JP6994633B2 - Decorative sheet and manufacturing method of decorative sheet - Google Patents

Description

The present invention relates to decorative sheets used for building materials used for exteriors and interiors of buildings, surfaces of fittings, surface materials of household appliances, etc., and is calculated from absorption spectra obtained by Fourier infrared spectroscopy. The present invention relates to a decorative sheet provided with a transparent resin layer made of a transparent resin sheet having a peak intensity ratio x specified within a predetermined range, and a method for producing the decorative sheet.

In recent years, as shown in Patent Documents 1 to 5, many decorative sheets using an olefin resin have been proposed as decorative sheets to replace the decorative sheets made of polyvinyl chloride.

However, by not using vinyl chloride resin for these decorative sheets, although the generation of toxic gas etc. at the time of incineration is suppressed, the surface is scratch resistant because a general polypropylene sheet or a soft polypropylene sheet is used. It was bad and was far inferior to the scratch resistance of the conventional polyvinyl chloride decorative sheet.

Therefore, the present inventors have proposed a decorative sheet having excellent surface scratch resistance and post-processability described in Patent Document 6 in order to eliminate these drawbacks. However, the use of decorative boards using such decorative sheets is expanding more and more, and consumers' awareness of quality is becoming more and more sophisticated.

In general, a crystalline resin such as a polypropylene resin can change its mechanical properties by controlling the crystallinity, which is the ratio of the crystalline component and the amorphous component in the resin. Factors for controlling the degree of crystallinity include material factors such as the molecular structure of the resin itself and the addition of a nucleating agent, and process factors such as molding processing conditions when processing the crystalline resin. In the present invention, the present inventors have conducted diligent research focusing on process factors, and by controlling the process factors, a resin sheet having an excellent post-processability and specifying a range of crystallinity is specified. We have completed the decorative sheet that we have prepared.

In addition, since the spherulite size in the crystal portion of polypropylene resin is usually larger than the wavelength of visible light (400 to 750 nm), light scattering increases and the spherulite is milky white, but polypropylene resin is expected to replace it. In the transparent resin layer, it is necessary that the pattern or pattern formed under the transparent resin layer can be clearly seen through the transparent resin layer, and high transparency is required from the viewpoint of designability.

Japanese Unexamined Patent Publication No. 2-128843 Japanese Unexamined Patent Publication No. 4-083664 Japanese Unexamined Patent Publication No. 6-001881 Japanese Unexamined Patent Publication No. 6-198831 Japanese Unexamined Patent Publication No. 9-328562 Japanese Patent No. 3772634

It is an object of the present invention to provide a decorative sheet and a method for producing a decorative sheet, which comprises a transparent resin layer having excellent post-processability and high transparency.

In order to achieve the above object, the decorative sheet according to the first aspect of the present invention comprises a concealing layer, a transparent resin layer formed on the concealing layer and containing 90 to 100% by weight of a crystalline polypropylene resin as a main component. The peak intensity ratio x calculated by using the following formula 1 from the absorption spectrum obtained by the Fourier type infrared spectroscopic measurement of the transparent resin sheet as the transparent resin layer. The value is x <0.65, and the concealing layer is an opaque layer containing aluminum. Here, in Equation 1, I997 represents a peak intensity value of wavenumber 997 cm ^-1 , I938 represents a peak intensity value of wavenumber 938 cm ^-1 , and I973 represents a peak intensity value of wavenumber 973 cm ^-1 .

By using such a decorative sheet according to the first aspect of the present invention, it is possible to provide a decorative sheet provided with a transparent resin layer having excellent post-processability. Further, according to the first aspect of the present invention, the concealing layer can surely maintain the concealing property on the back side of the transparent layer, and the transparent layer provides a decorative sheet with a high degree of freedom in design. be able to.

The decorative sheet according to the second aspect of the present invention is characterized in that the peak intensity ratio x of the transparent resin sheet is 0.55 ≦ x <0.65.

By using such a decorative sheet according to the second aspect of the present invention, it is possible to provide a decorative sheet provided with a transparent resin layer having excellent post-processability.

The decorative sheet according to the third aspect of the present invention is formed by adding a nano-sized nucleating agent vesicle containing a nucleating agent to a vesicle provided with an outer film of a single-layer film. It is characterized by. By using such a decorative sheet according to the third aspect of the present invention, it is possible to provide a decorative sheet having a transparent resin layer having higher transparency.

The method for producing a decorative sheet of the present invention comprises at least a concealing layer and a transparent resin layer formed on the concealing layer and containing 90 to 100% by weight of a crystalline polypropylene resin as a main component. In the production method, a nucleating agent vesicle containing a nucleating agent is added to a vesicle having an outer film of a single-layer film by a supercritical reverse-phase evaporation method to the crystalline polypropylene resin, and Fourier type red. A transparent resin sheet as the transparent resin layer is formed so that the peak intensity ratio x calculated by using the above formula 1 from the absorption spectrum obtained in the external spectroscopic measurement is x <0.65, and the concealing layer is formed. Is formed of an opaque layer containing aluminum.

