JP2014198469A - Decorative sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decorative sheet for a floor material excellent in terms of impact resistance, caster resistance, emboss impression potential, and emboss fastness in a state where the warpage thereof due to thermal shrinkage is being inhibited.SOLUTION: The provided decorative sheet for a floor material is a decorative sheet for a floor material possessing at least a transparent resin layer 5 atop a substrate sheet 2 where (1) the thickness ratio of the thickness of the transparent resin layer 5 (t1) with respect to the thickness of the substrate sheet 2 (t2), namely (t1)/(t2), is 1.5/1.0-1.0/1.5 and where (2) the sum of the thickness of the transparent resin layer 5 (t1) and the thickness of the substrate sheet 2 (t2), namely (t1)+(t2), is 300-600 μm.

Description

  The present invention relates to a decorative sheet useful as a decorative sheet for flooring.

  Conventionally, a method for increasing the thickness of the entire decorative sheet is known in order to improve the impact resistance and caster resistance of the decorative sheet for flooring. If such a decorative sheet is too thick, the embossing property becomes sweet, the roll becomes thickly wound, and the curl when it is rolled becomes strong so that roll lamination cannot be performed. There is.

  A decorative sheet having a backer layer on the back side of a decorative sheet has been proposed as a decorative sheet for flooring that solves the above-described problems (see, for example, Patent Document 1).

  However, the above-described decorative sheet has a problem in that it is necessary to provide a backer layer on the back surface side, so that the manufacturing cost is high and manufacturing process loss occurs. In addition, when the backer layer is formed by extrusion of the molten resin, the embossed shape on the decorative sheet surface disappears because the molten resin is at a high temperature, so the embossed shape that is inferior in embossing shape and remains without being actually used It is easy to disappear, and there is a problem that the embossing fastness is inferior.

  As a technique for solving the above-mentioned problem, a technique of increasing the thickness of the base sheet without providing a backer layer is used. However, if the thickness of the base sheet is excessively increased, the thickness of the entire decorative sheet increases. This causes a problem when the thickness of the entire decorative sheet is increased.

  In addition, a method of increasing the thickness of the transparent resin layer without providing a backer layer is used, but if the thickness of the transparent resin layer is too thick, there is not enough heat absorption in the embossing process, and embossing property and embossing There is a problem that the fastness is lowered and the base sheet is warped or cracked due to heat shrinkage after the flooring is processed.

  Therefore, it does not require a backer layer, is excellent in impact resistance, caster resistance, embossing formability and embossing fastness required for a decorative sheet for flooring, and has a warping caused by heat shrinkage and is suppressed from warping. Development of seats is desired.

2007-98855

  An object of the present invention is to provide a decorative sheet that is excellent in impact resistance, caster resistance, embossing formability, and embossing fastness, and that is prevented from warping due to heat shrinkage and is useful as a decorative sheet for flooring. And

  As a result of intensive research, the present inventors have determined the thickness ratio between the thickness of the base sheet and the thickness of the transparent resin layer in the decorative sheet for flooring having at least a transparent resin layer on the base sheet. The present inventors have found that the above object can be achieved by setting the specific range and the total of the thickness of the transparent resin layer and the thickness of the base sheet to achieve the present invention.

That is, the present invention relates to the following decorative sheet.
1. A decorative sheet having at least a transparent resin layer on a substrate sheet, wherein (1) the thickness ratio (t1) of the thickness (t1) of the transparent resin layer and the thickness (t2) of the substrate sheet / (T2) is 1.5 / 1.0 to 1.0 / 1.5, and (2) the sum of the thickness (t1) of the transparent resin layer and the thickness (t2) of the base sheet (t1) ) + (T2) is 300 to 600 μm,
A decorative sheet characterized by that.
2. Item 2. The decorative sheet according to Item 1, wherein the transparent resin layer has a thickness of 150 µm or more.
3. Item 3. The decorative sheet according to Item 1 or 2, wherein the transparent resin layer is an olefin resin layer.
4). Item 4. The decorative sheet according to any one of Items 1 to 3, wherein the base sheet contains at least one of a polyolefin resin and a polyester resin.
5. Item 5. The decorative sheet according to any one of Items 1 to 4, further comprising a pattern layer between the base sheet and the transparent resin layer.
6). Item 6. The decorative sheet according to any one of Items 1 to 5, wherein a surface protective layer is laminated on the transparent resin layer.
7). Item 7. The decorative sheet according to Item 6, wherein the surface protective layer is an ionizing radiation curable resin layer.
8). Item 8. The decorative sheet according to Item 6 or 7, further comprising a primer layer between the transparent resin layer and the surface protective layer.
9. Item 10. The decorative sheet according to any one of Items 1 to 8, which is embossed from the transparent resin layer side.
10. Item 10. The decorative sheet according to any one of Items 1 to 9, which is for flooring.
11. A decorative board obtained by laminating the decorative sheet according to any one of Items 1 to 10 on an adherend.

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

  The decorative sheet for flooring of the present invention has at least a transparent resin layer and a surface protective layer in order on the base sheet, and (1) the thickness (t1) of the transparent resin layer and the thickness of the base sheet. The thickness ratio (t1) / (t2) to (t2) is 1.5 / 1.0 to 1.0 / 1.5, (2) the thickness (t1) of the transparent resin layer and the substrate The total (t1) + (t2) with the thickness (t2) of the sheet is 300 to 600 μm.

