Decorative sheet

Abstract

The objective of the present invention is to provide a decorative sheet that has all of the following properties: workability in three-dimensional molding, adhesion to a substrate, and scratch resistance on the surface. [Solution] A three-dimensionally moldable decorative sheet having at least a resin substrate layer and a surface protective layer, wherein the surface protective layer is made of a cured product of a resin composition containing an ultraviolet-curable resin (A) and a thermosetting resin (B) in a mass ratio of 30:70 to 60:40, the ultraviolet-curable resin (A) being one or more urethane (meth)acrylates selected from polyesters, polyethers, and polycarbonates, each having 2 to 3 functional groups, and the cured product having a pencil hardness of HB to 4B, and the thermosetting resin (B) being made of an acrylic polyol resin and a polyisocyanate compound as a curing agent.

Description

[Technical Field]

[0001] The present invention is a cosmetic sheet To Regarding. [Background technology]

[0002] For example, decorative sheets are commonly applied to the surface of a three-dimensional substrate to impart design features to the interior and exterior components used in building materials. As a decorative sheet, for example, a decorative sheet has been proposed which has a substrate, a colored ink layer, a primer layer, and a surface protective layer in this order, the substrate being a biaxially stretched polyester film of 20 μm to 95 μm, and the surface protective layer being made of a cured product of a resin composition containing an ionizing radiation curable resin and a thermosetting resin in a mass ratio of 95:5 to 50:50 (Patent Document 1). This biaxially stretched polyester film is oriented in two directions and crystallized, so the film does not stretch at around 100°C and three-dimensional molding is not possible. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5949053 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with conventional techniques such as those in Patent Document 1, it is difficult to produce a decorative sheet that combines all of the following: processability in three-dimensional molding, adhesion to a substrate, and surface scratch resistance. The primary object of the present invention is to provide a decorative sheet that combines ease of processability in three-dimensional molding, adhesion to a substrate, and surface scratch resistance, and a method for producing the same. [Means for solving the problem]

[0005] The present invention includes the following configurations. [1]: A three-dimensionally moldable decorative sheet having at least a resin substrate layer and a surface protective layer, the surface protective layer is made of a cured product of a resin composition containing an ultraviolet-curable resin (A) and a thermosetting resin (B) in a mass ratio of 30:70 to 60:40; the ultraviolet curable resin (A) is one or more urethane (meth)acrylates selected from polyesters, polyethers, and polycarbonates, having 2 to 3 functional groups, and the pencil hardness of the cured product is HB to 4B; The decorative sheet is characterized in that the thermosetting resin (B) is composed of an acrylic polyol resin and a polyisocyanate compound as a curing agent. [2]: The resin substrate layer is made of a polyester-based sheet or a polypropylene-based sheet having a tensile elongation of 200% or more at 90°C and a load of 4.0 to 9.0 N / cm in the range of 50% to 200% tensile elongation, The decorative sheet according to [1], wherein the resin substrate layer has a thickness of 120 to 250 μm. [3]: The decorative sheet according to [2], wherein the polyester sheet having a tensile elongation of 200% or more at 90°C is an amorphous polyester sheet. [4]: The decorative sheet according to [2], wherein the polypropylene-based sheet having a tensile elongation of 200% or more at 90°C is an amorphous polypropylene-based sheet containing an olefin-based elastomer and a polyethylene resin. [5]: The decorative sheet according to any one of [1] to [4], wherein the resin substrate layer is a two-kind three-layer or three-kind three-layer structure using recycled polyethylene terephthalate resin or recycled polypropylene resin as the intermediate layer. [6]: A method for producing a three-dimensionally moldable decorative sheet having at least a resin substrate layer and a surface protective layer, The surface of the long sheet on which the resin substrate layer is formed is exposed to the following ultraviolet light: hardening Resin (A) and heat hardeninga resin composition containing a thermosetting resin (B) in a mass ratio of 30:70 to 60:40, and then the resin composition is applied to the substrate, the ultraviolet-curable resin (A) is cured by ultraviolet irradiation, the substrate is wound up into a roll, and the substrate is then cured at 35 to 55°C to completely cure the thermosetting resin (B), thereby forming a surface protective layer. UV-curable resin (A): an UV-curable resin that is one or more urethane (meth)acrylates selected from polyesters, polyethers, and polycarbonates, having 2 to 3 functional groups, and that has a pencil hardness of HB to 4B after curing. Thermosetting resin (B): A thermosetting resin composed of an acrylic polyol resin and a polyisocyanate compound as a curing agent. [7]: The resin substrate layer is made of a polyester-based sheet or a polypropylene-based sheet having a tensile elongation of 200% or more at 90°C and a load of 4.0 to 9.0 N / cm in the range of 50% to 200% tensile elongation, The method for producing a decorative sheet according to [6], wherein the thickness of the resin substrate layer is 120 to 250 μm. [8]: The method for producing a decorative sheet according to [7], wherein the polyester sheet having a tensile elongation of 200% or more at 90°C is an amorphous polyester sheet. [9]: The method for producing a decorative sheet according to [7], wherein the polypropylene-based sheet having a tensile elongation of 200% or more at 90°C is an amorphous polypropylene-based sheet containing an olefin-based elastomer and a polyethylene resin.

