Decorative sheets and boards

Abstract

To provide a decorative sheet from which a decorative board that is economically excellent, is excellent in adhesion between a plastic film and a resin-impregnated layer surface after hot-press molding, is easily peeled when intentionally peeled, and has mat feeling can be obtained.SOLUTION: Decorative sheets 1,1' have such a structure that resin-impregnated layers 2,2' obtained by impregnating an impregnation base material with a thermosetting type resin composition and a polybutylene terephthalate film 3 are laminated, and the polybutylene terephthalate film 3 has a mat-like transfer shape on a surface 3a on the sides of the resin-impregnated layers 2,2'.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a decorative sheet and a decorative board including the decorative sheet. [Background technology]

[0002] Conventionally, decorative panels have been used on the surfaces of tables, counters, walls, floors, etc., by laminating a resin-impregnated layer, such as impregnated paper obtained by impregnating a paper substrate such as titanium paper with a thermosetting resin such as diallyl phthalate resin, on the substrate, and then superimposing a mirror-finished plate on the resin-impregnated layer and thermo-compressing the resin to harden the thermosetting resin. The surface of the decorative panel may be subjected to a high-gloss treatment, a low-gloss treatment (matte treatment), an embossing treatment, etc., in order to impart a luxurious feel or a desired pattern.

[0003] A known method for imparting a matte finish to the surface of the resin-impregnated layer of the decorative sheet is to use a mirror-finished plate having a matte transfer surface, such as a textured surface for low gloss treatment, and then subject the matte transfer surface to thermocompression molding while facing the resin-impregnated layer. For example, a known example of such a mirror-finished plate is a metal plate having a roughened surface formed by projecting an abrasive composed of glass particles onto the surface, and then plating the roughened surface (see Patent Document 1).

[0004] Another known method for imparting a matte finish to the surface of a resin-impregnated layer is to perform thermocompression molding with a sheet material having a low surface gloss interposed between the resin-impregnated layer and a mirror-finished plate. One known example of such a sheet material is a release paper for decorative laminate transfer, which has a matte transfer coating layer made of a pigment and a binder on one side of a base paper mainly made of wood pulp, and is overcoated with silicone on the transfer coating layer (see Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 6-91776 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-7875 Summary of the Invention [Problem to be solved by the invention]

[0006] The degree of matte finish required for decorative panels varies depending on the application and purpose. Therefore, when using a mirrored panel with a matte transfer surface, it is necessary to prepare multiple mirrored panels according to the degree of matte finish required, which increases costs.

[0007] When a method of performing thermocompression molding with a sheet material having a low surface gloss interposed between the resin-impregnated layer and the mirror plate is adopted, the sheet material has the function of imparting a matte finish, so there is no need to prepare multiple mirror plates. However, when a sheet made of base paper mainly composed of wood pulp is used as the sheet material, the sheet material does not have the purpose of protecting the decorative board, so when shipping, it is necessary to peel off the sheet material and apply a separate protective film to the surface of the decorative board, which is time-consuming and requires disposal, resulting in increased costs.

[0008] By using a plastic film as the sheet material, the sheet material can be given the function of protecting the surface of the decorative board. According to this method, the plastic film can be used as a protective film without peeling after thermocompression molding, eliminating the need to attach a separate protective film. However, when using a plastic film as the sheet material, it is required that the plastic film is not easily peeled off from the surface of the resin-impregnated layer after thermocompression molding in order to effectively function as a protective film, and that the plastic film is easily peeled off from the surface of the resin-impregnated layer when the decorative board is in use.

[0009] Therefore, the object of the present invention is to provide a decorative sheet that is economically excellent, has excellent adhesion between the plastic film and the surface of the resin-impregnated layer after thermocompression molding, and is easy to peel off when intentionally attempted, and can produce a decorative plate with a matte finish. [Means for solving the problem]

[0010] As a result of intensive research into achieving the above object, the present inventors have found that by adopting a method of thermo-compression molding with a sheet material having a matte transfer pattern interposed therebetween and using a polybutylene terephthalate film as the sheet material, it is possible to obtain a decorative laminate having a matte finish that is economically excellent, has excellent adhesion between the plastic film and the surface of the resin-impregnated layer after thermo-compression molding, and is easy to peel off when intentionally attempted. The present invention was completed based on these findings.

[0011] That is, the present invention provides a decorative sheet having a structure in which a resin-impregnated layer in which a thermosetting resin composition has been impregnated into an impregnated substrate and a polybutylene terephthalate film are laminated together, and the polybutylene terephthalate film has a matte transfer pattern on the surface facing the resin-impregnated layer.

[0012] The decorative sheet preferably has an area where the resin-impregnated layer and the polybutylene terephthalate film are in contact with each other.

[0013] The thermosetting resin composition preferably contains a diallyl phthalate resin.

[0014] The thermosetting resin composition preferably contains an unsaturated polyester resin.

[0015] The matte transfer pattern preferably includes an uneven pattern.

[0016] The present invention also provides a decorative board including the decorative sheet, the decorative board comprising a substrate, the resin-impregnated layer, and the polybutylene terephthalate film.

