JP3823686B2 - Decorative sheet - Google Patents

Description

【００５４】
以上の結果から、本発明による材料にて作製された化粧シートは、従来の化粧シートと比較して、耐候性試験後における紫外線吸収能の向上により、褪色や樹脂劣化を抑制することができ、表面凹部の白化、劣化も抑制できた。
【００５５】
【発明の効果】
以上の様に、本発明の化粧シートは、塩化ビニル樹脂を使用していないので、焼却時に有害なガスが発生せず環境に優しく、耐候性の劣るオレフィン系樹脂を用いても、本発明における耐候剤を用いることにより、表面硬度を維持しながらも耐候性の向上した化粧シートを提供することができる。
【図面の簡単な説明】
【図１】本発明の実施例における化粧シートの一例を示す断面説明図である。
【符号の説明】
１ ……トップコート層
２ ……オレフィン系樹脂層（ポリプロピレン樹脂層）
３ ……接着性樹脂層
４ ……接着層
５ ……インキ層
６ ……基材
７ ……プライマー
８ ……埋め込み樹脂[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a decorative sheet used for building interior materials such as building interiors, surface and frame materials of joinery, surface materials of household electrical appliances, flooring materials, etc., and is applied to wooden boards, inorganic boards, metal plates, etc. In addition, the decorative sheet is used as a decorative board.
[0002]
[Prior art]
Conventionally, a sheet made of vinyl chloride has been used as a decorative sheet used for the above purpose. However, vinyl chloride resin has been said to generate chlorine gas during incineration, causing acid rain and dioxins, and the problem of bleeding out of plasticizer added to the sheet has also been raised. From the viewpoint of environmental problems, a decorative sheet not using a vinyl chloride resin is being demanded.
[0003]
For these reasons, many decorative sheets using an olefin resin have been proposed in recent years as decorative sheets that replace vinyl chloride decorative sheets. For example, according to Japanese Patent Laid-Open Nos. 2-128843, 4-83664, 6-1881, 6-198831, 9-328562, and the like. However, in these cases, since a general polyolefin sheet or a soft polyolefin sheet is used, scratch resistance and weather resistance are poor, and it is far inferior to the surface scratch resistance of a conventional vinyl chloride decorative sheet. For this reason, in order to improve surface scratch resistance, when a material with high crystallization and high isotacticity is used, the weather resistance may be severely deteriorated.
[0004]
Therefore, the surface of the polyolefin sheet is provided with a resin as a top coat to improve surface glossiness and surface damage. Further, since weather resistance is also required, a weathering agent is present in the olefin resin system, and a weathering agent is included in the topcoat agent. However, depending on the type of weathering agent, there are many cases where the function as a weathering agent cannot be performed sufficiently, and other problems are caused by bleed-out.
[0005]
Some decorative sheets may be embossed with a grain pattern in order to improve the design. In some cases, the embossed portion has a thinner layer thickness than other portions. In this case, the weather resistance is weakened, deterioration starts from that portion, and the conduit portion is often whitened or broken.
[0006]
[Problems to be solved by the invention]
Therefore, the present invention is to provide a decorative sheet in which the above-mentioned problems, that is, a decorative sheet of an olefin resin and a weather resistance of a decorative material are improved.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides: In a decorative sheet comprising an olefin resin layer having a concavo-convex pattern on the surface, a resin containing at least a triazine-based ultraviolet absorber as a weathering agent is embedded in a concave portion of the concavo-convex pattern on the surface of the olefin resin layer. This is a decorative sheet.
[0008]
Moreover, in the decorative sheet according to claim 1, The olefin resin contains a triazine UV absorber It is characterized by this.
[0009]
Moreover, in the decorative sheet according to claim 1 or 2, The olefin resin is a polypropylene resin It is characterized by this.
[0010]
further, It is a manufacturing method of the decorative sheet in any one of Claims 1 thru | or 3, Comprising: The process of forming an uneven | corrugated pattern by the embossing in the said olefin resin layer surface, and the recessed part of the uneven | corrugated pattern on this olefin resin resin layer surface A process for producing a decorative sheet comprising a step of embedding a resin containing at least a triazine-based ultraviolet absorber as a weathering agent by wiping It is.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The decorative sheet of the present invention is a decorative sheet having at least an olefin resin, in particular, a polypropylene transparent resin layer, and includes a translucent material. The polypropylene resin generally contains various additives. However, especially for UV absorbers as weathering agents, conventional benzophenone-based and benzotriazole-based UV absorbers are also in view of cost and the like. Although generally used, in the present invention, a triazine ultraviolet absorber is used.