[10] : The method for producing a decorative sheet according to any one of [6] to [9], wherein the resin substrate layer is a two-kind three-layer or three-kind three-layer structure using recycled polyethylene terephthalate resin or recycled polypropylene resin as the intermediate layer. [Effects of the Invention]

[0006] According to the present invention, a decorative sheet and a manufacturing method thereof are provided that combine ease of processability in three-dimensional molding, adhesion to a substrate, and surface scratch resistance. In particular, a decorative sheet using recycled resins that has the above properties can also be provided. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view that schematically shows a decorative sheet according to one example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] In this specification, the following terms have the following meanings: "(Meth)acrylic" means acrylic or methacrylic. The term "(meth)acryloyl group" means an acryloyl group or a methacryloyl group. "(Meth)acrylate" means acrylate or methacrylate. The symbol "to" indicating a range of values ​​means that the values ​​before and after it are included as the lower and upper limits.

[0009] The decorative sheet of the present invention will be described below by way of an example with reference to the drawings. Note that the dimensions of the drawings shown in the following description are merely examples, and the present invention is not necessarily limited thereto, and can be appropriately modified and implemented within the scope of the present invention.

[0010] [Decorative sheet] The decorative sheet according to the embodiment is a three-dimensionally moldable decorative sheet having at least a resin substrate layer and a surface protective layer, and the surface protective layer is made of a cured product of a resin composition containing an ultraviolet-curable resin (A) and a thermosetting resin (B) described below in a mass ratio of 30:70 to 60:40.

[0011] FIG. 1 is a cross-sectional view that schematically shows a decorative sheet according to one example of the embodiment. As shown in FIG. 1, a decorative sheet 10 according to one embodiment includes a resin substrate layer 12 and a surface protective layer 14 provided on the resin substrate layer 12. In addition, the decorative sheet according to the embodiment may have layers other than the resin substrate layer and the surface protective layer on one or more of the following: the side of the resin substrate layer 12 opposite the surface protective layer 14; between the resin substrate layer 12 and the surface protective layer 14; and the side of the surface protective layer 14 opposite the resin substrate layer 12.

[0012] (Resin base layer) The resin substrate layer may be a resin sheet. The resin sheet may be a single layer or a multi-layer. In the case of a multi-layer, for example, two types of two layers or two types of three layers can be used. In the case of a multi-layer, by using resin layers containing recycled resin as the main component except for the surface layer, resources can be used effectively.

[0013] The resin sheet is preferably a polyester sheet or a polypropylene sheet. The polyester resin used in the polyester-based sheet may be a homopolymer or a copolymer. Examples of polyester resins include polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. The polyester resins constituting the polyester-based sheet may be used singly or in combination of two or more.

[0014] The polyester sheet may be blended with modified polyester (PETG) obtained by copolymerizing ethylene glycol, cyclohexanedimethanol, and terephthalic acid to improve processability. The polyester sheet may also be made into an amorphous sheet to improve processability. The polypropylene-based sheet may contain at least one of an olefin-based elastomer and a polyethylene-based resin in order to improve processability.

[0015] The resin sheet preferably has a tensile elongation of 200% or more when a tensile test is performed using a sample having a thickness of 200 μm and a width of 10 mm at a temperature of 90°C and a tensile speed of 500 mm / min. Furthermore, the load measured in the tensile test at a tensile elongation range of 50% to 200% is preferably 4.0 to 9.0 N / cm, more preferably 4.5 to 8.5 N / cm. When the load is within the above range, the processability of three-dimensional molding such as vacuum forming, pressure forming, and membrane press molding is improved. Furthermore, when the load is equal to or less than the above upper limit, it is easy to prevent the processing pressure in three-dimensional molding from increasing. When the load is equal to or greater than the above lower limit, it is easy to prevent the decorative sheet from stretching too much and causing wrinkles during molding.

[0016] Amorphous polyester sheets are preferred as polyester sheets having a tensile elongation of 200% or more at 90° C. The amorphous polyester sheets are obtained by extrusion molding a sheet that has come out of a T-die and then rapidly cooling it with two cooling rolls at 20° C. or less to significantly reduce the crystallinity.