[0017] The present invention also provides a method for producing the above decorative board, which includes a thermo-compression molding step of overlaying a pressure plate on the polybutylene terephthalate film side of a laminate formed in this order on a substrate, the laminate having a resin-impregnated layer in which a thermosetting resin composition has been impregnated into the impregnated substrate and a polybutylene terephthalate film having a matte transfer pattern, and then performing thermo-compression molding to cure the thermosetting resin composition. [Effects of the Invention]

[0018] The decorative sheet of the present invention is economically advantageous when producing decorative boards, since the use of a polybutylene terephthalate film with a matte transfer pattern eliminates the need to prepare multiple mirror-finish plates according to the desired matte finish. Furthermore, after thermocompression molding, the plastic film exhibits excellent adhesion to the surface of the resin-impregnated layer, and peels easily when intentionally peeled off. Therefore, after thermocompression molding, the plastic film is less likely to peel off from the thermoset resin-impregnated layer, and can function adequately as a protective film during transportation, etc. Furthermore, since the polybutylene terephthalate film can function as a protective film, it is not necessary to replace it with a separate protective film during shipping, which is economically advantageous. Furthermore, when using the decorative board, the polybutylene terephthalate film can be easily peeled off when intentionally peeled off. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a cross-sectional view showing one embodiment of the decorative board of the present invention. [Figure 2] FIG. 3 is a cross-sectional view showing another embodiment of the decorative board of the present invention. [Figure 3] 3A to 3C are diagrams showing an embodiment of a method for manufacturing the decorative board shown in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0020] [Decorative sheet] The decorative sheet of the present invention has a structure in which a resin-impregnated layer, in which a thermosetting resin composition is impregnated into an impregnated substrate, and a polybutylene terephthalate (PBT) film are laminated together. The PBT film has a matte transfer pattern on the surface of the resin-impregnated layer.

[0021] In this specification, the thermosetting resin composition includes both a composition containing a thermosetting resin (thermosetting resin) and a composition containing a resin obtained by curing the thermosetting resin (thermocured resin). That is, the resin-impregnated layer includes a layer in which an impregnated base material is impregnated with a composition containing the thermosetting resin (a layer before thermosetting, a prepreg), and a layer in which the thermosetting resin in the composition is cured (a layer after thermosetting).

[0022] (resin impregnated layer) The resin-impregnated layer is a layer in which a thermosetting resin composition is impregnated into an impregnated substrate. The thermosetting resin composition contains at least a thermosetting resin. The thermosetting resin includes both a resin having thermosetting properties (thermosetting resin) and a resin obtained by curing the thermosetting resin (thermocured resin). The resin-impregnated layer may be a single layer or a multi-layer (laminate). Furthermore, the resin-impregnated layer may have a layer of a single thermosetting resin composition, or may have layers of multiple different thermosetting resin compositions (multi-laminate).

[0023] The thermosetting resin may be any known or commonly used resin used in the production of decorative panels, such as melamine resins, diallyl phthalate resins, phenolic resins, epoxy resins, benzoguanamine resins, urethane resins, alkyd resins, unsaturated polyester resins, urea resins, etc. Only one type of thermosetting resin may be used, or two or more types may be used.

[0024] Among the thermosetting resins, melamine-based resins, diallyl phthalate-based resins, and unsaturated polyester-based resins are preferred. In particular, diallyl phthalate-based resins are preferred, and diallyl phthalate-based resins and unsaturated polyester-based resins are more preferred.

[0025] When the thermosetting resin is a thermosetting resin, the resin is a prepolymer having a thermosetting functional group. When the thermosetting resin is a diallyl phthalate resin or an unsaturated polyester resin, the thermosetting functional group is an unsaturated carbon-carbon double bond.

[0026] The melamine-based resin contains at least a structural unit derived from a melamine derivative. Examples of the melamine derivative include melamine and compounds in which functional groups such as imino groups, methylol groups, and alkoxymethyl groups such as methoxymethyl groups and butoxymethyl groups have been introduced into melamine. Furthermore, compounds obtained by reacting a melamine derivative having a methylol group with a lower alcohol to partially or completely etherify the melamine derivative can also be used as a monomer. The melamine derivative may be used alone or in combination of two or more. The melamine resin may be either a melamine resin for high-pressure molding or a melamine resin for low-pressure molding. The melamine resin may be used alone or in combination of two or more.

[0027] The diallyl phthalate resin contains at least a constituent unit derived from a diallyl phthalate monomer. Examples of the diallyl phthalate monomer include diallyl orthophthalate, diallyl isophthalate, and diallyl terephthalate. The diallyl phthalate monomer may be used alone or in combination of two or more. The diallyl phthalate resin may be used alone or in combination of two or more. The weight average molecular weight of the diallyl phthalate resin measured by GPC is preferably 10,000 to 50,000.

[0028] The unsaturated polyester resin may be in a liquid state or a solid state at room temperature, and one or more kinds of the unsaturated polyester resins may be used.

[0029] The unsaturated polyester resin may be a compound containing a structural unit derived from a polybasic unsaturated acid and a structural unit derived from a polyhydric alcohol. The unsaturated polyester resin may further contain a structural unit derived from a polybasic saturated acid. The unsaturated acid, saturated acid, and polyhydric alcohol may each be used alone or in combination of two or more.

