Method for manufacturing cosmetic sheet and cosmetic sheet

Abstract

To provide a method for manufacturing a decorative sheet and the decorative sheet, the method for manufacturing a decorative sheet comprising irradiating a decorative sheet with a laser beam to form an embossed portion having irregularities thereby making it possible to eliminate embossing by using so-called an embossing roll.SOLUTION: The method comprises a first step of sequentially forming a printed picture layer 30 on which a picture is printed and a transparent polypropylene layer 40 on a surface of a colored film layer 20, a second step of irradiating a surface of the transparent polypropylene layer 40 with a laser beam 71 to form an embossed portion 41 having irregularities synchronized with the picture of the printed picture layer 30, a third step of applying a corona treatment to the surface on which the embossed portion 41 is formed, a fourth step of applying a transparent resin to the surface on which the corona treatment is applied to form a topcoat layer, and a fifth step of forming a primer layer 60 on a back surface of the colored film layer 20. A CO2 laser may be used as the laser beam 71.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a decorative sheet and a decorative sheet that are used, for example, indoors, pasted on the surface of fittings and building materials, and used by matching the patterns of fittings and building materials for each house or room. By irradiating the surface of a transparent polypropylene layer with laser light to form an embossed portion having irregularities, it is possible to provide a method for manufacturing a decorative sheet capable of eliminating the shaping of embossing using a so-called embossing roll.

Background Art

[0002] Conventionally, decorative sheets used indoors are pasted on the surfaces of fittings, building materials, etc. They are used by matching the patterns of fittings and building materials for each house or room. Among these, decorative sheets used there are mainly those made of olefin-based materials in recent years due to the problem of gas during combustion. In order to protect the pattern from surface wear, the decorative sheet is made into multiple layers, and a transparent olefin sheet is laminated on a printed one on a colored olefin sheet, which is widely used.

[0003] These decorative sheets mainly use those with wood grain patterns or abstract patterns. However, simply printing a pattern on a colored olefin sheet does not result in a flat sheet with the texture of real wood or stone. For this reason, an uneven shape imitating wood grain conduits is imparted to the surface of the transparent olefin sheet to be laminated thereon, or high-gloss and low-gloss portions are formed on the outermost surface protection layer (top coat) imitating wood grain conduits to reproduce a more realistic design. To impart an uneven shape to the surface, it is almost always the case that an embossing roll manufactured using metal corrosion or the like on the sheet surface is used (see paragraphs

[0023] to

[0026] and FIG. 4 of Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] When preparing the above-described conventional embossing roll for use in a decorative sheet for building materials, it is necessary to prepare a roll with a diameter that is sufficiently long so that the repeating design of the conduit does not become monotonous, with a width exceeding 1 m such as 3 feet and 4 feet, which are mainly used in building materials. There was a first problem in that a considerable number of types and amounts of embossing rolls had to be produced in order to reproduce those embossing rolls in various tree species.

[0006] In addition, when the embossing roll was damaged, it was necessary to reprint the roll with the same design, or when manufacturing the sheet, those embossing rolls had to be replaced for each embossing of the sheet. There was also a second problem in that it was necessary to pay sufficient attention to a considerable amount of time and labor, as well as safety in handling heavy objects. In view of the above-described first and second problems, the present invention irradiates the surface of a transparent polypropylene layer with laser light to form an embossed portion having irregularities, thereby enabling the elimination of the embossing shaping using a so-called embossing roll.

[0007] As a result, the cost, time, and replacement of manufacturing the embossing roll can be eliminated. In addition, it is also possible to change the embossing pattern during sheet production, or to synchronize the embossing by means of a pattern (pitch) or random shape that is not affected by the roll diameter and has a length, or by reading a pattern.

MEANS FOR SOLVING THE PROBLEMS

[0008] A method for manufacturing a decorative sheet according to an aspect of the present invention includes a first step of sequentially forming a printed pattern layer with a pattern printed thereon and a transparent polypropylene layer on the surface of a colored film layer, and irradiating the surface of the transparent polypropylene layer with laser light to form the pattern of the printed pattern layer toHomology make a second step of forming an embossed portion that is uneven, a third step of subjecting the surface on which the embossed portion is formed to a corona treatment, and applying a transparent resin to the surface that has been subjected to the corona treatment having unevenness that synchronizes with the embossed portion a fourth step of forming a top coat layer, and a fifth step of forming a primer layer on the back surface of the colored film layer, characterized by including these steps.

[0009] Also, the method for manufacturing a cosmetic sheet according to one aspect of the present invention is characterized in that the laser light uses a CO2 laser. A cosmetic sheet according to one aspect of the present invention is a cosmetic sheet in which a printed pattern layer with a pattern printed thereon and a transparent polypropylene layer are sequentially formed on the surface of a colored film layer, and a primer layer is formed on the back surface of the colored film layer. On the surface of the transparent polypropylene layer, there are unevenness formed by irradiating laser light, and the pattern of the printed pattern layer to is synchronized with the embossed portion, a corona treatment portion obtained by subjecting the surface having the embossed portion to a corona treatment, and applying a transparent resin to the surface having the corona treatment portion having unevenness synchronized with the embossed portion and a top coat layer, characterized by having these layers.

