Moistureproof decorative paper

Abstract

To provide moisture decorative paper that can prevent warpage of a decorative plate due to high moistureproof performance, even if it is used in a place having a large difference between temperature / humidity environments on both sides, and reduces a plastic used amount, which is environmentally friendly.SOLUTION: Moisture decorative paper 100 includes a moistureproof layer 10, and a decorative layer 20 in this order on one surface of a paper base material 11, wherein the moistureproof layer 10 is a laminate having such a structure that a first resin layer 12, an aluminum vapor deposition layer 13 and a second resin layer 14 are laminated in this order from the paper base material 11 side, thickness of the aluminum vapor deposition layer 13 is 60 nm or more, and the decorative layer 20 includes a printed layer 15, and a protective resin layer 16 in this order from the moistureproof layer 10 side.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a moisture-proof decorative paper used for fittings such as interior doors, kitchen doors, storage doors, and sliding doors, and more particularly to a moisture-proof decorative paper that is pasted onto the surface of decorative boards to prevent warping of the boards caused by changes in humidity, temperature, etc. [Background technology]

[0002] Traditionally, interior doors, kitchen doors, storage doors, and other fixtures have been known to gradually warp during use due to humidity and temperature fluctuations. This phenomenon occurs primarily due to uneven moisture content distribution within the wooden fixture caused by humidity and temperature differences between indoors and outdoors. Humidity differences create differences in the amount of moisture absorbed and released on the front and back surfaces of the wooden fixture, resulting in expansion due to high moisture content on the higher humidity side and contraction on the lower humidity side, resulting in warping. Temperature differences also cause moisture to migrate to the colder side of the wood substrate, creating a moisture content gradient across the thickness, resulting in warping. Typically, the lower temperature side is more humid and has a higher moisture content. In this case, the two effects act in the same direction, which is thought to be the most pronounced cause of warping.

[0003] A widely used method for preventing such warping of wooden fixtures is to use moisture-proof sheets with low moisture permeability in the fixture components, thereby reducing the amount of moisture absorbed and released by the components. Patent Document 1 also proposes that a moisture-proof decorative sheet having a five-layer structure consisting of a protective resin layer / printed pattern layer / interleaf reinforced paper / synthetic resin layer / interleaf reinforced paper be attached to the front side of a board substrate such as plywood using an adhesive, and that a moisture-proof back sheet having a three-layer structure consisting of interleaf reinforced paper / synthetic resin / interleaf reinforced paper be attached to the back side of the board substrate using an adhesive to form a moisture-proof decorative board, which is then attached to the front and back of a flush door using an adhesive. The moisture permeability of the moisture-proof sheet in this case is 5 (g / m 2 ·24hr) or more 30(g / m) 2 It is said that a minimum of 24 hours is best.

[0004] Furthermore, when even higher moisture resistance is required, a method is known for preventing deformation of the decorative board, such as laminating a moisture-proof sheet having a vapor-deposited layer on a synthetic resin substrate. To achieve high moisture-proof performance, a vapor-deposited layer must be formed on a smooth surface, so synthetic resin substrates are generally chosen, and it is considered technically difficult to achieve high moisture-proof performance using a paper substrate.

[0005] On the other hand, however, in recent years, growing environmental awareness stemming from issues such as marine plastic waste has led to a growing trend toward a plastic-free society. From the perspective of reducing the amount of plastic used, the use of paper instead of plastic materials has been considered in various fields. Furthermore, from the perspective of effective resource utilization under the Resource Effective Utilization Promotion Act, there is a demand to increase the proportion of paper in the overall laminate having barrier properties. For example, Patent Document 2 below discloses a base paper for metallized paper, which has a specific clay coat layer and a resin layer, in that order, on at least one side of a specific paper substrate, for forming a metallized layer by vapor deposition. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 3206408 [Patent Document 2] Patent No. 6958755 Summary of the Invention [Problem to be solved by the invention]

[0007] Conventional moisture-proof sheets can sometimes have insufficient moisture-proofing properties, and when used for long periods of time on doors, sliding doors, partitions, etc. where there is a large difference in temperature and humidity environments on both sides, the degree of expansion and contraction on both sides can differ, causing the decorative panel to warp. Furthermore, both of these are primarily made of plastic materials, and there is a demand to reduce their use in order to reduce the environmental impact.

[0008] The present inventors have investigated various laminates comprising a paper substrate, a first resin layer, an aluminum vapor-deposited layer, and a second resin layer as laminates with excellent environmental compatibility. They have found that such laminates have a high water vapor permeability and are unstable. In other words, the present inventors have newly discovered a problem in that some of the above-mentioned laminates according to conventional technology have low and unstable water vapor barrier properties (i.e., some have uneven water vapor barrier performance and have low yields).

[0009] The present invention has been made to solve this problem, and aims to provide an environmentally friendly moisture-proof decorative paper that has high moisture-proof performance, can prevent warping of the decorative board even when used in a place where there is a large difference in temperature and humidity environment on both sides, and reduces the amount of plastic used. [Means for solving the problem]

[0010] The inventors of the present invention speculate as follows as to why conventional laminates have high and unstable water vapor permeability and why the laminate according to the present disclosure has high and stable water vapor barrier properties (i.e., low and stable water vapor permeability).

[0011] Compared to plastic films, paper experiences greater dimensional changes due to moisture absorption and release. However, the moisture content of paper varies depending on the production lot. Furthermore, the moisture content of paper changes depending on the environmental conditions during the manufacture, storage, and use of moisture-proof decorative paper. In paper made continuously on a paper machine, the fibers are oriented in the machine direction (MD) of the paper machine, resulting in greater expansion and contraction in the cross direction (CD). As a result, the aluminum vapor-deposited layer cannot keep up with the dimensional changes in the paper due to changes in moisture content, resulting in defects parallel to the MD. The defects impair the continuity of the aluminum vapor-deposited layer, increasing the water vapor permeability of the laminate.

[0012] The second resin layer is formed, for example, by wet-coating a mixture of resin and solvent onto the aluminum vapor-deposited layer to form a coating film and then drying the coating film. Here, as the coating film dries, the solvent volatilizes and the second resin layer is formed. If the formation of the surface layer of the second resin layer proceeds without the solvent being completely volatilized, the solvent contained in the second resin layer may bump. This bumping of the solvent may cause micro-sized defects in the second resin layer. Furthermore, due to differences in the thermal shrinkage behavior between the paper substrate and the second resin layer, similar defects may occur in the second resin layer when the coating film for forming the second resin layer is dried. These defects in the second resin layer may reach the aluminum vapor-deposited layer. These defects in the aluminum vapor-deposited layer can cause unstable water vapor barrier properties.