  In the decorative sheet for flooring of the present invention having the above characteristics, the total thickness of the transparent resin layer and the base sheet is within a specific range, and the thickness ratio between the transparent resin layer and the base sheet is Since it is in an appropriate range, it is excellent in impact resistance and caster resistance. For this reason, a backer layer is not required, and it is excellent in emboss shapeability and emboss fastness combined with the thickness ratio and the total thickness being in a specific range.

  Furthermore, by defining the thickness ratio and the sum of the thicknesses, the thickness of the transparent resin layer is not too thick, and warpage due to thermal shrinkage of the decorative sheet for flooring is suppressed.

  In the decorative sheet for flooring of the present invention, the total (t1) + (t2) of the thickness (t1) of the transparent resin layer and the thickness (t2) of the base sheet is 300 to 600 μm. When (t1) + (t2) is less than 300 μm, the impact resistance and caster resistance are poor. Moreover, when (t1) + (t2) exceeds 600 micrometers, it is inferior to emboss shaping property and emboss fastness. (T1) + (t2) is preferably 300 to 500 μm, and more preferably 300 to 400 μm. If (t1) + (t2) is too thick, there is a risk that winding will occur and it will be difficult to roll.

  In the decorative sheet for flooring of the present invention, the thickness ratio (t1) / (t2) between the thickness (t1) of the transparent resin layer and the thickness (t2) of the base sheet is 1.5 / 1.0 to 1. 0 / 1.5. When (t1) / (t2) is smaller than 1.0 / 1.5, the thickness of the transparent resin layer becomes thin, so that the impact resistance is inferior. Moreover, when (t1) / (t2) is smaller than 1.0 / 1.5, the wear resistance is inferior and the sense of depth of the pattern is also lowered.

  On the other hand, if (t1) / (t2) is greater than 1.5 / 1.0, the thickness of the transparent resin layer is increased, so that there is insufficient heat absorption in the embossing process, resulting in poor embossing formability and embossing fastness. . Further, when the thickness of the transparent resin layer is increased, the amount of warpage due to heat shrinkage of the transparent resin layer is increased, and thus the amount of warpage of the decorative sheet for flooring is also increased.

Note that the above (t1) / (t2) is smaller than 1.0 / 1.5 means that the thickness ratio (t1) / (t2) is less than 1.0 / 1.5. The ratio is small and the ratio of (t2) is large. Moreover, (t1) / (t2) is larger than 1.5 / 1.0 means that the ratio of (t1) is larger than the state where the thickness ratio (t1) / (t2) is 1.5 / 1.0. Is large and the ratio of (t2) is small. Hereinafter, the same applies to the present specification.
The thickness ratio (t1) / (t2) is preferably 1.2 / 1.0 to 1.0 / 1.0.

(Substrate sheet)
Although it does not limit as a base material sheet, the base material sheet which contains polyolefin resin as a resin component is preferable. In practice, a sheet made of polyolefin resin is used.

  It does not specifically limit as polyolefin resin, The thing normally used in the field | area of the decorative sheet can be used. For example, polyethylene, polypropylene, polybutene, polymethylpentene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-propylene-butene copolymer, polyolefin-based thermoplastic elastomer, etc. Is mentioned. Of these, polypropylene, polyolefin thermoplastic elastomer, and the like are particularly preferable.

  A homopolymer or copolymer having polypropylene as a main component is also preferable, for example, a homopolypropylene resin, a random polypropylene resin, a block polypropylene resin, and a polypropylene crystal part and having 2 to 20 carbon atoms other than propylene. -Olefins. In addition, a propylene-α-olefin copolymer containing 15 mol% or more of a comonomer of ethylene, butene-1,4-methylpentene-1, hexene-1, or octene-1 is also preferable.

  The polyolefin-based thermoplastic elastomer is preferably a mixture of isotactic polypropylene in the hard segment and atactic polypropylene in the soft segment in a weight ratio of 80:20.

  The polyolefin resin may be formed into a film by, for example, a calendar method, an inflation method, a T-die extrusion method, or the like.

  The base sheet may also be a base sheet containing a polyester resin as a resin component. In this case, a sheet substantially made of a polyester resin is used.

  It does not specifically limit as a polyester resin, What is normally used in the field | area of a decorative sheet can be used. Examples thereof include polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), and polyethylene naphthalate (PEN). Among these, polybutylene terephthalate is particularly preferable.

  Moreover, the base material sheet may contain at least 1 sort (s) of polyolefin resin and polyester resin. In addition, when a base material sheet contains polyolefin resin and polyester resin, the base material sheet which consists of one layer may be formed with resin which mixed polyolefin resin and polyester resin, and the base material which consists of several layers The sheet may be formed by laminating a sheet containing a polyolefin resin and a sheet containing a polyester resin.