[0030] Examples of the polybasic unsaturated acid include maleic acid, fumaric acid, itaconic acid, and phthalic acid monomers (orthophthalic acid, isophthalic acid, terephthalic acid).

[0031] Alternatively, the unsaturated polyester resin may be an air-curable unsaturated polyester resin, such as a polyester resin containing a structural unit derived from an aliphatic cyclic unsaturated acid such as tetrahydrophthalic acid, 3,6-endomethylenetetrahydrophthalic acid, or methyl-3,6-endomethylenetetrahydrophthalic acid as the unsaturated acid, and a structural unit derived from allyl glycidyl ether as the polyhydric alcohol.

[0032] The content of the thermosetting resin in the thermosetting resin composition is preferably 20 to 100% by mass, more preferably 40 to 90% by mass, and even more preferably 50 to 80% by mass, relative to the total amount (100% by mass) of the thermosetting resin composition. When the content is 20% by mass or more, a resin-impregnated layer having sufficient strength can be obtained by thermocompression molding.

[0033] When the thermosetting resin contains a diallyl phthalate resin and / or an unsaturated polyester resin, the content of the diallyl phthalate resin and / or the unsaturated polyester resin in the thermosetting resin is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more, relative to the total amount (100% by mass) of the thermosetting resin.

[0034] When the thermosetting resin contains a diallyl phthalate resin and / or an unsaturated polyester resin, the mass ratio of the diallyl phthalate resin to the unsaturated polyester resin (former:latter) is preferably 10:90 to 100:0, more preferably 10:90 to 90:10, even more preferably 20:80 to 80:20, still more preferably 30:70 to 70:30, and particularly preferably 40:60 to 60:40. When the mass ratio is within the above range, the adhesion between the resin-impregnated layer and the polybutylene terephthalate after thermocompression molding becomes more appropriate.

[0035] The thermosetting resin composition may contain a monomer constituting the thermosetting resin or an oligomer of the monomer (e.g., a polymer of two or three units). For example, when the thermosetting resin contains a diallyl phthalate-based resin, the thermosetting resin composition may contain the diallyl phthalate-based monomer, which is a structural unit of the diallyl phthalate-based resin.

[0036] The thermosetting resin composition may contain a crosslinking agent for crosslinking the thermosetting resin. The crosslinking agent is appropriately selected depending on the type of the thermosetting resin. When the thermosetting resin is a diallyl phthalate resin or an unsaturated polyester resin, examples of the crosslinking agent include polyfunctional compounds such as polyfunctional monomers having at least two polymerizable functional groups with unsaturated carbon-carbon double bonds, such as (meth)acryloyl groups or vinyl groups, and polymers of such polyfunctional monomers. The crosslinking agents may be used singly or in combination of two or more.

[0037] Examples of the polyfunctional monomer include polyfunctional (meth)acrylates such as hexanediol di(meth)acrylate, dodecanediol di(meth)acrylate, butanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, butyl di(meth)acrylate, and hexyl di(meth)acrylate. Of the polyfunctional compounds, poly(meth)acrylates of dipentaerythritol having three or more (meth)acryloyl groups in the molecule are preferred.

[0038] The content of the crosslinking agent (or the structural portion derived from the crosslinking agent when the thermosetting resin is a thermoset resin) is preferably 0.5 to 50 parts by mass relative to 100 parts by mass of the total amount of the thermosetting resin. When the content is within the above range, the hardness of the resin-impregnated layer after thermosetting becomes more appropriate. The content of the curing agent may be 10 to 47 parts by mass or 30 to 45 parts by mass relative to 100 parts by mass of the total amount of the thermosetting resin. In particular, when the content of the diallyl phthalate resin in the thermosetting resin is high (for example, 60% by mass or more, preferably 80% by mass or more), the content of the crosslinking agent is preferably within the above range. Furthermore, the content of the crosslinking agent may be 0.6 to 20 parts by mass or 1 to 16 parts by mass relative to 100 parts by mass of the total amount of the thermosetting resin. In particular, when the thermosetting resin contains the diallyl phthalate resin and the unsaturated polyester resin, the content of the crosslinking agent is preferably within the above range. Furthermore, it is preferable that the content of the crosslinking agent relative to 100 parts by mass of the diallyl phthalate resin and the unsaturated polyester resin combined is within the above-mentioned range.

[0039] The thermosetting resin composition preferably contains a polymerization initiator (curing agent). By using the polymerization initiator, the curing rate becomes faster than when the thermosetting resin is polymerized alone, and a thermosetting layer having a sufficient degree of curing can be obtained in a short time. When the thermosetting resin is a diallyl phthalate resin or an unsaturated polyester resin, examples of the polymerization initiator include organic peroxide curing agents such as benzoyl peroxide, tertiary butyl perbenzoate, methyl ethyl ketone peroxide, and dicumyl peroxide.

[0040] The content of the polymerization initiator (or the structural portion derived from the polymerization initiator when the thermosetting resin is a thermoset resin) is preferably 0.1 to 10 parts by mass, and more preferably 0.5 to 5 parts by mass, relative to 100 parts by mass of the total amount of the thermosetting resin.

