. The release property is improved by adding a release agent. Examples of release agents include silicone-based release agents such as silicone oil, wax-based release agents such as polyolefin wax, and fluorine-based release agents. Examples of silicone oils include reactive silicone oils and non-reactive silicone oils.

Reactive silicone oil refers to modified silicone oils with organic groups introduced into the side chains or terminals, which are reactive according to the properties of the introduced organic groups. Specifically, reactive silicone oils include: modified silicone oil side chain type, modified silicone oil both terminal type, modified silicone oil single terminal type, modified silicone oil side chain both terminal type, etc., in which the organic groups introduced are amino modified, epoxy modified, hydroxyl modified, carboxyl modified, methanol modified, phenol modified, methacrylic modified, heterofunctional modified, etc. Such reactive silicone oils can be used alone or in combination of two or more.

There are no particular restrictions on non-reactive silicone oils as long as they do not have reactive functional groups such as amine, epoxy, alkyl, carboxyl, hydroxyl, (meth)acryl, and allyl groups. Non-reactive silicone oils include, in addition to silicone oils containing polysiloxane, polyether-modified silicone oils, aralkyl-modified silicone oils, fluoroalkyl-modified silicone oils, long-chain alkyl-modified silicone oils, higher fatty acid ester-modified silicone oils, higher fatty acid amide-modified silicone oils, and phenyl-modified silicone oils. These non-reactive silicone oils can be used alone or in combination of two or more.

The content of the release agent relative to 100 parts by mass of the resin component of the release layer is, for example, 0.1 parts by mass to 50 parts by mass, 0.5 parts by mass to 20 parts by mass, 3 parts by mass to 20 parts by mass, or 3 parts by mass to 10 parts by mass.

Furthermore, the release layer may be colorless or colored. In the latter case, the release layer preferably contains a colorant. The colorant may be the same as the colorant used in the pattern layer described later.

The release layer may also contain additives such as ultraviolet absorbers, infrared absorbers, light stabilizers, polymerization inhibitors, crosslinking agents, antistatic agents, antioxidants, leveling agents, coupling agents, plasticizers, defoaming agents, fillers, thermal free radical generators, aluminum chelating agents, etc. as needed. The thickness of the release layer is not particularly limited, for example, it is 0.1μm or more and 20μm or less.

The release layer can be obtained, for example, by applying a release layer forming ink containing a curable resin X to the surface of the pattern layer opposite to the white coating layer and curing it. As an example of the coating method, a printing method can be cited. As an example of the printing method, gravure printing, offset printing, screen printing, flexographic printing, electrostatic printing, and inkjet printing can be cited.

When the ink for forming the release layer contains an electron beam curable resin, the cured product of the electron beam curable resin is usually obtained by irradiating an electron beam. Examples of electron beam sources include various electron beam accelerators such as Cockcroft-Walton type, Van de Graaff type, resonant transformer type, insulating core transformer type, linear type, Dynamitron type, and high frequency type. The energy of the electron beam is, for example, 100 kV to 1000 kV, and can be 100 kV to 300 kV. The irradiation amount of the electron beam is, for example, 2 Mrad to 15 Mrad.

When the release layer forming ink contains a UV-curable resin, a cured product of the UV-curable resin is usually obtained by irradiating with UV rays. Examples of UV sources include ultra-high pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, carbon arc lamps, black light fluorescent lamps, and metal halide lamps. The wavelength of the UV rays is, for example, 190 nm or more and 380 nm or less.

When the ink for forming the release layer contains a thermosetting resin, the cured product of the thermosetting resin is usually obtained by heating. The heating temperature is appropriately set depending on the type of thermosetting resin. In addition to the thermosetting resin, the ink for forming the release layer may also contain a curing agent such as a crosslinking agent and a polymerization initiator, and a polymerization accelerator. Examples of the curing agent include isocyanates, organic sulfonates, organic amines, peroxides (such as methyl ethyl ketone peroxide), and free radical initiators (azoisobutyronitrile).

烷等醚化合物；二氯甲烷、氯仿等鹵化烴化合物；二甲基亞碸。 The ink for forming the release layer may contain a solvent as necessary. Examples of the solvent include water; hydrocarbon compounds such as toluene and xylene; alcohol compounds such as methanol, ethanol, and methyl glycol; ketone compounds such as acetone and methyl ethyl ketone; ester compounds such as methyl formate and ethyl acetate; nitrogen-containing compounds such as N-methylpyrrolidone and N,N-dimethylformamide; tetrahydrofuran, dimethicone, etc.

Ether compounds such as alkanes; halogenated hydrocarbon compounds such as dichloromethane and chloroform; dimethyl sulfoxide.

(2) Pattern layer

The pattern layer portion (especially the patterned portion) of the present invention is disposed on the surface of the white coating layer opposite to the porous substrate. Examples of the pattern (pattern) in the pattern layer include: stone pattern, sand pattern, tile pattern, wood pattern, masonry pattern, cloth pattern, leather pattern, geometric figure, text, symbol, abstract pattern, and floral pattern.

顏料等有機顏料；鋁粉、青銅粉等金屬粉顏料；氧化鈦被覆雲母、氧氯化鉍等珍珠光澤顏料；螢光顏料；夜光顏料。作為著色劑，可使用染料。 The pattern layer contains, for example, a colorant and a resin component (binder resin). Examples of the colorant include: inorganic pigments such as carbon black, titanium white, zinc white, red lead, iron blue, cadmium red, etc.; azo pigments, pigments, anthraquinone pigments, quinacridone pigments, phthalocyanine pigments, isoindolone pigments, dioxane pigments, etc.

Pigments and other organic pigments; aluminum powder, bronze powder and other metal powder pigments; titanium oxide coated mica, bismuth oxychloride and other pearlescent pigments; fluorescent pigments; luminous pigments. Dyes can be used as colorants.

Examples of the resin component include ester urethane resins, acrylamide resins, (meth) acrylic resins, ethylene oxide resins, N-vinyl pyrrolidone resins, ester resins, amide resins, vinyl acetate resins, vinyl chloride resins, urethane (meth) acrylic resins, amine resins, phenolic resins, natural polymers (e.g., polynucleotides, polypeptides, polysaccharides), natural rubbers, and synthetic rubbers. The resin component may be water-soluble or fat-soluble.

The pattern layer preferably contains a resin having a polar group as a resin component. The reason for this is that the resin impregnation property in the porous substrate is good. Examples of polar groups include hydroxyl group (-OH), amine group (-NH ₂ ), carboxyl group (-COOH), etc. The above polar groups may be ionized and stabilized due to the influence of solvents and other functional groups. Therefore, the above "hydroxyl group (-OH)" includes the concept of "-O ^- " in an ionized state, the above "amine group (-NH ₂ )" includes the concept of "-NH ₃ ⁺ " in an ionized state, and the "carboxyl group (-COOH)" includes the concept of "-COO ^- " in an ionized state.

