JP5729434B2 - Decorative sheet - Google Patents

Description

  The present invention relates to a decorative sheet.

  A decorative sheet having a surface protective layer made of an ionizing radiation curable resin on the outermost surface has excellent physical properties such as abrasion resistance, impact resistance, stain resistance, and scratch resistance. It is preferably used. Here, the ionizing radiation curable resin is appropriately blended with a prepolymer, an oligomer and / or a monomer containing a radical polymerizable double bond capable of undergoing a polymerization crosslinking reaction upon irradiation with ionizing radiation such as ultraviolet rays and electron beams. It will be. Such a decorative sheet is disclosed in Patent Document 1, for example.

  The surface protective layer made of ionizing radiation curable resin is excellent in physical properties such as abrasion resistance, impact resistance, contamination resistance, and scratch resistance, but it can further improve scratch resistance, wear resistance and the like. As a purpose, silica may be contained as a filler, a lubricant, or the like.

JP-A-2005-313600

  The above-mentioned decorative sheet is excellent in scratch resistance and abrasion resistance. However, when used for a long time as a decorative sheet for exterior floor materials such as a balcony and a veranda, there is a problem that the gloss retention ratio is greatly reduced. .

  Therefore, the object of the present invention is to reduce the gloss retention rate while maintaining scratch resistance and wear resistance even when used for a long time as a decorative sheet for exterior flooring as well as a decorative sheet for interior flooring. It is providing the decorative sheet which can be suppressed.

  As a result of intensive studies to achieve the above object, the present inventors have found that a decorative sheet having a specific layer can achieve the above object, and have completed the present invention.

That is, the present invention relates to the following decorative sheet.
1. A decorative sheet having a surface protective layer on the outermost surface,
(1) The surface protective layer contains silica having a pore volume of 1.6 to 1.8 ml / g ,
( 2) The average particle diameter D of the silica is 10 to 40 μm,
(3) The surface protective layer contains 8 to 18 parts by weight of the silica with respect to 100 parts by weight of the resin component,
(4) The surface protective layer is an ionizing radiation curable resin layer formed by resin crosslinking of an ionizing radiation curable resin.
A decorative sheet characterized by that.
2. When the thickness of the surface protective layer is T (μm) and the average particle diameter of silica is D (μm), the following conditions:
0.2T ≦ D ≦ 2.0T
The decorative sheet according to Item 1, which satisfies the above.
3. Item 3. The decorative sheet according to Item 1 or 2, wherein the surface protective layer has a thickness T of 10 µm or more.
4). Item 4. The decorative sheet according to any one of Items 1 to 3, wherein the silica has an average particle diameter D of 10 to 15 µm.
5 . Item 5. The decorative sheet according to any one of Items 1 to 4 , further comprising a pattern layer, a transparent adhesive layer, a transparent resin layer, a primer layer, and the surface protective layer in this order on the substrate sheet.
6 . A decorative material obtained by laminating the decorative sheet according to any one of Items 1 to 5 and an adherend.

  Hereinafter, the decorative sheet of the present invention will be described in detail.

The decorative sheet of the present invention is a decorative sheet having a surface protective layer on the outermost surface,
The surface protective layer is
(1) The surface protective layer contains silica having a pore volume of 1.5 ml / g or more, and (2) the surface protective layer has a gloss (60 ° gloss meter) of 10 to 20. ,
It is characterized by that.

  Since the decorative sheet of the present invention having the above characteristics contains specific silica in the specific surface protective layer, it is scratch resistant even after a long period of use as a decorative sheet for exterior flooring such as a balcony and a veranda. In addition, it is possible to suppress a decrease in gloss retention rate while maintaining wear resistance.

  Hereinafter, each layer which comprises a decorative sheet is demonstrated.

(Surface protective layer)
The decorative sheet of the present invention has a surface protective layer containing silica on the outermost surface.