[0012]
The amount added to the decorative sheet is often limited by the difference in compatibility with the resin used, but the amount added to the olefin resin is preferably 0.1 to 5 parts by weight, preferably Is about 1 part by weight, and the weather resistance can be improved by adding more weathering agents to the top coat of the outermost layer as long as there is no harmful effect. However, there are cases where poor adhesion due to bleed out after cost limitations or addition amount dissolution limitations in combination with other additives, coloring, curing inhibition, and weather resistance may occur. Therefore, the addition amount is 0.5 to 10 parts by weight, preferably about 1 to 3 parts by weight, but is appropriately selected in consideration of the required weather resistance of the decorative sheet and the adverse side effects caused by the addition. It is good to decide.
[0013]
In addition, with regard to the embossed pattern applied to improve the design, the same part has a thin layer thickness, and if it has not been treated with the corresponding weather resistance, it will be relatively in comparison with other parts. Early weathering deterioration occurs. In other words, repeated expansion and contraction due to light and heat, and further degradation occurs in a chain by breaking the molecular chain, but when the layer thickness is thin, the entire shrinkage strain concentrates on the embossed part, further promoting the deterioration. Shows severe deterioration. Thus, although it is already known that wiping in which a resin is embedded therein is effective, in the present invention, a triazine-based ultraviolet absorber is included as one of weathering agents particularly in the wiping resin. Has proposed.
[0014]
The decorative sheet has a thickness of 30 μm to 100 μm, and the total thickness when laminated with the base sheet is 80 μm to 250 μm, preferably 100 μm to 150 μm. Furthermore, the thickness of the top coat is 1 μm to 40 μm, but the thickness of the top coat layer varies depending on the application and the resin used, but it is preferable in view of curing conditions, cost, weather resistance, surface properties, post-processability, etc. Is in the range of about 5 μm to 15 μm.
[0015]
Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view showing an example of a decorative sheet in an embodiment of the present invention. As shown in FIG. 1, a transparent polypropylene resin and a base resin sheet are laminated here, and surface embossing is further performed.
[0016]
The topcoat layer 1 first has a role of protecting the surface and adjusts the surface hardness maintenance, the stain resistance, and the surface gloss. The material used can be appropriately selected from polyurethane, acrylic silicon, fluorine, epoxy, vinyl, polyester, melamine, aminoalkyd, urea, and the like. Any of aqueous, emulsion, and solvent systems can be used, and curing can be either a one-component type or a two-component type using a curing agent. Among these, a urethane-based topcoat using isocyanate is desirable from the viewpoint of workability, cost, cohesion of the resin itself, and the like.
[0017]
The isocyanates described above include tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), hexamethylene diisocyanate (HMDI), metadiisocyanate (MDI), lysine diisocyanate (LDI), isophorone diisocyanate (IPDI), methylhexane diisocyanate (HTDI). ), Methylcyclohexanone diisocyanate (HXDI), trimethylhexamethylene diisocyanate (TMDI), etc., but considering weather resistance, a type having a linear structure rather than a type having a double bond, particularly hexamethylene diisocyanate ( HMDI) is optimal. In addition, in order to further improve the surface hardness, it is also possible to use a resin that cures with active energy rays such as ultraviolet rays and electron beams. In addition to the single use, about the thermosetting type and the photocuring type hybrid curing type, It may be effective from the viewpoints of surface hardness, curing shrinkage and adhesion.
[0018]
Furthermore, the top coat also has a role of improving weather resistance, and an ultraviolet absorber and a light stabilizer are preferably added as appropriate. In order to impart various functions, functional additives such as antibacterial agents, fungicides, and flame retardancy can be added as appropriate. In addition, inorganic fillers such as alumina, silica, silicon nitride, silicon carbide, glass beads, etc. can be added to adjust the gloss from the design of the surface and to improve the wear resistance. Next, as flame retardant, aluminum hydroxide, magnesium hydroxide, Ni chelate as quencher, etc., as UV absorber, benzotriazole, benzoate, benzophenone, triazine, salicylate, cyanoacrylate, etc. As the light stabilizer, a hindered amine or the like is generally added in any combination. In particular, since the top coat layer is present on the outermost surface, the portion contributing to the weather resistance of the sheet is large. Therefore, it is necessary to fully consider the weather resistance, among which UV absorbers and light stabilizers are indispensable, and the amount added depends on the required physical properties and adverse effects due to the addition of large amounts depending on the solubility in the resin or solvent. , About 0.1 to 10 parts by weight, preferably about 0.2 to 3 parts by weight.