Resins with polar groups are preferably resins that are soluble or dispersed in water, methanol or ethanol. The reason is that uncured resins such as hydrophilic melamine resins have good impregnation properties. Here, "soluble or dispersed in water, methanol or ethanol" means that the following tests are carried out and specific standards are met. That is, refer to JIS K8001:2017 3.2 and perform the following operations.

1) Prepare 100 ml of water, methanol or ethanol as solvent.

2) Add 0.1g (0.1ml in the case of liquid) of each resin to the above solvents at 20℃±5℃.

3) Shake vigorously for 30 seconds every 5 minutes.

4) After 30 minutes, shake vigorously for 30 seconds and then leave it alone for 1 minute. If the following phenomena cannot be confirmed by visual inspection, it is judged as "dissolved or dispersed".

. There is solid sediment at the bottom of the container.

. Phase separation of solvent and resin occurs on the surface of the solvent, in the solvent or at the bottom of the container (oil droplets).

Examples of resins having polar groups include aqueous proteins such as casein, cellulose, cellulose derivatives represented by acetylcellulose, nitrocellulose, hydroxypropylcellulose, carboxymethylcellulose, etc., polyvinyl alcohol derivatives such as polyvinyl alcohol and polyvinyl butyral resin, amino resins such as melamine resin, (meth) acrylic resins, phenolic resins, acrylic polyols, natural polymers (e.g., polynucleotides, polypeptides, polysaccharides), etc.

The pattern layer in the present invention preferably contains casein, melamine resin, polyvinyl alcohol, polyvinyl alcohol derivatives, cellulose and cellulose derivatives as a resin having a polar group, and more preferably contains casein. As casein, α-casein, β-casein, γ-casein or a mixture thereof can be used. In addition, as casein, derivatives represented by sodium caseinate and ammonium caseinate can also be used alone or in combination.

The pattern layer may also contain fillers (such as silicon oxide), physical pigments (such as organic beads), neutralizers, surfactants and other additives as needed. The thickness of the pattern layer is not particularly limited, for example, it is 0.1μm or more and 20μm or less.

As a method for forming a pattern layer, for example, a coating method using a pattern layer forming ink containing a colorant, a binder resin, and a solvent (or a dispersion medium) can be cited. For example, the pattern layer can be obtained by coating the pattern layer forming ink on the surface of the white coating layer opposite to the porous substrate and drying it.

烷、四氫呋喃等醚系有機溶劑；二氯甲烷、四氯化碳、三氯乙烯、四氯乙烯等氯系有機溶劑；水等無機溶劑。 Examples of the solvent (or dispersion medium) include: petroleum-based organic solvents such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, and methylcyclohexane; ester-based organic solvents such as ethyl acetate, butyl acetate, 2-methoxyethyl acetate, and 2-ethoxyethyl acetate; alcohol-based organic solvents such as methanol, ethanol, n-propanol, isopropanol, isobutanol, ethylene glycol, and propylene glycol; ketone-based organic solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether, dimethicone, and the like;

Ether organic solvents such as alkanes and tetrahydrofuran; chlorine organic solvents such as dichloromethane, carbon tetrachloride, trichloroethylene, tetrachloroethylene; inorganic solvents such as water.

As the above-mentioned coating method, for example, a printing method can be cited. As the printing method, for example, gravure printing, offset printing, screen printing, flexographic printing, electrostatic printing, and inkjet printing can be cited.

(3) White coating layer

The white coating layer in the present invention is arranged to cover the entire surface of one side of the porous substrate. The entire surface of one side of the porous substrate refers to an area of more than 90% based on the portion of one side of the porous substrate that functions as a decorative sheet. The white coating layer can be arranged to cover more than 95% of the portion of one side of the porous substrate that functions as a decorative sheet, or it can be arranged to cover 100%.

The "white coating layer is configured to cover the entire surface of one side of the porous substrate" is explained in more detail using some examples. As shown in FIG6(a), when the white coating layer 2 completely covers the porous substrate 1 when viewed from the thickness direction, the white coating layer 2 is configured to cover the entire surface of the porous substrate 1 (100% of the portion that functions as a decorative sheet). Furthermore, as shown in FIG6(b), when both ends of the porous substrate 1 are exposed from the white coating layer 2 when viewed from the thickness direction, the two ends do not function as a decorative sheet. Therefore, the entire surface of the porous substrate 1 is defined except for the area that does not function as a decorative sheet. In FIG. 6(b), the white coating layer 2 is arranged to cover the entire surface of the porous substrate 1 (100% of the portion that functions as a decorative sheet). Similarly, as shown in FIG. 6(c), when the outer edge of the porous substrate 1 is located on the outer side of the outer edge of the white coating layer 2 in the entire circumference when viewed from the thickness direction, the area of the porous substrate 1 exposed from the white coating layer 2 does not function as a decorative sheet. Therefore, the entire surface of the porous substrate 1 is defined except for the area that does not function as a decorative sheet. In FIG. 6(c), the white coating layer 2 is arranged to cover the entire surface of the porous substrate 1 (100% of the portion that functions as a decorative sheet).

On the other hand, in FIG6(d), when viewed from the thickness direction, the entire surface of the porous substrate 1 functions as a decorative sheet. On the other hand, there is a region α where the white coating layer 2 is not formed (for example, an uncoated portion produced for the purpose of design expression) on the inner side of the outer edge of the white coating layer 2. In this case, when the total area of the region α relative to the surface of the porous substrate 1 (the portion that functions as a decorative sheet) does not reach 10%, it can be said that "the white coating layer is configured to cover the entire surface of one side of the porous substrate". In addition, in FIG6(e), when viewed from the thickness direction, the entire surface of the porous substrate 1 functions as a decorative sheet. On the other hand, there is a region α where the white coating layer 2 is not formed in a manner that divides the white coating layer 2 (for example, an uncoated portion produced for the purpose of design expression). In this case, when the total area of the region α relative to the surface of the porous substrate 1 (the portion that functions as a decorative sheet) does not reach 10%, it can be said that "the white coating layer is configured in a manner that covers the entire surface of one surface of the porous substrate." Similarly, in FIG. 6(f), when observed from the thickness direction, the entire surface of the porous substrate 1 functions as a decorative sheet. On the other hand, there is a region α where the white coating layer 2 is not formed. In this case, when the total area of the region α relative to the surface of the porous substrate 1 (the portion that functions as a decorative sheet) is less than 10%, it can be said that "the white coating layer is arranged to cover the entire surface of one side of the porous substrate."