  The pore volume of silica contained in the surface protective layer is 1.5 ml / g or more, more preferably 1.6 to 1.8 ml / g. When the pore volume of silica is the above-described value, it is possible to suppress the gloss reduction (gloss change) of the surface protective layer. The pore volume can be measured by a known method such as a BET method or a mercury intrusion method.

  The average particle size of silica is preferably 4 to 15 μm. By including the silica, the gloss reduction of the surface protective layer can be further suppressed. Furthermore, a preferable average particle diameter is 10-15 micrometers, The addition amount of the silica required in order to obtain the decorative sheet of the same gloss value can be reduced, and gloss retention can be improved more.

  The average particle diameter of the silica can be measured by a known method such as a laser diffraction method, a Coulter counter method, or a precipitation method. The average particle diameter means a particle diameter (D50) corresponding to a cumulative frequency of 50%.

When the thickness of the surface protective layer is T (μm) and the average particle diameter of silica is D (μm), 0.2T ≦ D ≦ 2.0T
When satisfy | filling, the gloss fall of a surface protective layer can be suppressed more. More preferably, 0.2T ≦ D ≦ 1.0T is satisfied.

  The thickness T of the surface protective layer is preferably 10 μm or more, more preferably 10 to 30 μm, and even more preferably 12 to 20 μm.

  In the present specification, the thickness of the surface protective layer refers to the length from the bottom of the resin forming the surface protective layer to the smooth portion where no convex portion is formed by silica. Moreover, in this specification, the thickness of the convex part formed with a silica means the length from the smooth part of the surface protective layer in which the convex part is not formed with the silica to the top part formed with the silica. Each thickness described above is described in detail in FIG.

  The surface protective layer preferably contains silica so that the surface has irregularities. In the decorative sheet of the present invention, the silica is usually present inside the surface protective layer, but a part of the silica protrudes from the surface of the surface protective layer as long as the effect of the present invention is not hindered (the surface protective layer is removed). You may break through).

  The content of silica is preferably 8 to 18 parts by weight, and more preferably 10 to 15 parts by weight with respect to 100 parts by weight of the resin component forming the surface protective layer.

  The surface protective layer is preferably an ionizing radiation curable resin layer formed by resin crosslinking of an ionizing radiation curable resin from the viewpoint of scratch resistance and the like. The ionizing radiation curable resin refers to a resin that crosslinks and cures when irradiated with ultraviolet rays, electron beams, or the like.

  As the ionizing radiation curable resin, a known or commercially available product can be used. Specifically, a composition containing at least one of a prepolymer, an oligomer and a monomer having a polymerizable unsaturated bond or an epoxy group in the molecule is used.

  Examples of the prepolymer or oligomer include methacrylates such as polyester methacrylate, polyether methacrylate, polyol methacrylate, and melamine methacrylate, polyester acrylate, polyether acrylate, urethane acrylate, polyol acrylate, and melamine acrylate. Examples include acrylates.

  Monomers include styrene monomers such as styrene and α-methylstyrene, acrylic acid such as methyl acrylate, 2-ethylhexyl acrylate, methoxyethyl acrylate, butoxyethyl acrylate, butyl acrylate, and phenyl acrylate. Examples include esters, methyl methacrylate, ethyl methacrylate, propyl methacrylate, ethoxymethyl methacrylate, phenyl methacrylate, and lauryl methacrylate.

  As substituted amino alcohol esters of unsaturated acids, acrylic acid-2- (N, N-diethylamino) ethyl, methacrylic acid-2- (N, N-diethylamino) ethyl, acrylic acid-2- (N, N -Substituted amino alcohol esters of unsaturated acids such as -dibenzylamino) methyl and acrylic acid-2- (N, N-diethylamino) propyl.