  Moreover, the base material sheet may be formed by laminating | stacking several layers containing polyolefin resin. In this case, each layer which forms a base material sheet may differ in the kind and compounding quantity of contained polyolefin resin, and may differ in the kind and compounding quantity of an additive. Examples of such a base sheet include, for example, (i) a base sheet in which a plurality of layers having different blending ratios of the polyolefin block copolymer and random copolymer in the layer are laminated, and (ii) a pigment. And a base sheet in which a layer containing a filler and the like are laminated, and a base sheet in which (iii) a plurality of layers having different blending amounts of pigment, filler, etc. in the layer are laminated.

Similarly, the base material sheet may be formed by laminating a plurality of layers containing a polyester resin. Also in this case, each layer which forms a base material sheet may differ in the kind and compounding quantity of the polyester resin to be used, and the kind and compounding quantity of an additive.
The structure of these base material sheets may be appropriately selected according to the thickness, hardness, etc. of the adherend such as a wooden base material used when the decorative sheet is laminated on the adherend to make a decorative board. .

  The thickness of the substrate sheet is not particularly limited and can be set according to product characteristics, but is preferably 150 to 300 μm, more preferably 160 to 240 μm, and still more preferably about 180 to 200 μm.

  An additive may be mix | blended with a base material sheet as needed. Examples of the additive include a filler such as calcium carbonate and clay, a flame retardant such as magnesium hydroxide, an antioxidant, a lubricant, a foaming agent, and a colorant (see below). The blending amount of the additive can be appropriately set according to the product characteristics.

  It does not specifically limit as a coloring agent, Well-known coloring agents, such as a pigment and dye, can be used. For example, titanium white, zinc white, petal, vermilion, ultramarine blue, cobalt blue, titanium yellow, yellow lead, carbon black and other inorganic pigments; isoindolinone, Hansa Yellow A, quinacridone, permanent red 4R, phthalocyanine blue, indanthrene Organic pigments (including dyes) such as blue RS and aniline black; metal pigments such as aluminum and brass; pearlescent pigments made of foil powder such as titanium dioxide-coated mica and basic lead carbonate.

  One or both surfaces of the base sheet may be subjected to surface treatment such as corona discharge treatment, ozone treatment, plasma treatment, ionizing radiation treatment, dichromic acid treatment, etc., as necessary. For example, when the corona discharge treatment is performed, the surface tension of the substrate sheet surface may be 30 dyne or more, preferably 40 dyne or more. The surface treatment may be performed according to a conventional method for each treatment.

  A primer layer may be provided on one side or both sides of the base sheet as necessary.

  A primer layer can be formed by apply | coating a well-known primer agent to the single side | surface or both surfaces of a base material sheet. Examples of the primer agent include a urethane resin primer agent made of acrylic modified urethane resin, a primer agent made of urethane-cellulose resin (for example, a resin made by adding hexamethylene diisocyanate to a mixture of urethane and nitrified cotton), and the like. Is mentioned.

The application amount of the primer agent is not particularly limited, but is usually 0.1 to 20 g / m ² , preferably about 0.5 to 10 g / m ² .

(Transparent resin layer)
The transparent resin layer may be colored as long as it is transparent, and may be translucent as long as the pattern layer is visible.

  Examples of the resin for forming the transparent resin layer include polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyamide, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, and ethylene-acrylic acid. Examples thereof include ester copolymers, ionomers, polymethylpentene, acrylic acid esters, methacrylic acid esters, polycarbonates, and cellulose triacetates. Among these, polyolefin resins such as polypropylene are preferable. More preferably, it is a polyolefin resin having stereoregularity. When using a polyolefin resin, it is desirable to form a transparent resin layer by extruding a molten polyolefin resin.

  For the transparent resin layer, if necessary, a filler, matting agent, foaming agent, flame retardant, lubricant, antistatic agent, antioxidant, ultraviolet absorber, light stabilizer, radical scavenger, soft component Various additives such as rubber (for example, rubber) may be included.

  The thickness of the transparent resin layer is not particularly limited, but is preferably 150 μm or more. By setting the thickness of the transparent resin layer to 150 μm, when a pattern layer is laminated on the lower layer, the sense of depth of the pattern is increased and the design is improved, and the wear resistance of the decorative sheet for flooring is improved. improves. The thickness of the transparent resin layer is preferably about 150 to 300 μm, more preferably about 160 to 240 μm, and still more preferably about 200 to 220 μm. When the said thickness is too thin, there exists a possibility that it may be inferior to impact resistance and caster resistance. If it is too thick, the embossing property and embossing fastness may be inferior, and the amount of warping due to heat shrinkage of the transparent resin layer may increase. Following this, the amount of warping of the decorative sheet for flooring May also become large.

  The surface of the transparent resin layer on which the surface protective layer is formed is subjected to surface treatment such as corona discharge treatment, ozone treatment, plasma treatment, ionizing radiation treatment, dichromic acid treatment as necessary. Also good. The surface treatment may be performed according to a conventional method for each treatment.

  The layer structure of the decorative sheet for flooring of the present invention is not particularly limited as long as it has the base sheet and the transparent resin layer. For example, a pattern layer, transparency on the base sheet. What laminated | stacked a resin layer and a surface protective layer in order is preferable. Moreover, the layer structure which laminates | stacks a pattern pattern layer, an adhesive bond layer, a transparent resin layer, a primer layer, and a surface protective layer in order on a base material sheet is also suitable.