Furthermore, as shown in FIG6(g), when both ends of the porous substrate 1 are exposed from the white coating layer 2 when viewed from the thickness direction, the two ends do not function as decorative sheets. Therefore, the entire surface of the porous substrate 1 is defined except for the area that does not function as a decorative sheet. In FIG6(g), there is an area α (for example, an uncoated portion produced for the purpose of design expression) where the white coating layer 2 is not formed, which is closer to the inner side of the outer edge of the white coating layer 2. In this case, when the total area of the area α that functions as a decorative sheet relative to the surface of the porous substrate 1 does not reach 10%, it can be said that "the white coating layer is configured to cover the entire surface of one side of the porous substrate." Furthermore, as shown in FIG6(h), when the outer edge of the porous substrate 1 is located outside the outer edge O1 of the white coating layer 2 in the entire circumference when viewed from the thickness direction, the area of the porous substrate 1 exposed from the white coating layer 2 outside the outer edge O1 does not function as a decorative sheet. Therefore, the entire surface of the porous substrate 1 is defined except for the area that does not function as a decorative sheet. As shown in FIG6(h), when the outer edge O2 of the white coating layer 2 has a complex shape, the outer edge O1 of the quadrilateral is set so that the area of the white coating layer 2 becomes the largest. Furthermore, in FIG6(h), there is an area α where the white coating layer 2 is not formed. In this case, when the total area of the region α that functions as a decorative sheet relative to the surface of the porous substrate 1 is less than 10%, it can be said that "the white coating layer is arranged to cover the entire surface of one side of the porous substrate."

The white coating layer contains white pigment. Although not particularly limited, examples of white pigment include titanium oxide, calcium carbonate, zinc oxide, barium sulfate, silicon oxide, etc. Among them, titanium oxide and calcium carbonate are preferred. In the present invention, titanium oxide is particularly preferred in terms of good whiteness and concealment. The ratio of white pigment in the white coating layer is, for example, 50% by mass or more, preferably 60% by mass or more. On the other hand, the ratio of white pigment is, for example, 95% by mass or less, preferably 90% by mass or less.

The white coating layer contains, in addition to white pigment, resin components, additives, and solvents (or dispersion media). Examples of the resin components, additives, and solvents (or dispersion media) include the same resin components, additives, and solvents (or dispersion media) as those exemplified in the above-mentioned pattern layer.

In addition, the white coating layer preferably contains a resin having a polar group as a resin component. The reason is that the resin impregnation property in the porous substrate is good. As the resin having a polar group, the same resin having a polar group as the resin exemplified in the above-mentioned pattern layer can be cited.

The white coating layer in the present invention preferably contains casein, melamine resin, polyvinyl alcohol, polyvinyl alcohol derivatives, cellulose and cellulose derivatives as a resin having a polar group, and more preferably contains casein. As casein, α-casein, β-casein, γ-casein or a mixture thereof can be used. In addition, as casein, derivatives represented by sodium caseinate and ammonium caseinate can also be used alone or in combination.

Furthermore, when observing the decorative sheet from the thickness direction, the ratio (S ₂ /S ₁ ) of the area S ₂ of the white area (area not covered by the pattern layer) in the white coating layer to the entire area S ₁ of the white coating layer is, for example, 5% or more, and can be 10% or more. When the above ratio (S ₂ /S ₁ ) is within the above range, the design effect of the white area can be fully obtained. On the other hand, the above ratio (S ₂ /S ₁ ) is, for example, 95% or less, 80% or less, or 70% or less.

In the area exposed from the release layer observed from the thickness direction, the pure water contact angle is preferably lower. The area exposed from the release layer observed from the thickness direction refers to the area where the white coating layer is formed and the release layer is not formed. The surface of the area exposed from the release layer can be the surface of the white coating layer or the surface of the pattern layer. The reason is that the impregnation property of uncured resins such as hydrophilic melamine resins is good. The pure water contact angle is obtained by the following method. That is, the decorative sheet is placed on a horizontal plane in such a way that the release layer side becomes the upper surface. Next, water drops (pure water, 2.0μL) are dripped onto the white coating layer from a direction perpendicular to the horizontal plane. At this time, the water droplets do not drip onto the boundary between the white coating layer and the release layer, for example, but drip in a manner that all the water droplets contact the area exposed from the release layer. After dripping the water droplets, wait for 1 second and use a contact angle meter (fully automatic contact angle meter DMo-702, manufactured by Kyowa Interface Science Co., Ltd.) to measure the contact angle between the white coating layer and pure water. The above measurement is performed at any 10 locations, and the average value is set as the pure water contact angle. The pure water contact angle can be less than 80.0°, less than 70.0°, or less than 60.0°. On the other hand, the pure water contact angle can also be 0°. That is, pure water can completely penetrate the decorative sheet.

In the present invention, the wettability in the area exposed from the release layer is preferably higher. The reason is that the impregnation of uncured resins such as hydrophilic melamine resins is good. The wettability is obtained by the following method.

1) Prepare tension testers with dynamometer factors of 40mN/m, 46mN/m, 50mN/m, 54mN/m, 60mN/m, 67mN/m, and 70mN/m (manufactured by Pacific Chemical Co., Ltd.).

2) Use a tension tester to draw a line of more than 30 cm on the surface of the decorative sheet. At this time, do not just draw the line on the release layer, but make sure that the line includes the area exposed from the release layer.

3) After drawing the line, wait for 2 seconds and wipe the surface with a dry cloth. Afterwards, visually check whether there are ink marks or discoloration caused by the tension tester in the white area. This operation is performed 3 times with 1 dynamometer.

4) Use the prepared factors to implement the above operations 2) and 3) respectively.

5) The largest value among the results of 4) above where ink marks or discoloration are observed (including the case where ink marks or discoloration are observed even once out of 3 times) is determined as the wettability of the decorative sheet.

The above-mentioned wettability is, for example, 50 mN/m or more, 54 mN/m or more, or 60 mN/m or more. On the other hand, the above-mentioned wettability is, for example, 70 mN/m or less.

The ratio of the resin having a polar group to the resin component contained in the white coating layer is, for example, 20% by mass or more, 30% by mass or more, 40% by mass or more, or 50% by mass or more. On the other hand, the ratio of the resin having a polar group is, for example, 100% by mass or less, or 90% by mass or less. If the content of the resin having a polar group is within the above range, the penetration of the ink of the release layer into the porous substrate can be further suppressed without hindering the penetration of the uncured resin into the porous substrate.

