Recoatable decorative sheet and coloring method for decorative sheet using the same

Abstract

To provide a decorative sheet for recoat that has excellent staynability and is excellent also in surface characteristics such as water resistance, and a coloring method of the decorative sheet therewith.SOLUTION: A decorative sheet for recoat comprises a paper substrate, an adhesive layer, a non-woven fabric layer, and a surface layer constituted of a cured material of a composition containing a polyol compound having a hydroxyl group in one molecule and an isocyanate curing agent in this order, in which the non-woven fabric layer partially has, on a surface side on which the adhesive layer is provided in a thickness direction in the layer is provided, a filling layer A formed by filling a resin that forms the adhesive layer on a part of voids of fibers constituting the non-woven fabric, and on a surface side provided with the surface layer in the thickness direction in the layer, a filling part B formed by filling the cured material in a part of void of fibers constituting the non-woven fabric, in which a content of remaining hydroxyl groups contained in the surface layer and a ratio of an amount of isocyanate groups in the isocyanate curing agent, and an amount of hydroxyl groups in the polyol compound are in a predetermined range, and a coloring method of the decorative sheet therewith is also provided.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a decorative sheet for recoating and a method for coloring a decorative sheet using the same. [Background technology]

[0002] It is common practice, mainly in Europe and the United States, for ordinary consumers to paint the surfaces of wooden building interior materials, furniture surfaces, etc., using colored paints such as water-based or oil-based stain paints, and to paint the surfaces of wooden furniture, etc. (DIY: Do It Yourself).Such stain paints penetrate into the wood to color it, and because they do not conceal the wood grain itself or form a film on the surface, they have the advantage of making the most of the wood's unique design and appearance, such as the grain and luster (pearl-like luster).

[0003] In recent years, decorative sheets made by laminating a sheet-like substrate with a printed wood grain pattern on its surface have come to be used instead of natural wood as interior materials for buildings, surface materials for furniture, etc., and decorative sheets that can be stained using the above-mentioned stain paints have been manufactured. Specifically, these recoatable decorative sheets are surface-treated to ensure the adhesion of stain paint, assuming that the purchaser will achieve the desired texture by coating the stain paint themselves.

[0004] Proposed examples of such decorative sheets include recoatable decorative sheets in which a pattern layer is printed on a polyvinyl chloride (PVC) resin substrate and then heat-fused to a nonwoven fabric (see, for example, Patent Document 1), and stainable decorative sheets that use a paper substrate and nonwoven fabric (see, for example, Patent Document 2). These recoatable and stainable decorative sheets are popular with consumers because they can be recoated, and the nonwoven fabric imparts fine irregularities to the surface, giving them a texture that closely resembles wood. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 9-262934 [Patent Document 2] Japanese Patent Application Publication No. 2019-64131 Summary of the Invention [Problem to be solved by the invention]

[0006] However, using a PVC substrate as the substrate has the problem of increasing the cost of the decorative sheet, and when a PVC substrate is used as the substrate, incineration can cause environmental problems by generating gases containing chlorine atoms, such as hydrogen chloride (HCl), when disposed of.

[0007] To address the above-mentioned problems, it has been considered to change the substrate to a paper substrate, but such a change is expected to cause various problems. For example, when laminating a nonwoven fabric on a paper substrate, the paper substrate and the nonwoven fabric do not adhere to each other, so the method of adhering the paper substrate and the nonwoven fabric becomes an issue. If an adhesive layer is provided between the paper substrate and the nonwoven fabric to adhere them, the unevenness of the nonwoven fabric may be lost, which may result in the loss of the texture that closely resembles wood. On the other hand, if the unevenness of the nonwoven fabric is taken advantage of too much, the texture may be lost due to the fuzzing of the nonwoven fabric, and the fuzzing (surface unevenness) and even differences in refractive index due to the voids in the fibers that make up the nonwoven fabric may reduce the transparency of the decorative sheet, resulting in a decrease in design.

[0008] To prevent a decrease in transparency due to changes in refractive index and a decrease in tactile feel due to fuzzing, it is conceivable to provide a surface layer, for example. However, providing a surface layer may reduce the permeability and inking ability of a stain or other colored paint. On the other hand, if a material with high affinity for a stain or other colored paint is used to improve the permeability and inking ability, the surface layer may deteriorate and whiten due to the solvent (water, solvent, alcohol, etc.) contained in the stain or other colored paint, which may cause an appearance problem. This problem can occur not only with stain or other colored paint, but also outdoors, for example, when exposed to wind and rain.

[0009] Therefore, it is difficult to achieve both application suitability (called "stainability" in English, but in this specification, the term "stainableness" is used even when used as a noun) that ensures penetration and adhesion of colored paints such as stain paints, and surface properties (water resistance, etc.) that prevent deterioration (whitening, etc.) caused by colored paints such as stain paints.

[0010] In view of the above problems, the present invention aims to provide a recoatable decorative sheet that has excellent stainability and also has excellent surface properties such as water resistance, and a method for coloring a decorative sheet using the same. [Means for solving the problem]

[0011] In order to solve the above problems, the present inventors have conducted extensive research and have found that the above problems can be solved by a decorative recoat sheet having the following configuration.

[0012] 1. A paper substrate, an adhesive layer, a nonwoven fabric layer, and a surface layer formed in this order from a cured product of a composition containing a polyol compound having a hydroxyl group in the molecule and an isocyanate curing agent, wherein the nonwoven fabric layer partially has a filled portion A on the side of the layer in the thickness direction where the adhesive layer is provided, where the resin forming the adhesive layer fills some of the voids of the fibers constituting the nonwoven fabric layer, and a filled portion B on the side of the layer in the thickness direction where the surface layer is provided, where the cured product fills some of the voids of the fibers constituting the nonwoven fabric layer, wherein the content of residual hydroxyl groups contained in the surface layer is 0.25% by mass or more and 1.10% by mass or less, and the amount of isocyanate groups in the isocyanate curing agent is C. NCO (mmol), and the amount of hydroxyl groups in the polyol compound C OH (mmol) and the ratio (C NCO / C OH ) is 0.20 or more. 2. The decorative sheet for recoating according to the above item 1, wherein the fibers are at least one type of fiber selected from thermoplastic resin fibers and recycled fibers. 3. The decorative sheet for recoat according to the above 1 or 2, wherein the fibers are cellulose resin fibers. 4. The decorative sheet for recoat according to any one of the above 1 to 3, wherein the resin forming the adhesive layer is at least one resin selected from urethane resins and polyolefin resins. 5. The decorative sheet for recoat according to any one of the above items 1 to 4, wherein the polyol compound is at least one selected from the group consisting of acrylic polyol, polyester polyol, polyether polyol, and polycarbonate polyol. 6. The decorative sheet for recoat according to any one of the above items 1 to 5, wherein the isocyanate curing agent is a polyvalent isocyanate compound. 7. The decorative sheet for recoat according to any one of the above 1 to 6, further comprising a decorative layer between the paper substrate and the adhesive layer. 8. The decorative sheet for recoat according to the above item 7, wherein the decorative layer has a wood grain pattern. 9. A method for coloring a decorative sheet, comprising applying a colored paint to the surface of the surface layer side of the decorative sheet for recoat described in any one of 1 to 8 above, thereby coloring the nonwoven fabric layer. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a recoatable decorative sheet that has excellent stainability and also has excellent surface properties such as water resistance, and a method for coloring a decorative sheet using the same. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic cross-sectional view showing one embodiment of a decorative sheet for recoating according to the present embodiment. [Figure 2] 1 is a schematic cross-sectional view showing one embodiment of a decorative sheet for recoating according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention (hereinafter, sometimes referred to as "the present embodiment") will be described. In this specification, the numerical values ​​associated with "greater than or equal to," "less than or equal to," and "to" in describing a numerical range can be arbitrarily combined, and the numerical values ​​in the examples are numerical values ​​that can be used as the upper and lower limits of the numerical range.