[0017] As the polypropylene-based sheet having a tensile elongation of 200% or more at 90°C, an amorphous polypropylene-based sheet containing an olefin-based elastomer and a polyethylene resin is preferred. Olefin elastomers include ethylene-α-olefin random copolymers, propylene-α-olefin random copolymers, and butene-1-α-olefin random copolymers, and have a density of 0.91 g / cm 3 or less, preferably 0.90 g / cm 3 Examples of the α-olefins include 1-hexene and 1-octene. As commercially available products of these olefin-based elastomers, for example, those manufactured by Mitsui Chemicals, Inc., Japan Polyethylene Corporation, and Dow Chemical Company can be used.

[0018] For the resin substrate layer, it is preferable to use a polyethylene terephthalate sheet using recycled polyethylene terephthalate resin (hereinafter referred to as "recycled PET"). Recycled PET usually contains discoloration and foreign matter. Therefore, when using recycled PET, it is preferable to use a three-layer colored sheet in which recycled PET is used for the middle layer of the resin substrate layer and virgin polyethylene terephthalate (PET) resin is used for both outer layers. This allows for effective use of recycled PET while ensuring color stability. The resin substrate layer using recycled PET is preferably a layer made of a two-kind three-layer or three-kind three-layer sheet using recycled PET as the intermediate layer.

[0019] The polyester sheet using recycled PET is preferably an amorphous polyester sheet. For example, recycled PET is used as the material for the intermediate layer, and a sheet extruded from a T-die capable of forming a two-kind three-layer or three-kind three-layer sheet is sandwiched between two cooling rolls at 20°C or less and rapidly cooled to significantly reduce the crystallinity, thereby obtaining an amorphous polyester sheet using recycled PET for the intermediate layer.

[0020] It is also preferable to use a polypropylene sheet using recycled polypropylene resin (hereinafter referred to as "recycled PP") for the resin substrate layer. Normally, recycled PP also has coloring and foreign matter contamination. Therefore, when using recycled PP, it is preferable to use a three-layer colored sheet in which recycled PP is used for the middle layer of the resin substrate layer and virgin polypropylene (PP) resin is used for both outer layers. This allows for effective use of recycled PP while ensuring color stability. The resin substrate layer using recycled PP is preferably a layer made of a two-kind three-layer or three-kind three-layer sheet using recycled PP as the intermediate layer.

[0021] The polypropylene sheet using recycled PP is preferably an amorphous polypropylene sheet. For example, an amorphous polyester sheet using recycled PP for the intermediate layer can be obtained by blending an olefin elastomer and a polyethylene resin with recycled PP to significantly reduce the crystallinity.

[0022] The thickness of the resin substrate layer is preferably 150 to 300 μm, more preferably 180 to 250 μm. When the thickness of the resin substrate layer is equal to or greater than the lower limit, the decorative sheet is more easily stretchable, making three-dimensional molding easier. When the thickness of the resin substrate layer is equal to or less than the upper limit, the decorative sheet has excellent moldability. The thickness of the resin substrate layer is the average value of thicknesses measured at any three points on the resin substrate.

[0023] A colorant may be blended into the resin sheet constituting the resin substrate layer 12. Furthermore, the resin sheet may also be blended with additives such as fillers, flame retardants, antioxidants, lubricants, ultraviolet absorbers, and light stabilizers, as needed. These additives may be used alone or in combination of two or more.

[0024] A pattern may be provided on the surface of the resin substrate layer 12 on which the surface protective layer 14 is provided. The pattern can be applied by gravure printing, inkjet printing, etc. The pattern is not particularly limited, and examples thereof include wood grain patterns, stone grain patterns, sand grain patterns, tile patterns, brickwork patterns, fabric patterns, leather-striped patterns, geometric shapes, and abstract patterns.

[0025] The surface of the resin substrate layer 12 on which the surface protective layer 14 is to be provided may be subjected to a surface treatment by an oxidation method or an easy-adhesion coating treatment in order to improve the adhesion between the resin substrate layer 12 and the surface protective layer 14. Examples of surface treatments using oxidation methods include corona discharge treatment and ozone / ultraviolet treatment. Examples of resins used in the easy-adhesion coating treatment include polyester resins, acrylic resins, and urethane resins. These resins may be used alone or in combination of two or more.

[0026] (Surface protective layer) The surface protection layer 14 is a layer made of a cured product of a resin composition containing an ultraviolet curable resin (A) and a thermosetting resin (B) in a mass ratio of 30:70 to 60:40.