  Hereinafter, as a specific description of the layer configuration, the above-described layer configuration will be exemplified, and layers other than the surface protective layer will be described.

(Pattern pattern layer)
A pattern layer can be formed on the base sheet. The design pattern layer imparts design properties with a desired design to the decorative sheet for flooring, and the type of design is not particularly limited. Examples thereof include a wood grain pattern, a stone pattern, a grain pattern, a tiled pattern, a brickwork pattern, a cloth pattern, a leather pattern, a geometric figure, a character, a symbol, and an abstract pattern.

  The method for forming the pattern layer is not particularly limited. For example, a colored ink or coating obtained by dissolving (or dispersing) a known colorant (dye or pigment) in a solvent (or dispersion medium) together with a binder resin. What is necessary is just to form by the printing method etc. which used the agent.

  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 further contain fillers such as silica, extender pigments such as organic beads, neutralizing agents, surfactants and the like.

  Examples of the binder resin include acrylic resin, styrene resin, polyester resin, urethane resin, chlorinated polyolefin resin, vinyl chloride-vinyl acetate copolymer resin, polyvinyl butyral resin, alkyd resin, petroleum Resin, ketone resin, epoxy resin, melamine resin, fluorine resin, silicone resin, fiber derivative, rubber resin and the like. These resins can be used alone or in admixture of two or more.

  Examples of the solvent (or dispersion medium) include petroleum organic solvents such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, and methylcyclohexane; ethyl acetate, butyl acetate, 2-methoxyethyl acetate, and acetic acid-2 -Ester-based organic solvents such as ethoxyethyl; alcohol-based organic solvents such as methyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol, isobutyl alcohol, ethylene glycol, propylene glycol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone Organic solvents; ether organic solvents such as diethyl ether, dioxane, tetrahydrofuran; dichloromethane, carbon tetrachloride, trichloroethylene, tetrachloroethylene Inorganic solvents and the like, such as water; chlorinated organic solvents. These solvents (or dispersion media) can be used alone or in admixture of two or more.

  Examples of the printing method used for forming the pattern layer include a gravure printing method, an offset printing method, a screen printing method, a flexographic printing method, an electrostatic printing method, and an inkjet printing method. When forming a solid pattern pattern layer, for example, roll coating method, knife coating method, air knife coating method, die coating method, lip coating method, comma coating method, kiss coating method, flow coating method, dip coating Various coating methods such as a coating method may be mentioned. In addition, the hand-drawn method, the ink-sink method, the photographic method, the transfer method, the laser beam drawing method, the electron beam drawing method, the metal partial evaporation method, the etching method, etc. may be used or combined with other forming methods. Good.

  The thickness of the pattern layer is not particularly limited and can be set as appropriate according to the product characteristics, but the layer thickness after drying is about 0.1 to 20 μm.

(Primer layer)
A primer layer for facilitating formation of the surface protective layer can be provided on the transparent resin layer.
The primer layer can be formed by applying a known primer agent to the transparent resin layer. Examples of the primer agent include a urethane resin-based primer agent composed of an acrylic-modified urethane resin and the like, and a resin-based primer agent composed of a block copolymer of acrylic and urethane.

The application amount of the primer agent is not particularly limited, but is usually 0.1 to 20 g / m ² , preferably about 0.5 to 10 g / m ² .

(Surface protective layer)
A surface protective layer can be provided on the front surface of the decorative sheet for flooring in order to impart surface physical properties such as scratch resistance, abrasion resistance, water resistance and stain resistance. As the resin for forming the surface protective layer, a curable resin such as a thermosetting resin or an ionizing radiation curable resin is preferable. In particular, ionizing radiation curable resins are preferable from the viewpoint of high surface hardness, productivity, and the like.

  Examples of thermosetting resins include unsaturated polyester resins, polyurethane resins (including two-component curable polyurethane), epoxy resins, amino alkyd resins, phenol resins, urea resins, diallyl phthalate resins, melamine resins, guanamine resins, and melamines. -Urea co-condensation resin, silicon resin, polysiloxane resin and the like.

A curing agent such as a crosslinking agent and a polymerization initiator, and a polymerization accelerator can be added to the resin.
For example, as curing agents, isocyanates, organic sulfonates, etc. can be added to unsaturated polyester resins, polyurethane resins, etc., organic amines, etc. can be added to epoxy resins, peroxides such as methyl ethyl ketone peroxide, azoisobutyl nitrile, etc. A radical initiator can be added to the unsaturated polyester resin.

  Examples of the method for forming the surface protective layer with a thermosetting resin include a method in which a solution of a thermosetting resin is applied by a coating method such as a roll coating method or a gravure coating method and then dried and cured. The coating amount of the solution is about 5 to 30 μm, preferably about 10 to 20 μm, in terms of solid content after the solution is dried.

  The ionizing radiation curable resin is not limited as long as it is a resin that undergoes a crosslinking polymerization reaction upon irradiation with ionizing radiation and changes to a three-dimensional polymer structure. For example, one or more prepolymers, oligomers and monomers having a polymerizable unsaturated bond or epoxy group that can be crosslinked by irradiation with ionizing radiation in the molecule can be used. Examples thereof include acrylate resins such as urethane acrylate, polyester acrylate, and epoxy acrylate; silicon resins such as siloxane; polyester resins; epoxy resins and the like.