Advantages of the Invention

[0010] According to one aspect of the present invention, by irradiating laser light on the surface of the transparent polypropylene layer to form an embossed portion that is uneven, it is possible to eliminate the embossing using a so-called embossing roll.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0012] (Embodiment 1) Embodiment 1 of the present invention will be described below with reference to the drawings. Here, the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, etc. are different from the actual ones. Further, the embodiments shown below are examples of the configurations for embodying the technical idea of the present invention, and the technical idea of the present invention is not limited to the following in terms of the material, shape, structure, etc. of the components. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.

[0013] (Cosmetic sheet 10 according to Embodiment 1) In FIG. 1, reference numeral 10 denotes a cosmetic sheet. Although not shown, for example, it is used indoors and is pasted on the surfaces of fixtures (interior doors, entrance storage), building materials (partitions, moldings, lintels, window frames, door frames), etc., and is used by matching the patterns of the fixtures and building materials for each house or room. As shown in FIG. 1, the cosmetic sheet 10 includes the following layers, and each layer is formed in order from (1).

[0014] Note that the following (1) to (5) will be described later. (1) Colored film layer 20 (2) Printed pattern layer 30 (3) Transparent polypropylene layer 40 (4) Top coat layer 50 (5) Primer layer 60 Note that the layer structure of the cosmetic sheet 10 is not limited to the above (1) to (5). Although not shown, a corona treatment portion obtained by subjecting the surface of the transparent polypropylene layer 40 formed with the embossed portion 41 described later to corona treatment is formed.

[0015] Note that each layer of the cosmetic sheet 10 is not limited to the above (1) to (5). Although not shown, a substrate may be adhered to the back surface side of the primer layer 60 to form a decorative board, or an adhesive layer and a release paper may be added to the back surface side of the primer layer 60 to form a cosmetic tack sheet. Further, on the surface of the transparent polypropylene layer 40, as shown in FIG. 2, an embossed portion 41, which is unevenness synchronized with the pattern of the printed pattern layer 30, is formed by laser light 71 irradiated from a laser processing machine 70.

[0016] (Main features of the decorative sheet 10) The main features of the decorative sheet 10 according to the first embodiment are as follows. (1) The manufacturing method of the decorative sheet 10 according to the first embodiment includes the following steps, as shown in FIG. 3. (1-1) First step The first step is a step of sequentially forming a printed pattern layer 30 with a pattern printed thereon and a transparent polypropylene layer 40 on the surface of the colored film layer 20. (1-2) Second step The second step is a step of forming an embossed portion 41, which is unevenness synchronized with the pattern of the printed pattern layer 30, by irradiating the surface of the transparent polypropylene layer 40 with laser light 71.

[0017] (1-3) Third step The third step is a step of performing a corona treatment on the surface on which the embossed portion 41 is formed. (1-4) Fourth step The fourth step is a step of applying a transparent resin to the surface subjected to the corona treatment to form a top coat layer. (1-5) Fifth step The fifth step is a step of forming a primer layer 60 on the back surface of the colored film layer 20.

[0018] According to the first embodiment, it is possible to eliminate the embossing using a so-called embossing roll. As a result, the cost, time, and replacement of manufacturing the embossing roll can be eliminated. In addition, it is also possible to change the pattern of the embossed portion 41 during the production of the decorative sheet 10, or to synchronize the embossing with a pattern (pitch) of a length that is not affected by the roll diameter, a random shape, or a pattern reading.

[0019] Furthermore, according to the first embodiment, since the surface of the transparent polypropylene layer 40 formed with the embossed portion 41 is subjected to corona treatment, the wettability is generally improved, and at the same time, printing characteristics, coating characteristics, bonding characteristics, etc. can be improved. In addition to the corona treatment, surface treatment such as pretreatment for coating may be performed.

[0020] (2) Since the manufacturing method of the decorative sheet 10 according to the first embodiment uses a CO 2 laser, the transparent polypropylene layer 40 is also suitable for laser processing. Compared with the other two types of processing machines such as a solid-state laser processing machine and a semiconductor laser processing machine, it is inexpensive and can reduce the manufacturing cost of the decorative sheet 10.

[0021] (3) According to the decorative sheet 10 according to the first embodiment, the embossing by using a so-called embossing roll can be abolished.

[0022] (Colored film layer 20) As shown in FIG. 1, the colored film layer 20 is located on the surface of the primer layer 60 and is formed by using a printing method, and is mainly provided for the purpose of imparting concealability. The colored film layer 20 is, for example, printed with a two-component urethane resin by a gravure printing method.