[0027] The ultraviolet curable resin (A) is a resin that is crosslinked and cured by irradiation with ultraviolet light. The ultraviolet curable resin (A) is one or more urethane (meth)acrylates having 2 to 3 functional groups and selected from polyester-based urethane (meth)acrylates, polyether-based urethane (meth)acrylates, and polycarbonate-based urethane (meth)acrylates. The pencil hardness of the cured product of the ultraviolet curable resin (A) is HB to 4B.

[0028] The functional group contained in the ultraviolet curable resin (A) may be a (meth)acryloyl group, and the ultraviolet curable resin (A) has two or three (meth)acryloyl groups. The ultraviolet curable resin (A) may be an oligomer or a prepolymer. The ultraviolet curable resin (A) can be obtained, for example, by esterifying a polyurethane oligomer obtained by reacting a polyether polyol, a polyester polyol, or a polycarbonate polyol with a polyisocyanate with (meth)acrylic acid. As the ultraviolet curable resin (A), one type may be used alone, or two or more types may be used in combination.

[0029] The pencil hardness of the cured product of the ultraviolet curable resin (A) is HB to 4B, and preferably HB to 2B. If the pencil hardness of the cured product of the ultraviolet curable resin (A) is within the above range, the processability for three-dimensional molding such as vacuum molding and membrane press molding will be excellent. The pencil hardness is measured in accordance with JIS K 5600-5-4:1999.

[0030] When the ultraviolet-curable resin (A) is cured by ultraviolet light, a photopolymerization initiator may be used. The photopolymerization initiator can be appropriately selected from conventionally used ones, and preferred examples thereof include benzoin-based photopolymerization initiators, acetophenone-based photopolymerization initiators, phenyl ketone-based photopolymerization initiators, benzophenone-based photopolymerization initiators, and anthraquinone-based photopolymerization initiators. The amount of the photopolymerization initiator used is preferably 0.1 to 5 parts by mass relative to 100 parts by mass of the ultraviolet curable resin (A).

[0031] The thermosetting resin (B) is a resin that is crosslinked and hardened by heating, and preferably comprises an acrylic polyol resin and a hardener. Examples of the acrylic polyol-based resin include an acrylic polyol having two or more hydroxy groups in the molecule, which can be obtained, for example, by copolymerizing a (meth)acrylic acid ester with a hydroxy group-containing (meth)acrylic acid ester.

[0032] Examples of (meth)acrylic acid esters used in acrylic polyol-based resins include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and octyl (meth)acrylate. These (meth)acrylic acid esters may be used alone or in combination of two or more.

[0033] Examples of hydroxyl group-containing (meth)acrylic acid esters used in acrylic polyol-based resins include 2-hydroxyethyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 2-hydroxy-3-phenoxypropyl (meth)acrylate. These hydroxyl group-containing (meth)acrylic acid esters may be used alone or in combination of two or more.

[0034] The weight-average molecular weight of the acrylic polyol-based resin is preferably 20,000 to 200,000, more preferably 25,000 to 150,000, and even more preferably 30,000 to 100,000. When the weight-average molecular weight of the acrylic polyol-based resin is equal to or greater than the lower limit, the drying properties are excellent. When the weight-average molecular weight of the acrylic polyol-based resin is equal to or less than the upper limit, sufficient processability is likely to be obtained. The weight average molecular weight of the acrylic polyol resin is a value calculated as a standard polystyrene as measured by gel permeation chromatography (GPC).

[0035] The glass transition temperature (Tg) of the acrylic polyol resin is preferably 65 to 110°C, more preferably 75 to 105°C. When the Tg of the acrylic polyol resin is equal to or higher than the lower limit, the drying property and heat resistance are excellent. When the Tg of the acrylic polyol resin is equal to or lower than the upper limit, the drying property is excellent and sufficient hardness is easily maintained. The Tg of the acrylic polyol resin is the midpoint between the extrapolated glass transition onset temperature and the extrapolated glass transition end temperature measured using a differential scanning calorimeter.

[0036] The hydroxyl value of the acrylic polyol resin is preferably 5 to 30 mmHg / KOH, more preferably 10 to 25 mmHg / KOH. When the hydroxyl value of the acrylic polyol resin is equal to or greater than the lower limit, the drying properties are excellent. When the hydroxyl value of the acrylic polyol resin is equal to or less than the upper limit, the occurrence of blocking is easily suppressed. The hydroxyl value of the acrylic polyol resin is the amount of potassium hydroxide in milligrams that corresponds to the number of hydroxyl groups per 1 g of sample, and is a value measured based on the potentiometric titration method specified in JIS K 0070:1992.