[0013] However, by making the thickness of the aluminum vapor deposition layer 60 nm or more, defects caused by moisture absorption and desorption of the paper and defects caused by bumping of the solvent contained in the second resin layer can be suppressed, and as a result, the laminate has high and stable water vapor barrier properties. [Effects of the Invention]

[0014] According to the present disclosure, it is possible to provide a moisture-proof decorative paper that is a laminate having high and stable water vapor barrier properties and has a high paper component ratio. Furthermore, according to one aspect of the present invention, a moisture-proof decorative paper can be provided that contributes to reducing the amount of plastic materials used. In other words, according to one embodiment of the present invention, the moisture-proof decorative paper has high moisture-proof performance, which makes it possible to prevent warping of the decorative panel even when used in a place where there is a large difference in temperature and humidity environment on both sides, and by reducing the amount of plastic used, it is possible to provide an environmentally friendly moisture-proof decorative paper. Problems, configurations, and effects other than those described above will become apparent from the following description of the preferred embodiment of the invention. [Brief explanation of the drawings]

[0015] [Figure 1]1 is a schematic cross-sectional view showing an example of the configuration of moisture-proof decorative paper according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The drawings are schematic, and the relationship between thickness and planar dimensions, the ratio of each thickness, etc., differ from the actual ones. Furthermore, the embodiments shown below are merely examples of configurations for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention is not limited to the materials, shapes, etc. of the components described below. The technical idea of ​​the present invention can be modified in various ways within the technical scope defined by the claims.

[0017] <Moisture-proof decorative paper 100> FIG. 1 is a schematic cross-sectional view showing the structure of moisture-proof decorative paper 100 according to this embodiment. As shown in Figure 1, the moisture-proof decorative paper 100 of this embodiment is formed by laminating a paper base material 11, a first resin layer 12, an aluminum vapor deposition layer 13, a second resin layer 14, a printed pattern layer 15, and a protective resin layer 16 in this order. The thickness of the aluminum vapor deposition layer 13 is 60 nm or more. In the moisture-proof decorative paper 100 according to this embodiment, the moisture-proof layer 10 is composed of a first resin layer 12, an aluminum vapor deposition layer 13, and a second resin layer 14, and the decorative layer 20 is composed of a printed pattern layer 15 and a protective resin layer 16.

[0018] The moisture-proof decorative paper 100 according to this embodiment is a moisture-proof paper that is used by being stuck to the surface of a decorative panel used for an interior door panel, for example, although this is not shown. The moisture-proof decorative paper 100 is used to prevent warping of the decorative board caused by moisture absorption and release due to changes in temperature and humidity in the room. By using the moisture-proof decorative paper 100, it is possible to provide moisture-proof paper that addresses the movement to eliminate plastic and the problem of marine litter, has a high proportion of paper components, and has stable and excellent water vapor barrier properties.

[0019] [Moisture permeability (water vapor permeability) of moisture-proof decorative paper 100] The moisture-proof decorative paper 100 has a water vapor permeability of 5g / (m) at a temperature of 40°C and a relative humidity (RH) of 90%. 2 ·24hr) or less, 4g / (m 2 ·24hr) or less, 3g / (m 2 ·24hr) or less, 2g / (m 2 24hr) or less, or 1g / (m 2 The water vapor transmission rate may be less than 1 / 24 hr. Here, the water vapor transmission rate refers to a value measured by the method described in the Examples below.

[0020] <Paper base material> The paper substrate 11 is not particularly limited and may be selected appropriately depending on the intended use of the moisture-proof decorative paper 100 . Specific examples of the paper substrate 11 include tissue paper, fine paper, art paper, cast coated paper, kraft paper, titanium paper, linter paper, paperboard, gypsum board paper, coated paper, parchment paper, glassine paper, parchment paper, paraffin paper, and Japanese paper. Preferably, thin paper (so-called inter-sheet reinforced paper) in which synthetic resin is mixed into paper components (e.g., cellulose fiber) to enhance inter-sheet strength, or paper impregnated with latex or synthetic resin, is used.

[0021] The basis weight of the paper base material 11 is not particularly limited, but the basis weight of the paper base material 11 is preferably 20 g / m 2 If the paper substrate 11 has a basis weight of less than 200 g / m, it is too flexible and wrinkles tend to occur during processing. 2 If the basis weight is more than 20 g / m, peeling from the paper layer is likely to occur. 2 More than 200g / m 2 The following range is preferred: 20 g / m 2 More than 100g / m 2 The following range is more preferable: 20 g / m2 More than 50g / m 2 The following ranges are more preferred: Furthermore, the surface of the paper substrate 11 may be subjected to a surface treatment such as corona treatment, plasma treatment, or flame treatment, if necessary.

[0022] The paper substrate 11 may have a coating layer (not shown) on at least the side of the paper substrate 11 that contacts the first resin layer 12. When the paper substrate 11 has a coating layer, the paper substrate 11 may have at least a paper layer and a coating layer. The coating layer may be provided on both surfaces (i.e., the front and back surfaces) of the paper substrate 11. The coating layer can prevent the resin that constitutes the first resin layer 12 from seeping into the paper layer, and can also serve as a sealant that fills in unevenness in the paper layer, allowing the first resin layer 12 to be formed uniformly and without defects. The coating layer may contain, as a binder resin, various copolymers such as styrene-butadiene, styrene-acrylic, and ethylene-vinyl acetate copolymers, polyvinyl alcohol resins, cellulose resins, paraffin (wax), etc. The coating layer may also contain, as a filler, clay, kaolin, calcium carbonate, talc, mica, etc. The coating layer may be a clay coating layer containing at least clay as a filler.

[0023] The change rate of the dimensions of the paper substrate 11 in the cross direction (CD) at 40°C and 90% RH (relative humidity) relative to the dimensions at 40°C and 20% RH may be 0.3% or more, 0.4% or more, or 0.6% or more, and may be 1.5%, 1.3%, or 1.0% or less. The change rate of the dimensions of the paper substrate 11 in the machine direction (MD) at 40°C and 90% RH relative to the dimensions at 40°C and 20% RH may be 0.05% or more, and 0.20% or less. If the rate of change of the paper substrate 11 is within the above range, the aluminum vapor deposition layer 13 can follow the dimensional changes of the paper that accompany changes in the moisture content, and defects parallel to the MD are less likely to occur.