[0016] [Decorative sheet for recoating] The decorative sheet for recoat of this embodiment comprises, in order, a paper substrate, an adhesive layer, a nonwoven fabric layer, and a surface layer constituted by a cured product of a composition containing a polyol compound having a hydroxyl group in its molecule and an isocyanate curing agent, wherein the nonwoven fabric layer partially has a filled portion A on the side of the layer in the thickness direction where the adhesive layer is provided, where the resin forming the adhesive layer has filled some of the voids of the fibers constituting the nonwoven fabric layer, and a filled portion B on the side of the layer in the thickness direction where the surface layer is provided, where the cured product has filled some of the voids of the fibers constituting the nonwoven fabric layer, wherein the content of residual hydroxyl groups contained in the surface layer is 0.25% by mass or more and 1.10% by mass or less, and the amount of isocyanate groups in the isocyanate curing agent isNCO (mmol), and the amount of hydroxyl groups in the polyol compound C OH (mmol) and the ratio (C NCO / C OH ) is 0.20 or more.

[0017] The decorative recoat sheet of this embodiment has the above-described configuration, and thus has excellent stainability and excellent surface properties such as water resistance. Generally, when a surface layer is provided to improve surface properties such as water resistance or scratch resistance, stainability tends to decrease. To improve surface properties, the affinity with colored paints such as stain paints is reduced, that is, a material with low affinity is used, which makes it easier to prevent whitening by suppressing deterioration of the material caused by the colored paint, mainly the solvents (water, solvent, alcohol, etc.) contained in the colored paint. However, with a material with low affinity with the colored paint, it becomes difficult to obtain the application suitability that ensures the penetration and ink-receiving ability of the colored paint, that is, stainability.

[0018] The polyol compound having a hydroxyl group in the molecule used in this embodiment (hereinafter, sometimes simply referred to as "polyol compound") is a material that inherently has a high affinity with colored paints such as stain paints, that is, it has a high affinity with the solvents (water, solvent, alcohol, etc.) contained in the colored paints, and therefore is likely to achieve excellent stainability. However, this high affinity with colored paints can conversely promote the deterioration of the polyol compound, causing whitening and other deterioration in surface properties such as water resistance.

[0019] In the recoat decorative sheet of this embodiment, excellent stainability is obtained by using a polyol compound having such properties, and the surface layer is formed from a cured product of a composition containing a polyol compound and an isocyanate curing agent, and the content of residual hydroxyl groups contained in the surface layer is in the range of 0.25 mass % or more and 1.10 mass % or less, and the amount of isocyanate groups in the isocyanate curing agent is C NCO (mmol), and the amount of hydroxyl groups in the polyol compound COH (mmol) and the ratio (C NCO / C OH ) is 0.20 or more, that is, by using a certain amount or more of isocyanate curing agent to obtain a good cured product while leaving some of the hydroxyl groups of the polyol compound, it is possible to achieve a high level of compatibility between stainability and surface properties such as water resistance, which are contradictory properties.

[0020] The content and ratio of the residual hydroxyl groups (C NCO / C OH It is surprising that the relatively simple method of adjusting the viscosity of the resin makes it possible to achieve both stainability and surface properties such as water resistance, which are contradictory properties, at a high level. This effect is possible only because a polyol compound is selected as the main agent for the material that forms the surface layer, and a urethane resin (cured product) using an isocyanate curing agent is used. Furthermore, when a resin composition using a PVC-based resin is used to form a layer, as with the substrate, incineration for disposal may generate gases containing chlorine atoms, such as hydrogen chloride (HCl), which may cause environmental problems. Therefore, one of the benefits of using a urethane resin (cured product) to form the surface layer is the reduction of the burden on the environment. Furthermore, it is preferable not to use PVC resin not only for the substrate and surface layer, but also for forming other layers.

[0021] The recoat decorative sheet of this embodiment will be described below with reference to the drawings. In the following description of the drawings, identical or similar parts are represented by identical or similar symbols. However, the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each layer, etc., differ from reality. Therefore, specific thicknesses and dimensions should be determined in light of the following description. Furthermore, it goes without saying that the drawings also include parts with different dimensional relationships and ratios.

[0022] The decorative sheet for recoat 1 shown in Figure 1 comprises, in that order, a paper substrate 10, an adhesive layer 20, a nonwoven fabric layer 30, and a surface layer 40, with the adhesive layer 20 being provided on at least one surface 11 of the paper substrate 10. The nonwoven fabric layer 30 is shown to partially have a filled portion A31 on the surface 30a in the thickness direction of the layer where the adhesive layer 20 is provided (hereinafter also referred to as the "surface on which the adhesive layer of the nonwoven fabric layer is provided"), where the resin that forms the adhesive layer 20 fills some of the voids of the fibers that make up the nonwoven fabric layer 30, and a filled portion B33 on the surface 30b in the thickness direction of the layer where the surface layer 40 is provided (hereinafter also referred to as the "surface on which the surface layer of the nonwoven fabric layer is provided") where the composition that forms the surface layer 40 fills some of the voids of the fibers that make up the nonwoven fabric layer 30. It is also shown that the nonwoven fabric layer 30 has a fiber portion 32 between the filling portion A31 and the filling portion B33 as a portion other than the filling portion A31 and the filling portion B32.

[0023] In addition, the recoating sheet 1 shown in Figure 2 is the recoating sheet 1 shown in Figure 1, and has a decorative layer 50 consisting of a full-colored layer 51 and a pattern layer 52 between the paper base material 10 and the adhesive layer 20. Hereinafter, each layer constituting the decorative sheet for recoat of this embodiment will be described with reference to FIGS.

[0024] [Surface layer 40] The surface layer 40 in the recoat decorative sheet of this embodiment is composed of a cured product of a composition containing a polyol compound having hydroxyl groups in its molecule and an isocyanate curing agent, and the content of residual hydroxyl groups contained in the surface layer is 0.25% by mass or more and 1.10% by mass or less. By having the surface layer 40, it is possible to achieve a high level of both surface properties such as water resistance and stainability, as described above.

[0025] (Residual hydroxyl group content) The surface layer 40 is composed of a cured product of a composition containing a polyol compound and an isocyanate curing agent (hereinafter sometimes simply referred to as the "curing agent"), and contains 0.25% to 1.10% by mass of residual hydroxyl groups. If the content of residual hydroxyl groups is less than 0.25% by mass, the surface layer 40 will not have affinity with colored paints such as stain paints, and therefore will not be stainable. On the other hand, if the content of residual hydroxyl groups is more than 1.10% by mass, the surface layer 40 will have too high an affinity with solvents (water, solvents, alcohol, etc.), especially water, which will accelerate deterioration of the surface layer and make it more susceptible to whitening, and therefore will not have surface properties such as water resistance and scratch resistance.

[0026] From the viewpoint of improving the surface properties as well as the stainability, the content of residual hydroxyl groups in the surface layer 40 is preferably 0.30% by mass or more, more preferably 0.35% by mass or more, even more preferably 0.40% by mass or more, and still more preferably 0.45% by mass or more, with the upper limit being preferably 1.05% by mass or less, more preferably 1.00% by mass or less, even more preferably 0.95% by mass or less, and still more preferably 0.90% by mass or less. Note that, since the surface layer 40 is made of a cured product, the content of residual hydroxyl groups in the surface layer 40 is substantially the same as the content of residual hydroxyl groups in the cured product.