[0023] (Printed pattern layer 30) As shown in FIG. 1, the printed pattern layer 30 is located on the surface of the colored film layer 20 and is formed by using a printing method, and is provided for the purpose of imparting design properties to the decorative sheet 10. The printed pattern layer 30 is, for example, printed with a urethane resin pattern by a gravure printing method. As an example of the printing method, the gravure printing method is illustrated, but it is not limited thereto. For example, various printing methods such as an offset printing method, a relief printing method, a flexographic printing method, a screen printing method, an inkjet printing method, and an electrostatic printing method can be applied.

[0024] The pattern type of the printed pattern layer 30 is arbitrary depending on the purpose of use, the preferences of the user, etc. For example, wood grain patterns, stone grain patterns, abstract patterns, etc. are common. The pattern type is not limited to the types exemplified above, and for example, full-surface solid printing or the like may be used. As the printing ink used for the printing method, for example, vinyl chloride-based inks (cyan, magenta, yellow) are used. Note that, although urethane-based resins were exemplified as the printing ink, it is not limited thereto, and for example, coloring agents such as organic or inorganic dyes or pigments may be used, or it may be a material dispersed in a binder made of a synthetic resin or the like together with appropriate additives such as fillers, tackifiers, plasticizers, stabilizers, dispersants, defoaming agents, leveling agents, surfactants, drying agents, etc., solvents or diluents.

[0025] (Transparent polypropylene layer 40) The transparent polypropylene layer 40 serves as a support for the decorative sheet 10 and is made of a transparent olefin sheet. As shown in FIG. 2, the transparent polypropylene layer 40 is manufactured in two types and three layers in the order of a transparent skin layer 42, a transparent core layer 43 made of transparent polypropylene, and a transparent skin layer 42. The transparent skin layer 42 is preferably formed by adding a dispersant as a nano-sized additive to a transparent polypropylene-based thermoplastic resin. In addition to the dispersant as a nano-sized additive, it is desirable to add an inorganic filler to the transparent skin layer 42.

[0026] Note that, although two types and three layers were exemplified as the transparent polypropylene layer 40, it is not limited thereto, and it may be a single layer. Even when the transparent polypropylene layer 40 is a single layer, it is preferably formed by adding a dispersant as a nano-sized additive, or by adding an inorganic filler in addition to the dispersant as a nano-sized additive.

[0027] (Embossed portion 41) On the surface of the transparent polypropylene layer 40, as shown in FIG. 2, an embossed portion 41, which is unevenness synchronized with the pattern of the printed pattern layer 30, is formed by laser light 71 irradiated from a laser processing machine 70. The portion irradiated with the laser light 71 becomes a concave portion, and the flat surface of the transparent polypropylene layer 40 other than that becomes a convex portion.

[0028] The concave portions of the embossed portion 41 are formed in a fine groove shape, and the cross-sectional shape of the groove is formed in a rectangle, for example, as shown in FIG. 2. Although a rectangle is exemplified as the cross-sectional shape of the groove, the present invention is not limited thereto. Although not shown, for example, it may be formed in a V shape or a U shape.

[0029] The laser processing machine 70 uses, for example, a CO 2 laser (carbon dioxide laser). For example, the case where the pattern of the printed pattern layer 30 is a "wood grain pattern" will be described. The laser processing machine 70 reads, for example, "wood grain conduit-like" data synchronized with the "wood grain pattern" of the printed pattern layer 30, and irradiates the surface of the transparent polypropylene layer 40 with laser light 71 based on the data. As a result, a "wood grain conduit-like" embossed portion 41 synchronized with the "wood grain pattern" of the printed pattern layer 30 is formed on the surface of the transparent polypropylene layer 40.

[0030] (Top coat layer 50) The top coat layer 50, also referred to as a top coat, is located on the surface side of the transparent polypropylene layer 40 as shown in FIG. 1, and is formed by using a printing method and provided for the purpose of imparting surface physical properties such as abrasion resistance and water resistance. As the top coat layer 50, an acrylic two-component curable resin (acrylic urethane resin manufactured by DIC Graphic Co., Ltd.) is applied to the surface of the transparent polypropylene layer 40 on which the embossed portion 41 is formed so as to have a thickness of 6 μm.

[0031] Furthermore, the top coat layer 50 is subjected to an antiviral treatment. As an antiviral treatment, an antiviral agent is added to the top coat layer 50. As the antiviral agent, for example, a silver-based inorganic additive (Bioside TB-B100) manufactured by Taisho Technos Co., Ltd. carrying silver ions is used.

[0032] (Corona treatment) Also, prior to the formation of the top coat layer 50, the surface of the transparent polypropylene layer 40 on which the embossed portion 41 is formed is subjected to corona treatment, although not shown in the figure. A corona treatment portion is formed. As a result, the top coat layer 50 is located on the corona treatment portion. By corona treatment, wettability is generally improved, and at the same time, printing characteristics, coating characteristics, bonding characteristics, etc. can be improved. In addition to corona treatment, surface treatment such as pre-treatment of coating may be performed.