[0019]
The coating liquid may be appropriately selected in consideration of solvent, solventless, water-based, emulsion-based, hot-melt, etc., drying properties and heat resistance of the sheet, blocking properties after drying, adhesion to the sheet, and the like. . The coating method may be selected according to the properties, viscosity, and coating amount of the coating liquid. A special coating method is not necessary and may be selected from general coating methods such as gravure coating, micro gravure coating, comma coating, and lip coating. Further, the coating amount is usually about 1 to 40 μm, preferably 3 to 15 μm in terms of the thickness, although it depends on the performance of the top coat, the required physical properties, film formation, curing, and the like. Further, an uneven embossed pattern may be applied to improve the design.
[0020]
Regarding the embossed pattern, it is directly applied to the olefin sheet before the top coat application, and the method is a method of applying an embossed pattern using an embossed plate having an uneven pattern by heat and pressure, There is a method of providing embossing at the same time as cooling using a cooling roll having a concavo-convex pattern when forming a film using an extruder. Here, it is also possible to embed ink in the embossed portion to further improve designability or to embed resin to improve weather resistance. It is also possible to forcibly emboss the sheet after applying the top coat by heat and pressure.
[0021]
The olefin-based resin layer 2 shown in the figure may be a normal polypropylene, and may be a homopolymer, that is, a homopolymer, or a binary or ternary random polymer copolymer copolymerized with ethylene or ptene.
[0022]
In particular, when the decorative sheet has surface strength, it is preferable to use highly crystallized polypropylene, but the present invention is not limited thereto. However, in order to maintain the surface hardness and other necessary physical properties, other resins can be mixed. However, if the physical properties of the highly crystallized polypropylene are not significantly adversely affected, they can be selected as appropriate depending on the intended formulation. Is possible. However, when post-processing such as bending is performed, those having good compatibility with the highly crystallized polypropylene resin constituting the transparent resin layer are particularly preferable.
[0023]
In terms of highly crystallized polypropylene, the initial flexural modulus is 10,000 kgf / cm. ² 22,000 kgf / cm ² Hereinafter, those having a tensile elongation at break of 200% or more and a molecular weight distribution MWD of 4 or less, mmmm (Pendad fraction) of 96% or more, MFR (melt flow rate) of 5 g / 10 min (230 ° C.) or more and 40 g / 10 min. (230 ° C.) In the following, a resin in which a highly crystallized polypropylene having a molecular weight distribution MWD of 4 or less is 90 to 100% can also be used. In this case, the surface hardness is good and the bendability (V-cut), which is the post-processability of the decorative sheet, is also good.
[0024]
The olefin sheet used here includes a heat stabilizer, a flame retardant, an ultraviolet absorber, a light stabilizer, an antiblocking agent, a catalyst accelerator, a colorant within a range that maintains transparency, and a semi-transparent material as necessary. A light scattering agent, a gloss adjusting agent, and the like can be added. As the antioxidant, phenol-based, sulfur-based, and phosphorus-based antioxidants are used. Any combination can be used, but it is necessary to pay attention to the surface bleeding and coloring caused by the addition of a large amount, and the synergistic / antagonistic action with the ultraviolet absorber and the light stabilizer. As heat stabilizer, hindered phenol type, sulfur type, fertilizer resin type, etc., as flame retardant, aluminum hydroxide, magnesium hydroxide, etc., as quencher, Ni chelate type, as UV absorber, benzotriazole As a light stabilizer, a hindered amine system or the like is generally added in any combination as a light stabilizer such as a system, a bezoate system, a benzophenone system, a triazine system, a salicylate system, or a cyanoacrylate system. Especially in this application, it is necessary to consider the weather resistance, the ultraviolet absorber and the light stabilizer are essential, and the amount added depends on the required physical properties and the compatibility of the resin picture to be added, but 0.1% each. About 5 parts by weight is preferred.