[0037] The curing agent used for the thermosetting resin (B) is preferably a polyisocyanate compound. A polyisocyanate compound is a compound having two or more isocyanate groups in the molecule. Examples of polyisocyanate compounds include aliphatic polyisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, and dicyclohexylmethane diisocyanate; and polyisocyanates having an aromatic ring such as tolylene diisocyanate, xylylene diisocyanate, and diphenylmethane diisocyanate. These polyisocyanate compounds may be used alone or in combination of two or more.

[0038] The mass ratio of the ultraviolet curable resin (A) to the thermosetting resin (B) is 30:70 to 60:40, preferably 30:70 to 50:50, and more preferably 35:65 to 48:52. When the ratio of the thermosetting resin (B) is equal to or greater than the lower limit, the processability in three-dimensional molding such as vacuum molding and membrane press molding is excellent. When the ratio of the thermosetting resin (B) is equal to or less than the upper limit, the scratch resistance is improved.

[0039] The resin composition forming the surface protective layer may contain other resins in addition to the ultraviolet curable resin (A) and the thermosetting resin (B). The other resin is not particularly limited, and examples thereof include polyester polyol resins. These other resins may be used alone or in combination of two or more.

[0040] The surface protective layer may contain various additives depending on the desired physical properties. Examples of the additives include ultraviolet absorbers, light stabilizers, abrasion resistance improvers, antistatic agents, leveling agents, coupling agents, fillers, and solvents.

[0041] The ultraviolet absorber may be either an inorganic ultraviolet absorber or an organic ultraviolet absorber. As inorganic ultraviolet absorbers, titanium oxide, cerium oxide, and zinc oxide having an average particle size of about 5 to 120 nm can be preferably used. As organic ultraviolet absorbers, for example, benzotriazole-based ultraviolet absorbers, triazine-based ultraviolet absorbers, and benzophenone-based ultraviolet absorbers can be preferably mentioned. As ultraviolet absorbers, triazine-based ones are preferred because they have high ultraviolet absorption ability and are resistant to degradation even when exposed to high energy such as ultraviolet light. Examples of triazine-based ultraviolet absorbers include those available under the trade names "TINUVIN 479," "TINUVIN 400," "TINUVIN 405," and "TINUVIN 460" manufactured by BASF.

[0042] When the surface protective layer contains an ultraviolet absorber, the content of the ultraviolet absorber is preferably 0.5 to 10 parts by mass, more preferably 1 to 5 parts by mass, based on 100 parts by mass of the resin that forms the surface protective layer. When the surface protective layer contains a light stabilizer, the content of the light stabilizer is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, based on 100 parts by mass of the resin that forms the surface protective layer.

[0043] The thickness of the surface protective layer is preferably 5 to 20 μm, more preferably 6 to 12 μm. When the thickness of the surface protective layer is equal to or greater than the lower limit, the scratch resistance is excellent. When the thickness of the surface protective layer is equal to or less than the upper limit, the hardness is easily maintained and the deterioration of scratch resistance is easily suppressed. The thickness of the surface protective layer is the average value of thicknesses measured at any three positions on the surface protective layer.

[0044] The uses of the decorative sheet according to the embodiment are not particularly limited, and examples include surface materials for doors, furniture, etc. The decorative sheet according to the embodiment is suitable for imparting design by being attached to the surface of a substrate having a three-dimensional shape by three-dimensional forming such as vacuum forming or membrane press forming.

[0045] [Manufacturing method of decorative sheet] The decorative sheet described above can be produced, for example, by the method described below. The method for producing a decorative sheet according to the embodiment is a method for producing a three-dimensionally moldable decorative sheet having at least the resin substrate layer and surface protective layer described above. In a method for producing a decorative sheet according to an embodiment, the surface of the long sheet on which the resin substrate layer is formed is irradiated with ultraviolet light. hardening Resin (A) and heat hardening A resin composition containing a thermosetting resin (B) and a UV-curable resin (A) in a mass ratio of 30:70 to 60:40 is applied to the substrate, and the UV-curable resin (A) is cured by UV irradiation and taken up into a roll. The substrate is then cured at 35 to 55°C to completely cure the thermosetting resin (B), thereby forming a surface protection layer.

[0046] As the long sheet, the above-mentioned long resin sheet can be used. When forming a surface protection layer made of a resin composition containing an ultraviolet curable resin (A) and a thermosetting resin (B), for example, the ultraviolet curable resin (A) and the thermosetting resin (B) are mixed in a predetermined ratio, a solvent is added to adjust the viscosity, and various additives are added as necessary to prepare a coating agent. The viscosity of the coating agent is not particularly limited as long as it is a viscosity that allows coating. The solvent is preferably ethyl acetate, butyl acetate, or methyl ethyl ketone, but is not limited thereto.