In addition, the white coating layer may have other resins as resin components in addition to the above-mentioned resins having polar groups. Examples of other resins include: (meth) acrylic resins, ester urethane resins, acrylamide resins, ethylene oxide resins, N-vinyl pyrrolidone resins, ester resins, amide resins, vinyl acetate resins, vinyl chloride resins, urethane (meth) acrylic resins, natural rubbers, and synthetic rubbers. Among them, (meth) acrylic resins and urethane (meth) acrylic resins are preferred.

The thickness of the white coating layer is not particularly limited, for example, it is 1 μm or more, preferably 2 μm or more, and can be 3 μm or more. If the thickness of the white coating layer is within the above range, it has excellent whiteness. On the other hand, it is preferably 8 μm or less, and can be 6 μm or less. If the thickness of the white coating layer is within the above range, the resin impregnation in the porous substrate is good. The thickness of the white coating layer is the average value of the thickness measured at 10 locations by observing the cross section obtained by cutting the decorative sheet along the thickness direction using an optical microscope.

The coating weight (basis weight) of the white coating layer is not particularly limited, and is, for example, 1.0 g/m ² or more, preferably 2.0 g/m ² or more, and can be 3.0 g/m ² or more. If the coating weight of the white coating layer is greater than the above value, a white coating layer having excellent whiteness can be obtained. On the other hand, the coating weight (basis weight) of the white coating layer is, for example, preferably less than 10 g/m ² , and can be less than 8 g/m ^2. If the coating weight of the white coating layer is less than the above value, the resin impregnation in the porous substrate is good.

In the present invention, the 75° gloss value of the white area (area not covered by the pattern layer) of the white coating layer is, for example, 6.0 or more, preferably 8.0 or more, and more preferably 10.0 or more. If the 75° gloss value of the white area of the white coating layer is within the above range, it is easy to obtain a resin-impregnated decorative board that can express a white design. On the other hand, the 75° gloss value is, for example, 25.0 or less, preferably 20.0 or less. If the 75° gloss value of the white area of the white coating layer is within the above range, it is possible to prevent the melamine impregnation from being hindered by the white coating layer and maintain good processability.

In the present invention, the 75° gloss value of the white area of the white coating layer is the 75° mirror gloss measured according to method 2 of JIS Z 8741:1997, and is measured by the following method.

Place the decorative sheet with the release layer facing upward, and use a gloss meter to measure the 75° mirror gloss from the release layer side according to JIS Z 8741:1997 method 2.

The 75° gloss value of the white area of the white coating layer is the average value of the measured values of any 10 locations of the white area (area not covered by the pattern layer). At each measured location, the white area of the white coating layer is located at the center of the measurement area of the gloss meter, and the area ratio of the white area is confirmed to be more than 50% of the area of the measurement area for measurement.

The 75° gloss value of the white area of the white coating layer can be increased by increasing the thickness of the white coating layer, and can be reduced by reducing the thickness of the white coating layer.

As a method for forming a white coating layer, for example, a coating method using a white coating layer ink containing a white pigment, a resin component, an additive, and a solvent (or a dispersion medium) can be cited. For example, a white coating layer is obtained by coating the white coating layer ink on one side of a porous substrate and drying it.

烷、四氫呋喃等醚系有機溶劑；二氯甲烷、四氯化碳、三氯乙烯、四氯乙烯等氯系有機溶劑；水等無機溶劑。 Examples of the solvent (or dispersion medium) include: petroleum-based organic solvents such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, and methylcyclohexane; ester-based organic solvents such as ethyl acetate, butyl acetate, 2-methoxyethyl acetate, and 2-ethoxyethyl acetate; alcohol-based organic solvents such as methanol, ethanol, n-propanol, isopropanol, isobutanol, ethylene glycol, and propylene glycol; ketone-based organic solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether, dimethicone, and the like;

Ether organic solvents such as alkanes and tetrahydrofuran; chlorine organic solvents such as dichloromethane, carbon tetrachloride, trichloroethylene, tetrachloroethylene; inorganic solvents such as water.

In addition, as coating methods for forming the white coating layer, for example, various coating methods such as roller coating, scraper coating, air knife coating, die nozzle coating, die lip coating, notch wheel coating, contact coating, flow coating, and immersion coating can be cited. As printing methods, for example, gravure printing can be cited.

The white coating layer can be arranged in a manner to cover the entire surface of one side of the porous substrate by coating once, or can be arranged in a manner to cover the entire surface of one side of the porous substrate by coating multiple times. In the latter case, the layer formed by coating once can have a pattern.

(4) Porous substrate

The porous substrate in the present invention is a substrate impregnated with an uncured resin (curable resin Y) such as a thermosetting resin when manufacturing a resin-impregnated decorative board. As a porous substrate, for example, a permeable fiber substrate can be cited. As a permeable fiber substrate, for example, paper, synthetic paper, non-woven fabric, woven fabric can be cited. As the above-mentioned paper, for example, titanium paper, thin paper, kraft paper, short-pile paper, paperboard, gypsum board paper, high-grade paper, painted paper, parchment paper, Japanese paper can be cited. In addition, as a fiber substrate, a vinyl wallpaper stock sheet (paper on which a polyvinyl chloride resin is dry-laminated) can also be used. As other examples of fiber substrates, nonwoven fabrics or woven fabrics containing synthetic resin fibers such as polyester, vinyl, polyethylene, and polypropylene can be cited. Among these porous substrates, titanium paper, thin paper, kraft paper, coated paper, copperplate paper, sulphate paper, glass paper, parchment paper, wax paper, and Japanese paper are preferred in terms of impregnation with thermosetting resins. In the present invention, titanium paper is preferred from the perspective of obtaining the above-mentioned L* value. Furthermore, titanium paper is excellent in impregnation with curable resin Y.

The porous substrate can also be colored. For example, a porous substrate colored in white can be obtained by mixing a white pigment in the manufacturing stage of the porous substrate. For example, when the porous substrate is paper, a white paper colored in white can be obtained by mixing a white pigment such as titanium dioxide in the papermaking stage. In addition, the amount of white pigment mixed is not particularly limited as long as it is an amount that is a ratio of the above-mentioned ash content. In particular, the white pigment used in the porous substrate constituting the decorative sheet of the present invention needs to be used for the function of adjusting the whiteness of the porous substrate and the function of adjusting the permeability of the porous substrate. In the present invention, the type and amount of white pigment are set in a manner to obtain the above-mentioned L* value and the above-mentioned ash content is within a specified range, that is, in a manner to adjust the permeability of the porous substrate. In addition, the porous substrate may also contain various additives such as fillers, matting agents, foaming agents, flame retardants, lubricants, antistatic agents, antioxidants, ultraviolet absorbers, light stabilizers, etc. as needed.