[0041] The thermosetting resin composition may contain components other than the thermosetting resin. Examples of the other components include curing catalysts, curing accelerators, polymerization inhibitors, release agents, fillers, plasticizers, dispersants, thickeners, viscosity modifiers, flame retardants, colorants (pigments, dyes, etc.), antifoaming agents, preservatives, UV absorbers, depleting agents, antibacterial agents, leveling agents, and silane coupling agents. Only one of the other components may be used, or two or more may be used.

[0042] The impregnated substrate is not particularly limited as long as it can be impregnated with the thermosetting resin composition, and examples thereof include impregnated paper fabrics such as titanium paper, tissue paper, reinforced paper, kraft paper, and cellulose paper; and woven or nonwoven fabrics such as polyester, rayon, acrylic, and vinylon. The impregnated paper fabrics may be printed. The impregnated substrate may be single-layered or multi-layered.

[0043] The amount of the thermosetting resin composition impregnated into the impregnated substrate is 10 to 500 g / m per area of ​​the impregnated substrate. 2 is preferable, and more preferably 50 to 300 g / m 2 The impregnation amount is 10 g / m 2 When the impregnation amount is 500 g / m or more, the impregnation amount is sufficient and the adhesion to the polybutylene terephthalate film is improved. 2 If it is less than this, costs can be reduced.

[0044] The thickness of the resin-impregnated layer is not particularly limited, but is, for example, 10 to 200 μm, and preferably 20 to 100 μm. If the thickness is 10 μm or more, defects such as poor flow during thermocompression molding can be suppressed. If the thickness is 200 μm or less, warping of the molded product due to resin shrinkage can be suppressed.

[0045] The resin-impregnated layer can be produced by known or conventional methods, for example, as follows. First, a thermosetting resin composition, which is a composition before thermosetting, is prepared. The thermosetting resin composition is obtained by mixing the thermosetting resin and, if necessary, the various components described above. If the thermosetting resin composition has a low viscosity, the impregnated substrate can be immersed in a bath of the thermosetting resin composition to be impregnated. If the thermosetting resin composition is a high-viscosity liquid or solid, the thermosetting resin composition is diluted or dissolved in an appropriate organic solvent, such as acetone, toluene, or methyl ethyl ketone, to obtain a resin liquid of appropriate viscosity. The impregnated substrate is then immersed in the liquid and dried to volatilize the solvent. The impregnation temperature is, for example, 10 to 35°C, preferably 20 to 30°C. While the method of immersing the impregnated substrate in a bath of the thermosetting resin composition has been described, the impregnation may also be performed by applying the thermosetting resin composition to the surface of the impregnated substrate and leaving it to soak in.

[0046] (PBT film) The PBT film has a shape (matte transfer shape) for transferring a matte finish on the surface on the resin-impregnated layer side (i.e., the surface on which the resin-impregnated layer is laminated). It is necessary to select a plastic film having a heat resistance that can withstand the temperatures during thermocompression molding as the matte transfer shape. Polypropylene films have relatively low heat resistance, and therefore require time-consuming cooling after thermocompression molding before being removed from the press. Furthermore, polyethylene terephthalate films (PET films) have low adhesion to the resin-impregnated layer and are prone to peeling after thermocompression molding. In contrast, the decorative sheet of the present invention can solve these problems by using a PBT film. The PBT film is preferably an unstretched film. The PBT film may be a single layer or a multilayer.

[0047] The matte transfer pattern may be formed only on the surface of the PBT film facing the resin-impregnated layer, or may be formed on both surfaces of the PBT film, and is transferred to the opposing surface of the resin-impregnated layer during thermocompression molding.

[0048] The matte transfer shape may be, for example, an uneven shape formed by kneading particles into a film and forming the particles protruding from the film surface. The matte transfer shape may be appropriately designed depending on the desired matte finish.

[0049] For the purpose of improving adhesion to the resin-impregnated layer, the PBT film may be subjected to surface treatments such as physical treatments such as corona discharge treatment, plasma treatment, sand matting treatment, ozone exposure treatment, flame exposure treatment, high-voltage shock exposure treatment, and ionizing radiation treatment; chemical treatments such as chromic acid treatment; and adhesion-enhancing treatments using a coating agent (primer). However, from the viewpoint of ensuring appropriate adhesion between the resin-impregnated layer and the PBT resin in the PBT film, it is preferable that the surface on the resin-impregnated layer side is an untreated surface that has not been subjected to such treatments.

[0050] In the decorative sheet of the present invention, the PBT film preferably has an area on the surface facing the resin-impregnated layer that contacts the resin-impregnated layer. It is more preferable that no other layers, such as an easy-adhesion layer or a release layer, are present between the PBT film and the resin-impregnated layer. When the PBT film has an area in contact with the resin-impregnated layer (particularly when no other layers are present), the matte finish can be transferred more closely. Furthermore, the adhesion between the resin-impregnated layer and the PBT film is excellent even after heat curing.