  Examples of the ionizing radiation include visible light, ultraviolet light (near ultraviolet light, vacuum ultraviolet light, etc.), X-rays, electron beams, ion beams, etc. Among them, ultraviolet light and electron beams are preferable.

  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, or a metal halide lamp can be used. The wavelength of ultraviolet light is about 190 to 380 nm.

  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 energy of the electron beam is preferably about 100 to 1000 keV, more preferably about 100 to 300 keV. The irradiation amount of the electron beam is preferably about 2 to 15 Mrad.

  The ionizing radiation curable resin is sufficiently cured when irradiated with an electron beam, but it is preferable to add a photopolymerization initiator (sensitizer) when it is cured by irradiation with ultraviolet rays.

  Examples of the photopolymerization initiator in the case of a resin system having a radically polymerizable unsaturated group include acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether, Michler benzoylbenzoate, Michler ketone, diphenyl sulfide, dibenzyl disulfide. , Diethyl oxide, triphenylbiimidazole, isopropyl-N, N-dimethylaminobenzoate and the like can be used. In the case of a resin system having a cationic polymerizable functional group, for example, at least one kind such as an aromatic diazonium salt, an aromatic sulfonium salt, a metallocene compound, a benzoin sulfonic acid ester, and a freeloxysulfoxonium diallyl iodosyl salt. Can be used.

  Although the addition amount of a photoinitiator is not specifically limited, Generally it is about 0.1-10 weight part with respect to 100 weight part of ionizing radiation curable resins.

  As a method of forming the surface protective layer with an ionizing radiation curable resin, for example, a solution of an ionizing radiation curable resin may be applied by a coating method such as a gravure coating method or a roll coating method. The coating amount of the solution is about 5 to 30 μm, preferably about 10 to 20 μm, in terms of solid content after the solution is dried.

  The surface protective layer preferably contains a hard filler for the purpose of further improving scratch resistance. The hard filler is not particularly limited as long as the scratch resistance of the surface protective layer can be further improved, but it is preferable to use spherical inorganic fine particles. Examples of the inorganic fine particles include powdered aluminum oxide, silicon carbide, silicon dioxide, calcium titanate, barium titanate, magnesium pyroborate, zinc oxide, silicon nitride, zirconium oxide, chromium oxide, iron oxide, boron nitride, Diamond, gold sand, glass fiber, fused silica and the like can be mentioned.

  Specific examples of the hard filler include spherical silica particles described in Japanese Patent No. 4834999.

The pore volume of the hard filler is preferably less than 1.0 ml / g, more preferably 0 ml / g or more and less than 1.0 ml / g. The apparent specific gravity when the hard filler is silica is preferably more than 0.4 g / cm ² and not more than 2.2 g / cm ² .

  The content of the hard filler is 1 to 10 parts by weight with respect to 100 parts by weight of the resin component forming the surface protective layer, which is a curable resin such as the thermosetting resin or ionizing radiation curable resin. Is preferred.

  The average particle size of the hard filler is preferably 1 to 5 μm.

  The surface protective layer may contain a matting agent as necessary. Although it does not specifically limit as said matting agent, For example, a silica is mentioned. The silica is preferably an amorphous, non-spherical particle in that the matte effect can be sufficiently exhibited.

  As the matting agent, one having a pore volume of 1.8 to 3.0 ml / g, an apparent specific gravity of 0.05 to 0.22 g / ml, and an oil absorption of 300 ml / 100 g or more is used. It is preferable. It is more preferable to use one having a pore volume of 1.9 to 2.5 ml / g, an apparent specific gravity of 0.10 to 0.20 g / ml, and an oil absorption of 300 to 400 ml / 100 g. By using a matting agent having a pore volume of 1.8 to 3.0 ml / g, an effect of irregular reflection of light can be efficiently obtained, so that a good matting effect can be obtained.

  It is preferable that content of the said matting agent is 8-20 weight part with respect to 100 weight part of resin components which form a surface protective layer. Moreover, it is preferable that the average particle diameter of the said matting agent is 9-15 micrometers.

  The thickness of the surface protective layer is preferably 5 to 30 μm. If the thickness of the surface protective layer is less than 5 μm, the scratch resistance may be poor. On the other hand, if it is thicker than 30 μm, the decorative sheet for flooring may be easily curled. The thickness of the surface protective layer is more preferably 10 to 20 μm.

  The surface protective layer may contain an ultraviolet absorber, a light stabilizer, a plasticizer, a stabilizer, a filler, a dispersant, a colorant such as a dye and a pigment, a solvent, an antibacterial agent, and the like, if necessary. .

(Embossing)
The decorative sheet for flooring of the present invention may be embossed from the transparent resin layer side after forming the transparent resin layer. Further, when a surface protective layer is formed on the transparent resin layer, the surface protective layer may be laminated on the transparent resin layer and then embossed from the surface protective layer side. .