[0024] When the paper substrate 11 has a coating layer, the thickness of the coating layer may be 1.5 μm or more and 15 μm or less. The thickness of the coating layer may also be 1.8 μm or more, 3 μm or more, 5 μm or more, or 6 μm or more. Furthermore, the thickness of the coating layer may be 12 μm or less, or 10 μm or less. When the thickness of the coating layer is within the above range, the moisture-proof decorative paper 100 can more stably achieve higher water vapor barrier properties.

[0025] The mass of the paper components contained in the paper base material 11 is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more, based on the entire moisture-proof decorative paper 100. If the mass of the paper components contained in the paper base material 11 is 50% by mass or more based on the entire moisture-proof decorative paper 100, the amount of plastic material used can be sufficiently reduced, the entire moisture-proof decorative paper 100 can be said to be made of paper, and it has excellent recyclability.

[0026] <First resin layer> The first resin layer 12 is provided on the surface of the paper base material 11 to improve adhesion between the paper base material 11 and the aluminum vapor deposition layer 13 described later, and to improve the gas barrier properties (especially the water vapor barrier properties) of the moisture-proof decorative paper 100. The first resin layer 12 may contain at least one selected from the group consisting of a polyolefin having an acidic group, a polyvinyl alcohol-based resin, and a polyurethane-based resin. From the viewpoint of more stably obtaining higher water vapor barrier properties, the first resin layer 12 preferably contains at least one of a polyolefin having an acidic group and a polyurethane-based resin, and more preferably contains a polyolefin having an acidic group.

[0027] When the first resin layer 12 contains a polyolefin having acidic groups, the first resin layer 12 has excellent flexibility, can suppress cracking of the aluminum vapor-deposited layer 13 that may occur after bending (folding), and can improve adhesion between the first resin layer 12 and the aluminum vapor-deposited layer 13. Furthermore, the inclusion of a polyolefin having acidic groups makes it possible to form a dense film due to the crystallinity of the polyolefin, and water vapor barrier properties are exhibited. In other words, with the polyolefin having the above-mentioned acidic groups, water vapor barrier properties are exhibited due to the crystallinity of the polyolefin, and the presence of acidic groups exhibits adhesion to the aluminum vapor-deposited layer 13. The polyolefin having an acidic group may have at least one selected from a carboxyl group, a salt of a carboxyl group, a carboxylic anhydride group, and a carboxylic acid ester.

[0028] Examples of polyolefins having acidic groups include copolymers of ethylene or propylene with unsaturated carboxylic acids (unsaturated compounds having a carboxyl group, such as acrylic acid, methacrylic acid, and maleic anhydride), unsaturated carboxylic acid esters, and salts of carboxylic acids neutralized with basic compounds, as well as copolymers of vinyl acetate, epoxy compounds, chlorine compounds, urethane compounds, polyamide compounds, etc. The first resin layer 12 preferably contains an ethylene-unsaturated carboxylic acid copolymer, as this provides more stable water vapor barrier properties. Specific examples of polyolefins having an acidic group include copolymers of acrylic acid ester and maleic anhydride, ethylene-vinyl acetate copolymers, and ethylene-glycidyl methacrylate copolymers.

[0029] When the first resin layer 12 contains a polyvinyl alcohol-based resin, the polyvinyl alcohol-based resin has hydroxyl groups that easily bond with metals such as aluminum in the aluminum vapor-deposited layer 13, which can easily improve the adhesion between the aluminum vapor-deposited layer 13 and the first resin layer 12. Furthermore, such a first resin layer 12 has excellent flexibility and can suppress cracks in the aluminum vapor-deposited layer 13 that may occur after bending (folding). Polyvinyl alcohol-based resins are resins that contain vinyl alcohol as a constituent unit, and examples of polyvinyl alcohol-based resins include fully saponified polyvinyl alcohol resins, partially saponified polyvinyl alcohol resins, modified polyvinyl alcohol resins, and ethylene-vinyl alcohol copolymer resins.

[0030] Polyurethane resins are obtained by bonding the acid groups of an acid group-containing polyurethane with the amino groups of a polyamine used as a crosslinking agent. That is, polyurethane resins can be said to be a reaction product of an acid group-containing polyurethane and a polyamine, or to be formed by crosslinking an acid group-containing polyurethane with a polyamine. The bond between the acid groups of the acid group-containing polyurethane and the amino groups of the polyamine may be an ionic bond (e.g., an ionic bond between a carboxyl group and a tertiary amino group) or a covalent bond (e.g., an amide bond).

[0031] The acid group-containing polyurethane constituting the polyurethane-based resin has anionic properties and self-emulsifying properties due to the presence of acid groups, and is also referred to as anionic self-emulsifying polyurethane. The acid groups of the acid group-containing polyurethane can bond with amino groups (primary amino groups, secondary amino groups, tertiary amino groups, etc.) of the polyamine constituting the polyurethane-based resin. Examples of the acid group include a carboxyl group and a sulfonic acid group. The acid group can usually be neutralized with a neutralizing agent (base) and may form a salt with the base. The acid group may be located at the terminal or on the side chain of the acid group-containing polyurethane, but is preferably located at least on the side chain.

[0032] The acid value of the acid group-containing polyurethane can be selected within a range that ensures water dispersibility, and can be 5 to 100 mgKOH / g, or alternatively 10 to 70 mgKOH / g, or 15 to 60 mgKOH / g. When the acid value of the acid group-containing polyurethane is at least the lower limit of the above range (5 mgKOH / g), water dispersibility of the acid group-containing polyurethane is easily achieved, and uniform dispersion of the polyurethane resin with other materials and dispersion stability of the coating agent are easily ensured. When the acid value of the acid group-containing polyurethane is at most the upper limit of the above range (100 mgKOH / g), water resistance and gas barrier properties of the first resin layer 12 are easily ensured. The acid value of the acid group-containing polyurethane is measured by a method in accordance with JIS K 0070.

[0033] From the viewpoint of gas barrier properties, the total concentration of urethane groups and urea groups in the acid group-containing polyurethane can be 15% by mass or more, or may be 20 to 60% by mass, of the entire acid group-containing polyurethane. When the total concentration of urethane groups and urea groups is equal to or greater than the lower limit (15% by mass) of the above range, the gas barrier properties of the first resin layer 12 tend to be good. When the total concentration of urethane groups and urea groups is equal to or less than the upper limit (60% by mass) of the above range, the first resin layer 12 tends to be prevented from becoming rigid and brittle.