  In addition, unsaturated carboxylic acid amides such as acrylamide and methacrylamide, ethylene glycol diacrylate, propylene glycol diacrylate, neobenzyl glycol diacrylate, 1,6-hexanediol diacrylate, ethyl carbitol acrylate, diethylene glycol diacrylate, Multifunctional materials such as triethylene glycol diacrylate, dipropylene glycol diacrylate, ethylene glycol acrylate, diethylene glycol dimethacrylate, polyethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate; Trimethylolpropane trithioglycolate, Trime Trimethylolpropane tri thio propiolate, there is a polythiol compound having two or more thiol groups in the molecule, such as dipentaerythritol tetra thioglycolic.

  About the resin of the said illustration, 1 type (s) or 2 or more types can be used together.

  About the formation method of the surface protection layer by ionizing radiation curable resin, what is necessary is just to follow a well-known method. For example, a composition (coating material) containing an ionizing radiation curable resin may be prepared and applied by a known coating method such as a gravure coating method or a roll coating method. The coating amount of the composition in this case is not particularly limited, and may be set as appropriate so that the thickness of the surface protective layer falls within the above range.

  After application, the formed coating film is irradiated with ionizing radiation. Ionizing radiation means an electromagnetic wave or charged particle beam having an energy quantum capable of polymerizing and crosslinking molecules, such as visible light, ultraviolet light (near ultraviolet light, vacuum ultraviolet light, etc.), X-ray, electron beam, ion beam, etc. There is. In particular, ultraviolet rays, electron beams, and the like can be used as ionizing radiation. In particular, the surface protective layer is preferably a layer formed by irradiating the coating film containing the ionizing radiation curable resin with an electron beam. By irradiating the electron beam, a surface protective layer uniformly crosslinked with resin can be obtained with certainty. Moreover, when the resin is crosslinked by electron beam irradiation, the resin can be stably crosslinked and cured without using a photopolymerization initiator, and unlike the resin crosslinking by UV irradiation, the curing reaction rate is influenced by temperature. This is advantageous in that it does not receive much.

  As the ultraviolet light source, a light source such as an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc lamp, a black light fluorescent lamp, a metal halide lamp can be used. As the wavelength of the ultraviolet light, a wavelength range of about 190 to 380 nm can be used.

  As the electron beam source, various electron beam accelerators such as a cockcroft-wald type, a bandegraft type, a resonant transformer type, an insulating core transformer type, a linear type, a dynamitron type, and a high frequency type can be used. The acceleration voltage of the electron beam is generally about 100 to 1000 keV, preferably about 100 to 300 keV. The irradiation amount of the electron beam is usually about 2 to 15 Mrad.

  In the present invention, the surface protective layer preferably has a glossiness (60 ° gloss meter) of 10 to 20 (more preferably 12 to 16). The glossiness (60 ° gloss meter) is a glossiness measured according to JISZ-8741. Examples of the method for setting the gloss (60 ° gloss meter) of the surface protective layer to 10 to 20 include a method of adding a matting agent such as silica or plastic beads to the surface protective layer.

  If the glossiness (60 ° gloss meter) of the surface protective layer is 10 to 20, excellent design and texture (for example, if the decorative sheet has a wood grain pattern, it is the same as the actual wood grain pattern by wood) Can be reproduced.

  The glossiness (60 ° gloss meter) can be measured using each glossiness measuring instrument. For example, the glossiness can be measured using GMX-202 manufactured by Murakami Color Research Laboratory.

The gloss retention of the decorative sheet is expressed as a gloss ratio before and after the weather resistance test. That is, the gloss retention is

Indicated by

  The weather resistance test can be measured using various weather meters. For example, it can be measured using an eye super UV tester (manufactured by Iwasaki Electric).

In the decorative sheet of the present invention, the conditions of the weather resistance test (eye super UV tester) are strength 60 mW / cm ² , in-machine temperature 63 ° C., in-machine humidity 60% RH, and the test exposure time is 400 hours. In some cases, the gloss retention is 70% or more, and when the exposure time is 800 hours, the gloss retention is preferably 30% or more.