[0027] In this specification, the content of residual hydroxyl groups in the surface layer 40 refers to the content (mass %) of hydroxyl groups in the polyol compound contained in the resin composition that remain without forming a urethane bond by reacting with an isocyanate group (-NCO) in the curing agent relative to the cured product constituting the surface layer 40, more specifically, the total amount of the polyol compound and the curing agent. Specifically, this content can be calculated by the following method. Based on JIS K1557-1:2007 (Plastics - Polyurethane raw material polyol test method - Part 1: Determination of hydroxyl value), the hydroxyl value X of polyol compounds having hydroxyl groups in the molecule OH Calculate the hydroxyl value (mgKOH / g). OHUsing the following amounts, the content of residual hydroxyl groups is calculated according to the following formula (1).

[0028] Residual hydroxyl group content (mass%) = (amount of residual hydroxyl groups) / (amount of polyol compound used + amount of curing agent used) × 100 (1) Amount of residual hydroxyl groups = Amount of hydroxyl groups in polyol compound - Amount of isocyanate groups in curing agent Amount of hydroxyl groups in polyol compound (g) = X OH / 56.1×A P ×17.0 Amount of isocyanate groups in the curing agent (g) = X NCO ×A C ×42.0 A P (g): Amount of polyol compound used A C (g): Amount of hardener used X NCO (mmol / g): Isocyanate group content in the curing agent

[0029] (Ratio of isocyanate group amount to hydroxyl group amount) In the surface layer 40, the amount of isocyanate groups in the isocyanate curing agent C NCO (mmol) and the amount of hydroxyl groups in the polyol compound, C OH (mmol) and the ratio (C NCO / C OH If the ratio is less than 0.20, the crosslinking rate caused by the isocyanate group will be low, making it impossible to obtain excellent surface properties.

[0030] Amount of isocyanate groups in the curing agent C NCO (mmol) and the amount of hydroxyl groups in the polyol compound, C OH (mmol) and the ratio (C NCO / C OH) is preferably 0.25 or more, more preferably 0.30 or more, from the viewpoint of improving stainability and surface properties. There is no particular upper limit, but in order to improve stainability, it is preferably 0.90 or less, more preferably 0.80 or less, even more preferably 0.60 or less, and still more preferably 0.45 or less.

[0031] Here, the amount of isocyanate groups in the curing agent, C NCO (mmol) and the amount of hydroxyl groups in the polyol compound C OH (mmol) is a value calculated by the following formulas (2) and (3). Amount of isocyanate groups in the curing agent C NCO (mmol)=X NCO ×A C (2) Amount of hydroxyl groups in polyol compound C OH (mmol)=X OH / 56.1×A P (3)

[0032] (Polyol compound) The surface layer 40 is made of a cured product of a composition containing a polyol compound having a hydroxyl group in the molecule and an isocyanate curing agent. Preferred examples of the polyol compound include acrylic polyol, polyester polyol, polyether polyol, and polycarbonate polyol, which can be used alone or in combination. From the viewpoint of improving the surface properties as well as the stainability, acrylic polyol is particularly preferred.

[0033] Specific examples of acrylic polyols include those in which a plurality of hydroxyl groups have been introduced by copolymerizing an alkyl (meth)acrylate ester such as ethyl (meth)acrylate with a hydroxyacrylate such as 2-hydroxyethyl acrylate or 2-hydroxy-3-phenoxypropyl acrylate. Specific examples of polyester polyols include poly(ethylene adipate), poly(butylene adipate), poly(neopentyl adipate), poly(hexamethylene adipate), poly(butylene azelaate), poly(butylene sebacate), and polycaprolactone.

[0034] Specific examples of polyether polyols include those having an alkyleneoxy group as a repeating unit, such as polyoxyethylene monomethyl ether, polyethylene glycol, polyoxyethylene glycerol ether, polyoxyethylene trimethylolpropane ether, polyoxyethylene neopentylglycerol ether, polyoxyethylene pentaerythritol ether, polypropylene glycol, and polytetramethylene glycol.

[0035] Specific examples of polycarbonate polyols include polycarbonate diols produced by condensing one or more alkylene diols having an alkylene group with 4 to 12 carbon atoms with a low molecular weight carbonate compound (for example, a dialkyl carbonate having an alkyl group with 1 to 6 carbon atoms, an alkylene carbonate having an alkylene group with 2 to 6 carbon atoms, and a diaryl carbonate having an aryl group with 6 to 9 carbon atoms), while causing a dealcoholization reaction. More specific examples include polybutylene carbonate polyol, polyhexamethylene carbonate polyol, and polycyclohexanedimethylene carbonate polyol.

[0036] The polyol compound preferably has a hydroxyl value (mgKOH / g) of 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, even more preferably 15 mgKOH / g or more, still more preferably 20 mgKOH / g or more, with the upper limit being preferably 60 mgKOH / g or less, more preferably 55 mgKOH / g or less, even more preferably 50 mgKOH / g or less, and still more preferably 45 mgKOH / g or less. When the hydroxyl value of the polyol compound is within the above range, it is easy to adjust the content of residual hydroxyl groups to 0.25 mass% or more and 1.10 mass% or less, and it is possible to improve the surface properties as well as the stainability.

[0037] (Isocyanate hardener) The isocyanate curing agent is preferably a polyvalent isocyanate compound, and examples thereof include aliphatic diisocyanates, aromatic diisocyanates, and prepolymer, isocyanurate, urea, and carbodiimide modified products of these diisocyanates. Examples of the aliphatic diisocyanate include alicyclic diisocyanates such as isophorone diisocyanate (hereinafter also referred to as "IPDI"), 4,4'-dicyclohexylmethane diisocyanate (hereinafter also referred to as "DCI"), 4-methyl-1,3-cyclohexylene diisocyanate, and 1,2-bis(isocyanatomethyl)cyclohexane; and linear or branched chain aliphatic diisocyanates such as hexamethylene diisocyanate (hereinafter also referred to as "HMDI") and trimethylhexamethylene diisocyanate. Examples of aromatic diisocyanates include 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, 1,5-naphthalene diisocyanate, and 3,3'-dimethyl-4,4'-biphenylene diisocyanate.

[0038] The content of isocyanate groups (-NCO) contained in the isocyanate curing agent is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, with the upper limit being preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less. When the content of isocyanate groups contained in the isocyanate curing agent is within the above range, it is easy to adjust the content of residual hydroxyl groups to 0.25% by mass or more and 1.10% by mass or less, and it is possible to improve the surface properties as well as the stainability.

[0039] Among the above isocyanate curing agents, from the viewpoint of improving surface properties as well as stainability, a chain aliphatic diisocyanate is preferred, and hexamethylene diisocyanate is particularly preferred.

[0040] The content of residual hydroxyl groups contained in the surface layer 40 can be adjusted by the type and content of the polyol compound and isocyanate curing agent contained in the composition used to form the surface layer. The content of the polyol compound and the isocyanate curing agent in the composition is not particularly limited as long as the content of the residual hydroxyl group is 0.25% by mass or more and 1.10% by mass or less. For example, NCO (mmol) and the amount of hydroxyl groups in the polyol compound, C OH (mmol) and the ratio (C NCO / C OH ) is preferably contained in an amount within the above-mentioned preferred range.

[0041] For example, the amount of isocyanate curing agent used per 100 parts by mass of polyol compound in the composition is preferably 0.3 parts by mass or more, more preferably 1.0 parts by mass or more, even more preferably 1.5 parts by mass or more, even more preferably 2.0 parts by mass or more, and particularly preferably 2.5 parts by mass or more, with the upper limit being preferably 20.0 parts by mass or less, more preferably 12.5 parts by mass or less, even more preferably 10.0 parts by mass or less, even more preferably 7.0 parts by mass or less, and particularly preferably 5.5 parts by mass or less. When the amount of isocyanate curing agent used falls within the above range, it becomes easy to adjust the content of residual hydroxyl groups to 0.25% by mass or more and 1.10% by mass or less, thereby improving both stainability and surface properties. Furthermore, the isocyanate curing agent used in forming the surface layer can also contribute to improving the adhesion between the paper substrate and the nonwoven fabric layer, as described below, allowing the thickness of the adhesive layer to be relatively thin.