[0051] The arithmetic mean surface roughness (Ra) of the surface of the PBT film having the matte transfer pattern is not particularly limited, but is, for example, 0.03 to 1.0 μm, preferably 0.3 to 0.7 μm. When the Ra is 0.03 μm or more (particularly, 0.3 μm or more), the matte pattern is more easily transferred to the resin-impregnated layer. Furthermore, when the Ra is within the above range, adhesion to the resin-impregnated layer after thermocompression molding is more likely to be adequate.

[0052] The haze of the PBT film is not particularly limited, but is, for example, 10 to 80%, and preferably 70 to 80%. When the haze is 10% or more (particularly, 70% or more), the matte finish is more easily transferred to the resin-impregnated layer. Furthermore, when the haze is within the above range, adhesion to the resin-impregnated layer after thermocompression molding is more likely to be adequate. Furthermore, the 60° gloss value of the PBT film is not particularly limited, but is, for example, 3 to 50.

[0053] The thickness of the PBT film is not particularly limited, but is, for example, 10 to 100 μm, and preferably 30 to 70 μm. When the thickness is 10 μm or more, the film has sufficient strength and is less likely to tear when peeled off. When the thickness is 100 μm or less, the embossed shape can be deeply transferred when embossing is performed, resulting in an excellent texture. It is also economically advantageous.

[0054] The peel strength between the PBT film and the resin-impregnated layer after thermal curing is preferably 20 to 200 g, more preferably 40 to 150 g, and even more preferably 50 to 100 g. If the peel strength is 20 g or more, the PBT film is less likely to peel after thermocompression molding. If the peel strength is 200 g or less (particularly 150 g or less), the PBT film can be easily peeled when intentionally peeled. The peel strength can be measured using a spring balance, with the end of the PBT film adhered to the hook of the spring balance, at a peel angle of 90° and a PBT film width of 15 mm.

[0055] [Decorative panel] A decorative board can be produced using the decorative sheet of the present invention. The decorative board comprises, for example, a substrate and a decorative sheet provided on one side of the substrate. More specifically, the decorative board comprises, in this order, a substrate, a resin-impregnated layer in which a thermosetting resin composition is impregnated into the impregnated substrate, and a PBT film. In the decorative board, the layers may be directly laminated, or other layers may be interposed between the layers.

[0056] One embodiment of the decorative board is shown in Figures 1 and 2. The decorative board 10 shown in Figure 1 includes a substrate 4, a resin-impregnated layer 2, and a PBT film 3. The resin-impregnated layer 2 and the PBT film 3 together form a decorative sheet 1. The resin-impregnated layer 2 is a layer (prepreg) in which a thermosetting resin composition is impregnated into an impregnated substrate before thermosetting, and is formed on one surface of the substrate 4. The PBT film 3 is formed on the surface of the resin-impregnated layer 2 opposite the substrate 4. The PBT film 3 has a matte transfer pattern on the surface 3a facing the resin-impregnated layer 2.

[0057] The decorative board 10' shown in Figure 2 comprises a base material 4, a resin-impregnated layer 2', and a PBT film 3. The resin-impregnated layer 2' and the PBT film 3 together constitute a decorative sheet 1'. The resin-impregnated layer 2' is a layer in which an impregnated base material is impregnated with a thermosetting resin composition that has already been heat-cured, and is obtained by heat-curing the resin-impregnated layer 2.

[0058] (base material) The substrate may be a known or commonly used substrate used in decorative boards. The substrate may be an organic substrate or an inorganic substrate. The organic substrate may be, for example, a wood substrate such as a wooden veneer, plywood, laminated wood, particle board, medium-density fiberboard (MDF), high-moisture fiberboard, or kenaf board; a fibrous substrate such as paperboard, woven fabric, nonwoven fabric, resin-impregnated paper, or resin-impregnated fabric; or a synthetic resin substrate such as an acrylic resin board, a styrene resin board, an ABS resin board, a polycarbonate resin board, a nylon resin board, a polystyrene resin board, a polypropylene resin board, a polyester resin board, or a glass fiber-reinforced plastic board. Examples of the inorganic substrate include metal plate substrates such as aluminum plates, stainless steel plates, duralumin plates, steel plates, and brass plates; and inorganic substrates such as magnesium oxide plates, aluminum hydroxide plates, aluminum oxide plates, silicon oxide plates, titanium oxide plates, magnesium chloride plates, calcium silicate plates, volcanic glass material plates, gypsum (calcium sulfate) plates, slag gypsum plates, limestone (calcium carbonate) plates, wood wool cement plates, slag cement plates, lightweight aerated concrete plates, and glass fiber reinforced concrete plates. The substrate may be a single layer or a laminate of the same or different layers. The substrate may also be subjected to an easy-adhesion treatment, such as a sealer treatment or a primer treatment, to improve adhesion to the resin-impregnated layer.

[0059] The thickness of the substrate is not particularly limited, but is, for example, 2 to 50 mm, and preferably 3 to 30 mm. If the thickness is 2 mm or more, the substrate has sufficient strength and is less likely to break. If the thickness is 50 mm or less, the substrate is lightweight and easy to handle.