According to the present invention, it is possible to provide a decorative sheet provided with a transparent resin layer having excellent post-processability and high transparency.

Further, by adding a nano-sized nucleating agent, more specifically, a nucleating agent vesicle containing a nucleating agent to a vesicle having an outer film of a single-layer film, to a transparent resin sheet. , It is possible to provide a decorative sheet that realizes extremely high transparency.

Sectional drawing which shows 1st Embodiment of the decorative sheet of this invention Sectional drawing which shows the 2nd Embodiment of the decorative sheet of this invention

The decorative sheet of the present invention is a decorative sheet comprising at least a transparent resin layer containing 90 to 100% by weight of a crystalline polypropylene resin as a main component, and the Fourier type infrared of the transparent resin sheet as the transparent resin layer. It is important that the value of the peak intensity ratio x calculated from the absorption spectrum obtained in the spectroscopic measurement using the following formula 1 is x <0.65. Here, in Equation 1, I997 represents a peak intensity value of wavenumber 997 cm ^-1 , I938 represents a peak intensity value of wavenumber 938 cm ^-1 , and I973 represents a peak intensity value of wavenumber 973 cm ^-1 .

Further, it is particularly preferable that the peak intensity ratio x of the transparent resin sheet is 0.55 ≦ x <0.65. By setting the peak intensity ratio x within the above range, it is possible to provide a decorative sheet provided with a transparent resin layer having extremely excellent post-workability.

In the decorative sheet of the present invention, the peak strength value x of the transparent resin sheet is set within the above range by controlling the film forming condition as a process factor. At this time, it is important that the transparent resin sheet is formed to a thickness of 20 to 200 μm, and if it is thinner than the above range, it is difficult to secure scratch resistance, and it is thicker than the above range. And, the resin sheet is not uniformly cooled in the thickness direction, and as a result, the resin cannot be uniformly cured. The transparent resin layer is particularly preferably formed to a thickness of 30 to 150 μm.

More specifically, the resin temperature is the temperature at which the molten resin is discharged during film formation, and the higher the resin temperature (higher temperature), the larger the peak intensity ratio x. The cooling temperature is a temperature at which the discharged resin is cooled, and the higher the cooling temperature (higher temperature), the larger the peak intensity ratio x. Regarding the cooling time, the peak intensity ratio x becomes larger by lengthening the transit time near the crystallization temperature of the polypropylene resin (100 to 130 ° C.). By combining the above conditions, the crystallization and crystal size in the resin can be controlled to appropriately adjust the peak intensity ratio x.

Here, the Fourier type infrared spectroscopic measurement will be described. First, infrared spectroscopic measurement is the principle that the amount of infrared light absorbed by a substance, which is light having a wavelength of 2.5 to 25 μm, changes based on the vibration and rotational motion of the molecule of the substance. This is a measurement method for obtaining information on the chemical structure and state of a substance by measuring the infrared light absorbed by the substance. The specific measurement method is to irradiate a substance with infrared light from a light source, generate an interference wave by synthesizing the divided transmitted light and reflected light, and obtain each wave number from the signal intensity of the interference wave. The infrared spectrum is measured by calculating the light intensity of the component. In particular, in the present invention, the interference wave is calculated by using the Fourier transform method, and the measurement is performed by Fourier-type infrared spectroscopic measurement, which is a method for measuring the infrared spectrum. The graph in which the wave number obtained by the above method is plotted on the horizontal axis and the measured absorbance (or transmittance) is plotted on the vertical axis is called the infrared absorption spectrum (or infrared transmission spectrum), and a pattern peculiar to each substance is recognized. Be done. At this time, the absorbance on the vertical axis changes in proportion to the concentration and thickness of the substance, and in the case of crystalline resin, the amount of the crystalline part or the amorphous part, so that the value of the peak intensity at a predetermined wave number changes. It is also possible to perform quantitative analysis from the height and area of the peak.

In the present invention, utilizing the above-mentioned characteristics of the infrared absorption spectrum, a peak having a wave number of 997 cm ^-1 corresponding to the absorbance of the crystalline part of the transparent resin sheet of polypropylene in the absorption spectrum obtained by the above measurement. The ratio of the strength to the peak intensity of the wave number 973 cm ^-1 , which corresponds to the absorbance of the amorphous part of the transparent resin sheet, that is, the peak intensity ratio x representing the crystallinity of polypropylene was calculated using the above formula 1. By clarifying the relationship between the peak strength ratio x and the scratch resistance of the transparent resin sheet, a decorative sheet having excellent scratch resistance is provided in which a transparent resin sheet having a peak strength ratio x within a predetermined range is used for the transparent resin layer. be. The peak intensities with a wave number of 997 cm ^-1 and the peak intensities with a wave number of 973 cm ^-1 are background-corrected using the peak intensities with a wave number of 938 cm ^-1 .