  The embossing method is not particularly limited. For example, a preferable method is to heat and soften the front surface of the transparent resin layer or the surface protective layer, pressurize and shape with an embossing plate, and then cool. For embossing, a known single-wafer or rotary embossing machine is used. Examples of the concavo-convex shape include a wood grain plate conduit groove, a stone plate surface unevenness (such as granite cleaved surface), a cloth surface texture, a satin texture, a grain, a hairline, a ridge line, and the like.

  The decorative sheet of the present invention can be used as a decorative board by being laminated on an adherend. The adherend is not limited, and the same materials as those used for known decorative panels can be used.

  Examples of the adherend include wood base materials, metals, ceramics, plastics, and glass. In particular, the decorative sheet of the present invention can be suitably used for a wooden substrate. Wood substrates include veneer, wood veneer, wood plywood, wood fiberboard (MDF, HDF, etc.) made from various materials such as cedar, firewood, firewood, pine, firewood, firewood, firewood, lawan, teak, melapie ), A hard chip board (such as a particle board), a soft chip board (such as a cork), or a composite base material on which chip boards are laminated. Among the above-mentioned wood base materials, wood fiber boards, soft chip boards, or composite base materials on which soft chip boards are laminated are preferred, and further, wood fiber boards can be suitably used from the viewpoint of cost and robustness, From the viewpoint of warmth and walking, a soft chip board or a composite base material in which a soft chip board and a wood fiber board are laminated can be preferably used.

  The decorative sheet of the present invention has at least a transparent resin layer on the base sheet, and a thickness ratio (t1) / (t2) between the thickness (t1) of the transparent resin layer and the thickness (t2) of the base sheet. Is 1.5 / 1.0 to 1.0 / 1.5, and the total (t1) + (t2) of the thickness (t1) of the transparent resin layer and the thickness (t2) of the base sheet is 300 to Since it is 600 micrometers, it is excellent in impact resistance, caster resistance, embossing shapeability, and embossing fastness, and the curvature by heat contraction is controlled.

It is sectional drawing showing an example of the decorative sheet for flooring of this invention.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the examples.

(Preparation of decorative sheet for flooring)
Example 1
As a base material sheet, a colored polypropylene sheet (thickness: 160 μm) was prepared. After performing the corona discharge treatment on the front surface and the back surface of the base sheet, a primer agent was applied to each of the front surface and the back surface to form a primer layer (each thickness: 2 μm). The primer agent is a mixture of 100 parts by weight of a resin composition and 5 parts by weight of hexamethylene diisocyanate (curing agent). The resin composition contains an acrylic urethane copolymer, an acrylic polyol, and a triazine ultraviolet absorber (5 mass). %).

  Next, a pattern layer (thickness 2 μm) was formed on the primer layer on the surface, and a transparent adhesive layer (thickness 3 μm) was formed thereon. A transparent thermoplastic polypropylene resin was heated and melt-extruded by a T-die extruder on the transparent adhesive layer to form a transparent resin layer (thickness: 240 μm).

  Next, a corona discharge treatment was applied to the surface of the transparent resin layer, and a two-component curable urethane resin was applied to form a primer layer (thickness 2 μm) on the transparent resin layer.

  Next, the surface protective layer-forming composition was applied to the primer layer with a thickness of 15 μm by a gravure coating method. The composition for forming a surface protective layer comprises 80 parts by weight of a bifunctional urethane acrylate oligomer as a resin component (weight average molecular weight 1500 glass transition temperature -55 ° C.) and a hexafunctional aliphatic urethane acrylate oligomer (weight average molecular weight 1500 glass transition temperature). 20 parts by weight of UA306H manufactured by Kyoeisha Chemical Co., Ltd. at 200 ° C. or higher, and 14 parts by weight of amorphous silica having an average particle diameter of 11 μm as a matting agent with respect to 100 parts by weight of the resin component.

  Next, in an atmosphere having an oxygen concentration of 200 ppm, the coating film of the composition for forming a surface protective layer is irradiated with an electron beam under the conditions of an acceleration voltage of 175 keV and 5 Mrad (50 kGy) to crosslink and cure the coating film. Thus, a surface protective layer was formed.

Finally, a decorative sheet for flooring was produced by embossing from the surface protective layer side under the conditions of a sheet temperature of 140 ° C. and a pressure of 10 to 40 kg / cm ² . The thickness ratio (t1) / (t2) between the thickness (t1) of the transparent resin layer and the thickness (t2) of the base sheet is 1.5 / 1.0, and the total thickness (t1) + (t2) Was 400 μm.

Examples 2-7, Comparative Examples 1-7
The thickness (t1) of the transparent resin layer, the thickness (t2) of the base sheet, the thickness ratio (t1) / (t2), the total thickness (t1) + (t2), and the resin forming the base sheet Except having changed like 1, it carried out similarly to Example 1, and produced the decorative sheet for flooring of Examples 2-7 and Comparative Examples 1-7.

(Preparation of decorative materials for floors)
Examples 1-7, Comparative Examples 1-7
The decorative sheet for flooring was made into a water-based adhesive so that the back primer layer side of the decorative sheet for flooring of Examples 1 to 7 and Comparative Examples 1 to 7 produced as described above was in contact with the wooden substrate (MDF). (BA-10L / BA-11B, manufactured by Chuo Rika Kogyo Co., Ltd., coating amount: 7 g / scale angle) and pasting to a wooden substrate, Examples 1 to 7 and Comparative Examples 1 to 7 Was made.