[0060] The decorative sheet may have other layers in addition to the above-mentioned layers. Examples of the other layers include a primer layer for improving adhesion between the resin-impregnated layer and the substrate, and a reinforcing layer provided on the PBT film (on the side opposite the resin-impregnated layer) for improving the protective function of the PBT film. As mentioned above, it is preferable that no other layers, such as an easy-adhesion layer or a release layer, are present between the PBT film and the resin-impregnated layer.

[0061] [Method of manufacturing decorative sheets and decorative panels] The decorative board having the above-mentioned thermosetting resin-impregnated layer can be manufactured by a process (thermocompression molding process) in which a pressure plate is placed on the PBT film side of a laminate in which a resin-impregnated layer (resin-impregnated layer before thermosetting) in which the thermosetting resin composition has been impregnated into an impregnated base material and the PBT film are laminated in this order on a base material, and then thermocompression molding is performed to cure the thermosetting resin composition.

[0062] One embodiment of the manufacturing method for the decorative sheet and decorative board of the present invention will be described with reference to Figure 3. First, as described above, an impregnated substrate is impregnated with a thermosetting resin composition prepared by diluting or dissolving with a solvent as necessary, and then dried as necessary to volatilize the solvent, producing a resin-impregnated layer 2 in which the thermosetting resin composition has impregnated the impregnated substrate. Next, the resin-impregnated layer 2 and a PBT film 3 are overlapped with each other so that the matte-finishing surface 3a faces the resin-impregnated layer 2, thereby obtaining a decorative sheet 1. When overlapping, a small amount of volatile solvent may be applied to the edge of the PBT film 3 to temporarily adhere them together, to prevent misalignment during thermocompression molding.

[0063] Next, decorative sheet 1 is placed on substrate 4 with resin-impregnated layer 2 facing the substrate 4, and pressure plate 5 is superimposed on PBT film 3 to obtain a laminate in which decorative plate 10 and pressure plate 5 are laminated. The above laminate includes decorative plate 10 which has, in this order, substrate 4, resin-impregnated layer 2 before heat curing provided on substrate 4, and PBT film 3 provided on resin-impregnated layer 2.

[0064] Next, a press is used to apply heat and pressure from above and below the laminate including the decorative sheet 10 to perform thermocompression molding, curing the resin-impregnated layer 2 to form a thermoset resin-impregnated layer 2', and obtaining a laminate in which the decorative sheet 10' and the pressure plate 5 are laminated. As described above, the thermocompression molding method is preferably a lamination thermocompression molding method, in which the decorative sheet 1 and the substrate 2 are overlapped and placed in a mold, and then heated and pressurized for curing. The thermocompression molding is carried out, for example, at a pressure of 10 to 25 kgf / cm. 2 The heating can be preferably carried out at a temperature of 120 to 190° C. for 30 seconds to 15 minutes.

[0065] The laminate obtained after thermocompression molding includes a decorative sheet 1' in which a resin-impregnated layer 2' and a PBT film 3 are laminated. The laminate also includes a decorative board 10' having, in this order, a substrate 2, a thermoset resin-impregnated layer 2' provided on the substrate 2, and a PBT film 3 provided on the resin-impregnated layer 2'. Thereafter, the pressing plate 5 is removed, and the decorative board 10' is obtained.

[0066] In manufacturing the decorative board 10', the matte transfer shape of the PBT film 3 can be transferred to the resin-impregnated layer 2', so there is no need to use a mirror plate having a shape for transferring the matte finish to the resin-impregnated layer as the pressure plate 5. However, if it is desired to transfer a shape other than the matte transfer shape provided on the PBT film 3 to the resin-impregnated layer 2', a mirror plate having a shape for transferring the above shape may be used as the pressure plate 5. In this way, when imparting a matte finish to the resin-impregnated layer, using a PBT film having a matte transfer shape eliminates the need to prepare multiple mirror plates according to the degree of matte finish, which is economically advantageous.

[0067] Furthermore, after thermocompression molding, the PBT film exhibits excellent adhesion to the surface of the resin-impregnated layer, and peels easily when intentionally peeled off. Therefore, after thermocompression molding, the PBT film is less likely to peel off from the thermoset resin-impregnated layer, and can function adequately as a protective film during transportation, etc. Furthermore, because the PBT film can function as a protective film, there is no need to replace it with a separate protective film after the thermocompression molding process, which is economically advantageous. Furthermore, because the PBT film is highly transparent when in close contact with the decorative sheet, visual inspection after molding can be performed without peeling off the PBT film. Furthermore, the PBT film is easily peeled off when intentionally peeled off during use. [Example]

[0068] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0069] Example 1 A resin composition solution was prepared by dissolving 60 parts by mass of diallyl orthophthalate prepolymer (viscosity (30°C) of 96.5 mPa·s in a 50% by mass solution in methyl ethyl ketone, manufactured by Osaka Soda Co., Ltd.), 50 parts by mass of unsaturated polyester (product name "DH-2000B", manufactured by DIC Materials Co., Ltd.), 5 parts by mass of dipentaerythritol hexaacrylate, 3 parts by mass of benzoyl peroxide, 1 part by mass of an internal mold release agent (product name "Zelec UN", manufactured by DuPont), 0.05 parts by mass of hydroquinone (polymerization inhibitor), and 3 parts by mass of finely powdered silica (product name "Carplex", manufactured by Shionogi & Co., Ltd.) in acetone. The resin composition solution at 25°C was diluted with 80 g / m 2 The printed pattern paper was immersed in the resin composition and then heated in a hot air circulating oven at 105°C for 90 seconds to volatilize the solvent, and a 190 g / m 2 Impregnated paper (amount of impregnation per 100 parts by mass of printed pattern paper: 138 parts by mass) was obtained.