[0034] The urethane group concentration refers to the ratio of the molecular weight of the urethane group (59 g / equivalent) to the molecular weight of the constituent units of the polyurethane resin. The urea group concentration refers to the ratio of the molecular weight of the urea group (primary amino group (amino group): 58 g / equivalent, secondary amino group (imino group): 57 g / equivalent) to the molecular weight of the constituent units of the polyurethane resin. When a mixture of two or more types of acid group-containing polyurethane is used, the urethane group concentration and urea group concentration can be calculated based on the charged reactants, i.e., the proportion of each component used.

[0035] The acid group-containing polyurethane may have at least rigid units (units composed of hydrocarbon rings) and short-chain units (e.g., units composed of hydrocarbon chains). The constituent units of the acid group-containing polyurethane may contain a hydrocarbon ring (at least one of an aromatic and a non-aromatic hydrocarbon ring) derived from a polyisocyanate component, a polyhydroxy acid component, a polyol component, or a chain extender component (particularly, at least a polyisocyanate component).

[0036] The proportion of units composed of hydrocarbon rings in the structural units of the acid group-containing polyurethane can be 10 to 70 mass %, alternatively 15 to 65 mass %, or even 20 to 60 mass %, relative to the total of all structural units. When the proportion of units composed of hydrocarbon rings is at least the lower limit of the above range (10 mass %), the gas barrier properties of the first resin layer 12 are likely to be improved. When the proportion of units composed of hydrocarbon rings is no more than the upper limit of the above range (70 mass %), the first resin layer 12 is likely to be prevented from becoming rigid and brittle.

[0037] The number-average molecular weight of the acid group-containing polyurethane can be appropriately selected, but can be 800 to 1,000,000, or alternatively 800 to 200,000, or 800 to 100,000. When the number-average molecular weight of the acid group-containing polyurethane is equal to or less than the upper limit (1,000,000) of the above range, the coating agent is likely to have an appropriate viscosity. When the number-average molecular weight of the acid group-containing polyurethane is equal to or greater than the lower limit (800) of the above range, the first resin layer 12 is likely to have good gas barrier properties. The number-average molecular weight of the acid group-containing polyurethane is a value measured by gel permeation chromatography (GPC) in terms of standard polystyrene.

[0038] The acid group-containing polyurethane may be crystalline to improve gas barrier properties. The glass transition temperature of the acid group-containing polyurethane may be 100°C or higher, or may be 110°C or higher, or may be 120°C or higher. When the glass transition temperature of the acid group-containing polyurethane is 100°C or higher, the gas barrier properties of the first resin layer 12 tend to be good. The glass transition temperature of the acid group-containing polyurethane may be 200°C or lower, or may be 180°C or lower, or may be 150°C or lower. Therefore, the glass transition temperature of the acid group-containing polyurethane may be 100 to 200°C, or may be 110 to 180°C, or may be 120 to 150°C. The glass transition temperature of the acid group-containing polyurethane is measured by differential scanning calorimetry (DSC).

[0039] The polyamine constituting the polyurethane resin is a compound having two or more basic nitrogen atoms. The basic nitrogen atom is a nitrogen atom that can bond with the acid group of the acid group-containing polyurethane, and examples thereof include nitrogen atoms in amino groups such as primary amino groups, secondary amino groups, and tertiary amino groups. The polyamine is not particularly limited as long as it can bond with the acid group of the acid group-containing polyurethane and improve the gas barrier property, and various compounds having two or more basic nitrogen atoms can be used. The polyamine can be a polyamine having two or more amino groups of at least one type selected from the group consisting of primary amino groups, secondary amino groups, and tertiary amino groups.

[0040] Examples of polyamines include alkylenediamines, polyalkylenepolyamines, and silicon compounds having multiple basic nitrogen atoms. Examples of alkylenediamines include alkylenediamines having 2 to 10 carbon atoms, such as ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, 1,4-butanediamine, and 1,6-hexamethylenediamine. Examples of polyalkylenepolyamines include tetraalkylenepolyamine. Examples of silicon compounds having multiple basic nitrogen atoms (including nitrogen atoms such as amino groups) include silane coupling agents having multiple basic nitrogen atoms, such as 2-[N-(2-aminoethyl)amino]ethyltrimethoxysilane and 3-[N-(2-aminoethyl)amino]propyltriethoxysilane.

[0041] The amine value of the polyamine can be 100 to 1900 mgKOH / g, or alternatively, 150 to 1900 mgKOH / g, 200 to 1900 mgKOH / g, 200 to 1700 mgKOH / g, or 300 to 1500 mgKOH / g. When the amine value of the polyamine is at least the lower limit of the above range (100 mgKOH / g), the gas barrier properties of the first resin layer 12 tend to be good. When the amine value of the polyamine is at most the upper limit of the above range (1900 mgKOH / g), the aqueous dispersion stability of the polyurethane resin tends to be good.

[0042] [Method for measuring amine value] The amine value of the polyamine is measured by the following method. Accurately weigh out 0.5 to 2 g of sample (sample weight S g). Add 30 g of ethanol to the weighed sample and dissolve. Add bromophenol blue as an indicator to the resulting solution and titrate with 0.2 mol / L ethanolic hydrochloric acid solution (titer f). The point at which the color of the solution changes from green to yellow is set as the endpoint, and the titer (A mL) at this point is used to calculate the amine value using the following formula 1. Calculation formula 1: Amine value = A x f x 0.2 x 56.108 / S [mgKOH / g]

[0043] When forming the polyurethane resin, the molar ratio of the acid groups of the acid group-containing polyurethane to the basic nitrogen atoms of the polyamine (acid groups / basic nitrogen atoms) can be 10 / 1 to 0.1 / 1, or may be 5 / 1 to 0.2 / 1. As the polyurethane-based resin, a commercially available polyurethane-based resin may be used, or a polyurethane-based resin produced by a known production method may be used.