Further, in the decorative sheet of the present invention, it is important to form a transparent resin sheet as a transparent resin layer by adding a nano-sized nucleating agent, and in particular, a vesicle provided with an outer film of a single-layer film. It is preferable to add the nucleating agent vesicle contained in the above. By adding the nucleating agent vesicle to the polypropylene resin, the crystallinity of the polypropylene resin can be improved and a transparent resin sheet having extremely high transparency can be obtained.

The nucleating agent vesicle can be produced by a supercritical reverse phase evaporation method. The supercritical reverse phase evaporation method is a method for producing nano-sized vesicles (capsules) containing a target substance using carbon dioxide under supercritical conditions, temperature conditions above the critical point, or pressure conditions above the critical point. Is. The carbon dioxide in a supercritical state means carbon dioxide in a supercritical state having a critical temperature (30.98 ° C.) and a critical pressure (7.3773 ± 0.0030 MPa) or higher, and is under temperature conditions above the critical point or above the critical point. Carbon dioxide under pressure conditions above the critical point means carbon dioxide under conditions where only the critical temperature or only the critical pressure exceeds the critical condition.

Specifically, an aqueous phase is injected into a mixed fluid of supercritical carbon dioxide, phospholipids, and a nucleating agent as an encapsulating substance, and the mixture is stirred to form an emulsion of supercritical carbon dioxide and the aqueous phase. After that, when the pressure is reduced, carbon dioxide expands and evaporates to cause phase inversion, and phospholipids form nanoparticles in which the surface of the nucleating agent nanoparticles is covered with a monolayer film. According to this supercritical reverse phase evaporation method, a vesicle of a monolayer film can be generated, so that a vesicle having an extremely small size can be obtained.

The average particle size of the nucleating agent vesicle is preferably 1/2 or less of the visible light wavelength (400 to 750 nm), more specifically 200 nm to 375 nm or less. The nucleating agent vesicle exists in the resin composition in a state where the outer film of the vesicle is broken and the nano-sized nucleating agent is exposed. By making the particle size of the nucleating agent extremely small as within the above range, it is possible to realize a transparent resin sheet having high transparency by reducing light scattering.

The nucleating agent is not particularly limited as long as it is a substance that is the starting point of crystallization when the resin crystallizes, but for example, a phosphate ester metal salt, a benzoic acid metal salt, a pimelic acid metal salt, and rosin. Examples thereof include metal salts, benzylidene sorbitol, chitocridon, cyanine blue and talc. In particular, in the present invention, it is preferable to use a phosphate ester metal salt, a benzoic acid metal salt, a pimelic acid metal salt, or a rosin metal salt, which can be expected to be transparent.

Examples of phospholipids include phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylic acid, phosphatidylglycerol, phosphatidylinositol, cardiopine, yellow egg lecithin, hydrogenated yellow egg lecithin, soy lecithin, hydrogenated soy lecithin and other glycerophospholipids, and spingo. Examples thereof include sphingolin lipids such as myerin, ceramide phosphoriethanolamine and ceramide phosphorylglycerol.

The crystalline polypropylene resin is not particularly limited, but is a homopolymer of propylene having a pentad fraction (mm mm fraction) of 95% or more, more preferably 96% or more, that is, a highly crystalline homopolymer. It is preferable to use polypropylene resin.

The pentad fraction (mm mm fraction) is a resin composition constituting the transparent resin layer by a 13C-NMR measurement method (nuclear magnetic resonance measurement method) using carbon C (nuclear species) having a mass of 13. It is calculated from a numerical value (electromagnetic wave absorption rate) obtained by resonance at a predetermined resonance frequency, and defines the atomic arrangement, electronic structure, and molecular fine structure in the resin composition, and is a polypropylene resin. The pentad fraction is a ratio in which five propylene units determined by 13C-NMR are lined up, and is used as a measure of crystallinity or stereoregularity. Such a pentad fraction is one of the important factors that mainly determine the scratch resistance of the surface. Basically, the higher the pentad fraction, the higher the crystallinity of the sheet, and therefore the scratch resistance. Is improved.

Hereinafter, a specific example of the configuration of the decorative sheet of the present invention and the method for producing the decorative sheet will be described with reference to FIGS. 1 and 2.