  Further, in order to improve the weather resistance, it is preferable to add a UV absorber such as benzotriazole, benzophenone, salicylate or triazine to the surface protective layer. In the case of curing the resin layer by irradiating with ultraviolet rays, as photopolymerization initiators, acetophenones, benzophenones, Michler benzoylbenzoate, α-aminoxime ester, tetramethylthiuram monosulfide, thioxanthones, aromatic diazonium salts N-butylamine, triethylamine, tri-n-butylphosphine and the like are used as photopolymerization accelerators (sensitizers) such as aromatic sulfonium salts and metallocenes.

  In addition, an antibacterial agent may be added to the surface protective layer in order to impart antibacterial properties. Antibacterial agents include inorganic antibacterial agents and organic antibacterial agents. In particular, inorganic antibacterial agents are desirable because they are generally safer than organic antibacterial agents and are excellent in durability and heat resistance. Inorganic antibacterial agents are those in which antibacterial metals such as silver, copper and zinc are supported on various inorganic carriers. The addition amount of the antibacterial agent is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the resin component.

  In addition, the surface protective layer may contain various additives such as colorants such as solvents, dyes and pigments, fillers such as gloss adjusters and extenders, antifoaming agents, leveling agents, and thixotropy imparting agents as necessary. Can be added.

  The decorative sheet of the present invention only needs to have the surface protective layer on the outermost surface, and the specific configuration may be appropriately set according to the use of the decorative sheet. For example, the decorative sheet which has a pattern layer, a transparent resin layer, a primer layer, and the said surface protective layer in order on a base material sheet is mentioned.

  Hereinafter, regarding the decorative sheet of the present invention, a decorative sheet having a pattern layer, a transparent adhesive layer, a transparent resin layer, a primer layer, and the surface protective layer in this order on a base sheet as a representative example, specifically, explain.

(Base material sheet)
The substrate sheet has a pattern layer or the like sequentially laminated on its surface (front surface).

  As the base sheet, for example, a sheet (film) formed of a thermoplastic resin is suitable. Specifically, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyamide, polyethylene, polypropylene, polycarbonate, polyethylene naphthalate, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / acrylic acid ester copolymer Examples include polymers, ionomers, acrylic esters, and methacrylic esters. The said base material sheet is formed by using these resin individually or in combination of 2 or more types.

  The base material sheet may be colored. In this case, a coloring material (pigment or dye) can be added to the above thermoplastic resin for coloring. As the colorant, for example, inorganic pigments such as titanium dioxide, carbon black and iron oxide, organic pigments such as phthalocyanine blue, and various dyes can be used. These can be selected from one or more known or commercially available ones. Further, the addition amount of the colorant may be appropriately set according to the desired color tone.

  The base sheet contains various additives such as fillers, matting agents, foaming agents, flame retardants, lubricants, antistatic agents, antioxidants, UV absorbers, and light stabilizers as necessary. It may be.

  Although the thickness of a base material sheet can be suitably set with the use of a final product, a usage method, etc., generally 20-300 micrometers is preferable.

  If necessary, the base sheet may be subjected to corona discharge treatment on the surface (front surface) in order to enhance the adhesion of the ink for forming the pattern layer. What is necessary is just to implement the method and conditions of a corona discharge process according to a well-known method. Moreover, you may give a corona discharge process to the back surface of a base material sheet, and may form a back surface primer layer as needed.

(Pattern pattern layer)
The design pattern layer imparts a desired design (design) to the decorative sheet, and the type of the design is not limited. For example, a wood grain pattern, a leather pattern, a stone pattern, a grain pattern, a tiled pattern, a brickwork pattern, a cloth pattern, a geometric figure, a character, a symbol, an abstract pattern, and the like can be given.

  The method for forming the pattern layer is not particularly limited. For example, an ink obtained by dissolving (or dispersing) a known colorant (dye or pigment) in a solvent (or dispersion medium) together with a binder resin is used. What is necessary is just to form on the base-material sheet | seat surface by the printing method. As the ink, an aqueous composition can be used from the viewpoint of reducing the VOC of the decorative sheet.