[0044] Methods for producing polyurethane resins are not particularly limited, and include conventional aqueous polyurethane resin technologies such as the acetone method and the prepolymer method. In the urethanization reaction, urethanization catalysts such as amine catalysts, tin catalysts, and lead catalysts may be used as needed. For example, acid group-containing polyurethanes can be prepared by reacting a polyisocyanate compound with a polyhydroxy acid and, optionally, at least one of a polyol component and a chain extender component in an inert organic solvent such as a ketone such as acetone, an ether such as tetrahydrofuran, or a nitrile such as acetonitrile. More specifically, a polyisocyanate compound, a polyhydroxy acid, and a polyol component are reacted in an inert organic solvent (particularly a hydrophilic or water-soluble organic solvent) to produce a prepolymer having isocyanate groups at its terminals. The resulting prepolymer is then neutralized with a neutralizing agent and dissolved or dispersed in an aqueous medium. A chain extender component is then added and reacted, and the organic solvent is removed to produce an aqueous dispersion of the acid group-containing polyurethane. A polyurethane resin in the form of an aqueous dispersion can be prepared by adding a polyamine to the aqueous dispersion of the acid group-containing polyurethane obtained in this manner and heating it as needed. When heating, the heating temperature can be 30 to 60°C.

[0045] The first resin layer 12 may contain other components in addition to the above-mentioned polyolefin having an acidic group, polyvinyl alcohol-based resin, and polyurethane-based resin, such as polyolefins other than the above-mentioned polyolefin having an acidic group, silane coupling agents, organic titanates, polyacrylics, polyesters, polyurethanes, polycarbonates, polyureas, polyamides, polyimides, melamine, and phenols. The content of at least one resin selected from the group consisting of polyolefins having acidic groups, polyvinyl alcohol-based resins, and polyurethane-based resins in the first resin layer 12 may be, for example, 50% by mass or more of the entire first resin layer 12, 70% by mass or more, 90% by mass or more, or 100% by mass.

[0046] The thickness of the first resin layer 12 may be, for example, 0.5 μm or more, 1 μm or more, 2 μm or more, 20 μm or less, 10 μm or less, or 5 μm or less. If the thickness of the first resin layer 12 is 0.5 μm or more, the unevenness of the paper base material 11 described above can be efficiently filled, and the aluminum vapor deposition layer 13 described below can be laminated uniformly. Furthermore, if the thickness of the first resin layer 12 is 20 μm or less, the aluminum vapor deposition layer 13 can be laminated uniformly while keeping costs down.

[0047] Examples of solvents contained in the coating liquid for forming the first resin layer 12 include water, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, n-butyl alcohol, n-pentyl alcohol, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, toluene, hexane, heptane, cyclohexane, acetone, methyl ethyl ketone, diethyl ether, dioxane, tetrahydrofuran, ethyl acetate, and butyl acetate. These solvents may be used alone or in combination. Among these, from the viewpoint of properties, methyl alcohol, ethyl alcohol, isopropyl alcohol, toluene, ethyl acetate, methyl ethyl ketone, and water are preferred. Furthermore, from the viewpoint of the environment, methyl alcohol, ethyl alcohol, isopropyl alcohol, and water are preferred.

[0048] Methods for providing the first resin layer 12 include applying a coating liquid containing the above-mentioned polyolefin, polyvinyl alcohol-based resin, or polyurethane-based resin having an acidic group and a solvent, etc., onto the paper substrate 11 to form a coating film, and then drying the coating film.

[0049] <Aluminum vapor deposition layer> The aluminum vapor-deposited layer 13 is a layer formed by vapor-depositing aluminum or an aluminum compound. The aluminum vapor-deposited layer 13 may be obtained by vapor-depositing aluminum, or may contain aluminum oxide (AlOx), silicon oxide (SiOx), or the like. The thickness of the aluminum vapor-deposited layer 13 is 60 nm or more, and may be greater than 60 nm, greater than 70 nm, 80 nm or more, or 90 nm or more. The thickness of the aluminum vapor-deposited layer 13 may be 300 nm or less, 200 nm or less, or 100 nm or less. The thickness of the aluminum vapor-deposited layer 13 is measured by the method in the examples described below.

[0050] <Second resin layer> The second resin layer 14 is provided on the surface of the aluminum vapor-deposited layer 13 so as to be in contact with the aluminum vapor-deposited layer 13. The second resin layer 14 may contain a polyolefin having an acidic group. The polyolefin having an acidic group may have at least one selected from a carboxyl group, a salt of a carboxyl group, a carboxylic anhydride group, and a carboxylic acid ester.

[0051] Examples of polyolefins having an acidic group include copolymers of ethylene or propylene with unsaturated carboxylic acids (unsaturated compounds having a carboxyl group, such as acrylic acid and methacrylic acid) or unsaturated carboxylic acid esters, and salts of carboxylic acids neutralized with basic compounds. Other examples of polyolefins that can be used include copolymers of ethylene or propylene with vinyl acetate, epoxy compounds, chlorine compounds, urethane compounds, polyamide compounds, and the like. Specific examples of polyolefins having an acidic group include copolymers of acrylic acid esters and maleic anhydride, ethylene-unsaturated carboxylic acid copolymers, ethylene-vinyl acetate copolymers, and ethylene-glycidyl methacrylate copolymers.

[0052] By including a polyolefin having an acidic group, the second resin layer 14 has excellent flexibility, can suppress cracking of the aluminum vapor-deposited layer 13 that may occur after bending (folding), and has excellent adhesion to the aluminum vapor-deposited layer 13. Furthermore, by including the polyolefin having the above-mentioned acidic group, it is possible to form a dense film due to the crystallinity of the polyolefin, and water vapor barrier properties are exhibited. Furthermore, the polyolefin having an acidic group exhibits adhesion to the aluminum vapor-deposited layer 13.

[0053] The second resin layer 14 preferably contains an ethylene-unsaturated carboxylic acid copolymer, as this provides more stable water vapor barrier properties. The second resin layer 14 may contain other components in addition to the polyolefin having an acidic group, such as a silane coupling agent, organic titanate, polyacrylic, polyester, polyurethane, polycarbonate, polyurea, polyamide, polyolefin emulsion, polyimide, melamine, and phenol. The content of the polyolefin having an acidic group in the second resin layer 14 may be, for example, 50% by mass or more of the entire second resin layer 14, 70% by mass or more, 90% by mass or more, or 100% by mass.

[0054] The thickness of the second resin layer 14 may be, for example, 0.05 μm or more, 0.5 μm or more, 1 μm or more, 2 μm or more, 20 μm or less, 10 μm or less, or 5 μm or less. If the thickness of the second resin layer 14 is 0.05 μm or more, it can fully fulfill its role as a protective layer for the aluminum vapor-deposited layer 13 described above. If the thickness of the second resin layer 14 is 20 μm or less, it can fully fulfill its adhesion to the aluminum vapor-deposited layer 13 and its barrier properties while keeping costs down. Furthermore, by setting the thickness of the second resin layer 14 to 2 μm or more and 10 μm or less, the aluminum vapor-deposited layer 13 becomes less likely to crack, and sufficient water vapor barrier properties and oil resistance can be obtained even after bending.