[0047] The solid resin content of the coating agent is preferably 30 to 70% by mass, more preferably 35 to 55% by mass. When the solid resin content is equal to or greater than the lower limit, the coating agent can be easily applied to a resin substrate layer to form a surface protective layer. When the solid resin content is equal to or greater than the lower limit, the amount of solvent used can be reduced, and the drying time can be shortened.

[0048] For example, a surface protection layer can be formed by applying a coating agent onto a resin substrate layer so that the thickness after curing is 5 to 20 μm to form an uncured resin composition layer, irradiating the layer with ultraviolet light to cure the ultraviolet-curable resin (A), and heating to cure the thermosetting resin (B). The coating agent can be applied by known methods such as gravure coating, bar coating, and reverse coating, with gravure coating being preferred.

[0049] The wavelength of the ultraviolet light used to cure the ultraviolet curable resin (A) is preferably 254 to 436 nm, more preferably 300 to 365 nm.As a light source, for example, a high-pressure mercury lamp can be used. The cumulative amount of ultraviolet light irradiation when curing the ultraviolet curable resin (A) is preferably 100 to 500 mJ / cm 2 , more preferably 300 to 400 mJ / cm 2 is.

[0050] The curing at 35 to 55°C during curing of the thermosetting resin (B) is preferably carried out in a constant temperature cabinet. The heating temperature for curing the thermosetting resin (B) is preferably 35 to 55°C, more preferably 40 to 53°C. If the heating temperature exceeds 55°C, the long sheet forming the resin substrate layer softens and shrinks due to residual stress during extrusion molding, which is undesirable. If the heating temperature is lower than 35°C, it takes a long time for curing, which is undesirable. The heating time for curing the thermosetting resin (B) varies depending on the heating temperature, but is preferably 2 to 10 days, more preferably 5 to 7 days. The curing conditions for the thermosetting resin (B) may be, for example, curing at 40°C for 5 days or at 50°C for 3 days.

[0051] The method for producing the decorative sheet according to the embodiment is not limited to the method described above. For example, the timing of curing the ultraviolet-curable resin (A) by ultraviolet irradiation and curing the thermosetting resin (B) by heating is preferably such that the ultraviolet-curable resin (A) is cured first and then the thermosetting resin (B), but the ultraviolet-curable resin (A) may also be cured after the thermosetting resin (B) is cured, or the ultraviolet-curable resin (A) and the thermosetting resin (B) may be cured simultaneously.

[0052] As explained above, in the present invention, by forming a surface protection layer on a resin substrate layer using a cured product of a resin composition containing a specific ultraviolet-curable resin (A) and a thermosetting resin (B) in a specific ratio, it is possible to obtain a decorative sheet that combines processability in three-dimensional molding, adhesion to the substrate, and surface scratch resistance. [Example]

[0053] The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following descriptions.

[0054] [material] The materials used in this example are listed below. (Ultraviolet curing resin (A)) A-1: Polyester-based urethane (meth)acrylate, functional group number: 3, pencil hardness of cured product: 2B A-2: Polyether-based urethane (meth)acrylate, functional group number: 2, pencil hardness of cured product: B A-3: Polycarbonate-based urethane (meth)acrylate, functional group number: 2, pencil hardness of cured product: 3B

[0055] (Other UV-curable resins (X)) X-1: Polyester-based urethane (meth)acrylate, Functional groups: 7, Pencil hardness of cured product: 2H X-2: Polyester-based urethane (meth)acrylate, Functional groups: 6, Pencil hardness of cured product: 3H X-3: Polycaprolactam-based urethane (meth)acrylate, Functional groups: 2, Pencil hardness: B

[0056] (Curable resin (B)) B-1: A mixture of acrylic polyol (Tg: 100°C, hydroxyl value: 15 mmHg / KOH, solid resin content: 38% by mass, weight average molecular weight: 55,000) and curing agent (hexamethylene diisocyanate) in a mass ratio of 5:1 B-2: A mixture of acrylic polyol (Tg: 93°C, hydroxyl value: 10 mmHg / KOH, solid resin content: 38% by mass, weight average molecular weight: 75,000) and curing agent (hexamethylene diisocyanate) in a mass ratio of 6:1

[0057] (Other ingredients) Photopolymerization initiator: "Omnilat 184" manufactured by IGM Resins BV UV absorber: "Tinuvin 400" manufactured by BASF