  Examples of the colorant include inorganic pigments such as carbon black, titanium white, zinc white, dial, bitumen, and cadmium red; azo pigments, lake pigments, anthraquinone pigments, quinacridone pigments, phthalocyanine pigments, isoindolinone pigments, dioxazine pigments. Organic pigments such as aluminum powder, metal powder pigments such as bronze powder, pearlescent pigments such as titanium oxide-coated mica and bismuth oxide chloride; fluorescent pigments; These colorants can be used alone or in admixture of two or more. These colorants may be used together with fillers such as silica, extender pigments such as organic beads, neutralizing agents, surfactants and the like.

  As binder resin, in addition to polyester urethane resin treated with hydrophilicity, polyester, polyacrylate, polyvinyl acetate, polybutadiene, polyvinyl chloride, chlorinated polypropylene, polyethylene, polystyrene, polystyrene-acrylate copolymer, rosin derivative Alcohol adducts of styrene-maleic anhydride copolymers, cellulose resins, and the like can also be used in combination. More specifically, for example, polyacrylamide resins, poly (meth) acrylic resins, polyethylene oxide resins, poly N-vinyl pyrrolidone resins, water-soluble polyester resins, water-soluble polyamide resins, water-soluble amino acids. Also usable are water-based resins, water-soluble phenolic resins, other water-soluble synthetic resins; water-soluble natural polymers such as polynucleotides, polypeptides, polysaccharides, and the like. Also, for example, natural rubber, synthetic rubber, polyvinyl acetate resin, (meth) acrylic resin, polyvinyl chloride resin, polyurethane-polyacrylic resin, etc. modified or a mixture of the above natural rubber, etc. Resin can also be used. The binder resin can be used alone or in combination of two or more.

  The pattern layer may be formed by a known printing method such as a gravure printing method, an offset printing method, a screen printing method, a flexographic printing method, an electrostatic printing method, or an ink jet printing method.

  The thickness of the pattern layer is not particularly limited and can be set as appropriate according to product characteristics. The layer thickness at the time of coating is about 1 to 15 μm, and the layer thickness after drying is about 0.1 to 10 μm.

(Colored hiding layer)
In the decorative sheet of the present invention, a colored concealing layer may be further formed between the base sheet and the pattern layer.

  The colored concealment layer only needs to conceal the ground color of the adherend when the decorative sheet and the adherend are joined, and is usually formed so as to cover the base sheet.

  The known printing method can be used for forming the colored concealing layer. Moreover, the ink used for formation of the said pattern pattern layer can be used as it is.

  The known printing method can be used for forming the colored concealing layer.

The coating amount is desirably in the range of ^{2 to} 30 g / m2.

  The thickness of the colored masking layer is usually about 0.1 to 20 μm, preferably about 1 to 10 μm.

(Transparent adhesive layer)
In order to enhance the adhesion between the transparent resin layer and the pattern layer described later, a transparent adhesive layer may be formed. The transparent adhesive layer is not particularly limited as long as it is transparent, and includes any of transparent and colorless, colored and translucent.

  It does not specifically limit as an adhesive agent, A well-known adhesive agent can be used in the field of a decorative sheet.

  Examples of known adhesives in the field of decorative sheets include thermoplastic resins such as polyamide resins, acrylic resins and vinyl acetate resins, and thermosetting resins such as urethane resins. These colorants are used alone or in combination of two or more. Further, a two-component curable polyurethane resin or polyester resin using isocyanate as a curing agent can also be applied.

  The known printing method can be used for forming the transparent adhesive layer.

  Although the thickness of a transparent adhesive bond layer is not specifically limited, The thickness after drying is about 0.1-30 micrometers, Preferably it is about 1-20 micrometers.

(Transparent resin layer)
A transparent resin layer is formed on the transparent adhesive layer.