[0055] Examples of solvents contained in the coating liquid for forming the second resin layer 14 include water, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, n-butyl alcohol, n-pentyl alcohol, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, toluene, hexane, heptane, cyclohexane, acetone, methyl ethyl ketone, diethyl ether, dioxane, tetrahydrofuran, ethyl acetate, and butyl acetate. These solvents may be used alone or in combination. Among these, from the viewpoint of properties, methyl alcohol, ethyl alcohol, isopropyl alcohol, toluene, ethyl acetate, methyl ethyl ketone, and water are preferred. Furthermore, from the viewpoint of the environment, methyl alcohol, ethyl alcohol, isopropyl alcohol, and water are preferred.

[0056] The second resin layer 14 can be provided by applying a coating liquid containing the above-described polyolefin having acidic groups and a solvent onto the aluminum vapor-deposited layer 13 to form a coating film, followed by drying the coating film. The melting point of the polyolefin having acidic groups in the coating liquid is preferably 70 to 160°C, more preferably 80 to 120°C. If the melting point of the polyolefin having acidic groups is 70°C or higher, blocking tends to be less likely to occur in high-temperature environments. To prevent blocking, the particle size of the polyolefin having acidic groups should preferably be large so as to reduce the contact area. Although not particularly limited, the particle size of the polyolefin having acidic groups may specifically be 1 nm or more, 0.1 μm or more, 1 μm or less, 0.7 μm or less, or 0.5 μm or less.

[0057] <Printed pattern layer> The printed pattern layer 15 is intended to impart design, and any pattern can be used as the pattern, such as a wood grain pattern, a stone pattern, a fabric pattern, a cork pattern, an abstract pattern, or a combination of two or more of these. Furthermore, by utilizing the brightness of the aluminum vapor deposition layer 13, the print pattern layer 15 can be provided with a metallic pattern, providing excellent design expression. To ensure hiding power, a solid ink layer can be provided between the print pattern layer 15 and the second resin layer 14. The printing method is not particularly limited, and known printing methods such as gravure printing, offset printing, silk screen printing, and inkjet printing can be used.

[0058] There are no particular limitations on the printing ink, etc., and either oil-based or water-based inks are acceptable. The printing ink, etc. used for the print pattern layer 15 can be the same as the printing ink, etc. used for print pattern layers in conventional decorative paper, and for example, acrylic ink can be used. For example, the acrylic ink can be a two-component curing urethane resin ink made by blending an isocyanate curing agent with an acrylic polyol vehicle.

[0059] <Protective resin layer> The protective resin layer 16, which functions as a surface protective layer, is a layer for protecting the surface of the moisture-proof decorative paper 100, and is provided to impart the surface properties required of the moisture-proof decorative paper 100, such as scratch resistance, abrasion resistance, stain resistance, water resistance, and weather resistance. The formation of the protective resin layer (surface protective layer) 16 is not particularly limited, and it can be formed by a known coating method such as gravure coating.

[0060] The material for the protective resin layer (surface protective layer) 16 is not particularly limited, and materials similar to those used as surface protective layers in conventional decorative paper can be used. Examples of materials that can be used for the protective resin layer (surface protective layer) 16 include acrylic urethane resins and ionizing radiation curable resins. Examples of acrylic urethane resins that can be used include reaction products containing an acrylic polyol compound as the main component and an isocyanate compound as the curing agent. Examples of ionizing radiation curable resins that can be used include compositions containing, as the main component, at least one of a prepolymer, oligomer, and monomer having a polymerizable unsaturated bond such as a (meth)acryloyl group, which undergoes a crosslinking reaction upon irradiation with ionizing radiation such as electron beams or ultraviolet rays.

[0061] The protective resin layer (surface protective layer) 16 may be a single layer or a multi-layer structure of two or three layers. When the protective resin layer 16 is a multi-layer structure, a glossy matte appearance can be achieved by applying matte resin and glossy resin separately. It is also possible to provide a textured appearance by partially raising the resin. Furthermore, antibacterial agents, antiviral agents, etc. can also be added.

[0062] <Uses of moisture-proof decorative paper> As mentioned above, the moisture-proof decorative paper 100 of this embodiment is suitable for use in building materials such as interior doors, kitchen doors, storage doors, and sliding doors, but it is also suitable for use in other building materials such as door frames, furniture doors, door facings, wall surfaces, and flooring materials, and is also suitable for use as facings for flush panels (flush doors) and the like. Flush panels are hollow flat panels made by gluing plywood, medium-density fiberboard (MDF), or other boards to the front and back of a core material made of frame materials such as square timber joined together lengthwise and crosswise. By using a small amount of inexpensive material for the large, thick flat panels, flush panels have the advantage of being lightweight yet strong enough to be manufactured, and are therefore widely used for interior doors, furniture doors, and other applications.

[0063] In such flash panels, if the two sides of the panel are exposed to environments with significantly different temperatures and humidity, or if the panel is placed in an environment with drastic changes in temperature and humidity, the moisture content inside the boards on the front and back of the core material will become uneven, causing dimensional changes and resulting in warping of the entire flash panel. To prevent this, moisture-proof sheets (moisture-proof paper) are often attached to the front and back surfaces of the boards on the front and back of the core material.

[0064] The moisture-proof decorative paper 100 of this embodiment not only has sufficient moisture-proof properties, but also maintains sufficient moisture-proof properties without any significant reduction in water vapor barrier properties. In such applications, it is suitable for use by being attached to the surfaces of the front and back boards of flash panels (the surfaces opposite the core material). The moisture-proof sheet (moisture-proof paper) to be attached to the back surface (core material side) of the front and back boards of the flash panel may of course be a moisture-proof sheet equipped with the moisture-proof layer 10 of this embodiment (i.e., the moisture-proof decorative paper 100 of this embodiment), but a normal moisture-proof sheet (moisture-proof paper) that does not use the moisture-proof decorative paper 100 of this embodiment may also be used. Specifically, the moisture-proof sheet (moisture-proof paper) to be attached to the back side (the side facing the core material) of the front and back boards of the flash panel can be, for example, a moisture-proof sheet made of paper / polyethylene / paper, or a moisture-proof film made of synthetic resin film with metal vapor deposition and a protective layer.