The basis weight of the porous substrate is not particularly limited, and is, for example, 40 g/m ² or more and 150 g/m ² or less. The thickness of the porous substrate is not particularly limited, and is, for example, 50 μm or more and 170 μm or less. For example, in order to improve the adhesion of the ink forming the white coating layer, the surface of the porous substrate on the white coating layer side may be subjected to a corona discharge treatment.

3. Decorative sheets

The b* value of the white area of the decorative sheet in the present invention in the L*a*b* colorimetric system is preferably 4.5 or less, and more preferably 4.0 or less. If such a decorative sheet is used, a resin-impregnated decorative board with high whiteness and suppressed yellow tones can be obtained. On the other hand, the above b* value is, for example, 3.0 or more.

The decorative sheet in the present invention is used to manufacture a resin-impregnated decorative board. Since the resin-impregnated decorative board will be described below, the description is omitted here.

When the decorative sheet of the present invention is subjected to an impregnation test using melamine resin, the impregnation amount of the melamine resin of the decorative sheet is, for example, 35 g/ ^m2 or more, and can be 45 g/ ^m2 or more. On the other hand, the impregnation amount of the melamine resin of the decorative sheet is, for example, 80 g/m2 or less, and can be 60 g/ ^m2 or less. The details of the impregnation test will be described in the embodiments described below.

B. Resin impregnated decorative board

The resin impregnated decorative board of the present invention will be described in detail below. FIG. 2 is a schematic cross-sectional view of the resin impregnated decorative board of the present invention. The resin impregnated decorative board 100 shown in FIG. 2 comprises: the decorative sheet 10 described above; a core substrate 20, which is arranged opposite to the porous substrate 1 in the decorative sheet; and a hardened resin layer 32, which is arranged in the white area X and contains a hardened product of the hardening resin Y; the core substrate 20 and the porous substrate 1 contain a hardened product of the hardening resin Y. When the resin impregnated decorative board 100 of the present invention measures the L* value in the white area X through the hardened resin layer 32, its L* value is 88.0 or more.

Since the resin-impregnated decorative board of the present invention has the above-mentioned decorative sheet, it can express a white design and stably express a glossy matte design.

1. Decorative sheets

Details about the decorative sheets are as mentioned above.

2. Core substrate

The resin-impregnated decorative board of the present invention has a porous core substrate 20 on the surface of the porous substrate 1 side of the decorative sheet 10 (the surface of the decorative sheet 10 located on the porous substrate 1 side based on the white coating layer 2). As the core substrate 20, for example, phenolic resin impregnated paper can be cited. Phenolic resin impregnated paper is, for example, paper obtained by impregnating kraft paper as a core paper with phenolic resin and drying it.

3. Hardened material of hardening resin and hardening resin layer

The core substrate and the porous substrate in the present invention contain a cured product of a curable resin Y. The resin-impregnated decorative board has a cured resin layer disposed in the white area. As described later, the cured product of the curable resin filled in the core substrate and the porous substrate and the cured product of the curable resin contained in the curable resin layer are formed by the same curable resin Y. Such curable resins are, for example, cured products of thermosetting resins described later.

The thickness of the hardened resin layer is not particularly limited, and may be, for example, 1 μm or more, or 10 μm or more. On the other hand, it may be, for example, 500 μm or less, or 300 μm or less.

4.L* value

When the L* value of the resin-impregnated decorative board in the present invention is measured in the white area X through the hardened resin layer 32, the L* value is 88.0 or more, and can be 90.0 or more. On the other hand, the above L* value is not particularly limited, for example, it can be 92.0 or less, and can also be 91.0 or less.

5. Manufacturing method

FIG3 is a schematic cross-sectional view illustrating a method for manufacturing a resin-impregnated decorative board using the decorative sheet of the present invention.

First, as shown in FIG. 3(a) and FIG. 3(b), a thermosetting resin layer 30' is formed on the porous substrate 1 of the decorative sheet 10, with one side interposed with the white coating layer 2 impregnated with the thermosetting resin and the other side containing the thermosetting resin and covering the white coating layer 2, the pattern layer 3 and the release layer 4. As the thermosetting resin, a wide range of thermosetting resins can be used. Examples of the thermosetting resin include melamine resins (melamine resin precursors), melamine-urea cocondensate resins, unsaturated polyester resins, polyurethane resins (including two-component curing polyurethanes), epoxy resins, aminoalkyd resins, phenol resins, urea resins, diallyl phthalate resins, guanamine resins, silicone resins, and polysiloxane resins. As the impregnation method of the thermosetting resin, for example, there can be cited: a method of immersing the decorative sheet 10 in a bath containing the thermosetting resin; a method of applying the thermosetting resin to the decorative sheet 10 by a coating machine such as a contact coating machine or a notch wheel coating machine; a method of blowing the thermosetting resin to the decorative sheet 10 by a spraying device or a shower device.

Furthermore, as shown in FIG. 3(c), a release film 40 is arranged on the side of the thermosetting resin layer 30' opposite to the white coating layer 2, and a core substrate 20 is arranged on the surface of the decorative sheet 10 on the porous substrate 1 side (the surface of the decorative sheet 10 located on the porous substrate 1 side with the white coating layer 2 as the reference) to produce the first laminate 51'. Furthermore, the release film may have a peeling layer containing a cured product of the ionizing radiation curing resin composition on the surface opposite to the thermosetting resin layer.

Next, as shown in FIG3(d), the first laminate 51' is heated and pressurized to harden the thermosetting resin, and the thermosetting resin layer 30' is used to form a hardened resin layer 31' to produce the second laminate 52'. The heating temperature is, for example, 90°C to 160°C. The heating time is, for example, 30 seconds to 30 minutes. In addition, by applying pressure, the smoothness of the release film 40 is reflected on the surface of the hardened resin layer 31'.

Next, as shown in FIG3(e), the release film 40 is peeled off from the second laminate 52', and the hardened resin layer 31' between the release layer 4 and the release film 40 is also peeled off toward the release film 40. At this time, the hardened resin layer 31' that is not peeled off toward the release film 40 becomes the hardened resin layer (glossy layer) 32. Thus, a resin-impregnated decorative board 100 is obtained, which has a porous substrate 1, a white coating layer 2 disposed on the entire surface of one side of the porous substrate 1, a pattern layer 3 partially disposed on the surface of the white coating layer 2 opposite to the porous substrate 1, a release layer (matte layer) 4 disposed on the surface of the pattern layer 3 opposite to the white coating layer 2 and having a pattern shape, and a hardened resin layer (glossy layer) 32 disposed on the white area of the decorative sheet.