  The transparent resin layer is not particularly limited as long as it is transparent, and includes any of colorless and transparent, colored and transparent, and translucent. Examples of the resin constituting the transparent resin layer include polyethylene terephthalate, polybutylene terephthalate, polyamide, polyethylene, polypropylene, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, and ethylene / acrylic acid ester copolymer. Examples thereof include coalescence, ionomer, polymethylpentene, acrylic acid ester, methacrylic acid ester, polycarbonate, and cellulose triacetate. These resins are used alone or in combination of two or more.

  Preferably, a polyolefin resin typified by polypropylene resin is used. Therefore, when using polyolefin-type resin as a transparent resin layer, the various polyolefin-type resin quoted as what comprises a base material sheet can be used.

  The transparent resin layer may be colored as long as it has transparency, but it is particularly desirable not to add a colorant.

  The method for forming the transparent resin layer is not limited, for example, a method of laminating a preformed sheet or film on an adjacent layer, an adjacent layer by melt-extruding a resin composition capable of forming a transparent resin layer Any of a method of coating on top and a method of laminating together with an adjacent layer can be employed. Examples of the laminating method include a laminating method by a dry laminating method.

  The thickness of the transparent resin layer is usually about 20 to 200 μm, but may exceed the above range depending on the use of the decorative sheet.

(Primer layer 1)
By providing the primer layer (primer layer 1), the surface protective layer can be easily formed. The primer layer is not particularly limited as long as it is transparent, and includes any of colorless and transparent, colored and translucent.

  The primer layer 1 can be formed by applying a known or commercially available primer agent on the transparent resin layer. In particular, the primer layer 1 is preferably a layer formed by crosslinking a resin. Examples of the primer agent for forming such a layer include a urethane resin primer agent made of an acrylic-modified urethane resin and the like, a resin primer agent made of a block copolymer of acrylic and urethane, and the like. These primer agents are used alone or in combination of two or more.

The primer layer 1 may contain silica as a matting agent. The content of silica in the primer agent is preferably 0.1 to 50 parts by weight with respect to 100 parts by weight of the resin component,
10-40 weight part is more preferable.

  Furthermore, you may make a primer agent contain a well-known additive as needed. For example, the adhesiveness of the said transparent resin layer and the said surface protective layer can be improved more by making a primer agent contain a hexamethylene diisocyanate type hardening | curing agent.

  For the formation of the primer layer 1, the above known method can be used. For example, a method similar to the method of forming the surface protective layer using the ionizing radiation curable resin can be employed.

  The thickness of the primer layer 1 is not particularly limited, but is usually about 0.1 to 100 μm, preferably about 0.5 to 15 μm.

(Primer layer 2)
A primer layer (primer layer 2) may be provided on the back surface of the base sheet, if necessary. For example, it is advantageous when a base material sheet and an adherend are bonded to produce a decorative material.

The primer layer 2 can be formed by applying a known primer agent to one side or both sides of the base sheet. Examples of the primer agent include a urethane resin-based primer agent made of an acrylic-modified urethane resin (acrylic urethane resin), a urethane-cellulose resin (for example, a resin obtained by adding hexamethylene diisocyanate to a mixture of urethane and nitrified cotton) ), A resinous primer agent made of a block copolymer of acrylic and urethane, and the like. You may mix | blend an additive with a primer as needed.
Examples of the additive include fillers such as calcium carbonate and clay, flame retardants such as magnesium hydroxide, antioxidants, lubricants, foaming agents, ultraviolet absorbers, and light stabilizers. The blending amount of the additive can be appropriately set according to the product characteristics.

Although the application amount of the primer agent is not particularly limited, it is usually 0.1 to 100 g / m ² , preferably about 0.1 to 50 g / m ² .

  The thickness of the primer layer 2 is not particularly limited, but is usually 0.01 to 10 μm, preferably about 0.1 to 1 μm.

Decorative plate The decorative plate of the present invention is formed by laminating the decorative sheet on an adherend such that the surface protective layer of the decorative sheet is the outermost surface layer.