[0033] (Primer layer 60) As shown in FIG. 1, the primer layer 60 is located on the back side of the transparent polypropylene layer 40 and mainly aims to improve adhesiveness. In addition to improving adhesiveness, the functions of the primer layer 60 also include surface stabilization after surface treatment, corrosion prevention of the metal surface, imparting adhesiveness, preventing deterioration of the adhesive, etc. The primer layer 60 is formed by coating a urethane-based resin so that the solid content is 1 g / m 2 by, for example, the gravure printing method.

[0034] (Transparent core layer 43) In the drawing, the transparent polypropylene layer 40 is represented as if the transparent core layer 43 and the transparent skin layer 42 form separate layers, but in reality, the transparent core layer 43 and the transparent skin layer 42 are continuous and are a single-layer sheet without an interface. For the transparent core layer 43, for example, a material obtained by blending a weather-resistant agent with a transparent polypropylene resin is used.

[0035] (Transparent skin layer 42) In the transparent skin layer 42, in addition to a dispersant as a nano-sized additive, an inorganic filler is added, and a transparent polypropylene resin is used. Transparent skin layer 42: Transparent core layer 43: The transparent skin layer 42 is co-extruded so that the thickness ratio is 0.5:9:0.5 to produce a transparent polypropylene layer 40 with a total thickness of 50 μm.

[0036] The total thickness of the two types of three layers, namely the transparent skin layer 42, the transparent core layer 43, and the transparent skin layer 42, is made to match the thickness of the single-layer transparent polypropylene layer 40, for example, 70 μm. Of course, although two types of three layers are exemplified, it is not limited thereto, and the transparent polypropylene layer 40 may be a single layer.

[0037] (Resin material of the transparent core layer 43) Examples of the resin material constituting the transparent core layer 43 include thermoplastic resins. There are no particular restrictions on the thermoplastic resin, and the same materials as those of the thermoplastic resins conventionally used as the base material layer or the like in the conventional cosmetic sheet 10 can be used. Examples of the thermoplastic resin include polyolefin resins such as polyethylene, polypropylene, polymethylpentene, polybutene, ethylene-propylene copolymer, ethylene-α-olefin copolymer, and propylene-α-olefin copolymer; polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polytetramethylene terephthalate, polyethylene naphthalate, polyethylene terephthalate-isophthalate copolymer, 1,4-cyclohexanedimethanol copolymerized polyethylene terephthalate, polyarylate, and polycarbonate; olefin-based copolymer resins such as ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-(meth)acrylic acid (ester) copolymer, and ethylene-unsaturated carboxylic acid copolymer metal neutralized product (ionomer); acrylic resins such as poly(meth)acrylonitrile, polymethyl (meth)acrylate, polyethyl (meth)acrylate, polybutyl (meth)acrylate, and polyacrylamide; polyamide resins such as 6-nylon, 6,6-nylon, and 6,10-nylon; styrene resins such as polystyrene, AS resin, and ABS resin; vinyl resins such as polyvinyl chloride, polyvinyl acetate, polyvinyl alcohol, polyvinyl acetal, and polyvinyl butyral; fluorine-based resins such as polyvinyl fluoride, polyvinylidene fluoride, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, and ethylene-perfluoroalkyl vinyl ether copolymer; or a mixture, copolymer, composite, laminate, etc. of two or more of them can be used.

[0038] In particular, in view of the increasing social concern about environmental problems in recent years, it is not preferable to use a thermoplastic resin containing chlorine (halogen) such as polyvinyl chloride resin as the thermoplastic resin, and it is preferable to use a non-halogen-based thermoplastic resin. In particular, from the viewpoints of various physical properties, processability, versatility, economy, etc., it is most preferable to use polyester resins (amorphous or biaxially stretched) or polyolefin resins, especially polyolefin resins, as non-halogen-based thermoplastic resins. For example, as the polyolefin resin, it is preferable to use a polypropylene resin containing 30% by mass or more and 100% by mass or less of a highly crystalline homopolypropylene resin having an isotactic pentad fraction (mmmm fraction) of 95% or more.

[0039] In the transparent core layer 43, if necessary, for example, one or more selected from various additives such as fillers, ultraviolet absorbers, light stabilizers, heat stabilizers, antioxidants, antistatic agents, lubricants, flame retardants, antibacterial agents, antifungal agents, antifriction agents, light scattering agents, and gloss modifiers may be added.

[0040] (Resin material of the transparent skin layer 42) Examples of the resin material constituting the transparent skin layer 42 include thermoplastic resins. The thermoplastic resin is not particularly limited, and the same resin material as that of the transparent core layer 43 can be used.

[0041] (Additives of nano size etc. (nucleating agent)) The transparent skin layer 42 contains an inorganic filler in addition to a dispersant as an additive of nano size, and is hereinafter also referred to as a "nano-sized nucleating agent". The nano-sized nucleating agent is preferably added to the polypropylene resin in the form of a nucleating agent vesicle encapsulated in a vesicle having an outer membrane of a single-layer film and used. Further, in the first embodiment, the nucleating agent in the resin constituting the transparent skin layer 42 may be encapsulated in a vesicle with a part of the nucleating agent exposed. Since the transparent skin layer 42 contains a nucleating agent, the crystallinity can be improved, and the scratch resistance (scratch resistance) of the cosmetic sheet 10 can be improved.