FIG. 1 shows a first embodiment of the decorative sheet 1 of the present invention, and the configuration of the decorative sheet 1 consists of a primer layer 6, a concealing layer 2, a pattern printing layer 3, and a transparent layer from the base material B side to which the decorative sheet 1 is attached. The resin layer 4 and the top coat layer 5 are laminated in this order. Examples of the base material B include wood boards, inorganic boards, and metal plates.

As the primer layer 6, nitrified cotton, cellulose, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyurethane, acrylic, polyester, etc. as a binder can be used alone or appropriately selected from modified products. .. These are not particularly limited in their form such as water-based, solvent-based, and emulsion type. Further, the curing method can be appropriately selected from a one-component type that cures independently, a two-component type that uses a curing agent in combination with the main agent, and a type that cures by irradiation with ultraviolet rays, electron beams, or the like. As a general curing method, a two-component type that cures by combining an isocyanate-based curing agent with a urethane-based main agent is used, and this method has workability, price, and cohesive force of the resin itself. It is suitable from the viewpoint. In addition to the above binders, colorants such as pigments and dyes, extender pigments, solvents, various additives and the like are added. In particular, since the primer layer 6 is located on the backmost surface of the decorative sheet 1, considering that the decorative sheet 1 is wound as a continuous plastic film (web-like), the films are in close contact with each other and are not slippery. Inorganic fillers such as silica, alumina, magnesia, titanium oxide, and barium sulfate may be added in order to prevent blocking such as becoming or not peeling off and to improve the adhesion with the adhesive. The layer thickness is preferably in the range of 0.1 to 3 μm because the purpose is to secure the adhesion to the base material B.

As the concealing layer 2, basically, the material used for the primer layer 6 can be used, but when the concealing property is emphasized, it is preferable to use opaque pigments such as titanium oxide and iron oxide as the pigment. .. Further, in order to further improve the concealing property, it is also preferable to add a metal such as gold, silver, copper or aluminum. In general, flaky aluminum is often added. The concealing layer 2 can be formed by using the above materials by a comma coater, a knife coater, a lip coater, a metal vapor deposition method, a sputtering method, or the like. If the layer thickness is less than 2 μm, the concealing property is insufficient, and if it exceeds 10 μm, the cohesive force of the resin material as the main component is weakened. Therefore, it is appropriate to set the layer thickness to about 2 to 10 μm.

As for the pattern printing layer 3, the same material as the primer layer 6 can be used. Examples of highly versatile pigments include pearl pigments such as condensed azo, insoluble azo, quinacridone, isoindoline, anthraquinone, imidazolone, cobalt, phthalocyanine, carbon, titanium oxide, iron oxide, and mica. The pattern printing layer 3 can be formed by subjecting the transparent resin layer 4 to gravure printing, offset printing, screen printing, flexographic printing, electrostatic printing, ink jet printing, or the like using the above-mentioned materials. Further, apart from the method of applying an ink composed of a mixture of the binder and the pigment to form the pattern printing layer 3, it is also possible to apply a pattern by vapor deposition or sputtering of various metals.

The transparent resin layer 4 contains 90 to 100% by weight of a crystalline polypropylene resin as a main component, and if necessary, an existing heat stabilizer, flame retardant, ultraviolet absorber, light stabilizer, anti-blocking agent, etc. A transparent resin sheet 4 obtained by molding a resin composition containing various additives such as a catalyst scavenger, a colorant, a light scattering agent, and a gloss adjusting agent into a sheet can be used. In particular, in the decorative sheet 1 of the present invention, the peak intensity ratio x calculated by using the above formula 1 from the infrared absorption spectrum measured by Fourier-type infrared spectroscopic measurement by controlling the molding processing conditions is x. It is important to use the transparent resin sheet 4 set to <0.65. At this time, the thickness of the transparent resin sheet 4 is set to 20 to 200 μm. Specific examples of the molding processing conditions include the melting temperature of the resin composition, the temperature conditions such as the extrusion temperature and the roll temperature related to film formation, the transport conditions such as the winding speed of the sheet, and the like, and these temperature conditions and transport. By controlling the conditions, the crystallinity of the transparent resin sheet 4 obtained by adjusting the cooling rate at the time of film formation is adjusted, and the peak intensity ratio x is x <0.65, preferably 0.55 ≦ x. <0.65.

Further, a nucleating agent vesicle is added to the resin composition constituting the transparent resin layer 4.
As a result, the crystallinity of the resin composition can be easily improved, and the transparent resin sheet 4 having extremely excellent transparency can be obtained.

As the heat stabilizer, a phenol-based, sulfur-based, phosphorus-based, hydrazine-based, or the like can be used. As the flame retardant, aluminum hydroxide, magnesium hydroxide and the like can be used. As the ultraviolet absorber, a benzotriazole type, a benzoate type, a benzophenone type, a triandine type and the like can be used. As the light stabilizer, a hindered amine system or the like can be used.