The resin impregnated decorative board of the present invention is used, for example, by being arranged on the surface of a substrate. As the substrate, for example, wooden components, resin components, metal components, and kiln components can be cited. As wooden components, for example, wooden veneer, wooden plywood, plastic plywood, and wooden fiberboard can be cited. As the wood used for the wooden components, for example, cedar, cypress, pine, and lauan can be cited. Examples of resins used in resin components include vinyl chloride resins, (meth) acrylic resins, ester resins, styrene resins, olefin resins, acrylonitrile-butadiene-styrene copolymers (ABS resins), phenolic resins, cellulose resins, carbonate resins, melamine resins, and rubber. Examples of metals used in metal components include iron and aluminum. The material of kiln components may be ceramics such as glass and ceramics, non-cement kiln materials such as gypsum, and non-ceramic kiln materials such as ALC (lightweight aerated concrete).

Examples of uses of the resin-impregnated decorative board of the present invention include: building materials and furniture. Building materials can be interior materials or exterior materials. Examples of building materials include: walls, floors, ceilings, doors, and sheds. Examples of furniture include: tables, desks, and cabinets.

The present invention is not limited to the above-mentioned implementation methods. The above-mentioned implementation methods are illustrative, and any method having substantially the same structure and exerting the same effect as the technical idea described in the scope of the patent application of the present invention is included in the technical scope of the present invention.

[Implementation example] [Implementation Example 1] (Manufacturing of decorative sheets)

Titanium paper (PM-77P, manufactured by KJ Special Paper Co., Ltd.) with a basis weight of 80 g/ ^m2 was prepared as a porous substrate, and a white coating layer with a thickness of 2 μm was formed on the entire surface of one side of the porous substrate by gravure printing using a printing ink for forming a white coating layer having the following composition. Furthermore, a patterned layer with a stone pattern was formed on the surface of the white coating layer opposite to the porous substrate using a printing ink for forming a patterned layer having the following composition.

<Printing ink for forming white coating layer>

．White pigment (titanium oxide) 40 parts by weight

．Casein/acrylic resin (mass ratio 45:55) 10 parts by mass

． 40 parts by weight of water

． 5 parts by weight of dipropylene glycol

． 5 parts by weight of isopropyl alcohol

<Ink for pattern layer formation>

． Pigments (azo, quinacridone, carbon black, etc.) 10 parts by weight

．Casein/acrylic acid (mass ratio 45:55) 10 parts by mass

． 70 parts by weight of water

． 5 parts by weight of dipropylene glycol

． 5 parts by weight of isopropyl alcohol

Using PROCESS HOMOGENIZER PH91 (manufactured by SMT Co., Ltd.), 60 parts by mass of ionizing radiation curable monomer (ARONIX M400 manufactured by Toagosei Co., Ltd.), 0.6 parts by mass of reactive silicone (X-22-164B manufactured by Shin-Etsu Chemical Co., Ltd.), and 40 parts by mass of methyl ethyl ketone (Maruzen Petrochemical Co., Ltd.) were stirred at a rotation speed of 2000 rpm for 1 hour to prepare the ink for forming the release layer.

Furthermore, a release layer-forming ink was applied to the pattern layer in the same manner as the stone pattern of the pattern layer, and electron beam irradiation of 3 Mrad was performed at an accelerating voltage of 165 kV to form a release layer with a thickness of 2 μm having a pattern shape. In this way, a decorative sheet having a porous substrate, a white coating layer, a pattern layer, and a release layer having a pattern shape was manufactured in this order. Furthermore, when viewed in the thickness direction, the ratio (S ₂ /S ₁ ) of the area S ₂ of the white region (region not covered by the pattern layer) to the entire area S ₁ of the white coating layer is adjusted to be 50% or more and 60% or less in all examples and comparative examples described below.

(Production of release membrane)

A coating liquid containing 100 parts by mass of an ionizing radiation curable monomer, 2 parts by mass of a reactive silicone, 8 parts by mass of silicon oxide, and 50 parts by mass of ethyl acetate was applied at a weight of 5 g/m ² (dry) on the adhesive surface of a 50 μm thick polyethylene terephthalate film (COSMOSHINE (registered trademark) A4160 manufactured by Toyobo Co., Ltd.) and cured by irradiating an electron beam of 5 Mrad at an accelerating voltage of 165 kV. Thus, a release film having a cured resin layer was manufactured.

(Production of melamine decorative panels)

The decorative sheet to be manufactured was impregnated with a liquid uncured melamine resin composition containing 60 parts by mass of an uncured melamine resin (water-soluble hydroxymethyl melamine resin, Nikaresin S-260 manufactured by Nippon Carbide Industries) 35 parts by mass of water and 5 parts by mass of isopropyl alcohol using an impregnation device so that the ratio of the uncured melamine resin composition became 80 g/m ² (drying), and dried to manufacture an impregnated decorative sheet.

The impregnated decorative sheet was laminated on three sheets of phenolic resin impregnated core paper (made by impregnating ^core kraft paper with a liquid uncured resin composition containing phenolic resin) with a basis weight of 245 g/m2, which was made by impregnating kraft paper with phenolic resin liquid. Furthermore, the above-mentioned release film was laminated on the release layer side of the impregnated decorative sheet in such a way that the cured resin layer of the release film was in contact with the printed surface of the impregnated decorative sheet, thereby obtaining the first laminate. The formed laminate was sandwiched between two mirror panels and heat-molded using a hot press at a pressure of 100 kg/ ^cm2 , a molding temperature of 150°C, and 10 minutes to produce a molded body (the second laminate). In the molded body, a melamine resin layer containing a hardened melamine resin is formed between the release layer and the release film.

By peeling off the release film from the hardened resin layer of the hardened material containing melamine resin, the portion of the hardened resin layer covered with the release layer is removed. In the portion where the release layer is not provided, the unpeeled hardened resin layer remains as a glossy layer. In this way, a melamine decorative board is obtained.

[Example 2]

Except that the thickness of the white coating layer is set to 6 μm, the decorative sheet is manufactured in the same manner as in Example 1 to obtain a melamine decorative board.

[Implementation Example 3]

Except that the thickness of the white coating layer is set to 1 μm, the decorative sheet is manufactured in the same manner as in Example 1 to obtain a melamine decorative board.

[Implementation Example 4]

Except that the porous substrate is changed to KW801P manufactured by KJ Special Paper Co., Ltd., the decorative sheet is manufactured in the same manner as in Example 1 to obtain a melamine decorative board.