[0070] The surface (front side) of a matte-treated PBT film (thickness: 50 μm, no surface treatment) bearing the matte transfer pattern was placed on top of the impregnated paper to produce a decorative sheet in which the impregnated paper and PBT film were laminated together.

[0071] A substrate (product name "Dailite", manufactured by Daiken Corporation, 3 mm thick, non-combustible material) was placed on the rotating board, and the decorative sheet was then placed on the substrate with the impregnated paper side in contact with the substrate. Then, using a press machine, pressure was applied so that the hot plate with the pressure plate (flat shape) was on the PBT film side and the other hot plate was on the rotating board side, and heat was applied to perform thermo-compression molding. The thermo-compression molding was performed at a temperature of 150°C and a pressure of 16 kgf / cm. 2 The pressure was then released, and the laminate of the transfer plate, substrate, and decorative sheet was removed from the press and cooled to room temperature to obtain a decorative board.

[0072] Example 2 Decorative sheets and decorative panels were produced in the same manner as in Example 1, except that the back side of the matte-treated PBT film (the side having a matte transfer pattern different from the matte transfer pattern formed on the front side) was superimposed on the impregnated paper.

[0073] Example 3 A resin composition solution was prepared by dissolving 70 parts by mass of diallyl orthophthalate prepolymer (viscosity (30°C) of 96.5 mPa·s in a 50% by mass solution in methyl ethyl ketone, manufactured by Osaka Soda Co., Ltd.), 30 parts by mass of dipentaerythritol hexaacrylate, 3 parts by mass of benzoyl peroxide, 1.5 parts by mass of an internal mold release agent (trade name "Zelec UN", manufactured by DuPont), 0.1 parts by mass of hydroquinone (polymerization inhibitor), 50 parts by mass of aluminum hydroxide (trade name "BF013STM", manufactured by Nippon Light Metal Co., Ltd.), 5 parts by mass of magnesium hydroxide (trade name "Magseeds N-6", manufactured by Konoshima Chemical Co., Ltd.), and 0.1 parts by mass of an antifoaming agent in acetone. The resin composition solution at 25°C was diluted with 60 g / m 2 The printed pattern paper was immersed in the resin composition and then heated in a hot air circulating oven at 105°C for 90 seconds to volatilize the solvent, and a 160 g / m 2 Impregnated paper (amount of impregnation per 100 parts by mass of printed pattern paper: 167 parts by mass) was obtained.

[0074] A decorative sheet and a decorative board were produced in the same manner as in Example 1, except that the above-mentioned impregnated paper was used.

[0075] Comparative Examples 1 to 15 Decorative sheets and decorative panels were produced in the same manner as in Example 1, except that the plastic film shown in Table 1 was used instead of the PBT film, and the side of the plastic film bearing the matte transfer pattern (front side) was laminated onto the impregnated paper.

[0076] (evaluation) The decorative boards obtained in the examples and comparative examples were evaluated as follows. The evaluation results are shown in the table. In the table, "-" indicates that no evaluation was performed.

[0077] (1) Adhesion strength The plastic film was peeled off by hand from each of the decorative sheets obtained in the Examples and Comparative Examples, and the adhesive strength between the resin-impregnated layer and the plastic film was evaluated according to the following criteria. [Judgment criteria] ○ (Good): Appropriate force is required for peeling, and the adhesive strength is appropriate. ×1 (bad): The film is not strong enough and breaks. ×2 (bad): The adhesion strength was too strong and it could not be peeled off. ×3 (bad): The adhesive strength is too weak and peels off easily.

[0078] (2) Stain resistance After the adhesion strength test, the plastic film was peeled off and the exposed surface of the resin-impregnated layer was painted black with a black marker and left for 10 minutes. The blackened area was then wiped off with acetone, and the staining of the resin-impregnated layer surface was evaluated according to the following criteria. Poor stain resistance indicates that the resin composition was also peeled off from the resin-impregnated layer when the plastic film was peeled off. [Judgment criteria] ○ (Good): The black color is completely wiped off or only a small amount remains. × (bad): Black color clearly remains.

[0079] (3) Matte finish After the adhesion strength test, the plastic film was peeled off and the exposed surface of the resin-impregnated layer was visually observed, and the matte feel of the surface of the resin-impregnated layer was evaluated according to the following criteria. [Judgment criteria] ○ (Good): The matte finish is equal to or better than that achieved by using a mirror plate without using a plastic film. × (bad): The matte finish is weaker than when a matte finish is imparted by a mirror plate without using a plastic film.