Example 8
A floor decorative material of Example 8 was produced in the same manner as in Example 3 except that the wooden substrate was changed to a cork material.

(Evaluation method)
Impact resistance (DuPont impact test)
In accordance with the JISK5600 DuPont impact test, a shooting die having a hemispherical tip with a radius of 6.3 mm is allowed to stand on the surface of the floor decorative material produced as described above, and a weight of 500 g is placed on the shooting die. Was evaluated by dropping from a height of 30 cm. Evaluation was performed based on the following evaluation criteria by the amount of dents.

In addition, the following evaluation criteria are criteria set with reference to a general color floor dent amount of 500 to 600 μm. Here, a general color floor is a veneer (thickness: 0.25 mm) laminated on a plywood (thickness: 11.8 mm), and UV coating (thickness: 0.02 mm) is applied to the veneer. Means the color floor that is being.
A: 300 μm or less ○: Over 300 μm, 500 μm or less Δ: Over 500 μm, 600 μm or less X: Over 600 μm

Castor-resistant flooring fatigue tester No. 159-S was evaluated using Yasuda Seiki Seisakusho. Specifically, the floor decorative material produced as described above was cut into a size of 5 cm × 20 cm to obtain a sample, and the sample was fixed to a fixed base. A weight of 15 kg was placed on the weighted part, and one caster was brought into contact with the surface of the flooring decorative material with the adjusting handle (total load 25 kg), the caster fixing base was operated, and 25,000 reciprocations were made at a speed of 10 m / min. . Evaluation was performed based on the following evaluation criteria by the amount of dents.
◎: 50 μm or less ○: Over 50 μm, 80 μm or less Δ: Over 80 μm, 100 μm or less X: Over 100 μm, 120 μm or less XX: Over 120 μm

The gloss value of the outermost surface of the decorative sheet for embossing flooring was measured. The gross value was measured using a gloss meter PG-3D manufactured by Nippon Denshoku Industries Co., Ltd. The measurement of gloss value and G, as the reference value G ₀ of the measured value of the decorative sheet for floor material of Comparative Example 1 was evaluated according to the following evaluation criteria. In addition, the embossing plate used for embossing used the same thing in each Example and the comparative example, and also made the embossing speed the same speed.
A: G is in the range of G ₀ ± G ₀ × 10% ○: G is out of the range of G ₀ ± G ₀ × 10% and is in the range of G ₀ ± G ₀ × 20% ×: G is out of the range of G ₀ ± G ₀ × 20%

Emboss fastness The gloss value of the outermost surface of each decorative sheet for flooring was measured. Next, each decorative sheet for flooring was immersed in glycerin heated to 130 ° C. for 30 seconds, and then the gloss value of the outermost surface of the decorative sheet for flooring was measured again. In measuring the gloss value, a gloss meter PG-3D manufactured by Nippon Denshoku Industries Co., Ltd. was used. The evaluation criteria were as follows. In the following evaluation criteria, the gloss value of the decorative sheet before immersion and G _B, the gloss value of the decorative sheet after immersion and G _A. It can be said that the closer G _A is to G _B , the better the embossing fastness is because there is less disappearance of the uneven pattern.
◎: _{G A} is in the range of _{G B ± G B × 10%} ○: G A is the outside of the _{G B ± G B × 10%} , G B ± G B × 20% within the range in a △: _{G a} is the outside of the _{G B ± G B × 20%} , × is in the range of _{G B ± G B × 30%} : G a is, _{G B} ± _{G B} × 30% Out of range

A decorative sheet for flooring was affixed to the warped MDF surface due to heat shrinkage to produce a 1 × 6 size floor decorative material (width 313 mm × length 1840 mm). The obtained flooring decorative material was subjected to a test in which 10 cycles of a cycle of “leaving at 80 ° C. for 2 hours and then leaving at −20 ° C. for 2 hours” as one cycle were performed, and then the amount of warpage of the flooring decorative material was determined. It was measured. The evaluation criteria were as follows.
○: The amount of warpage in the side direction of length 1840 mm is 5 mm or less. Δ: The amount of warpage in the side direction of length 1840 mm exceeds 5 mm and 10 mm or less. ×: The amount of warpage in the side direction of length 1840 mm exceeds 10 mm and 20 mm or less. XX: The amount of warpage in the side direction with a length of 1840 mm exceeds 20 mm

Visual contrast observation was performed based on the sense of depth of a decorative sheet having a pattern depth-sensitive transparent resin layer thickness of 200 μm, and evaluation was performed according to the following evaluation criteria.
◎: Depth feeling better than the standard ○: Depth feeling equivalent to the standard △: Depth feeling is inferior to the standard

It was investigated whether the decorative sheet for flooring produced by the roll test could be wound. The evaluation criteria were as follows.
In the following evaluation criteria, winding was possible if the roll deviation width when rolled was within 3 cm, and roll was not possible if the roll deviation width was larger than 3 cm.
○: Winding width 0cm
Δ: Rolling width exceeds 0 cm and can be rolled within 3 cm ×: Winding width exceeds 3 cm and cannot be rolled