[Implementation Example 5]

Except that the porous substrate is changed to PM-79P manufactured by KJ Special Paper Co., Ltd., the decorative sheet is manufactured in the same manner as in Example 1 to obtain a melamine decorative board.

[Comparative example 1]

Except that the white coating layer is not formed, the decorative sheet is manufactured in the same manner as in Example 1 to obtain a melamine decorative board.

[Comparative example 2]

Except that the printing ink of the white coating layer is changed to transparent ink (not containing titanium oxide), the decorative sheet is manufactured in the same manner as in Example 1 to obtain a melamine decorative board.

[Comparative example 3]

Except that the porous substrate is changed to PM-28P manufactured by KJ Special Paper Co., Ltd., the decorative sheet is manufactured in the same manner as in Example 1 to obtain a melamine decorative board.

[Comparative example 4]

Except that the porous substrate is changed to KSH801P manufactured by KJ Special Paper Co., Ltd., the decorative sheet is manufactured in the same manner as in Example 1 to obtain a melamine decorative board.

[Ash content determination]

The ash content of the decorative sheet produced above was measured by the above method. The results are shown in Table 1.

[Evaluation] (L* value and b* value of decorative sheets and melamine decorative boards)

By the above method, the L* value and b* value of the white area of the decorative sheet manufactured above in the L*a*b* color system, and the L* value and b* value of the white area measured in the L*a*b* color system of the intervening hardened resin layer of the melamine decorative board were measured. The results are shown in Table 1.

(75° gloss value of decorative sheet)

The 75° gloss value of the white area of the decorative sheet manufactured above was measured by the above method. The results are shown in Table 1.

(Pure water contact angle)

By the above method, the pure water contact angle in the area exposed from the release layer of the decorative sheet manufactured above was measured. The results are shown in Table 1.

[Determination of wettability]

The wettability of the decorative sheet exposed from the release layer was measured by the above method. The results are shown in Table 1.

(White design evaluation)

The white design of melamine decorative board was evaluated by visual observation. The evaluation used separately prepared reference melamine decorative board 1 and reference melamine decorative board 2 as the whiteness standard.

The standard melamine decorative board 1 is prepared by impregnating an uncured melamine resin composition in titanium paper (manufactured by KJ Special Paper Co., Ltd., PM-77P) and hot pressing in the same manner as in Example 1 (manufacture of melamine decorative board). The standard melamine decorative board 2 is prepared by impregnating an uncured melamine resin composition in titanium paper (manufactured by KJ Special Paper Co., Ltd., KW801P) and hot pressing in the same manner as in Example 1 (manufacture of melamine decorative board).

Observers visually compared the standard melamine decorative board 1 and the standard melamine decorative board 2 with the decorative boards produced in the embodiment and the comparative example. Each standard decorative board used was scored on a 1-5 scale (3 points equal to the standard, 1 point for the lowest white design, and 5 points for the highest white design). Ten observers performed the test, calculated the average score of all observers, and evaluated the white design according to the following criteria.

．Evaluation criteria

A: Regardless of whether the standard melamine decorative board 1 or 2 is used, the average score is 3 points or more.

B: The average score was less than 3 points when using the standard melamine decorative board 2, but the average score was more than 3 points when using the standard melamine decorative board 1.

C: Regardless of whether the standard melamine decorative board 1 or 2 was used, the average score was less than 3 points, and red or yellow was observed.

(Gloss and matte design evaluation)

The gloss and matte design of the melamine decorative board was evaluated visually. Specifically, the decorative board was visually observed from a distance of 50 cm under the light source of natural color fluorescent lamp color rendering AA (manufactured by Panasonic Co., Ltd., model: FLR40S.D-SDL/M) to confirm the gloss and matte design and the state of the matte part (release layer).

The observers rated the gloss-matte design on a scale of 1 to 5 (1 is the worst and 5 is the best). In addition, if most of the melamine peeling residues or significant whitening were observed in the matte part and the vicinity, and the gloss-matte design could not be confirmed, the evaluation was 1 point, and if the melamine peeling residues were not confirmed in the matte part, and the gloss-matte design could be confirmed, the evaluation was 5 points. The evaluation was carried out by 10 observers, and the average score of all observers was calculated, and the gloss-matte design was evaluated according to the following criteria.

．Evaluation criteria

A: The average score for evaluating gloss and matte design is 3 points or more

B: The average score for evaluating gloss and matte design is 2 points or more and less than 3 points

C: The average score for evaluating gloss and matte design is less than 2 points

(Impermeability evaluation)

The impregnation properties of the manufactured decorative sheets were evaluated by the following method.

1) Cut a circular sample with a radius of 2 cm from the decorative sheet and measure the sample mass (sample mass before the test).

2) FIG. 4(a) is a schematic cross-sectional view of the container used in the impregnation evaluation, and FIG. 4(b) and (c) are a schematic cross-sectional view and a schematic three-dimensional view of the container cover. As shown in FIG. 4, a polyethylene container (internal volume of about 300 ml) 51 having a first opening O1 (FIG. 4(a)) and a cover 52 having a second opening O2 that can be fixed to the container 51 (FIG. 4(b) and FIG. 4(c)) are prepared. The first opening is in the shape of a circle with a diameter of 3 cm (impregnation area of about 0.0007 ^m2 ). As shown in FIG. 5( a ), 100 g of uncured melamine resin U (60 g of water-soluble hydroxymethyl melamine resin (Nikaresin S-260 manufactured by Nippon Carbide Co., Ltd.) dissolved in 40 g of pure water) is placed inside the container 51. Next, the sample S is arranged so as to cover the first opening O1. Next, the container 51 is fixed with the lid 52 and the sample S is set. At this time, the sample S is set so that the surface of the white coating layer faces the inner side of the container.

3) As shown in Figure 5(b), turn the container 51 over so that the uncured melamine resin U is impregnated into the sample S.

4) After 30 seconds, as shown in Figure 5(c), turn the container 51 over again and quickly take out the sample S.

5) As shown in Figure 5(d), use a metal plate 53 to scrape and remove the unimpregnated melamine resin 54 remaining on the surface of the white coating layer of sample S.

6) As shown in Figure 5(e), sample S was dried at 80°C for 1 minute and the mass was measured again (mass of the sample after the test).

The melamine resin impregnation amount (g/m ² ) of the decorative sheet was calculated using the following formula, and the evaluation was performed according to the following evaluation criteria. The results are shown in Table 1.