[0042] (Embodiments of the surface layer 40) The form of the surface layer 40 is not particularly limited as long as it is present so as to have a filled portion B in which the cured product fills some of the voids in the fibers that make up the nonwoven fabric layer. For example, as shown in Figures 1 and 2, the surface layer 40 may be present in the form of a layer with a certain thickness on the surface 30b of the nonwoven fabric layer 30, or it may be present so as to cover the outermost fibers along the surface 30b of the nonwoven fabric layer 30, i.e., so that the voids in the fibers that make up the nonwoven fabric layer 30 are present on the outermost surface.

[0043] When the surface layer 40 exists in a layer of a certain thickness, it will be present on part of the surface of the recoat decorative sheet of this embodiment in order to ensure the adhesion of colored paints such as water-based stain paints and oil-based stain paints and to obtain excellent stainability. When the surface layer is present so as to cover the outermost surface fibers, from the viewpoint of ensuring ink receptivity and obtaining excellent stainability, it is preferable that voids formed by the fibers at the outermost surface and its vicinity (the vicinity in the thickness direction within the nonwoven fabric layer 30) are at least partially present. From the viewpoint of improving surface properties as well as stainability, and further improving transparency, touch, etc., the surface layer is preferably present so as to cover the outermost surface fibers, and more preferably present so as to cover the entire surface.

[0044] Thus, regardless of the form in which the surface layer 40 exists, in order to ensure the penetration of colored paints such as water-based stain paints and oil-based stain paints and to obtain excellent stainability, it is preferable that there are voids formed between fibers, at least in part of which the surface may be coated with resin, at the outermost surface and its vicinity (nearby in the thickness direction within the layer of the nonwoven fabric layer 30).

[0045] Depending on the desired performance, the surface layer 40 may contain additives such as colorants such as pigments and dyes, UV absorbers, weather resistance agents such as light stabilizers, extender pigments, solvents, stabilizers, plasticizers, catalysts, etc. That is, the composition containing the polyol compound and the isocyanate curing agent used to form the surface layer 40 may contain these additives. In this case, the content of the additives is not particularly limited as long as it is within a range that depends on the desired performance and does not inhibit the curing of the polyol compound and the isocyanate curing agent. For example, the total amount of additives used may be approximately 1 to 20 parts by mass per 100 parts by mass of the resin content of the surface layer 40 (i.e., the total amount of the polyol compound and the isocyanate curing agent), and is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, with the upper limit being preferably 15 parts by mass or less, more preferably 10 parts by mass or less.

[0046] The thickness of the surface layer 40 can be determined mainly by taking into consideration the balance between the filler B33, the fiber portion 32, and the filler A31 in the nonwoven fabric layer 30, as well as the thickness of the surface layer 40. From the viewpoint of forming a balanced structure among the filler A31, the filler B33, and the fiber portion 32 and improving stainability and surface characteristics, as well as transparency and tactile feel, the total thickness of the surface layer 40 and the filler B33 is preferably at least 0.5 μm, more preferably at least 1 μm, and even more preferably at least 2 μm, with the upper limit being preferably at most 10 μm, more preferably at most 8 μm, and even more preferably at most 6 μm. The total thickness of the surface layer 40 and the filler B33 is determined by measuring the thickness at any 30 points on a cross-sectional image taken using an electron microscope such as a transmission electron microscope (TEM), a scanning electron microscope (SEM), or a scanning transmission electron microscope (STEM), and is the average value of the thicknesses at these 30 points.

[0047] (Non-woven fabric layer 30) The nonwoven fabric layer 30 is a layer that ensures the ink-receiving ability of colored paints such as water-based stain paints and oil-based stain paints to penetrate into the voids in the fibers that form the nonwoven fabric layer 30, and exhibits stainability.The nonwoven fabric layer 30 partially has a filled portion A31 on the side 30a in the thickness direction of the layer where the adhesive layer 20 is provided, where the resin that forms the adhesive layer 20 has filled some of the voids in the fibers that form the nonwoven fabric layer 30, and a filled portion B33 on the side 30b in the thickness direction of the layer where the surface layer 40 is provided, where the cured material that forms the surface layer 40 has filled some of the voids in the fibers that form the nonwoven fabric layer 30.

[0048] Examples of fibers constituting the nonwoven fabric layer 30 include thermoplastic resin fibers, natural fibers, recycled fibers, and semi-synthetic fibers, and from the viewpoint of stainability, thermoplastic resin fibers and recycled fibers are preferred. In this embodiment, such fibers can be used alone or in combination.

[0049] Preferred examples of thermoplastic resin fibers include thermoplastic resin fibers made of (meth)acrylic resins such as poly(meth)acrylate esters; polyvinyl acetal (butyral resins) such as polyvinyl butyral; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; polyolefin resins such as polyethylene and polypropylene; styrene resins such as polystyrene and α-methylstyrene; acetal resins such as polyoxymethylene; thermoplastic elastomers such as polyolefin thermoplastic elastomers, polystyrene thermoplastic elastomers, polydiene thermoplastic elastomers, polyurethane thermoplastic elastomers, polyester thermoplastic elastomers, and fluororesin thermoplastic elastomers; fluororesins such as vinyl chloride resins, polyurethane resins, and ethylene-tetrafluoroethylene copolymers, polyamide resins, polyimide resins, polylactic acid resins, polycarbonate resins, polyvinyl acetal resins, and liquid crystalline polyester resins. Among these thermoplastic resin fibers, in consideration of dimensional stability, thermoplastic resin fibers made of resins such as polyester resin, polyolefin resin, polyurethane resin, etc. are preferred, and thermoplastic resin fibers made of polyester resin and polyolefin resin are more preferred.

[0050] The thermoplastic resin constituting the thermoplastic resin fiber may be a single type or a combination of multiple types, and may be a composite fiber such as a double-structure fiber in which the core is made of polyester resin and the sheath is made of polyolefin resin.

[0051] Furthermore, natural fibers include fibers made from natural materials such as cotton, wool, and silk, regenerated fibers include rayon, cupra, and lyocell, and semi-synthetic fibers include triacetate and promix.

[0052] There are no particular restrictions on the fiber diameter of the fibers constituting the nonwoven fabric layer 30, but considering the feel in particular, the average fiber diameter is preferably 0.5 μm or more, more preferably 1 μm or more, with the upper limit being preferably 50 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less. Nonwoven fabrics made of fibers with an average fiber diameter in this range tend to have a feel that closely resembles wood. The average fiber diameter of the fibers constituting the nonwoven fabric can be measured by using an electron microscope (300x magnification) to measure the fiber width (diameter) of 30 fibers present at any location on the nonwoven fabric and averaging the values ​​obtained for each measurement.

[0053] The fibers constituting the nonwoven fabric layer 30 can be formed, for example, by forming fleece using a spunbonding method and then bonding the formed fleece using a thermal bonding method, a spunlace method (hydroentanglement method), etc. Furthermore, the nonwoven fabric layer 30 formed by these methods tends to have a texture very similar to that of wood.

[0054] The basis weight of the fibers constituting the nonwoven fabric layer 30 is not particularly limited, but from the viewpoint of obtaining strength of the nonwoven fabric layer 30, it is preferably 10 g / m 2 More preferably, 15 g / m 2 The upper limit is preferably 40 g / m 2 Less than 30 g / m, more preferably 2 More preferably 20 g / m or less 2 The following is the result.

[0055] There are no particular restrictions on the thickness of the nonwoven fabric layer 30, but taking into consideration the physical properties of the recoat decorative sheet 1, such as strength, mass, and flexibility, it is preferably 30 μm or more, more preferably 50 μm or more, even more preferably 60 μm or more, and even more preferably 70 μm or more, with the upper limit being preferably 250 μm or less, more preferably 200 μm or less, even more preferably 150 μm or less, and even more preferably 100 μm or less.