[0042] (Particle size of the nano-sized nucleating agent) The nano-sized nucleating agent preferably has an average particle diameter of 1 / 2 or less of the wavelength region of visible light. Specifically, since the wavelength region of visible light is 400 nm or more and 750 nm or less, the average particle diameter is preferably 375 nm or less.

[0043] Since the nano-sized nucleating agent has an extremely small particle diameter, the number and surface area of the nucleating agents present per unit volume increase in inverse proportion to the cube of the particle diameter. As a result, the distance between each nucleating agent particle becomes close. When crystal growth occurs from the surface of one nucleating agent particle added to the resin, the end of the growing crystal immediately contacts the end of the crystal growing from the surface of another nucleating agent particle adjacent to the one nucleating agent particle, and the growth of each crystal is inhibited by the mutual inhibition of the growth of the crystal ends, and the growth of each crystal stops. Therefore, the average particle diameter of spherulites in the crystalline part of the crystalline resin can be reduced, for example, the spherulite size can be reduced to 1 μm or less.

[0044] As a result, a high-hardness resin film with a high degree of crystallinity can be obtained, and since the stress concentration between spherulites generated during bending processing is efficiently dispersed, a resin film that suppresses cracking and whitening during bending processing can be realized.

[0045] When the nucleating agent is simply added, the nucleating agent in the resin undergoes secondary aggregation, resulting in an increase in particle size. On the other hand, when the nucleating agent vesicle is added, the dispersibility in the resin is improved, so the number of crystal nuclei with respect to the amount of the added nucleating agent increases significantly as compared with the case of simply adding the nucleating agent. For this reason, the average particle diameter of spherulites in the crystalline part of the resin becomes smaller, and the occurrence of cracking and whitening during bending processing can be suppressed. Therefore, by adding the nucleating agent vesicle, the degree of crystallinity can be further increased, and it becomes possible to better balance the improvement of the elastic modulus and processability.

[0046] The transparent skin layer 42 is formed of, for example, a resin material to which a nucleating agent is added in a range preferably of 0.05 parts by mass or more and 0.5 parts by mass or less, more preferably 0.1 parts by mass or more and 0.3 parts by mass or less, based on 100 parts by mass of the polypropylene resin as the main component. When using a nucleating agent vehicle, the amount of the nucleating agent added to the resin material is the amount added in terms of the nucleating agent in the nucleating agent vehicle.

[0047] When the amount of the nucleating agent added is less than 0.05 parts by mass, the crystallinity of the polypropylene may not be sufficiently improved, and the scratch resistance of the transparent skin layer 42 may not be sufficiently improved. Also, when the amount of the nucleating agent added exceeds 0.5 parts by mass, due to an excessive number of crystal nuclei, the spherulite growth of the polypropylene is conversely inhibited, and as a result, the crystallinity of the polypropylene may not be sufficiently improved, and the scratch resistance of the transparent skin layer 42 may not be sufficiently improved. Here, the "main component" refers to a resin material that occupies 50% by mass or more of the resin material constituting the transparent skin layer 42.

[0048] (Method for nanosizing the nucleating agent) Also, as a method for nanosizing the nucleating agent, for example, a solid-phase method in which mainly mechanical pulverization is performed on the nucleating agent to obtain nano-sized particles, a liquid-phase method in which nano-sized particle synthesis or crystallization is performed in a solution in which the nucleating agent or the nucleating agent is dissolved, a gas-phase method in which nano-sized particle synthesis or crystallization is performed from a gas or vapor composed of the nucleating agent or the nucleating agent, etc. can be appropriately used. Examples of the solid-phase method include a ball mill, a bead mill, a rod mill, a colloid mill, a conical mill, a disk mill, a hammer mill, a jet mill, etc.

[0049] Also, examples of the liquid-phase method include a crystallization method, a coprecipitation method, a sol-gel method, a liquid-phase reduction method, a hydrothermal synthesis method, etc. Further, examples of the gas-phase method include an electric furnace method, a chemical flame method, a laser method, a thermal plasma method, etc.

[0050] (Supercritical reverse phase evaporation method) As a method for nanosizing the nucleating agent, the supercritical reverse phase evaporation method is preferable. The supercritical reverse phase evaporation method is a method for producing a capsule (nano-sized vehicle) encapsulating a target substance using carbon dioxide under supercritical conditions or temperature conditions or pressure conditions above the critical point. Supercritical carbon dioxide means carbon dioxide in a supercritical state at or above the critical temperature (30.98 °C) and critical pressure (7.3773 ± 0.0030 MPa). Carbon dioxide under temperature conditions or pressure conditions above the critical point means carbon dioxide under conditions where only the temperature or only the pressure exceeds the critical conditions.