  The adherend is not limited, and the same materials as known decorative sheets can be used. For example, a wood material, a metal, ceramics, plastics, glass, etc. are mentioned. In particular, the decorative sheet of the present invention can be suitably used for a wood material. Specifically, wood materials include veneer, wood veneer, wood plywood, particle board, medium density fiberboard (MDF) made from various materials such as cedar, firewood, firewood, pine, lawan, teak, and melapie. ) And the like.

  The lamination method is not limited. For example, a method of sticking a decorative sheet to an adherend with an adhesive or the like can be employed. What is necessary is just to select an adhesive agent suitably from well-known adhesive agents according to the kind etc. of to-be-adhered material. Examples thereof include polyvinyl acetate, polyvinyl chloride, vinyl chloride / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ionomer, butadiene / acrylonitrile rubber, neoprene rubber, natural rubber and the like. These adhesives are used alone or in combination of two or more.

  The decorative board manufactured in this way includes, for example, interior materials for buildings such as walls, ceilings, and floors; exterior materials such as balconies and verandas; surface decorative boards and furniture for furniture such as window frames, doors, and handrails; Alternatively, it can be used for a surface decorative plate of a cabinet such as a light electric or OA device. In particular, the decorative board of the present invention can be suitably used as a flooring decorative material (in particular, an exterior decorative material).

  The decorative sheet of the present invention is a decorative sheet having a surface protective layer on the outermost surface, (1) the surface protective layer contains silica having a pore volume of 1.5 ml / g or more, and (2 ) Since the surface protective layer has a glossiness (60 ° gloss meter) of 10 to 20, the surface protective layer has scratch resistance and abrasion resistance even after a long period of use as a decorative sheet for exterior floor materials such as balconies and verandas. While holding, it is possible to suppress a decrease in gloss retention.

It is a schematic diagram which illustrates sectional drawing of the decorative sheet of this invention. It is a schematic diagram which illustrates the layer structure of the decorative sheet of this invention.

  The present invention will be specifically described below with reference to examples and comparative examples. However, the present invention is not limited to the examples. Examples 1 and 2 are described as reference examples.

Example 1
A corona discharge treatment was applied to the front and back surfaces of a 60 μm-thick polypropylene sheet (base material sheet), and then a woodgrain pattern pattern layer was formed on the front surface by gravure printing.
Next, a primer layer having an acrylic urethane resin as a binder was formed on the back surface of the base sheet by gravure printing.

  Next, a coating solution made of a two-component curable polyurethane resin was applied on the pattern layer to form a transparent adhesive layer (thickness 3 μm). Furthermore, a transparent thermoplastic resin layer (thickness: 80 μm) was formed by melt extrusion coating a polypropylene thermoplastic elastomer made of an ethylene-propylene-butene copolymer with a T die.

  Next, a two-component curable urethane resin composed of an acrylic-urethane block polymer (main agent) and hexamethylene diisocyanate (curing agent) is applied onto the transparent resin layer, and a primer layer (thickness 2 μm) is applied. Formed.

  Next, a composition containing 13 parts by weight of silica particles, 1 part by weight of a triazine ultraviolet absorber, and 3 parts by weight of a light stabilizer is applied by gravure coating to 100 parts by weight of ionizing radiation curable trifunctional urethane oligomer. After forming the film, a surface protective layer (thickness: 15 μm) was formed by irradiating an electron beam under conditions of 125 keV and 5 Mrad (50 kGy) to crosslink and cure the coating film. As silica particles, “silica 3” (average particle diameter 8 μm, pore volume 2 ml / g) was used.

  Finally, the surface protective layer side is heated with an infrared non-contact heater to soften the base sheet and the transparent resin layer, and then immediately embossed with heat pressure from the surface of the surface protective layer, An irregular pattern was formed to obtain a predetermined decorative sheet.

Example 2
A decorative sheet was obtained in the same manner as in Example 1, except that “silica 4” (average particle size 4 μm, pore volume 2 ml / g) was used instead of “silica 3”.

Example 3
A decorative sheet was obtained in the same manner as in Example 1, except that “silica 6” (average particle size 10 μm, pore volume 1.6 ml / g) was used instead of “silica 3”.