[0065] <Effects> The moisture-proof decorative paper 100 of this embodiment has a lower moisture permeability (JIS Z 0208) than moisture-proof sheets made of synthetic resins such as vinyl chloride, polyethylene, or polypropylene, or paper / polyethylene / paper. Therefore, it is possible to provide a moisture-proof decorative paper with excellent moisture-proof performance. Furthermore, in the moisture-proof decorative paper 100, the mass of the paper base material 11 is 50% by mass or more based on the mass of the entire moisture-proof decorative paper 100. Therefore, compared to conventional moisture-proof materials such as synthetic resin sheets such as polyvinyl chloride, polyethylene, polypropylene, etc. (90% by mass or more of plastic material) or moisture-proof sheets made of paper / polyethylene / paper (50% by mass or more of plastic material), the mass (content) of plastic used is smaller, and the amount of plastic material used in the moisture-proof decorative paper can be significantly reduced. Furthermore, decorative panels and fittings such as doors that use this moisture-proof decorative paper 100 have high moisture-proof performance, and because they are made of wood materials and paper components, they are also highly recyclable. [Example]

[0066] The present disclosure will be explained in more detail by the following examples, but the present disclosure is not limited to these examples.

[0067] The following clay-coated papers 1 and 2 were prepared as paper substrates. Clay coated paper 1: When the temperature was changed from 40°C and 20% relative humidity (RH) to 40°C and 90% relative humidity (RH), the dimensional change was CD = 0.75%, MD = 0.13%, and the basis weight was 60g / m. 2 Clay-coated paper 2: When the temperature was changed from 40°C and 20% relative humidity (RH) to 40°C and 90% relative humidity (RH), the dimensional change was 0.55% CD, 0.07% MD, and 60g / m². 2

[0068] <Preparing moisture-proof paper> Example 1 Clay-coated paper 1 was used as the paper substrate. ZAIKXEN AC (Sumitomo Seika Chemicals, aqueous dispersion of ammonium salt of ethylene-acrylic acid copolymer) was applied to the surface of the paper substrate (on the clay coating layer) using a gravure coater to form a coating. The coating was dried to obtain a first laminate in which a first resin layer (thickness: 3 μm) was formed on the clay coating layer. Next, while the first laminate was being conveyed using a roll-to-roll vacuum deposition device, aluminum was deposited on the surface of the first resin layer to form an aluminum deposition layer (thickness: 66 nm). The method for measuring the thickness of the aluminum deposition layer will be described later. Next, Chemipearl S100 (Mitsui Chemicals, an aqueous dispersion of a metal salt of an ethylene-unsaturated carboxylic acid copolymer) was applied onto the aluminum vapor deposition layer using a gravure coater to form a coating, and the coating was dried to form a second resin layer (thickness: 3 μm), thereby obtaining the moisture-proof paper of Example 1.

[0069] Examples 2 and 3 The moisture-proof papers of Examples 2 and 3 were obtained in the same manner as Example 1, except that the conveying speed of the first laminate was slowed down when vapor-depositing aluminum to form an aluminum vapor-deposited layer of the thickness shown in Table 1.

[0070] (Comparative Examples 1 and 2) The moisture-proof papers of Comparative Examples 1 and 2 were obtained in the same manner as Example 1, except that the conveying speed of the first laminate was increased when vapor-depositing aluminum to form an aluminum vapor-deposited layer of the thickness shown in Table 2.

[0071] Example 4 Clay-coated paper 2 was used as the paper substrate. An aqueous solution of Poval PVA5-98 (Kuraray, fully saponified PVA) was applied to the surface of the paper substrate (on the clay coating layer) using a gravure coater to form a coating film. The coating film was dried to obtain a first laminate in which a first resin layer (thickness: 4 μm) was formed on the clay coating layer. Next, while the first laminate was being conveyed using a roll-to-roll type vacuum deposition device, aluminum was deposited on the surface of the first resin layer to form an aluminum deposition layer (thickness: 61 nm). Next, Chemipearl S500 (Mitsui Chemicals, an emulsion of acid-modified polyolefin) was applied onto the aluminum vapor deposition layer using a gravure coater to form a coating film, and the coating film was dried to form a second resin layer (thickness: 3 μm), thereby obtaining the moisture-proof paper of Example 4.

[0072] Examples 5 and 6 The moisture-proof papers of Examples 5 and 6 were obtained in the same manner as Example 4, except that the conveying speed of the first laminate was slowed down when vapor-depositing aluminum to form an aluminum vapor-deposited layer of the thickness shown in Table 1.

[0073] (Comparative Examples 3 and 4) The moisture-proof papers of Comparative Examples 3 and 4 were obtained in the same manner as Example 4, except that the conveying speed of the first laminate was increased when vapor-depositing aluminum to form an aluminum vapor-deposited layer of the thickness shown in Table 2.

[0074] Example 7 Clay-coated paper 2 was used as the paper substrate. Takelac WPB-341 (Mitsui Chemicals, polyurethane resin emulsion) was applied to the surface of the paper substrate (clay coating layer) using a gravure coater to form a coating film. The coating film was dried to obtain a first laminate in which a first resin layer (thickness: 1 μm) was formed on the clay coating layer. Next, aluminum was vapor-deposited onto the surface of the first resin layer while the first laminate was being transported using a roll-to-roll vacuum deposition device, forming an aluminum vapor-deposited layer (thickness: 68 nm). ZAIKXEN AC (Sumitomo Seika Chemicals, an aqueous dispersion of ammonium salt of ethylene-acrylic acid copolymer) was applied onto the aluminum vapor-deposited layer using a gravure coater to form a coating, and the coating was dried to form a second resin layer (thickness: 4 μm), thereby obtaining the moisture-proof paper of Example 7.

[0075] Examples 8 and 9 The moisture-proof papers of Examples 8 and 9 were obtained in the same manner as Example 7, except that the conveying speed of the first laminate was slowed down when vapor-depositing aluminum to form an aluminum vapor-deposited layer of the thickness shown in Table 1.

[0076] (Comparative Examples 5 and 6) The moisture-proof papers of Comparative Examples 5 and 6 were obtained in the same manner as in Example 7, except that the conveying speed of the first laminate was increased when vapor-depositing aluminum to form an aluminum vapor-deposited layer of the thickness shown in Table 2.