[0051] Also, as a specific nanosizing treatment by the supercritical reverse phase evaporation method, first, an aqueous phase is injected into a mixed fluid of supercritical carbon dioxide, a phospholipid as an outer membrane forming substance, and a nucleating agent as an encapsulated substance, and stirred to generate an emulsion of supercritical carbon dioxide and the aqueous phase. Next, by reducing the pressure, carbon dioxide expands and evaporates, causing a phase inversion, and generating nanocapsules (nanovesicles) in which the phospholipid covers the surface of the nucleating agent particles with a monolayer membrane.

[0052] By using this supercritical reverse phase evaporation method, unlike the conventional encapsulation method in which the outer membrane becomes a multi-layer membrane on the surface of the nucleating agent particles, capsules with a monolayer membrane can be easily generated, so that smaller diameter capsules can be prepared. The nucleating agent vesicles are prepared, for example, by the Bangham method, the extrusion method, the hydration method, the surfactant dialysis method, the reverse phase evaporation method, the freeze-thaw method, the supercritical reverse phase evaporation method, etc. Among them, the nucleating agent vesicles are preferably prepared using the supercritical reverse phase evaporation method in particular.

[0053] (Outer membrane constituting the nucleating agent vesicle) The outer membrane constituting the nucleating agent vesicle is composed of, for example, a monolayer membrane. Also, the outer membrane is composed of a substance containing a biological lipid such as a phospholipid, for example. In this specification, a nucleating agent vesicle whose outer membrane is composed of a substance containing a biological lipid such as a phospholipid is referred to as a nucleating agent liposome. Examples of phospholipids constituting the outer membrane include glycerophospholipids such as phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidic acid, phosphatidylglycerol, phosphatidylinositol, cardiolipin, egg yolk lecithin, hydrogenated egg yolk lecithin, soybean lecithin, hydrogenated soybean lecithin, and sphingolipids such as sphingomyelin, ceramide phosphorylethanolamine, and ceramide phosphorylglycerol.

[0054] (Other substances forming the outer membrane) Examples of other substances forming the outer membrane of the vesicle include nonionic surfactants and dispersants such as mixtures of these with cholesterol or triacylglycerol. Among these, examples of nonionic surfactants include one or more of polyglycerol ether, dialkylglycerol, polyoxyethylene hydrogenated castor oil, polyoxyethylene alkyl ether, polyoxyethylene sorbitan fatty acid ester, sorbitan fatty acid ester, polyoxyethylene polyoxypropylene copolymer, polybutadiene-polyoxyethylene copolymer, polybutadiene-poly(2-vinylpyridine), polystyrene-polyacrylic acid copolymer, polyethylene oxide-polyethyl ethylene copolymer, polyoxyethylene-polycaprolactam copolymer, etc. Examples of cholesterol include cholesterol, α-cholestanol, β-cholestanol, cholestane, desmosterol (5,24-cholestadien-3β-ol), sodium cholate, or colecalciferol, etc.

[0055] Also, the outer membrane of the liposome may be formed from a mixture of phospholipid and a dispersant. In the cosmetic sheet 10 of the present embodiment, it is preferable that the nucleating agent vesicle is a radical scavenging liposome having an outer membrane made of phospholipid. By forming the outer membrane from phospholipid, the compatibility between the resin material, which is the main component of the cosmetic sheet 10, and the vesicle can be made good.

[0056] The nucleating agent is not particularly limited as long as it is a substance that serves as a crystallization starting point when the resin crystallizes. Examples of the nucleating agent include metal phosphate esters, metal benzoates, metal pimelates, metal rosins, benzylidene sorbitol, quinacridone, cyanine blue, and talc. In particular, in order to maximize the effect of the nanosizing treatment, it is preferable to use metal phosphate esters, metal benzoates, metal pimelates, and metal rosins, which are non-melting types and can be expected to have good transparency. However, when the material itself can be made transparent by the nanosizing treatment, colored quinacridone, cyanine blue, talc, etc. can also be used. Further, a melting type of benzylidene sorbitol may be appropriately mixed and used with the non-melting type of nucleating agent.

[0057] (Features of the transparent skin layer 42) As described above, the cosmetic sheet 10 of the first embodiment is characterized in that the transparent skin layer 42 contains a resin material and a nucleating agent. Further, the cosmetic sheet 10 of the first embodiment is characterized in that when forming the transparent skin layer 42, a nucleating agent encapsulated in vesicles is added to the resin material to crystallize the resin material. By adding the nucleating agent encapsulated in vesicles to the resin composition, the effect of dramatically improving the dispersibility of the nucleating agent in the resin material, that is, in the transparent skin layer 42, is achieved. On the other hand, it can be considered difficult and unrealistic to directly identify the nucleating agent encapsulated in vesicles based on the structure and properties of the object in the state of the completed cosmetic sheet 10 depending on the situation. The reason is as follows.

[0058] The nucleating agent added in the state of vesicles is in a dispersed state with high dispersibility and is highly dispersed in the transparent skin layer 42 even in the state of the laminate, which is a precursor of the produced cosmetic sheet 10. However, in the manufacturing process of the cosmetic sheet 10, usually, various treatments such as compression treatment and curing treatment are performed on the laminate, and the outer membrane of the vesicles encapsulating the nucleating agent may be crushed or chemically reacted by such treatments.