Example 4
A decorative sheet was obtained in the same manner as in Example 1 except that “silica 7” (average particle size 10 μm, pore volume 1.8 ml / g) was used instead of “silica 3”.

Example 5
A decorative sheet was obtained in the same manner as in Example 1, except that “silica 2” (average particle size 13.5 μm, pore volume 1.6 ml / g) was used instead of “silica 3”. .

Comparative Example 1
The silica particles and the parts by weight of the silica particles are replaced with “silica 3” and 13 parts by weight, except that 20 parts by weight of “silica 1” (average particle size 8 μm, pore volume 1.3 ml / g) is used. A decorative sheet was obtained in the same manner as in Example 1.

Comparative Example 2
The silica particles and parts by weight of the silica particles are replaced with “silica 3” and 13 parts by weight, except that 20 parts by weight of “silica 5” (average particle size 4 μm, pore volume 1.2 ml / g) is used. A decorative sheet was obtained in the same manner as in Example 1.

Comparative Example 3
Except for using 10 parts by weight of “silica 1” (average particle size 8 μm, pore volume 1.3 ml / g) instead of “silica 3” and 13 parts by weight of silica particles and 13 parts by weight of silica particles. A decorative sheet was obtained in the same manner as in Example 1.

  The decorative sheets prepared in Examples 1 to 5 and Comparative Examples 1 to 3 each contained silica so that the glossiness (60 ° gloss meter) of the surface protective layer was 10 to 20. is there.

Test method ≪Weather resistance test≫
Using an i-super UV tester (Iwasaki Electric Co., Ltd.), exposure was performed for 400 hours and 800 hours under the conditions of strength 60 mW / cm ² , in-machine temperature 63 ° C., in-machine humidity 60% RH, and evaluated by gloss retention.

The glossiness (60 ° gloss meter) was measured using GMX-202 manufactured by Murakami Color Research Laboratory.
≪Scratch resistance test≫
The scratch resistance of the decorative sheets prepared in Examples 1 to 5 and Comparative Examples 1 to 3 was confirmed using a Hoffman scratch tester (BYK-Gardnar).

  Specifically, a scratch blade (a cylindrical edge portion having a diameter of 7 mm) is set so as to contact the surface protective layer of the decorative sheet at an angle of 45 degrees, and the surface is moved by pulling the scratch blade. Rubbed. At that time, it was confirmed whether or not the surface protective layer was damaged by changing the load applied to the scratch blade by 100 g in a range of 100 to 700 g.

  The case where the surface was hardly changed by a load of 500 g was evaluated as ◯, and the case where the scratches were conspicuous was evaluated as ×.

  The results are shown in Table 1.

Claims (6)

A decorative sheet having a surface protective layer on the outermost surface,
(1) The surface protective layer contains silica having a pore volume of 1.6 to 1.8 ml / g ,
(2) Average particle diameter D of the silica is a 10 to 40 mu m,
(3) The surface protective layer contains 8 to 18 parts by weight of the silica with respect to 100 parts by weight of the resin component ,
(4) The surface protective layer is an ionizing radiation curable resin layer formed by resin crosslinking of an ionizing radiation curable resin.
A decorative sheet characterized by that. When the thickness of the surface protective layer is T (μm) and the average particle diameter of silica is D (μm), the following conditions:
0.2T ≦ D ≦ 2.0T
The decorative sheet according to claim 1, wherein:   The decorative sheet according to claim 1 or 2, wherein a thickness T of the surface protective layer is 10 µm or more.   The decorative sheet according to any one of claims 1 to 3, wherein the silica has an average particle diameter D of 10 to 15 µm. The decorative sheet according to any one of claims 1 to 4 , comprising a pattern layer, a transparent adhesive layer, a transparent resin layer, a primer layer, and the surface protective layer in this order on the substrate sheet. A decorative material obtained by laminating the decorative sheet according to any one of claims 1 to 5 and an adherend.

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