[0025]
With respect to ultraviolet absorbers, benzophenone-based and benzotriazole-based ones have been mainly used because of the current cost, ultraviolet absorption range, variety, and application range. However, unless it is a resin-reactive type or a cross-linked type, the weather resistance is inevitably bleed over time or washed away by heat, light, rain, etc., and the deterioration of the absorbed species and the deterioration of the resin over time have been inevitable. Therefore, in order to achieve high weather resistance, it was necessary to add it at a high concentration, but conversely, there was a problem that adhesion was poor due to bleeding or the like, and depending on the resin, it could not be added at a high concentration. However, regarding the triazine system in the present invention, if there is no problem in compatibility with the resin, the molecular weight is larger than the conventional system, the triazine skeleton suppresses bleed, and there is less bleed and less volatilization than before. It is possible to maintain a long-term ultraviolet absorption ability. Even in the results of TG / DTA (simultaneous measurement of differential heat / thermogravimetry), the triazine series has lower volatility than the bezotriazole series and the like, and since it has high heat resistance, it can maintain long-term weather resistance.
[0026]
Furthermore, in consideration of improvement of machinability and other physical properties in this layer, a filler can be added in addition to the resin and additives. As this filler component, there are urethane crosslinked particles, acrylic crosslinked particles, melamine resin, natural collagen, etc. as organic component fillers, and as inorganic fillers, alumina, silica, silicon nitride, which are also used for general top coats, etc. Examples include silicon carbide, glass beads, aluminum hydroxide, calcium carbonate, and the like.
The filler used has an average particle diameter equal to or smaller than the film thickness of polypropylene to be formed. The addition amount is preferably 20 to 80 parts by weight with respect to 100 parts by weight of the resin, and the range is wide because the specific gravity varies depending on the filler, and the volume ratio with the resin greatly changes. Therefore, the addition amount should be selected appropriately in consideration of the familiarity between the filler and the resin, the influence on extrusion suitability, and the machinability at that time, and there is a problem even if the filler content is used not only in one kind but also in a mixed system of two or more kinds. There is no.
[0027]
Furthermore, by adding an appropriate amount of the filler described above, the surface hardness of the resin layer can be increased or the elongation to the yield point can be reduced. In this way, the resin itself is less stretched and further brittle, so that in the post-processing cutting process, the resin layer is free from fuzz such as whiskers and burrs due to the processing teeth at the time of cutting. Thus, in order to give the resin itself the above properties, a filler is added to improve the machinability. Accordingly, various fillers as described above can be used regardless of whether they are inorganic or organic, as long as they can give the resin the above properties.
[0028]
Next, 3 in the figure is an adhesive resin layer. This layer is unnecessary if the non-polar polypropylene and the lower layer have good adhesion, but in the case of poor adhesion or insufficient adhesion. This layer is required. This adhesive resin layer 3 is obtained by subjecting a polypropylene, polyethylene, acrylic resin or the like to acid modification, and the thickness is 2 μm or more from the viewpoint of improving the adhesiveness. If the thickness is too thick, the adhesive resin layer itself is flexible. The adhesive strength may affect the surface hardness, and conversely the adhesive strength may be lowered from the viewpoint of cohesive strength and heat resistance of the adhesive resin.
Further, the method for forming the adhesive resin layer is preferably coextrusion lamination with the polypropylene layer described above from the viewpoint of improving the adhesive strength.
[0029]
Further, the fourth layer below it is an adhesive layer 4 for improving the adhesion between the lower ink layer and the upper resin layer, and even without this layer, the desired adhesive strength can be obtained. If it is possible, it does not need to be present. The material for the adhesive layer is not particularly limited as long as it contributes to the improvement of the adhesive strength between arbitrary resin systems. In addition, various materials such as acrylic, polyester, polyurethane, and epoxy can be used as the material, but in general, a two-component curing type polyurethane adhesive having a high coating cohesive force is often used. . Further, the coating method can be appropriately selected depending on the viscosity of the coating solution, etc., but generally, dry coating with a gravure plate is performed, which can be said to be a preferable method from the viewpoint of low coating amount management.
The coating amount may be appropriately determined in consideration of adhesive strength, cost, etc., but a coating amount as low as possible is preferable.