As the top coat layer 5, a polyurethane-based, acrylic-based, acrylic silicon-based, fluorine-based, epoxy-based, vinyl-based, polyester-based, melamine-based, aminoalkyd-based, urea-based, or the like can be appropriately selected and used. The form of the material is not particularly limited to water-based, emulsion, solvent-based and the like. The curing method can also be appropriately selected from a one-component type that cures independently, a two-component type that uses a curing agent in combination with the main agent, and a type that cures by irradiation with ultraviolet rays, electron beams, or the like. In particular, a urethane-based main agent mixed with an isocyanate-based curing agent and cured is suitable from the viewpoints of workability, price, and cohesive force of the resin itself.

Here, the detailed film forming flow of the transparent resin sheet 4 will be described. First, the pellet of the resin composition to which various existing additives are added to the crystalline polypropylene resin as the main component is put into a melt extruder and kneaded while heating to melt the pellet into a liquid. Then, the liquid resin composition is extruded from the T-die provided at the extrusion port toward the cooling roll provided on the downstream side with a predetermined width. At this time, the liquid resin composition extruded from the T-die proceeds to crystallize up to the cooling roll, and the crystallization is completed by coming into contact with the cooling roll. The cooling roll is rotated around the central axis of the roll at a predetermined rotation speed, and the resin composition in contact with the cooling roll becomes a sheet-shaped transparent resin sheet 4, which is conveyed downstream at a predetermined transfer speed. Finally, it is wound on a take-up roll. In the present invention, in order to keep the peak intensity ratio x of the obtained transparent resin sheet 4 within a predetermined range, the temperature of the resin composition extruded from the melt extruder, the temperature of the cooling roll, and the temperature of the cooling roll are used as film forming conditions. It was decided to adjust the sheet transfer speed.

In the decorative sheet 1 of the present embodiment, the material is applied to one surface of the transparent resin sheet 4 formed by the film forming flow in the order of the pattern printing layer 3, the concealing layer 2, and the primer layer 6 by the above method. It is formed by laminating. When the transparent resin layer 4 is provided with the embossed pattern 4a, the transparent resin sheet 4 is pressed using an embossing die roll to apply the embossed pattern 4a to the other surface of the transparent resin sheet 4. Further, the top coat layer 5 is formed on the surface of the embossed pattern 4a to obtain the decorative sheet 1.

In the decorative sheet 1 of the first embodiment, the primer layer 6 is 0.1 to 3.0 μm, the concealing layer 2 is 2 to 10 μm, the pattern printing layer 3 is 20 to 200 μm, and the transparent resin sheet 4 as the transparent resin layer 4 is used. Is preferably 20 to 100 μm, the top coat layer 5 is preferably 3 to 20 μm, and the total thickness of the decorative sheet 1 is preferably in the range of 130 to 500 μm.

FIG. 2 shows a second embodiment of the decorative sheet 1 of the present invention, in which the decorative sheet 1 is composed of a primer layer 6, a raw fabric layer 7, a pattern printing layer 3 from the base material B side to which the decorative sheet 1 is attached. The adhesive layer 8, the transparent resin layer 4, and the top coat layer 5 are laminated in this order. Examples of the fabric B include wood boards, inorganic boards, and metal plates.

As the primer layer 6, the pattern printing layer 3, the transparent resin layer 4, and the top coat layer 5, those having the same configuration as that of the first embodiment can be used.

The raw fabric layer 7 includes paper such as thin leaf paper, titanium paper, resin-impregnated paper, polyethylene, polypropylene, polybutylene, polystyrene, polycarbonate, polyester, polyamide, ethylene-vinyl acetate polymer, polyvinyl alcohol, synthetic resin such as acrylic, or synthetic resin. , Foams of these synthetic resins, ethylene-propylene polymer rubber, ethylene-poropylene-diene copolymer rubber, styrene-butadiene copolymer rubber, styrene-isoprene-styrene block copolymer rubber, rubber such as polyurethane, organic or inorganic It can be arbitrarily selected and used from based non-woven fabrics, synthetic papers, metal foils such as aluminum, iron, gold and silver. When the raw fabric resin sheet 7 containing a polyolefin resin as a main component is used as the raw fabric layer 7, since the surface is inert, both sides of the raw fabric resin sheet 7 are subjected to corona treatment, plasma treatment, and ozone. It is preferable to carry out the surface activation treatment by treatment, electron beam treatment, ultraviolet treatment, heavy chromium acid treatment and the like. Further, a primer layer 6 may be provided between the raw resin sheet 7 and the pattern printing layer 3 in order to ensure sufficient adhesion. Further, when it is desired to impart concealing property to the decorative sheet 1, the concealing property may be provided by providing the concealing layer 2 or adding an opaque pigment or the like to the raw resin sheet 7 itself.