Melamine resin impregnation amount (g/m ² ) = {sample mass after test (g) - sample mass before test (g)} / container opening area (m ² )

．Evaluation criteria

A: Melamine resin impregnation content is 45g/m2 or ^more

B: The melamine resin content is 35g/ ^m2 or more and less than 45g/ ^m2

C: Melamine resin impregnation content is less than 35g/ ^m2

As shown in Table 1, the decorative sheets of Examples 1 to 5 can produce melamine decorative boards with good white design and glossy matte design. On the other hand, the white design of the melamine decorative board produced using the decorative sheet without a pure color layer as in Comparative Example 1 is low. The white design of the melamine decorative board produced using the decorative sheet with a pure transparent layer without white pigment as in Comparative Example 2 is also low. Although Comparative Example 3 is provided with a white coating layer, the ash content of the decorative sheet is low, so the white design of the melamine decorative board is low. In Comparative Example 4, since the decorative sheet has a higher ash content, the ink used in the release layer will penetrate, so the glossy and matte design is lower.

Thus, in the present invention, for example, the following invention is provided.

[1]

A decorative sheet material used for manufacturing a resin impregnated decorative board, and the decorative sheet material comprises: a porous substrate; a white coating layer, which is disposed on the entire surface of one side of the porous substrate and contains a white pigment; a pattern layer, which is partially disposed on the surface of the white coating layer opposite to the porous substrate; a release layer, which is disposed on the surface of the pattern layer opposite to the white coating layer and has a pattern shape; the white coating layer has a white area not covered by the pattern layer, the L* value in the white area is 93.0 or more, and the ash content contained in the decorative sheet is 20.0 mass % or more and 40.0 mass % or less.

[2]

The decorative sheet material as described in [1], wherein the white pigment is at least one of titanium oxide and calcium carbonate.

[3]

A decorative sheet as described in [1] or [2], wherein the thickness of the white coating layer is greater than 1 μm and less than 8 μm.

[4]

A decorative sheet as described in any one of [1] to [3], wherein the porous substrate comprises titanium paper.

[5]

A decorative sheet material as described in any one of [1] to [4], wherein the ash content in the decorative sheet material is not less than 22.0 mass % and not more than 30.0 mass %.

[6]

A decorative sheet as described in any one of [1] to [5], wherein the b* value of the white area of the decorative sheet is less than 4.50.

[7]

A decorative sheet as described in any one of [1] to [6], wherein the 75° gloss value of the white area of the decorative sheet is greater than 6.0.

[8]

A decorative sheet as described in any one of [1] to [7], wherein the pure water contact angle of the decorative sheet in the region exposed from the release layer when viewed in the thickness direction is less than 80.0°.

[9]

A decorative sheet as described in any one of [1] to [8], wherein the wettability of the decorative sheet in the area exposed from the release layer when observed in the thickness direction is 50 mN/m or more.

[10]

A decorative sheet as described in any one of [1] to [9], wherein the white coating layer contains a resin component, and the resin component includes a resin having a polar group.

[11]

The decorative sheet described in [10], wherein the ratio of the resin having a polar group to the resin component contained in the white coating layer is 20% by mass or more and 100% by mass or less.

[12]

A decorative sheet material as described in any one of [1] to [11], wherein the resin-impregnated decorative board is a melamine decorative board.

[13]

A decorative sheet as described in any one of [1] to [12], wherein the release layer contains a cured product of a curable resin X.

[14]

The decorative sheet described in [13], wherein the curable resin X is an ionizing radiation curable resin.

[15]

The decorative sheet described in [14], wherein the ionizing radiation curable resin is an electron beam curable resin.

[16]

A resin-impregnated decorative board comprising: a decorative sheet as described in any one of [1] to [15]; a core substrate arranged to face the porous substrate in the decorative sheet; a hardened resin layer arranged in the white area and containing a hardened product of a hardening resin Y; the core substrate and the porous substrate contain a hardened product of the hardening resin Y, and when the L* value in the white area is measured through the hardened resin layer, the L* value is 88.0 or more.

1: Porous substrate

2: White coating layer

3: Pattern layer

4: Release layer

10: Decorative sheets

X: White area

Claims (16)

A decorative sheet material used for manufacturing a resin-impregnated decorative board, and the decorative sheet material has: a porous substrate; a white coating layer, which is disposed on the entire surface of one side of the porous substrate and contains a white pigment; a pattern layer, which is partially disposed on the surface of the white coating layer opposite to the porous substrate; and a release layer, which is disposed on the surface of the pattern layer opposite to the white coating layer and has a pattern shape; the white coating layer has a white area not covered by the pattern layer, the L* value in the white area is 93.0 or more, and the ash content contained in the decorative sheet material is 20.0 mass % or more and 40.0 mass % or less. A decorative sheet as claimed in claim 1, wherein the white pigment comprises at least one of titanium oxide and calcium carbonate. The decorative sheet of claim 1, wherein the thickness of the white coating layer is not less than 1 μm and not more than 8 μm. A decorative sheet as claimed in claim 1, wherein the porous substrate comprises titanium paper. The decorative sheet material of claim 1, wherein the ash content in the decorative sheet material is not less than 22.0 mass % and not more than 30.0 mass %. The decorative sheet of claim 1, wherein the b* value of the white area of the decorative sheet is less than 4.50. The decorative sheet of claim 1, wherein the 75° gloss value of the white area of the decorative sheet is greater than 6.0. The decorative sheet of claim 1, wherein the pure water contact angle of the region exposed from the release layer when viewed from the thickness direction of the decorative sheet is less than 80.0°. The decorative sheet of claim 1, wherein the wettability of the decorative sheet in the area exposed from the release layer when viewed in the thickness direction is 50 mN/m or more. As for the decorative sheet of claim 9, the above-mentioned white coating layer further contains a resin component, and the resin component includes a resin having a polar group. The decorative sheet of claim 10, wherein the ratio of the resin having a polar group to the resin component contained in the white coating layer is greater than 20 mass % and less than 100 mass %. The decorative sheet material of claim 1, wherein the resin-impregnated decorative board is a melamine decorative board. The decorative sheet of claim 1, wherein the release layer contains a cured product of the curable resin X. The decorative sheet of claim 13, wherein the curable resin X is an ionizing radiation curable resin. The decorative sheet of claim 14, wherein the ionizing radiation curable resin is an electron beam curable resin. A resin-impregnated decorative board, comprising: A decorative sheet as claimed in any one of claims 1 to 15; A core substrate disposed opposite to the porous substrate in the decorative sheet; and A hardened resin layer disposed in the white area and containing a hardened product of hardening resin Y; The core substrate and the porous substrate contain a hardened product of hardening resin Y, When the L* value in the white area is measured through the hardened resin layer, the L* value is 88.0 or more.