[0056] (Filling section A31 and filling section B33) On the surface 30a side of the nonwoven fabric layer 30 where the adhesive layer 20 is provided in the thickness direction of the layer, there is a filled portion A31 in which a resin that forms the adhesive layer 20 is filled into some of the voids in the fibers, and on the other hand, on the surface 30b side where the surface layer 40 is provided in the thickness direction of the layer, there is a filled portion B33 in which a cured material that forms the surface layer 40 is filled into some of the voids in the fibers.

[0057] In order to obtain the effect of obtaining surface properties together with stainability, and further to improve the surface feel and transparency, the filling portion A formed from the adhesive layer 20 and the nonwoven fabric layer 30, and the filling portion B formed from the surface layer 40 and the nonwoven fabric layer 30, also play important roles in addition to the configuration of the surface layer 40 described above. In relation to the adhesive layer 20 and the surface layer 40, the nonwoven fabric layer 30 can be said to be a layer having two filling portions, filling portions A and B.

[0058] The filling portion A31 is formed by at least a portion of the resin forming the adhesive layer 20 penetrating into the nonwoven fabric layer 30, thereby achieving excellent adhesion between the paper base material 10 and the nonwoven fabric layer 30. In addition, by suppressing and protecting the paper base material 10 from the penetration of solvents (water, solvents, alcohol, etc.) contained in colored paints such as stain paints, the recoat decorative sheet as a whole is also water-resistant, in addition to the water-resistance as a surface characteristic. On the other hand, the filling portion B33 is formed by at least a portion of the resin forming the surface layer 40 penetrating into the nonwoven fabric layer 30, thereby providing stainability as well as surface properties, and further providing a pleasant feel by maintaining good nap in the nonwoven fabric layer 30 together with the surface layer 40, and also suppressing a decrease in transparency due to the nap (surface irregularities) and refractive index caused by voids in the nonwoven fabric layer 30, thereby achieving designability through excellent transparency. Furthermore, deterioration of the paper substrate 10 due to the penetration of solvents (water, solvents, alcohol, etc.) contained in colored paints such as stain paints can be suppressed, thereby providing water resistance for the recoat decorative sheet as a whole.

[0059] The filled portion A31 is a portion in which the resin that forms the adhesive layer 20 is filled into the voids in the fibers that form the nonwoven fabric layer 30, and no voids remain, so it is a portion that does not have the ability to accept colored paint such as stain paint. Filled section B33, like filled section A31, is in a state in which the voids in the fibers that form the nonwoven fabric layer 30 are filled with the cured material that forms the surface layer 40, leaving no voids, and therefore is a section that does not have the ability to accept colored paints such as water-based stain paints and oil-based stain paints.

[0060] In the decorative sheet for recoat 1 of this embodiment, the nonwoven fabric layer 30 partially has the above-mentioned filled portions A31 and B33. That is, the nonwoven fabric layer 30 needs to have the fibrous portion 32 described below, which is the portion other than the filled portions A31 and B33. Without the fibrous portion 32, which is the portion other than the filled portions, these filled portions will have no voids and will not have the ink-receptivity to allow a colored paint such as a stain paint to penetrate, and therefore will not be able to achieve stainability.

[0061] 1 and 2, filled portions A31 and B33 are shown schematically as being layered, but because the shapes of the fibers constituting nonwoven fabric layer 30 and the shapes of the voids in the fibers are not uniform, it is considered that they do not necessarily form uniform layers as shown in the figures. Considering that a coloring paint such as a stain paint has penetrated and colored the nonwoven fabric layer 30, it is considered that, for example, filled portions A31 and B33 shown in the figures are scattered within a certain range in the thickness direction of nonwoven fabric layer 30, in which the voids in the fibers constituting nonwoven fabric layer 30 are filled with the resin constituting adhesive layer 20 and the cured product constituting surface layer 40, respectively, and the remaining portions are scattered as fiber portions 32, which will be described later.

[0062] (Fiber part 32) As described above, the recoat decorative sheet of this embodiment is a layer that partially has the filler portion A31 and the filler portion B33, and therefore naturally has the portion other than these filler portions, i.e., the fiber portion 32. By having the fiber portion 32, the recoat decorative sheet of this embodiment ensures ink-receptivity, allowing colored paint such as stain paint to penetrate into the voids in the fibers, and exhibits stainability.

[0063] The form of the fiber portion 32 is not particularly limited as long as it is not filled with the cured product that forms the adhesive layer 20 and the surface layer 40 and voids remain, but examples include a form in which the resin that forms the adhesive layer 20 and the surface layer 40 does not penetrate at all into the voids of the fibers that form the nonwoven fabric layer 30, and the fibers remain as they are, with the voids in the fibers, and a form in which the resin that forms the adhesive layer 20 and the surface layer 40 penetrates to some extent, but the fibers are merely coated with these resins, with the coated resin having voids. In the decorative sheet for recoat of this embodiment, the form of the fiber portion 32 may be any one of these.

[0064] The fiber portion 32 is the portion not filled with the resin that forms the adhesive layer 20 and the surface layer 40, i.e., the portion other than the filled portion A31 and the filled portion B33. In Figures 1 and 2, the fiber portion 32 is shown schematically as existing in a layer, but as already described, the filled portion A31 and the filled portion B33 are scattered within a certain range in the thickness direction of the nonwoven fabric layer 30, and therefore, strictly speaking, they are not considered to exist in a layer. Therefore, the fiber portion 32 is considered to be scattered within a certain range in the thickness direction of the nonwoven fabric layer 30, which is shown as the fiber portion 32 in Figures 1 and 2.

[0065] One method for partially providing the nonwoven fabric layer 30 with the filled portions A31 and the filled portions B33 is to adjust the amount of resin composition applied when forming the adhesive layer 20 and the amount of resin composition applied when forming the surface layer 40. For example, increasing the amount of resin composition applied when forming the adhesive layer 20 increases the proportion of filled portions A31 in the nonwoven fabric layer 30. On the other hand, increasing the amount of composition applied when forming the surface layer 40 increases the proportion of filled portions B33 in the nonwoven fabric layer 30. Furthermore, increasing the amount of composition applied when forming the adhesive layer 20 and the surface layer 40 decreases the proportion of fiber portions 32 in the nonwoven fabric layer 30, and decreasing the amount of composition applied increases the proportion of fiber portions 32 in the nonwoven fabric layer 30. In this embodiment, the desired state of the nonwoven fabric layer 30 can be obtained by adjusting the amount of application, for example.

[0066] (adhesive layer 20) The adhesive layer 20 is a layer provided on at least one side of the paper substrate 10, and is a layer provided for bonding the paper substrate 10 to the nonwoven fabric layer 30. Furthermore, by providing the adhesive layer 20 so that it has the filling portion A, in addition to the adhesion between the paper substrate 10 and the nonwoven fabric layer 30, it is possible to suppress and protect the paper substrate 10 from the penetration of solvents (water, solvents, alcohol, etc.) contained in the stain paint, and therefore, in addition to water resistance as a surface property, the recoat decorative sheet as a whole is also provided with water resistance.

[0067] The adhesive used in the adhesive layer 20 can be any adhesive made of various resins without any particular limitations. Examples of resins that form the adhesive include urethane resin, polyolefin resin, acrylic resin, and epoxy resin. These resins can be used alone or in combination. Among these, urethane resin and polyolefin resin are preferred, and urethane resin is more preferred. The use of these resins can provide excellent adhesion while suppressing the penetration of the solvent (solvent, alcohol) of the stain paint applied to the nonwoven fabric layer 30 into the paper substrate 10, improving the surface properties of the recoat decorative sheet 1, such as water resistance, and also making it easier to maintain physical properties such as strength, mass, and flexibility. The nonwoven fabric layer 30 includes a filled portion A31 and a filled portion B33 filled with the resin that forms the adhesive layer 20 and the resin that forms the surface layer 40, and also includes a fiber layer 32 that is not filled with either resin, but also includes a portion where the resin that forms the adhesive layer and the resin that forms the surface layer come into contact. Therefore, if the adhesive used in the adhesive layer 20 is the same type of resin as the resin used to form the surface layer 40, i.e., a urethane resin, is used, the adhesive properties can be further improved. From this perspective, urethane resin is particularly preferred as the adhesive used in the adhesive layer 20.