[0080] (4) Peel strength after thermo-compression molding For each decorative panel obtained in the examples, cuts were made at 15 mm intervals on the surface of the PBT film using a cutter knife. The ends of the cut PBT film were then attached to the hook of a spring balance with adhesive tape, and the spring balance was pulled straight up to attempt peeling of the PBT film (peel angle 90°). The value indicated by the spring balance when the peeling progress of the PBT film was stable was then read, and this was taken as the peel strength.

[0081] [Table 1]

[0082] The plastic films used in the comparative examples are as follows: <PETフィルム> PTH-25: Product name "Emblet PTH-25", manufactured by Unitika Ltd., thickness 25 μm, gloss (20°) 45%, haze 26% PTH-50: Product name "Emblet PTH-50", manufactured by Unitika Ltd., thickness 50 μm, gloss (20°) 41%, haze 35% PTHA-25: Product name "Emblet PTHA-25", manufactured by Unitika Ltd., thickness 25 μm, gloss (20°) 24%, haze 41% Lumirror #26-X42: Product name "Lumirror #26-X42", manufactured by Toray Industries, Inc. Lumirror #25-X44: Product name "Lumirror #25-X44", manufactured by Toray Industries, Inc. Lumirror #50-X42: Product name "Lumirror #50-X42", manufactured by Toray Industries, Inc. Lumirror #50-X44: Product name "Lumirror #50-X44", manufactured by Toray Industries, Inc. Tetoron U4: Product name "Teijin Tetoron U4-50", manufactured by Toyobo Film Solutions Co., Ltd., thickness 50 μm, haze 90.1%, surface roughness 280 nm Melinex: Product name "Melinex 50μm", manufactured by Toyobo Film Solutions Co., Ltd., thickness 50μm, haze 95%, gloss (45°) 38%, surface roughness (Ra) 0.4μm YG: Product name "YG", manufactured by Toyobo Film Solutions Co., Ltd., thickness 48 μm, haze 95%, gloss (45°) 38% <PPフィルム> OPP-Type D: Kaisei Kogyo Co., Ltd., sand-matt processed PP film OP Mat-1: Product name "OP Mat-1 #20", manufactured by Mitsui Chemicals Tocello Co., Ltd., thickness 20 μm Torayfan BO #25-YM17S: Product name "Torayfan BO #25-YM17S", manufactured by Toray Industries, Inc., thickness 20 μm Alphan SO-204 #20: Product name "Alphan SO-204 #20", manufactured by Oji F-Tex Co., Ltd., thickness 20 μm, haze 81.7%, surface roughness (Rmax) 5.6 μm Alphan MAM-430 #25: Product name "Alphan MAM-430 #25", manufactured by Oji F-Tex Co., Ltd., thickness 25 μm, haze 90%, surface roughness (Ra) 0.75 μm, surface roughness (Rmax) 5.8 μm

[0083] As shown in the table, the decorative boards (Examples) of the present invention made using PBT film had a clear matte finish transferred to the surface of the resin-impregnated layer, and were evaluated as having excellent adhesion between the PBT film and the surface of the resin-impregnated layer after thermo-compression molding, and as being easy to peel off when intentionally attempted. On the other hand, when polyethylene terephthalate film or polypropylene film was used instead of PBT film, the matte finish was not clearly transferred to the surface of the resin-impregnated layer, adhesion was poor after thermo-compression molding, or peeling was difficult when intentionally attempted. [Explanation of symbols]

[0084] 1,1' decorative sheet 2 Resin-impregnated layer (before heat curing, prepreg) 2' Resin impregnated layer (heat cured) 3 PBT film 4 Base material 5 Pressure plate 10,10' decorative panel

Claims

1. The film has a structure in which a resin-impregnated layer in which a thermosetting resin composition is impregnated into an impregnated base material and a polybutylene terephthalate film are laminated together, the polybutylene terephthalate film has a matte transfer pattern on a surface of the resin-impregnated layer side, and the surface of the polybutylene terephthalate film on the resin-impregnated layer side is an untreated surface that has not been subjected to a surface treatment; The decorative sheet has a peel strength of 20 to 200 g between the polybutylene terephthalate film and the resin-impregnated layer after heat curing.

2. 2. The decorative sheet according to claim 1, wherein said resin-impregnated layer and said polybutylene terephthalate film have a contact area.

3. The decorative sheet according to claim 1 or 2, wherein the thermosetting resin composition contains a diallyl phthalate resin.

4. The decorative sheet according to any one of claims 1 to 3, wherein the thermosetting resin composition contains an unsaturated polyester resin.

5. The decorative sheet according to any one of claims 1 to 4, wherein the matte transfer pattern includes an uneven pattern.

6. A decorative board comprising the decorative sheet according to any one of claims 1 to 5, A decorative board comprising a substrate, the resin-impregnated layer, and the polybutylene terephthalate film.

7. 7. The method for producing a decorative panel according to claim 6, further comprising a thermo-compression molding step of: superimposing a pressure plate on the polybutylene terephthalate film side of a laminate in which a resin-impregnated layer in which a thermosetting resin composition has been impregnated into an impregnated substrate and a polybutylene terephthalate film having a matte transfer pattern are laminated in this order on a substrate; and performing thermo-compression molding to cure the thermosetting resin composition.

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