[0077] Next, a solid ink layer was formed by gravure printing on the upper surface of the moisture-proof layer 10 (specifically, the second resin layer 14) laminated on each paper substrate 11 of Examples 1 to 9 and Comparative Examples 1 to 6 using an ink containing soluble nitrocellulose and acrylic resin as a binder. Similarly, a pattern ink layer (printed pattern layer 15) was formed thereon by gravure printing using an ink containing soluble nitrocellulose and acrylic resin as a binder. Next, a surface protective layer (protective resin layer) 16 was formed by gravure printing using a urethane-based acrylic polyol and isocyanate, and moisture-proof decorative papers 100 each equipped with a moisture-proof layer 10 and a decorative layer 20 were obtained for Examples 1 to 9 and Comparative Examples 1 to 6.

[0078] <Evaluation> (Examples 1 to 9 and Comparative Examples 1 to 6) For the moisture-proof decorative paper of the examples and comparative examples, the moisture-proof decorative paper was cut into a total of nine regions, three rows along the TD direction and three rows along the MD direction, to obtain nine measurement samples. The film thickness and water vapor permeability of the aluminum vapor deposition layer were measured using the measurement samples thus prepared.

[0079] [Thickness of aluminum vapor deposition layer] The measurement sample was embedded in UV-curable resin. The measurement sample was cut using a cryomicrotome to expose a cross section, and a specimen for cross-sectional observation was obtained. The obtained sample was observed using a scanning electron microscope (observation magnification: 50,000x), and an image of the cross section was taken. The thickness of the aluminum vapor deposition layer was measured from the obtained image. The average value of the thickness of the aluminum vapor deposition layer measured for each of the nine measurement samples was taken as the film thickness of the aluminum vapor deposition layer. The results are shown in Tables 1 and 2.

[0080] [Water vapor permeability] According to JIS K7129-2, the water vapor permeability was measured by the Mocon method under conditions of a temperature of 40°C and a relative humidity (RH) of 90%. Measurements were performed twice for each of the nine measurement samples, yielding a total of 18 measurement data. The average value of the 18 data was used as the water vapor permeability. The standard deviation of the 18 data was also calculated. The results calculated in this way (unit of water vapor permeability: g / (m 2 The results are shown in Tables 1 and 2.

[0081] [Table 1]

[0082] [Table 2]

[0083] As is clear from the results in Tables 1 and 2, in Comparative Examples 1 to 6, in which the thickness of the aluminum vapor-deposited layer was less than 60 nm, the average water vapor permeability and standard deviation were large and the water vapor barrier property was unstable, whereas the moisture-proof papers of Examples 1 to 9, which have an aluminum vapor-deposited layer with a thickness of 60 nm or more, consistently achieved excellent water vapor barrier property. In other words, the moisture-proof papers of Examples 1 to 9, which have an aluminum vapor-deposited layer with a thickness of 60 nm or more, achieved excellent water vapor barrier property evenly (with good yield).

[0084] The moisture-proof decorative paper in each example has a moisture-proof layer with an aluminum vapor deposition layer of 60 nm or more, which has been shown to have improved water vapor barrier performance, and is expected to have the effect of reducing warping of the decorative panel caused by moisture absorption and release due to changes in indoor temperature and humidity compared to conventional products, and to reduce the amount of plastic material used. This has enabled us to verify that it is possible to provide a moisture-proof decorative paper that is environmentally friendly and can prevent warping of the decorative panel even when used in a location where there is a large difference in temperature and humidity environments on both sides, which is the objective of this invention.

[0085] Furthermore, for example, the present invention can have the following configuration. (1) A moisture-proof layer and a decorative layer are provided in this order on at least one surface of a paper substrate; The moisture-proof layer is a moisture-proof decorative paper having a structure in which a first resin layer, an aluminum vapor-deposited layer, and a second resin layer are laminated in this order from the paper base material side, The thickness of the aluminum vapor deposition layer is 60 nm or more, The decorative layer comprises a printed layer and a protective resin layer in this order from the moisture-proof layer side. (2) The moisture-proof decorative paper according to (1) above, wherein the second resin layer contains a polyolefin having an acidic group. (3) The moisture-proof decorative paper according to (1) or (2) above, wherein the first resin layer contains at least one selected from the group consisting of polyolefins having acidic groups, polyvinyl alcohol-based resins, and polyurethane-based resins. (4) Water vapor permeability at a temperature of 40°C and a relative humidity of 90% is 5g / (m 2 The moisture-proof decorative paper according to any one of (1) to (3) above, wherein the moisture-proof decorative paper has a durability of 24 hours or less. (5) The moisture-proof decorative paper according to any one of (1) to (4) above, wherein the second resin layer contains an ethylene-unsaturated carboxylic acid copolymer. (6) The moisture-proof decorative paper according to any one of (1) to (5) above, wherein the mass of the paper components contained in the paper base material is 50 mass % or more based on the mass of the entire moisture-proof decorative paper. (7) The moisture-proof decorative paper according to any one of (1) to (6) above, wherein the design expression of the pattern in the moisture-proof decorative paper has a metallic design. [Explanation of symbols]

[0086] 11...Paper base material 12...1st resin layer 13. Aluminum vapor deposition layer 14...Second resin layer 15...Print pattern layer (printing layer) 16...Protective resin layer (surface protection layer) 100··Moisture-proof decorative paper 10. Moisture barrier 20. Decorative layer

Claims

1. A moisture-proof layer and a decorative layer are provided in this order on one side of a paper substrate; the moisture-proof layer is a laminate having a structure in which a first resin layer, an aluminum vapor-deposited layer, and a second resin layer are laminated in this order from the paper base material side; The thickness of the aluminum vapor deposition layer is 60 nm or more, The decorative layer comprises a printed layer and a protective resin layer in this order from the moisture-proof layer side.

2. The moisture-proof decorative paper according to claim 1 , wherein the second resin layer contains a polyolefin having an acidic group.

3. 3. The moisture-proof decorative paper according to claim 1, wherein the first resin layer comprises at least one resin selected from the group consisting of polyolefins having acidic groups, polyvinyl alcohol-based resins, and polyurethane-based resins.

4. The water vapor permeability at a temperature of 40°C and a relative humidity of 90% is 5 g / (m ２ 3. The moisture-proof decorative paper according to claim 1, wherein the moisture-proof decorative paper has a moisture-proof life of 24 hours or less.

5. 3. The moisture-proof decorative paper according to claim 1, wherein the second resin layer contains an ethylene-unsaturated carboxylic acid copolymer.

6. 3. The moisture-proof decorative paper according to claim 1, wherein the mass of the paper component contained in the paper base material is 50% by mass or more based on the mass of the entire moisture-proof decorative paper.

7. 3. The moisture-proof decorative paper according to claim 1, wherein the design expression of the pattern on the moisture-proof decorative paper has a metallic design.

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