[0030]
The adhesive layer 4 is applied on the printed substrate side and laminated with the above-described polypropylene resin or adhesive resin. The bonding method at this time depends on the adhesive resin layer, but various methods such as heat lamination, extrusion lamination, and dry lamination may be selected according to the characteristics of the material.
Moreover, when embossing pattern is given, there are a method of forming embossing by hot pressure after laminating by various methods, and a method of embossing at the same time as extrusion laminating by providing an uneven pattern on a cooling roll. Further, there is a method in which a transparent resin layer and a base sheet that are simultaneously embossed at the time of extrusion are bonded together by heat or dry lamination. Furthermore, it is possible to improve the designability and weather resistance by embedding ink or resin in the embossed recess.
[0031]
6 in the figure is a substrate. The substrate 6 is paper such as thin paper, titanium paper, resin-impregnated paper, polyethylene, polypropylene, polystyrene, polybutylene, polycarbonate, polyester, polyamide, ethylene-vinyl acetate copolymer, polyvinyl alcohol, acrylic, or a synthetic resin thereof. Resin foam, ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, styrene-butadiene copolymer rubber, styrene-isoprene-styrene block copolymer rubber, styrene-butadiene-styrene block copolymer rubber, polyurethane, etc. Rubber, organic or inorganic nonwoven fabric, synthetic paper, aluminum, iron, gold, silver or other metal foil, etc. Moreover, the base material may be the same as the transparent resin layer 1 in the figure.
Further, in order to improve the machinability in this layer, a filler is added in addition to the resin and the additive. Examples of the filler include urethane crosslinked particles, acrylic crosslinked particles, melamine resin, and natural collagen as organic component fillers. Examples of the inorganic filler include alumina, silica, silicon nitride, silicon carbide, glass beads, aluminum hydroxide, calcium carbonate and the like used for general top coats. In the case of a transparent resin, a pigment or the like can be added in order to provide concealability.
[0032]
Next, 5 in the figure on the substrate is an ink layer. A pattern ink layer is provided on the solid ink layer 5 for providing concealability. In the case of using ink, the binder may be appropriately selected from nitrified cotton, cellulose, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyeletane, acrylic, polyester, and the like alone or modified products. These are water-based, solvent-based, and emulsion-based, and can be arbitrarily selected from one-pack type and two-pack type using a curing agent. Furthermore, it is possible to cure the ink by irradiation with active energy rays such as ultraviolet rays and electron beams. However, in the case of coloring, the electron beam curing may be more effective in the thickness direction than ultraviolet curing.
[0033]
Of these, the most common method is a method of curing an isocyanate with a urethane-based ink. In addition to these binders, colorants such as pigments and dyes contained in the ink, extender pigments, solvents, and various additives are added. Particularly well-known pigments include pearl pigments such as condensed azo, insoluble azo, cynadoline, isoindoline, anthraquinone, imidazolone, cobalt, phthalocyanine, carbon, titanium oxide, iron oxide, and mica. In addition to the application of ink, design properties may be applied by vapor deposition or sputtering of various metals. In addition, regarding the selection of the ink material, adhesion to the base material under the ink layer and the resin that comes over the ink layer is also required.
[0034]
In addition, the solid ink used for concealment may basically be the same as the design ink and its material, but it is necessary to have concealment for the purpose, so as an opaque pigment, titanium oxide, oxidation Use iron. It is also possible to add metals such as gold, silver, copper, and aluminum in order to provide concealment. In general, flaky aluminum is often added. However, if the coating amount is 2 μm or less, it is difficult to provide concealing properties, and if it is 10 μm or more, the cohesive force of the resin layer becomes weak, and therefore, about 2 to 10 μm is preferable.
[0035]
Methods for providing these pattern ink layers and solid ink layers include direct gravure printing, offset printing, screen printing, flexographic printing, electrostatic printing, ink jet printing, and the like. Further, when a concealing layer is further provided, a comma coater, knife coater, ripple coater, metal vapor deposition, sputtering method or the like may be used.
[0036]
The method for providing the top coat layer is not defined in the same manner as the method for providing the concealing layer, the solid ink layer, or the pattern ink layer.
[0037]
In addition, the above-described method for forming a polypropylene sheet is not particularly limited as long as it can form a film, and is not particularly defined, but an extruder is generally used.