[0068] As the urethane resin, either a thermoplastic urethane resin or a curable urethane resin may be used, and from the viewpoint of adhesiveness in particular, it is preferable to use a curable urethane resin. The curable polyurethane resin may be either a two-component curing type or a one-component curing type, and from the viewpoint of adhesiveness, a two-component curing type polyurethane resin is preferred. The two-component curing polyurethane resin is a polyurethane resin that uses a polyol as a main component and an isocyanate as a crosslinking agent (curing agent), and the polyol and isocyanate may be appropriately selected from the polyol compounds and isocyanate curing agents described above as being used to form the surface layer. Thermoplastic polyurethane resin is a copolymer obtained by copolymerizing monomers with urethane bonds formed by condensation of an isocyanate group and a compound having a hydroxyl group such as an alcohol group.

[0069] Examples of polyolefin resins include those containing one or more monoolefins such as ethylene, propylene, butene, pentene, hexene, heptene, octene, and 4-methyl-1-pentene as monomer units, as well as those containing monomer units other than monoolefins, such as alicyclic olefins such as cyclopentene and cyclohexene, linear or cyclic polyenes such as 1,4-hexadiene, 1,5-hexadiene, divinylbenzene, 1,3-cyclopentadiene, 1,3-cyclohexadiene, and 5-vinyl-2-norbornene, and aromatic vinyl compounds such as styrene and substituted styrene. From the viewpoint of adhesion to the paper substrate 10 and the nonwoven fabric layer 30, the polyolefin resin is preferably a polyethylene resin containing ethylene as a monomer unit.

[0070] When a urethane resin or a polyolefin resin is used, the proportion of the urethane resin or the polyolefin resin relative to the total resin forming the adhesive layer 20 is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, and even more preferably 100%.

[0071] In this embodiment, the resin forming the adhesive layer 20 can be used as a resin composition containing an appropriate amount of additives such as weathering agents such as ultraviolet absorbers and light stabilizers, extender pigments, solvents, stabilizers, plasticizers, etc. In other words, the adhesive layer 20 can be formed from a resin composition containing additives in addition to the resin.

[0072] The thickness of the adhesive layer 20 cannot be specified as a specific value because it can vary depending on the materials of the paper substrate 10 and the nonwoven fabric layer 30, the thickness of the nonwoven fabric layer 30, etc., but from the standpoint of achieving good adhesion between the paper substrate 10 and the nonwoven fabric layer 30, forming the filler A31, the filler B33, and the fiber portion 32 in a balanced manner, improving stainability and surface properties, and further improving transparency, for example, the total thickness of the adhesive layer 20 and the filler A31 is preferably 1 μm or more, more preferably 3 μm or more, even more preferably 5 μm or more, and still more preferably 8 μm or more, with the upper limit being preferably 25 μm or less, more preferably 20 μm or less, even more preferably 18 μm or less, and still more preferably 15 μm or less. Furthermore, being within the above ranges also improves the water resistance of the recoat decorative sheet as a whole. The total thickness of the adhesive layer 20 and the filling portion A31, like the total thickness of the surface layer 30 and the filling portion B33, is the average value of the thicknesses measured at any 30 points on a cross-sectional image taken using various electron microscopes, such as a transmission electron microscope (TEM), a scanning electron microscope (SEM), or a scanning transmission electron microscope (STEM).

[0073] (Paper base material 10) From the viewpoints of reducing the environmental impact and reducing costs, a paper substrate is used for the recoat decorative sheet 1 of this embodiment. The paper substrate 10 functions as a support for providing other layers in the recoat decorative sheet 1 of this embodiment. Examples of substrates that can be used for the paper substrate 10 include fine paper, tissue paper, linter paper, kraft paper, reinforced paper for paper lining, resin-impregnated paper, wallpaper backing paper, and flame-retardant paper obtained by mixing or impregnating a flame retardant into any of these papers. These materials may be used alone, or may be combined in any combination to form a laminate, such as a laminate of papers. The paper substrate 10 may contain additives such as flame retardants, inorganic agents, dry strength agents, wet strength agents, colorants, sizing agents, and fixing agents as needed.

[0074] There is no particular limitation on the thickness of the paper substrate 10, but considering the durability and ease of handling of the decorative sheet, a basis weight of 20 g / m 2 More than 150g / m 2 The following range is preferable, and 25 g / m 2 More than 120g / m 2 More preferably, the range is 35 g / m 2 More than 100g / m 2 More preferably, the range is 40 g / m 2 More than 60g / m 2 The following ranges are even more preferred:

[0075] (Decorative layer 50) From the viewpoint of improving design, the decorative sheet for recoat 1 of this embodiment preferably has a decorative layer 50. The decorative layer 50 may be provided between the paper substrate 10 and the nonwoven fabric layer 30, and is preferably provided between the paper substrate 10 and the adhesive layer 20. The decorative layer 50 may be a layer consisting of only an all-over colored layer 51 provided to cover the entire surface, or a layer consisting of only a patterned layer 52 provided to cover a portion of the decorative layer 50 and form a pattern, or a layer combining the all-over colored layer 51 and the patterned layer 52. These layer configurations may be determined according to the desired pattern.

[0076] The pattern imparted by the decorative layer 50 is not particularly limited and may be selected as desired, and examples thereof include wood grain patterns, marble patterns (e.g., travertine marble patterns), stone patterns imitating the surface of rock such as the cleavage plane of a granite slab, fabric patterns imitating cloth grain or fabric-like patterns, leather (leather grain) patterns expressing leather grain, tiled patterns, brickwork patterns, hairline patterns, linear grooves, pear-skin patterns, sand patterns, letters, symbols, geometric patterns, and patterns combining these, such as marquetry and patchwork.Further examples of patterns combining these include artificial stone patterns made by mixing crushed stone such as marble with white cement, hardening it, and polishing it to resemble marble, i.e., so-called artificial marble patterns. Although consumer design demands change with trends and the like, wood grain patterns remain popular, and so a wood grain pattern is preferred for the pattern of the decorative recoat sheet 1 of this embodiment. Wood grain patterns include straight grain patterns, cross grain patterns, figured grain patterns, and end grain patterns, and any of these may be used.

[0077] The decorative layer 50 is preferably formed from a resin composition containing at least a binder resin and a colorant such as a pigment or dye, and can be formed by appropriately mixing other components used as desired, such as a matting agent, an extender pigment, a stabilizer, a solvent, and weathering agents such as an ultraviolet absorber or a light stabilizer. In other words, the decorative layer 50 is a layer containing at least a binder resin and a colorant such as a pigment or dye, and can also contain other components used as desired as described above.

[0078] The binder resin is not particularly limited, and preferred examples include urethane resin, acrylic polyol resin, acrylic resin, polyester resin, alkyd resin, amide resin, butyral resin, styrene resin, urethane-acrylic copolymer, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-acrylic copolymer resin, nitrocellulose resin (nitrocellulose), cellulose acetate resin, and the like. Furthermore, curable resins such as two-component curable resins containing various polyols such as acrylic polyol as the base resin and various isocyanates as the curing agent may also be used. These may be used alone or in combination.