[0058] [Manufacturing Example 1] The composite consisted of 60% recycled PP, 5% virgin PP resin, and olefin elastomer (ethylene-α-olefin random copolymer, "Toughmer" manufactured by Mitsui Chemicals, Inc., density 0.89 g / cm). 3 Composition X-1 was prepared by blending a black pigment into a resin mixture containing 15% by mass of PP resin and 20% by mass of polyethylene resin. Composition X-2 was also prepared by blending 70% by mass of virgin PP resin and olefin-based elastomer (ethylene-α-olefin random copolymer, manufactured by Mitsui Chemicals, Inc., "Tafmer," density 0.89 g / cm). 3 Composition Y-1 was prepared by blending a black pigment with a resin mixture containing 10% by mass of polyethylene resin and 20% by mass of polyethylene resin. Composition X-1 was placed in one of two extruders, and composition Y-1 was placed in the other. Composition X-1 was used for the middle layer, and composition Y-1 was used for both outer layers. The mixture was extruded through a T-die with three layers of two kinds (outer layer: middle layer: outer layer (thickness ratio) = 1:6:1). The three-layer sheet with reduced crystallinity and a total thickness of 200 μm was wound up, and a 600-m roll of sheet A was obtained. Samples measuring 200 μm in thickness, 100 mm in length, and 10 mm in width were cut from Sheet A in the length and width directions, and tensile tests were conducted at a temperature of 90°C and a tensile speed of 500 mm / min. The load measured in both directions was 5.0 to 7.5 N / cm in the tensile elongation range of 50% to 200%.

[0059] [Manufacturing Example 2] Composition X-2 was prepared by blending a black pigment with a resin mixture containing 75% recycled PET and 15% methyl methacrylate-butadiene-styrene (MBS) copolymer as an impact-reinforced resin. Composition Y-2 was also prepared by blending a black pigment with a resin mixture containing 85% virgin PET resin and 15% MBS copolymer as an impact-reinforced resin. Composition X-2 was loaded into one extruder and composition Y-2 into the other. The extruded sheet was extruded through a two-type, three-layer (outer layer:intermediate layer:outer layer (thickness ratio) = 1:12:1) T-die, with composition X-2 as the middle layer and composition Y-2 as both outer layers. The extruded sheet was cooled between two cooling rolls at 15°C and 20°C. The resulting three-layer sheet with reduced crystallinity and a total thickness of 200 μm was wound up to obtain Sheet B, a 600-m roll. Samples of 200 μm thick, 100 mm long, and 10 mm wide were cut from Sheet B in the length and width directions, and tensile tests were conducted at a temperature of 90°C and a tensile speed of 500 mm / min. The load measured in both directions was 4.5 to 7.0 N / cm in the tensile elongation range of 50% to 200%.

[0060] [Examples 1 to 7] Ethyl acetate was added to a resin composition prepared by mixing an ultraviolet-curable resin (A) and a thermosetting resin (B) to adjust the viscosity so as to obtain the composition shown in Table 1, and a photopolymerization initiator and an ultraviolet absorber were added to prepare a coating agent. The resin sheet constituting the resin substrate layer was a 600 m long roll of sheet A obtained in Production Example 1. After subjecting the resin sheet to a surface corona treatment, a coating agent was applied to the treated surface of the resin sheet using a Guavia reverse coater so that the thickness after curing would be 7 to 8 μm. After application, the resin sheet was heated at 70°C for approximately 1 minute to remove the solvent and dried. The ultraviolet curable resin (A) was then cured by irradiating it with ultraviolet light of wavelengths 300 nm x 365 nm from a high-pressure mercury lamp, and sheet A with a surface protective layer was wound up. The wound sheet A was then aged at 50°C for 3 days to completely cure the thermosetting resin (B) and form a surface protective layer, yielding a decorative sheet.

[0061] [Comparative Examples 1 to 6] Decorative sheets were produced in the same manner as in Examples 1 to 7, except that the formulation of the resin composition was changed as shown in Table 1.

[0062] [Evaluation method] The decorative sheets obtained in each example were evaluated for adhesion, processability, and scratch resistance as follows.