[0038]
As described above, for the interface on which resin or ink is laminated, such as printing on a sheet or laminating sheets, if necessary, the printing or lamination can be performed in consideration of its adhesiveness. Before applying the surface, the surface may be activated by corona treatment, ozone treatment, plasma treatment, electron beam treatment, ultraviolet treatment, dichromate treatment, etc., and then each step may be effective. There is a case.
[0039]
The decorative sheet in FIG. 1 has the above-described layers, and the final decorative sheet manufacturing method includes a method in which an adhesive layer is applied to a printed base resin sheet, a transparent olefin resin ( Polypropylene) and an adhesive resin layer that are co-pressed are bonded together by dry lamination, extrusion lamination, or the like. In the case of dry lamination, since the adhesive layer is further increased, the layer structure in the figure shows the structure at the time of extrusion lamination.
[0040]
In the figure, 7 is a primer layer. This is used when the adhesiveness between the decorative sheet and the base material such as wood is insufficient, and is not particularly required when the adhesion is sufficient even without this layer.
[0041]
The material used here may be basically the same as the picture layer, the concealing layer, the top coat layer, etc., but considering that it is wound on the web because it is applied to the back of the sheet, avoid blocking, In order to enhance the adhesion with the lower layer adhesive, an inorganic filler such as silica, alumina, magnesia, titanium oxide, barium sulfate may be added. The coating thickness is intended to ensure close contact with the base material, so 0.1 μm to 3 μm is appropriate. In order to further improve the adhesion, the surface treatment as described above is preferably performed before the layer is provided on the surface.
[0042]
It is also desirable that the embedding resin in the embossed pattern in the figure be easily embedded in the recess. There is no problem if the embedding method is embedded only in the recess, but generally wiping is used to scrape the applied coating liquid with a squeegee or the like to embed only in the recess. It is necessary to make adjustments. In addition, the resin system is not particularly restricted, and the range of choices such as urethane system, epoxy system, polyester system, ether system, urea system, fluorine system, vinyl system, melamine system, acrylic silicon system, silicone system, etc. Widely selectable from water, solvent, emulsion, one-component curable, two-component curable, thermosetting, photo-curable, etc., adhesiveness to resin, volume expansion, small shrinkage, no coloration More preferably, the same resin as the top coat may be used. In consideration of adhesion and the like, a urethane system is generally used. Rather, the top coat and the same resin are better in terms of adhesion and the like. In addition, considering that the weather-resistant prescription here is slightly thinner than other parts due to the embedding of the recesses, it is preferable that the additive amount of the weathering agent is high as long as there is no harmful effect. It is preferable to add a weathering agent containing a UV absorber.
Also, depending on the case, the above-mentioned weathering agent can be added to the adhesive layer, which is a resin layer other than the top coat, the olefin resin layer, and the adhesive layer, further improving the weather resistance, and in a range without any harmful effects. It is even better if the amount is added.
[0043]
[Action]
As described above, since the decorative sheet of the present invention does not use a vinyl chloride resin in the sheet, it does not generate harmful gas at the time of incineration and is environmentally friendly. It has weather resistance that cannot be obtained with conventional polypropylene resins, and by embedding such coating liquid in embossed pattern recesses, it is possible to maintain UV absorption capacity after discoloration, fading, and whitening and deterioration of recesses. A decorative sheet with improved properties can be obtained.
[0044]
【Example】
<Example 1>
Homotype polypropylene resin for extrusion molding, phenolic antioxidant (Irganox 1010: manufactured by Ciba Specialty), 2000 ppm, triazine ultraviolet absorber: A, 2000 ppm, hindered amine light stabilizer (Kimasoap 944: Ciba Specialty) The resin to which 2000 ppm (made by Tees Co., Ltd.) was added was melt extruded using an extruder, and at the same time, the surface was embossed with a wood grain pattern to obtain a transparent resin sheet having a thickness of about 80 μm. The outermost surface of the sheet was dry-coated with a two-component curable urethane topcoat containing a triazine-based ultraviolet absorber to obtain a transparent resin sheet.
[0045]
<Example 2>
A polyethylene base resin sheet (100 μm) having a wood grain pattern printed on the surface and coated with about 2 μm of a two-component curable urethane resin system as an adhesive layer is extruded and laminated on the sheet produced in Example 1. A sheet was obtained.