[0079] The colorant can be appropriately selected from known pigments, such as inorganic pigments such as titanium white, lead white, carbon black, iron black, yellow lead, titanium yellow, red iron oxide, cadmium red, ultramarine blue, and cobalt blue; organic pigments or dyes such as quinacridone red, isoindolinone yellow, nickel azo complexes, and phthalocyanine blue; metal pigments consisting of scaly foil flakes of aluminum, brass, and the like; and pearlescent pigments consisting of scaly foil flakes of titanium dioxide-coated mica, basic lead carbonate, and the like.

[0080] Furthermore, from the viewpoint of further improving the design, the decorative layer 50 preferably contains a matting agent among the other components that may be used as desired. Examples of the matting agent include inorganic fillers such as silica, clay, heavy calcium carbonate, light calcium carbonate, precipitated barium sulfate, calcium silicate, synthetic silicate, and silicate fine powder; and organic fillers such as acrylic resin, urethane resin, nylon resin, polypropylene resin, and urea resin.

[0081] By including a matting agent in the decorative layer 50, the decorative layer has a lower gloss, which makes it possible to create a design that has a visually uneven appearance due to differences in gloss. For example, in the wood grain pattern exemplified as a preferred pattern, the wood grain pattern includes a lower gloss (matte or low gloss) vessel portion, a higher gloss (glossy or high gloss) spring wood portion, and an even higher gloss autumn wood portion (shiny portion). In the decorative layer 50, a highly decorative pattern can be formed by combining multiple pattern layers 52, such as a pattern layer forming a lower gloss vessel portion, a pattern layer forming a higher gloss spring wood portion, and a pattern layer forming an even higher gloss autumn wood portion. In this case, for example, by not including a matting agent in the full-colored layer 51 or by including a lower matting agent content than in the pattern layer 52, the difference in gloss from the pattern layer 52 can be increased, thereby improving the design.

[0082] The thickness of the decorative layer 50 is not particularly limited, but from the viewpoint of improving the design, it is preferably 0.1 μm or more, more preferably 0.5 μm or more, and even more preferably 1 μm or more, with the upper limit being preferably 10 μm or less, more preferably 9 μm or less, and even more preferably 7.5 μm or less. When the decorative layer 50 is formed from two or more layers, it is preferable that the total thickness of the layers be within the above range.

[0083] (Method of manufacturing decorative sheet for recoating) The method for producing the recoatable decorative sheet 1 of this embodiment will be described using the recoatable decorative sheet 1 shown in FIG. 2, which is one of the preferred embodiments of the recoatable decorative sheet 1 of this embodiment, as an example. The recoatable decorative sheet 1 of this embodiment shown in Figure 2 can be manufactured through step 1 of providing a decorative layer 50 on a paper substrate 10, step 2 of providing an adhesive layer 20 on the decorative layer 50, step 3 of providing a nonwoven fabric layer 30 and a filling portion A31 on the adhesive layer 20, and step 4 of applying a resin composition that forms a surface layer 40 to the surface of the nonwoven fabric layer 30, and forming a filling portion B33 together with the surface layer 40.

[0084] Step 1 is to provide a decorative layer 50 on a paper substrate 10 . The decorative layer 50 is preferably formed by printing the resin composition used to form the decorative layer 50 using gravure printing, silk screen printing, gravure offset printing, flexographic printing, ink jet printing, etc., and it is more preferable to use gravure printing for large lots and ink jet printing for small lots.

[0085] Step 2 is a step of providing an adhesive layer 20 on the decorative layer 50 . For example, a resin composition, preferably containing a urethane resin, is appropriately selected from the resins exemplified as resins capable of forming the adhesive layer 20 and is applied onto the decorative layer 50 to form the adhesive layer 20. In this case, the method for applying the resin composition may be selected from any of the known methods exemplified as the method for applying the resin composition to the decorative layer 50 described above.

[0086] In this case, the amount of resin composition applied to form the adhesive layer 20 (dry base) is preferably 2 g / m from the viewpoint of obtaining excellent adhesiveness, forming the filler A 31, the filler B 33, and the fiber portion 32 in a balanced manner, and improving stainability and transparency. 2 More preferably, 5 g / m 2 More preferably, 8 g / m 2 More preferably, 10 g / m 2 The upper limit is preferably 50 g / m 2 Less than 45 g / m 2 More preferably, 40 g / m or less 2 More preferably, 30 g / m or less 2 The following is the result.

[0087] Step 3 is a step of providing the nonwoven fabric layer 30 and the filling portion A31 on the adhesive layer 20. The nonwoven fabric layer 30 and the filling portion A31 are formed, for example, by forming an adhesive layer 20 by applying a resin composition, placing a nonwoven fabric on top of this, and then dry laminating the layers to form the nonwoven fabric layer 30, and the resin composition used to form the adhesive layer is filled into some of the voids in the nonwoven fabric to form the filling portion A31.

[0088] In this case, the thickness of the adhesive layer-forming resin is preferably 10% or more, more preferably 12% or more, and even more preferably 14% or more of the thickness of the nonwoven fabric layer 30, from the viewpoint of obtaining excellent adhesion between the paper base material 10 and the nonwoven fabric layer 30, forming the filling portion A31, the filling portion B33, and the fiber portion 32 in a balanced manner, improving stainability and transparency, and further improving transparency, touch, etc., and the upper limit is preferably 25% or less, more preferably 23% or less, and even more preferably 20% or less.

[0089] Step 4 is a step of applying a composition for forming the surface layer 40 to the surface of the nonwoven fabric layer 30, thereby forming the surface layer 40 and the filling portion B33. The composition for forming the surface layer 40 may be applied by selecting any of the known methods exemplified above as methods for applying the resin composition for the decorative layer 50. When forming the surface layer 40, the amount of composition to be applied may be determined mainly in consideration of the thickness of the surface layer 40 as well as the balance between the filler B33, the fiber portion 32, and the filler A31 in the nonwoven fabric layer 30. From the viewpoint of forming the filler A31, the filler B33, and the fiber portion 32 in a balanced manner and improving the surface properties as well as the stainability, as well as the transparency, the feel, etc., a coating amount of 2 g / m is usually selected. 2 More than 4g / m 2 More preferably, 6 g / m 2 The upper limit is preferably 20 g / m 2 Less than 15 g / m, more preferably 2 More preferably, 12 g / m or less 2 The following is the result.

[0090] By the above steps, a recoatable decorative sheet 1 having a preferred embodiment shown in Figure 2 can be produced, which has a paper base material 10, a decorative layer 50, an adhesive layer 20, a nonwoven fabric layer 30 (filling portion A31, fiber portion 32, filling portion B33), and a surface layer 40 in that order.

[0091] [Method for coloring decorative sheets] The method for coloring a decorative sheet of this embodiment is characterized by applying a colored paint to the surface layer side of the decorative sheet for recoat of this embodiment described above, thereby coloring the nonwoven fabric layer. Examples of the colored paint include stain paint (water-based or oil-based). The recoatable decorative sheet 1 of this embodiment has a nonwoven fabric layer 30, which ensures that colored paints such as water-based stain paints and oil-based stain paints can penetrate into the voids in the fibers. By applying colored paint using the coloring method of this embodiment, the colored paint is retained in the fiber portion 32 of the nonwoven fabric layer 30 as well as on the outermost surface of the recoatable decorative sheet, resulting in a decorative sheet that exhibits a design created by the colored paint. [Example]

[0092] Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples in any way.

[0093] (Evaluation method) The decorative sheets obtained in each of the Examples and Comparative Examples were evaluated as follows. <Evaluation of Steadiness> The decorative sheets obtained in each example and comparative example were cut to dimensions of 200 mm x 300 mm, and a water-based stain ("W Stain (trade name)", manufactured by Osaka Paint Industries Co., Ltd.) and an oil-based stain ("WOODFINISH (trade name)", manufactured by MINWAX) were each uniformly applied and allowed to dry. After that, a 25 mm wide cellophane adhesive tape ("Cellotape (registered trademark)", manufactured by Nichiban Co., Ltd.) was applied to the stained area and then peeled off, and the condition of the stain was visually evaluated according to the following criteria to assess stainability. In this evaluation, a rating of A is a pass. A: No peeling was observed for either the water-based stain or the oil-based stain. B: Peeling was observed for the water-based stain. C: Peeling was confirmed for both water-based and oil-based stains.