The adhesive layer 8 can be selected from acrylic type, polyester type, polyurethane type and the like. Generally, a two-component type material using a urethane-based polyol as a main agent and an isocyanate as a curing agent is used because of its high workability, price, and cohesive force.

In the decorative sheet 1 of the present embodiment, first, both sides of the raw fabric resin sheet 7 as the raw fabric layer 7 are subjected to corona treatment, and the pattern printing layer 3 and the primer are applied to one surface of the raw fabric resin sheet 7. The layers 6 are laminated in order. Then, the transparent resin sheet 4 as the transparent resin layer 4 formed by the film forming flow and the raw resin sheet 7 on which the pattern printing layer 3 and the primer layer 6 are laminated are sandwiched between the adhesive layer 8. Through, a laminated film is formed by adhering and laminating by using a method applying heat pressure, an extrusion laminating method, a dry laminating method, or the like. At this time, when the embossed pattern 4a is provided on the surface of the transparent resin layer 4, the embossed pattern 4a is formed on the laminated film by a method using heat pressure or a method using a cooling roll having irregularities formed therein. Will be done. Finally, the top coat layer 5 is laminated on the surface of the transparent resin layer 4 of the laminated film to obtain the decorative sheet 1.

In the decorative sheet 1 of the second embodiment, the raw fabric layer 7 is 100 μm to 250 μm in consideration of printing workability, cost, etc., the adhesive layer 8 is 1 μm to 20 μm, the transparent resin layer 4 is 20 μm to 200 μm, and the top coat. The layer 5 is preferably 3 μm to 20 μm, and the total thickness of the decorative sheet 1 is preferably in the range of 130 μm to 500 μm.

The decorative sheet 1 of the present invention has a peak intensity calculated by using Equation 1 from the absorption spectrum obtained by Fourier-type infrared spectroscopic measurement for the transparent resin sheet 4 as the transparent resin layer 4 as in the above embodiment. By setting the value of the ratio x within the range of x <0.65, more preferably 0.55 ≦ x <0.65, the decorative sheet has excellent post-processability as compared with the conventional decorative sheet. 1 can be provided.

Further, the decorative sheet 1 of the present invention is formed into a vesicle provided with a nano-sized nucleating agent, more specifically, an outer film of a single-layer film, with respect to the resin composition constituting the transparent resin sheet 4. Since the nucleating agent vesicle containing the nucleating agent is added, high dispersibility of the nucleating agent is realized in the resin composition, and the crystallinity of the resin composition is improved by the nucleating agent. It is possible to provide a decorative sheet 1 provided with a transparent resin sheet 4 having high transparency.

Hereinafter, specific examples of the decorative sheet 1 and the method for producing the decorative sheet 1 of the present invention will be described.

<Examples 1 to 4, Comparative Examples 1 to 4>
In Examples 1 to 4 and Comparative Examples 1 to 4 of the present invention, a hindered phenol-based antioxidant (Irganox 1010, manufactured by Ciba Specialty Chemicals) was added to 500 PPM and benzo with respect to a highly crystalline homopolypropylene resin. Triazole-based UV absorber (Chinubin 328, manufactured by Ciba Specialty Chemicals) 2000PPM, hindered amine-based photostabilizer (Kimasorb 944, manufactured by Ciba Specialty Chemicals) 2000PPM, and phosphate ester metal salt-based nucleating agent (Adekastab NA-). 21. Made by ADEKA Corporation) By performing the above film-forming flow of the resin composition containing 1000PPM using a melt extruder, a transparent resin sheet 4 having a thickness of 100 μm used as the transparent resin layer 4 is formed. do. For each of the obtained transparent resin sheets 4, the extrusion temperature, the roll temperature, and the sheet transfer speed at the time of film formation and the peak intensity ratio x of each of the obtained transparent resin sheets 4 are shown in Table 1.

<Examples 5 and 6>
In Examples 5 and 6 of the present invention, a hindered phenol-based antioxidant (Irganox 1010, manufactured by Ciba Speciality Chemicals) 500PPM and a benzotriazole-based ultraviolet absorber (Chinubin) are used for the highly crystalline homopolypropylene resin. 328, manufactured by Ciba Speciality Chemicals Co., Ltd.) 2000PPM, hindered amine-based photostabilizer (Kimasorb 944, manufactured by Ciba Speciality Chemicals Co., Ltd.) 2000PPM, and resin containing the nucleating agent Vesicle 1000PPM, which is manufactured as described above using a melt extruder. By performing the film flow, a transparent resin sheet 4 having a thickness of 100 μm to be used as the transparent resin layer 4 is formed.
For each of the obtained transparent resin sheets 4, the extrusion temperature, the roll temperature, and the sheet transfer speed at the time of film formation and the peak intensity ratio x of each of the obtained transparent resin sheets 4 are shown in Table 1.