[0046]
<Example 3>
When producing a resin sheet by the same method as in Example 1, a top coat is dry-coated on the outermost surface of the sheet, but a two-component curable urethane coating liquid is embedded in the concave portion of the embossed pattern on the surface. A transparent resin sheet was obtained from the coating liquid containing the triazine-based ultraviolet absorber A.
[0047]
<Example 4>
A polyethylene base sheet (100 μm) having a grain pattern printed on the surface and coated with about 2 μm of a two-component curable urethane resin system as an adhesive layer is extruded and laminated on the sheet prepared in Example 3. Got.
[0048]
<Comparative Example 1>
A resin sheet was prepared in the same manner as in Example 1, but a decorative sheet was obtained using the benzotriazole-based UV absorber B instead of the triazine-based UV absorber in the resin and the top coat.
[0049]
<Comparative example 2>
A polyethylene base sheet (100 μm) having a grain pattern printed on its surface and coated with about 2 μm of a two-component curable urethane resin system as an adhesive layer is extruded and laminated on the sheet produced in Comparative Example 1. Got.
[0050]
<Comparative Example 3>
A decorative sheet is prepared in the same manner as in Example 3, except that benzotriazole-based UV absorber B is added to the embossed recess embedding coating liquid used instead of triazine-based UV absorber A. A sheet was obtained.
[0051]
<Comparative Example 4>
For the decorative sheet prepared in Comparative Example 3, a polyethylene base sheet (100 μm) having a wood grain pattern printed on its surface and coated with about 2 μm of a two-component curable urethane resin system as an adhesive layer is extruded and laminated. A sheet was obtained.
[0052]
<Evaluation>
With respect to the resin sheets or decorative sheets prepared as described above as examples and comparative examples, they were stored in a weather resistance tester (Sunshine Weather Meter: manufactured by Suga Test Instruments Co., Ltd.) and subjected to carbon arc weathering according to JIS K5400. The resin sheet before and after the 3000 hour weather resistance test was visually checked for ultraviolet absorption ability, and for the decorative sheet, the color difference and whitening and breakage of the embossed recesses were visually judged.
The ultraviolet absorptivity was measured by measuring the difference in the ratio of ultraviolet absorption between 340 nm and 500 nm (340 nm / 500 nm) before and after the weather resistance test, and regarding the color difference, ΔE before and after the weather resistance test was measured. The evaluation results are shown in Table 1 below.
[0053]
[Table 1]

[0054]
From the above results, the decorative sheet made of the material according to the present invention can suppress discoloration and resin degradation by improving the ultraviolet absorbing ability after the weather resistance test, compared with the conventional decorative sheet, It was also possible to suppress whitening and deterioration of the surface recesses.
[0055]
【The invention's effect】
As described above, since the decorative sheet of the present invention does not use vinyl chloride resin, no harmful gas is generated during incineration, and it is environmentally friendly. By using a weathering agent, it is possible to provide a decorative sheet having improved weather resistance while maintaining surface hardness.
[Brief description of the drawings]
FIG. 1 is an explanatory cross-sectional view showing an example of a decorative sheet in an embodiment of the present invention.
[Explanation of symbols]
1 …… Topcoat layer
2 ...... Olefin resin layer (polypropylene resin layer)
3 …… Adhesive resin layer
4 ...... Adhesive layer
5 ...... Ink layer
6 …… Base material
7 …… Primer
8 ...... Embedded resin

Claims (4)

In the decorative sheet comprising an olefin resin layer having an uneven pattern on the surface,
A decorative sheet characterized in that a resin containing at least a triazine-based UV absorber as a weathering agent is embedded in a concave-convex pattern on the surface of the olefin resin layer . The decorative sheet according to claim 1, wherein the olefin resin contains a triazine-based ultraviolet absorber . The decorative sheet according to claim 1 or 2, wherein the olefin resin is a polypropylene resin . A method for producing a decorative sheet according to any one of claims 1 to 3,
Forming an uneven pattern on the surface of the olefin resin layer by embossing;
A method for producing a decorative sheet, comprising a step of embedding a resin containing at least a triazine-based ultraviolet absorber as a weathering agent in a concave and convex portion on the surface of the olefin resin resin layer by wiping.

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