The test was conducted in accordance with the wear resistance JAS flooring wear A test. Specifically, the number of revolutions was measured when a pattern of each floor decorative material started to be taken using a Taber abrasion tester on the floor decorative material produced as described above. The evaluation criteria were as follows. In the above test, the rotation was performed under the conditions of abrasive paper S-42, load of 1000 g (including one wheel load of 500 g, including a rubber disk load).
◎: The number of rotations when the pattern starts to be taken is more than 2000 times. ○: The number of rotations when the pattern starts to be taken is more than 1500 times and less than 2000 times. Δ: When the pattern starts to be taken. More than 1000 times, 1500 times or less x: The number of rotations when the pattern starts to be taken is more than 500 times, 1000 times or less xx: The number of rotations when the pattern starts to be taken is 500 Less than

Walking feeling On the floor decorative material produced in Examples 3 and 8, the ease of walking was evaluated by comparing with a general veneer floor (reaction of the flooring to the person with respect to stepping). The evaluation was performed by 10 people selected at random.
In addition, with a general veneer floor, a veneer (thickness 0.30 mm) is laminated on a plywood (thickness 11.6 mm), and further UV coating (thickness 0.05 mm) is applied on the veneer. Means a veneer floor.
○: 8 or more people who felt easier to walk than the veneer floor △: 6 or more people who felt easier to walk than the veneer floor

  As is clear from the results in Table 1, the thickness ratio (t1) / (t2) between the thickness (t1) of the transparent resin layer and the thickness (t2) of the base sheet is 1.5 / 1.0 to 1. Example in which the total thickness (t1) + (t2) of the thickness (t1) of the transparent resin layer and the thickness (t2) of the base sheet is in the range of 300 to 600 μm, within the range of 0 / 1.5. The decorative sheets for flooring materials 1 to 7 were excellent in impact resistance, caster resistance, embossing shapeability and embossing fastness, and warpage due to heat shrinkage was suppressed.

  Furthermore, since the thickness of the transparent resin layer laminated | stacked on a design pattern layer is appropriate for the decorative sheet for flooring of Examples 1-7, the depth feeling of a pattern increases and it is excellent in design property, and Abrasion resistance was also excellent. In addition, since (t1) + (t2) is in an appropriate range, excellent results were also obtained in the roll test, and it was found that rolls were possible in the roll production process.

  On the other hand, in Comparative Example 1 where (t1) + (t2) is as thin as 250 μm, the caster resistance is inferior, and in Comparative Example 2 where 700 μm is thick, the embossing property is inferior and it is difficult to roll. I understood.

  Regarding the thickness ratio (t1) / (t2) of the thickness (t1) of the transparent resin layer and the thickness (t2) of the base sheet, in Comparative Examples 3 to 5 where the ratio of (t1) is large, the transparent resin layer is thick. Therefore, the amount of warpage due to heat shrinkage was large. In Comparative Example 3 in which the ratio of (t1) was particularly large, the embossing property and the embossing fastness were also inferior. Moreover, in the comparative example 6 with a large ratio of (t2), since the thickness of the base material sheet was too thick, the transparent resin layer was relatively thin and the impact resistance was inferior.

  In Comparative Example 7 where (t1) + (t2) is as thick as 700 μm and the ratio of (t1) is large in the thickness ratio (t1) / (t2), although it has excellent impact resistance and caster resistance, emboss shaping It turned out that it is inferior to a property and embossing fastness, the curvature amount by heat shrink is also large, and roll formation is also difficult.

1. 1. Primer layer 2. base material sheet Pattern layer 4. 4. Transparent adhesive layer 5. Transparent resin layer Primer layer 7. Surface protective layer

Claims (11)

A decorative sheet having at least a transparent resin layer on a base sheet,
(1) The thickness ratio (t1) / (t2) between the thickness (t1) of the transparent resin layer and the thickness (t2) of the base sheet is 1.5 / 1.0 to 1.0 / 1.5. And
(2) The total (t1) + (t2) of the thickness (t1) of the transparent resin layer and the thickness (t2) of the base sheet is 300 to 600 μm.
A decorative sheet characterized by that.   The decorative sheet according to claim 1, wherein the transparent resin layer has a thickness of 150 μm or more.   The decorative sheet according to claim 1 or 2, wherein the transparent resin layer is an olefin resin layer.   The said base material sheet is a decorative sheet in any one of Claims 1-3 containing at least 1 sort (s) of polyolefin resin and polyester resin.   The decorative sheet according to any one of claims 1 to 4, further comprising a pattern layer between the base sheet and the transparent resin layer.   The decorative sheet according to any one of claims 1 to 5, wherein a surface protective layer is laminated on the transparent resin layer.   The decorative sheet according to claim 6, wherein the surface protective layer is an ionizing radiation curable resin layer.   The decorative sheet according to claim 6 or 7, further comprising a primer layer between the transparent resin layer and the surface protective layer.   The decorative sheet according to any one of claims 1 to 8, which is embossed from the transparent resin layer side.   The decorative sheet according to any one of claims 1 to 9, which is for flooring.   A decorative board obtained by laminating the decorative sheet according to claim 1 on an adherend.

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