[0063] (adhesion) A 2mm x 2mm checkerboard pattern was cut into the surface of the surface protective layer of the decorative sheet with a cutter knife, forming 100 checkerboard squares. Adhesive tape was attached to the checkerboard squares and the tape was peeled off at a 45-degree angle. This process was repeated three times. The percentage of peeled pieces that had been peeled off by the adhesive tape in the 100 checkerboard squares was then calculated, and adhesion was evaluated according to the following criteria. <Evaluation criteria> A: The percentage of peeled pieces is 0% B: The percentage of peeled pieces is 5-10% C: The percentage of peeled pieces is 11% or more

[0064] (processability) The decorative sheet was sandwiched in a vacuum forming chamber and heated, and held for approximately 2 minutes to raise the temperature of the decorative sheet to 100°C. The decorative sheet was then placed from above into a mold with a groove 3 cm deep and 4 cm wide, and the pressure was reduced to form the decorative sheet. The resulting molded product was removed and visually inspected for cracks and whitening, and evaluated according to the following criteria. <Evaluation criteria> A: No cracks or whitening B: Slight whitening C: Cracks and whitening D: Significant cracking or whitening

[0065] (scratch resistance) Steel wool was applied to the surface of the surface protective layer of the decorative sheet with a load of 1 kg and moved back and forth 10 times, after which the surface of the surface protective layer was visually observed and evaluated according to the following criteria. <Evaluation criteria> A: Almost no change in appearance B: There are some scratches or changes in appearance C: Significant damage or change in appearance

[0066] The evaluation results of Examples 1 to 7 and Comparative Examples 1 to 6 are shown in Table 1.

[0067] [Table 1]

[0068] As shown in Table 1, the decorative sheets of Examples 1 to 6, in which a surface protective layer was formed using a resin composition containing an ultraviolet-curable resin (A) and a thermosetting resin (B) in the ratio specified in the present invention, had excellent adhesion, processability, and scratch resistance. On the other hand, the decorative sheets of Comparative Examples 1-2 and 5-6, which did not use ultraviolet-curable resin (A), and the decorative sheets of Comparative Examples 3-4, which had an inappropriate ratio of ultraviolet-curable resin (A) to thermosetting resin (B), did not have the adhesion, processability, and scratch resistance.

[0069] [Example 8] Ethyl acetate was added to a resin composition prepared by mixing 40 parts by mass of ultraviolet-curable resin (A-1) and 60 parts by mass of thermosetting resin (B-1) to adjust the viscosity, and 2 parts by mass of a photopolymerization initiator and 2 parts by mass of an ultraviolet absorber were further added to prepare a coating agent. Sheet B obtained in Production Example 2 was used as the resin sheet constituting the resin substrate layer. The coating agent was applied to the treated surface of the resin sheet using a Guavia reverse coater so that the thickness after curing was 10 μm. After application, the sheet was passed through a heating zone at 70 ° C for about 1 minute to remove the solvent and dry, and then irradiated with ultraviolet light at a wavelength of 300 nm to cure the ultraviolet-curable resin (A-1). The sheet was then aged at 50 ° C for 3 days, completely curing the thermosetting resin (B-1) and forming a surface protective layer, resulting in a decorative sheet.

[0070] The resulting decorative sheet was rated "A" for adhesion and "B" for scratch resistance. Furthermore, when a decorative sheet was attached to a wooden door that had been given a three-dimensional texture by router processing using a membrane press molding machine set at approximately 100°C and then laminated, the result was an extremely clean finish with no cracks. [Explanation of symbols]

[0071] 10 Decorative Sheet 12 Resin base material layer 14 Surface protective layer

Claims

1. A three-dimensionally moldable decorative sheet having at least a resin substrate layer and a surface protective layer, the surface protective layer is made of a cured product of a resin composition containing an ultraviolet-curable resin (A) and a thermosetting resin (B) in a mass ratio of 30:70 to 60:40; the ultraviolet curable resin (A) is one or more urethane (meth)acrylates selected from polyesters, polyethers, and polycarbonates, each having 2 to 3 functional groups, and the pencil hardness of the cured product is HB to 4B; The decorative sheet, wherein the thermosetting resin (B) is composed of an acrylic polyol resin and a polyisocyanate compound as a curing agent.

2. the resin substrate layer is made of a polyester-based sheet or a polypropylene-based sheet having a tensile elongation of 200% or more at 90°C and a load of 4.0 to 9.0 N / cm in the range of 50% to 200% tensile elongation, 2. The decorative sheet according to claim 1, wherein the thickness of the resin substrate layer is 150 to 300 μm.

3. 3. The decorative sheet according to claim 2, wherein said polyester sheet having a tensile elongation of 200% or more at 90[deg.] C. is an amorphous polyester sheet.

4. 3. The decorative sheet according to claim 2, wherein said polypropylene-based sheet having a tensile elongation of 200% or more at 90°C is an amorphous polypropylene-based sheet containing an olefin-based elastomer and a polyethylene resin.

5. The decorative sheet according to any one of claims 1 to 4, wherein the resin substrate layer is a two-kind three-layer or three-kind three-layer structure using a recycled polyethylene terephthalate resin or a recycled polypropylene resin as an intermediate layer.

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