[0059] Therefore, due to the processing steps of the cosmetic sheet 10, the outer film of the nucleating agent in the completed cosmetic sheet 10 may be crushed, the state of chemical reaction may vary, and there is a high possibility that the nucleating agent is not encapsulated (enveloped) by the outer film. And when the nucleating agent is not encapsulated by the outer film, it is difficult to specify the physical properties of the nucleating agent itself within a numerical range, and it is also assumed that there may be cases where it is difficult to determine whether the constituent material of the crushed outer film is the outer film of the vesicle or a material added separately from the nucleating agent.

[0060] Thus, although this disclosure is different from the prior art in that the nucleating agent is compounded with high dispersion in the cosmetic sheet 10, it is also assumed that in the state of the cosmetic sheet 10, it is impractical to specify within a numerical range obtained by analyzing its structure and properties based on measurement whether it is because the nucleating agent is added in the state of a vesicle containing it.

[0061] (Top coat layer 50) The top coat layer 50 is coated with an acrylic two-component curable resin (acrylic urethane resin manufactured by DIC Graphics Co., Ltd.) to a thickness of 6 μm. On the surface of the top coat layer 50, an embossed portion 41 synchronized with the pattern of the printed pattern layer 30 is formed.

[0062] (Manufacturing method of the cosmetic sheet 10) The cosmetic sheet 10 has the above-described configuration, and its manufacturing method is as follows, as shown in FIG. 3. (1) First step The first step is a step of sequentially forming a printed pattern layer 30 with a printed pattern and a transparent polypropylene layer 40 on the surface of the colored film layer 20. Specifically, as the colored film layer 20, a pigment-containing colored polyethylene sheet (manufactured by Licentecnos) with a predetermined thickness, for example, a thickness of 55 μm, is used.

[0063] The printed pattern layer 30 is formed on the surface of the colored film layer 20 by gravure printing using, for example, urethane ink (Lamistar manufactured by Toyo Ink Manufacturing). On top of the printed pattern layer 30, a transparent polypropylene layer 40 (hereinafter also referred to as "transparent PP layer 40") is extrusion laminated, for example, with a homopolypropylene resin (manufactured by Prime Polymer Co., Ltd.) to a predetermined thickness, for example, a thickness of 70 μm, to produce a sheet with a flat surface.

[0064] (2) Second step The second step is a step of forming an embossed portion 41, which is unevenness synchronized with the pattern of the printed pattern layer 30, by irradiating the surface of the transparent polypropylene layer 40 with laser light 71. The surface of the transparent PP layer 40 is irradiated with laser light 71, for example, a CO 2 laser, to form, as the embossed portion 41, for example, unevenness in the form of a wood grain conduit. At this time, it is necessary to ensure that the unevenness formed by the laser light 71 does not exceed the thickness of the transparent polypropylene layer 40.

[0065] (3) Third step The third step is a step of subjecting the surface on which the embossed portion 41 is formed to a corona treatment. The surface of the transparent PP layer 40 on which the unevenness of the embossed portion 41 is formed is subjected to a corona treatment. (4) Fourth step The fourth step is a step of applying a transparent resin to the surface subjected to the corona treatment to form a top coat layer 50. As the top coat layer 50, for example, an acrylic two-component curable resin (acrylic urethane resin manufactured by DIC Graphic Co., Ltd.) is applied to a predetermined thickness, for example, a thickness of 6 μm.

[0066] (5) Fifth step The fifth step is a step of forming a primer layer 60 on the back surface of the colored film layer 20. On the back surface of the colored film layer 20, for example, by the gravure printing method, for example, a urethane-based resin is coated so that the solid content is 1 g / m 2 and the primer layer 60 is applied to manufacture the decorative sheet 10.

Example

[0067] (Example) The following describes Example 1 of the cosmetic sheet according to the present invention and Comparative Example 1 with respect to the embossed portion 41. Note that the present invention is not limited to Example 1 below.

[0068] (Example 1) Example 1 was produced with the following materials and procedures for the cosmetic sheet 10. As the colored film layer 20, a pigment-blended colored polyethylene sheet (manufactured by Liken Technos) with a thickness of 55 μm was used. On the surface of the colored film layer 20, a printed pattern layer 30 was formed by gravure printing using urethane ink (Lamister manufactured by Toyo Ink Manufacturing Co., Ltd.). On the printed pattern layer 30, a homopolypropylene resin (manufactured by Prime Polymer Co., Ltd.) with a thickness of 70 μm was extrusion laminated as the transparent PP layer 40 to produce a sheet with a flat surface. On the surface of the transparent PP layer 40, CO 2 laser (laser beam 71) was irradiated to form an embossed portion 41 which is a wood grain-like concavo-convexity.