[0094] <Evaluation of surface properties (water resistance)> The decorative sheets obtained in each Example and Comparative Example were cut to a size of 100 mm x 100 mm, water-soaked absorbent cotton was placed on the surface of the sheet, and the absorbent cotton was covered with a cap and left for 24 hours. After that, the cap was removed, the water was wiped off, and the appearance of the surface was visually evaluated according to the following criteria to evaluate the surface characteristics (water resistance). In this evaluation, an A rating is a pass. A: No changes in appearance were observed. B: Slight whitening was observed on the surface. C: Significant whitening was observed on the surface.

[0095] Example 1 The paper substrate was printing paper (HPT30 (product number), manufactured by Hokuetsu Kishu Paper Co., Ltd., thickness: 60 μm, basis weight: 45 g / m 2A decorative layer (thickness: 2-6 μm) with a wood grain pattern was formed on the printed paper by gravure printing using an ink containing an acrylic resin as a binder and a pigment (an ink containing an acrylic resin as a binder and carbon black as a pigment). Next, a resin composition (urethane resin, base: polyester polyol (product name: Seikabond E-295NTL-D50, manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.), and an isocyanate curing agent (product name: Seikabond C-55, manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) was applied to the decorative layer by gravure printing to form an adhesive layer (thickness: 3 μm). Separately, a nonwoven fabric made of rayon fiber (product number "3016", manufactured by Kinsei Paper Co., Ltd., thickness: 80 μm, basis weight: 17 g / m) was used. 2 ) was prepared, and the paper base material on which the decorative layer and adhesive layer were formed was dry laminated with a nonwoven fabric to obtain a laminate having a paper base material, a decorative layer, an adhesive layer, and a nonwoven fabric layer consisting of a filling portion A and a fiber portion. Next, a composition containing 100 g of acrylic polyol compound 1 (hydroxyl value: 41 mgKOH / g) and 5 g of an isocyanate curing agent (hexamethylene diisocyanate, isocyanate group content: 19% by mass) was applied in an amount of 12 g / m to the nonwoven fabric layer side of the laminate as a composition for forming a surface layer. 2 (dry base) to form the filling section B and the surface layer, and then cured at 70°C for 48 hours to obtain a decorative sheet for recoating having a paper base material, a decorative layer, an adhesive layer, the filling section A, a nonwoven fabric layer consisting of the fiber section and the filling section B, and the surface layer. The resulting decorative recoat sheet was evaluated by the above-mentioned methods, and the results are shown in Table 1.

[0096] Example 2 A recoatable decorative sheet was obtained in the same manner as in Example 1, except that in the composition used to form the surface layer in Example 1, acrylic polyol compound 1 was changed to acrylic polyol compound 2 (hydroxyl value: 24 mg KOH / g) and the amount of isocyanate curing agent used was changed from 5 g to 3 g. The resulting decorative recoat sheet was evaluated by the above-mentioned methods, and the results are shown in Table 1.

[0097] (Comparative Examples 1 to 4) A decorative sheet was obtained in the same manner as in Example 1, except that the amounts of acrylic polyol compound 1 and isocyanate curing agent used in the composition used to form the surface layer were changed as shown in Table 1. The decorative sheet obtained was evaluated by the above-mentioned methods, and the results are shown in Table 1.

[0098] [Table 1]

[0099] From the results of the examples, it was confirmed that the recoatable decorative sheet of this embodiment is excellent in surface properties such as water resistance as well as stainability. On the other hand, the decorative sheet of Comparative Example 1 had a high content of residual hydroxyl groups and an excessively high affinity for moisture on the surface of the surface layer, resulting in poor water resistance. The decorative sheets of Comparative Examples 2 and 3 also had a low content of residual hydroxyl groups, and the decorative sheet of Comparative Example 3 had a low molar ratio (C NCO / C OH ) was also smaller than 0.20, resulting in poor stainability and / or surface properties.

[0100] Regarding the decorative sheet of Comparative Example 4, the content of the residual hydroxyl groups was appropriate, but the molar ratio (C NCO / C OH ) was less than 0.20, the surface properties (water resistance) were poor. From the above results, the content and molar ratio of residual hydroxyl groups (C NCO / C OH It has been confirmed that unless both of the above conditions are satisfied, it is not possible to achieve both stainability and surface properties. [Industrial Applicability]

[0101] The recoat decorative sheet of this embodiment is excellent in surface properties such as water resistance as well as stainability, and is therefore suitable for applications requiring repainting using a colored paint such as a stain paint, such as interior or exterior components of buildings such as walls, ceilings, and floors, fittings or fixtures such as window frames, doors, handrails, baseboards, moldings, and other components, as well as surface decorative panels for kitchen equipment, furniture, or cabinets for low-voltage and office equipment, and as layers constituting interior or exterior components of vehicles. [Explanation of symbols]

[0102] 1: Recoat decorative sheet 10:Paper base material 20: Adhesive layer 30: Non-woven fabric layer 30a: Surface of the nonwoven fabric layer on which the adhesive layer is provided 30b: Surface on which the surface layer of the nonwoven fabric layer is provided 31: Filling part A 32: Fiber section 33: Filling part B 40: Surface layer 50:Decorative layer 51: Full colored layer 52: Picture layer

Claims

1. A decorative sheet for recoat comprising, in order, a paper substrate, an adhesive layer, a nonwoven fabric layer, and a surface layer made of a cured product of a composition containing a polyol compound having a hydroxyl group in its molecule and an isocyanate curing agent, the nonwoven fabric layer partially has a filled portion A on the side of the layer in the thickness direction where the adhesive layer is provided, in which a resin forming the adhesive layer is filled into some of the voids of the fibers constituting the nonwoven fabric layer, and a filled portion B on the side of the layer in the thickness direction where the surface layer is provided, in which the cured product is filled into some of the voids of the fibers constituting the nonwoven fabric layer, the outermost surface of the decorative sheet for recoat has at least partial voids between the fibers constituting the nonwoven fabric layer; the content of residual hydroxyl groups contained in the surface layer is 0.25% by mass or more and 1.10% by mass or less, Amount C of isocyanate groups in the isocyanate curing agent ＮＣＯ (mmol), and the amount of hydroxyl groups in the polyol compound C ＯＨ (mmol) and the ratio (C ＮＣＯ / C ＯＨ ) is 0.20 or more, Decorative sheet for recoating.

2. 2. The decorative sheet for recoating according to claim 1, wherein the fibers are at least one type of fibers selected from thermoplastic resin fibers and recycled fibers.

3. 3. The decorative sheet for recoat according to claim 1, wherein the fibers are cellulose resin fibers.

4. The decorative sheet for recoat according to any one of claims 1 to 3, wherein the resin forming the adhesive layer is at least one resin selected from the group consisting of urethane resins and polyolefin resins.

5. The decorative sheet for recoat according to any one of claims 1 to 4, wherein the polyol compound is at least one selected from the group consisting of acrylic polyols, polyester polyols, polyether polyols, and polycarbonate polyols.

6. The decorative sheet for recoat according to any one of claims 1 to 5, wherein the isocyanate curing agent is a polyvalent isocyanate compound.

7. The decorative sheet for recoat according to any one of claims 1 to 6, further comprising a decorative layer between the paper substrate and the adhesive layer.

8. 8. The decorative sheet for recoat according to claim 7, wherein the decorative layer has a wood grain pattern.

9. A method for coloring a decorative sheet, comprising applying a colored paint to the surface of the surface layer side of the decorative sheet for recoat according to any one of claims 1 to 8, thereby coloring the nonwoven fabric layer.

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