The nucleating agent vesicle is a high-pressure stainless steel in which 100 parts by weight of methanol, 82 parts by weight of a phosphate ester metal salt-based nucleating agent (ADEKA STAB NA-21, manufactured by ADEKA), and 5 parts by weight of phosphatidylcholine are maintained at 60 ° C. It is placed in a container, sealed, and carbon dioxide is injected so that the pressure becomes 20 MPa to bring it into a supercritical state, and then 100 parts by weight of ion-exchanged water is injected while vigorously stirring and mixing. After stirring for 15 minutes while maintaining the temperature and pressure inside the container, carbon dioxide is discharged and the pressure is returned to atmospheric pressure to enclose the phosphate ester metal salt-based nucleating agent in the vesicle provided with the outer membrane of the single-layer membrane. Obtain the phosphoric acid vesicles that have been made. The particle size of the obtained nucleating agent vesicle was set to a size of 0.05 to 0.8 μm.

Subsequently, both sides of the transparent resin sheets 4 of Examples 1 to 6 and Comparative Examples 1 to 4 obtained by the above method were subjected to corona treatment to make the surface wet to 40 dyn / cm or more, and the transparent resin sheet 4 was used. A two-component curable urethane ink (V180, manufactured by Toyo Ink Mfg. Co., Ltd.) is used to print a pattern on one surface to form a pattern printing layer 3, and the pattern printing layer 3 is superposed on the pattern printing layer 3 to have a concealing property. A liquid effect type urethane ink (V180, manufactured by Toyo Ink Mfg. Co., Ltd.) was applied at a coating amount of 6 g / m ² to form a concealing layer 2. Further, a two-component curable urethane ink (PET-E, Regiuser, manufactured by Dainichiseika Co., Ltd.) was applied over the concealing layer 2 at a coating amount of 1 g / m ² to form a primer layer 6. Then, the other surface of the transparent resin sheet 4 is pressed with an embossing die roll to apply an embossed pattern 4a, and the surface of the embossed pattern 4a is coated with a two-component curable urethane top coat (W184, large). A decorative sheet 1 having a layer thickness of 110 μm shown in FIG. 1 was obtained by applying (manufactured by Nippon Ink Co., Ltd.) at a coating amount of 3 g / m ² .

The decorative sheets 1 of Examples 1 to 6 and Comparative Examples 1 to 4 obtained by the above method were subjected to a V-groove bending appropriateness test and a haze value measurement test to evaluate post-workability.

<V-groove bending suitability test>
The detailed method of the V-groove bending suitability test will be described below. First, each of the decorative sheets 1 of Examples 1 to 7 and Comparative Examples 1 to 3 obtained by the above method is bonded to one surface of the medium density fiberboard (MDF) as the base material B with a urethane system. A boundary where the base material B and the decorative sheet 1 are stuck together with a V-shaped groove so that the decorative sheet 1 on the opposite side is not scratched with respect to the other surface of the base material B. Put up to. Next, the base material B is bent up to 90 degrees along the V-shaped groove so that the surface of the decorative sheet 1 is mountain-folded, and the bent portion of the surface of the decorative sheet 1 is not whitened or cracked. This is observed using an optical microscope to evaluate the superiority or inferiority of post-workability. The evaluation was performed in the following three stages.
○: No whitening or cracks were observed. ×: Whitening or cracks that were unacceptable as a decorative sheet were observed.

<Haze value measurement test>
Here, the haze value is the integrated value (total light transmittance) of all the light rays emitted from the other surface when the light incident from one surface of the object is emitted to the other surface from the other surface. The value obtained by subtracting the integrated value (straight transmittance) of only the linear component from the emitted light rays (diffusion transmittance) is divided by the total light transmittance and expressed as a percentage. The smaller the value, the more transparent. Indicates that the sex is high. This haze value depends on the internal haze determined by the internal state of the object such as the degree of crystallinity and the spherulite size in the crystal part, and the external haze determined by the surface condition of the object such as the presence or absence of unevenness on the entrance surface and the exit surface. It is decided. In the present invention, when simply referred to as a haze value, it means a value determined by an internal haze and an external haze. In this example, the haze value measurement test was performed on each transparent resin sheet using a haze value measurement tester (manufactured by Nippon Denshoku Co., Ltd .; NDH2000). Perform blank measurement in advance with nothing attached to the sample holder. In the measurement of each transparent resin sheet, the sample was attached to the sample holder and the sample permeation measurement was performed under the same conditions as the blank measurement, and the ratio of the sample permeation measurement and the blank measurement was calculated as a percentage as the haze value. Then, in the present invention, those having a haze value of less than 15% were judged to be acceptable.