[0069] The surface of the transparent PP layer 40 on which the embossed portion 41 was formed was subjected to corona treatment. Furthermore, as the top coat layer 50, an acrylic two-component curable resin (acrylic urethane resin manufactured by DIC Graphic Co., Ltd.) was applied to a thickness of 6 μm. Finally, on the back surface of the colored film layer 20, a urethane-based resin was applied by the gravure printing method so that the solid content was 1 g / m 2 and the primer layer 60 was applied to produce the evaluation sheet of Example 1.

[0070] (Comparative Example 1) Comparative Example 1 is different from Example 1 in that an embossed portion having concavo-convexities was formed using an embossing roll. As the colored film layer, a pigment-blended colored polyethylene sheet (manufactured by Liken Technos) with a thickness of 55 μm was used as in Example 1. On the surface of the colored film layer, a printed pattern layer was formed by gravure printing using urethane ink (Lamister manufactured by Toyo Ink Co., Ltd.). On the printed pattern layer, a homopolypropylene resin (manufactured by Prime Polymer Co., Ltd.) was extrusion laminated as a transparent PP layer with a thickness of 70 μm.

[0071] At that time, in order to reproduce the surface shape of the transparent PP layer as the wood grain conduit, an embossing roll that reproduced the unevenness of the wood grain conduit was used during the extrusion lamination to form a transparent PP layer with an embossed portion on the surface that was the unevenness of the wood grain conduit. The surface of the transparent PP layer with the embossed portion that was unevenness was subjected to corona treatment. Furthermore, as the top coat layer, an acrylic two-component curable resin (acrylic urethane resin manufactured by DIC Graphic Co., Ltd.) was applied to a thickness of 6 μm.

[0072] Finally, on the back surface of the colored film layer, a urethane-based resin was coated by the gravure printing method so that the solid content was 1 g / m 2 and a primer layer was applied to produce an evaluation sheet for Comparative Example 1.

[0073] (Evaluation Method and Evaluation Criteria) The evaluation method of the evaluation sheet prepared as described above is as follows. (1) Delicacy (2) Texture

[0074] (Delicacy) For the delicacy test, for each of the evaluation sheets, the state of the embossed portion that was the unevenness of the transparent PP layer was visually observed and evaluated. The evaluation was performed in three levels: "◎", "○", and "×". Those that were delicate were rated as "◎" and considered qualified. Other than the above, that is, "○" and "×", were considered unqualified.

[0075] (Texture) For the texture test, for each of the evaluation sheets, the state of the embossed portion that was the unevenness of the transparent PP layer was visually observed and evaluated. The evaluation was conducted in three levels: "◎", "○", and "×". Those that reproduced the texture of real wood grain were rated "◎" and considered qualified. Others, that is, "○" and "×", were considered unqualified. (Evaluation results) The evaluation results on the evaluation sheet are as shown in Table 1 below.

Table 1

[0076] (Example 1 and Comparative Example 1) Among the two evaluation sheets of Example 1 and Comparative Example 1, the one with both fineness and texture rated "◎" (qualified) is only the evaluation sheet of Example 1. The remaining evaluation sheet of Comparative Example 1 had both fineness and texture rated "○", being "unqualified".

[0077] It can be speculated that Comparative Example 1 was due to the use of an embossing roll. In contrast, the product of Example 1, compared with Comparative Example 1 which created an uneven shape using an embossing roll, was able to create a finer uneven shape and produce a decorative sheet that better reproduced the texture of the real thing.

Explanation of reference signs

[0078] 10 Decorative sheet 20 Colored film layer 30 Printed pattern layer 40 Transparent polypropylene layer 41 Embossed part 42 Transparent skin layer 43 Transparent core layer 50 Top coat layer 60 Primer layer 70 Laser processing machine 71 Laser beam

Claims

1. A first step of sequentially forming a printed pattern layer with a pattern printed thereon and a transparent polypropylene layer on the surface of the colored film layer; A second step of forming an embossed portion, which is unevenness synchronized with the pattern of the printed pattern layer, on the surface of the transparent polypropylene layer by irradiating laser light; A third step of performing corona treatment on the surface on which the embossed portion is formed; A fourth step of applying a transparent resin to the surface on which the corona treatment is performed to form a top coat layer having unevenness synchronized with the embossed portion; A fifth step of forming a primer layer on the back surface of the colored film layer, the method for manufacturing a decorative sheet being characterized by including the steps.

2. The method for manufacturing a decorative sheet according to claim 1, wherein the laser light uses a CO2 laser.

3. A decorative sheet in which a printed pattern layer with a pattern printed thereon and a transparent polypropylene layer are sequentially formed on the surface of a colored film layer, and a primer layer is formed on the back surface of the colored film layer, wherein on the surface of the transparent polypropylene layer, there are unevenness formed by irradiating laser light and an embossed portion synchronized with the pattern of the printed pattern layer, a corona treatment portion obtained by performing corona treatment on the surface having the embossed portion, and a top coat layer having unevenness synchronized with the embossed portion by applying a transparent resin to the surface having the corona treatment.

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