Table 1 shows the results of the above V-groove bending suitability test and haze value measurement test.

As shown in Table 1, the evaluation test results of each decorative sheet 1 show that each of the decorative sheets 1 of Examples 1 to 6 in which the peak intensity ratio x of the transparent resin sheet 4 is 0.55 ≦ x <0.65. And it is clear that the decorative sheet 1 of Comparative Example 1 in which x = 0.53 has excellent post-workability, with no whitening or cracks observed in the V-groove bending suitability test. became. In Comparative Example 1 in which the peak intensity ratio x was x <0.53, film formation could not be performed. Regarding the decorative sheet 1 of Comparative Examples 3 and 4 in which the peak intensity ratio x was x> 0.65, whitening / cracking that was unacceptable as a decorative sheet was observed.

The haze value was 15% or less in both Examples 1 to 6 and Comparative Examples 2 to 4, and had transparency suitable for the decorative sheet 1. In particular, in the decorative sheets 1 of Examples 5 and 6 to which the nucleating agent vesicle was added, the haze value was smaller than that of the decorative sheets 1 of Comparative Examples 1 and 2 having the same peak intensity ratio x. It can be seen that it has better transparency. It is considered that this is because the dispersibility of the nucleating agent added to the resin composition is improved, so that the scattering of light is reduced and the transparency is improved.

From the above results, the peak intensity ratio x of the transparent resin sheet 4 as the transparent resin layer 4 is set to x ≦ 0.65, preferably 0.55 ≦ x ≦ 0.65, so that the post-workability and transparency are achieved. It has been clarified that the decorative sheet 1 having excellent properties can be obtained.

Further, by adding the nucleating agent vesicle to the transparent resin sheet 4, the dispersibility of the nucleating agent in the transparent resin sheet 4 is improved, and the decorative sheet 1 having extremely high transparency and excellent design is achieved. It became clear that

The decorative sheet 1 and the method for producing the decorative sheet 1 of the present invention are not limited to the above-described embodiments and examples, and various modifications can be made as long as the characteristics of the present invention are not impaired.

1 Decorative sheet 2 Concealing layer 3 Picture printing layer 4 Transparent resin layer, transparent resin sheet 4a Embossed pattern 5 Top coat layer 6 Primer layer 7 Original fabric layer, Original fabric resin sheet 8 Adhesive layer

Claims (3)

A decorative sheet or a concealing layer comprising at least a concealing layer, a pattern printing layer , a transparent resin layer containing 90 to 100% by weight of a crystalline polypropylene resin as a main component, and a top coat layer in this order, and crystals. A transparent resin layer containing 90 to 100% by weight of a polypropylene resin as a main component and a top coat layer are provided in this order at least, and an embossed pattern is provided on the surface of the transparent resin layer on the top coat layer side. It ’s a decorative sheet ,
The value of the peak intensity ratio x calculated by using the following formula 1 from the absorption spectrum obtained by the Fourier type infrared spectroscopic measurement of the transparent resin sheet as the transparent resin layer is 0.55 ≦ x <0.65. And
The concealing layer is an opaque layer containing aluminum .
A decorative sheet characterized by forming the transparent resin sheet by adding a nano-sized nucleating agent .
Here, in Equation 1, I997 represents a peak intensity value of wavenumber 997 cm ^-1 , I938 represents a peak intensity value of wavenumber 938 cm ^-1 , and I973 represents a peak intensity value of wavenumber 973 cm ^-1 .

The decorative sheet according to claim 1, wherein the transparent resin sheet is formed by adding a nano-sized nucleating agent vesicle containing a nucleating agent to a vesicle having an outer film of a single-layer film. .. A decorative sheet or a concealing layer comprising at least a concealing layer, a pattern printing layer , a transparent resin layer containing 90 to 100% by weight of a crystalline polypropylene resin as a main component, and a top coat layer in this order, and crystals. A transparent resin layer containing 90 to 100% by weight of a polypropylene resin as a main component and a top coat layer are provided in this order at least, and an embossed pattern is provided on the surface of the transparent resin layer on the top coat layer side. It is a method of manufacturing decorative sheets .
To the crystalline polypropylene resin, a nucleating agent vesicle containing a nucleating agent is added to a vesicle having an outer film of a single-layer film by a supercritical reverse-phase evaporation method, and the vesicle is obtained by Fourier-type infrared spectroscopic measurement. A transparent resin sheet as the transparent resin layer was formed so that the peak intensity ratio x calculated from the absorption spectrum using the following formula 1 was 0.55 ≦ x <0.65.
A method for producing a decorative sheet, which comprises forming the concealing layer with an opaque layer containing aluminum.

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