JP4998044B2 - Decorative sheet - Google Patents

Description

The present invention relates to a decorative sheet.

  Conventionally, a polyvinyl chloride resin sheet is frequently used as a constituent material of a resin-made decorative sheet. As a manufacturing method of a polyvinyl chloride resin sheet, there is a method of adding a plasticizer to a polyvinyl chloride resin (Patent Document 1). When the sheet is used, the polyvinyl chloride resin sheet hardness (hard to soft) can be easily adjusted by adjusting the amount of plasticizer added, and it has excellent scratch resistance and can be easily embossed. There is.

  However, polyvinyl chloride resin may release harmful black smoke and chlorinated gas during incineration. In recent years, instead of polyvinyl chloride resin, olefin-based resins have been used as resins that do not release chlorine-based gas during incineration.

  Generally as a decorative sheet, what laminated | stacked a pattern pattern layer, a transparent adhesive layer, and a transparent resin layer in order on the base material sheet is used. The decorative material sheet is usually used by cutting according to the product size.

However, when an olefin resin is used as a constituent material of a resin-made decorative sheet, depending on the type of the olefin resin, the scratch resistance of the decorative sheet is inferior. When cut into a product size, the transparent resin layer portion of the cut surface There are problems such as whitening. When the cut surface is whitened, it is not preferable because the design property is lowered.
JP 2004-019343 A

  The main object of the present invention is to provide a decorative sheet that is excellent in scratch resistance and has a cut surface that is hardly whitened when cut.

  As a result of intensive studies, the present inventor has found that a decorative sheet having a specific configuration can achieve the above object, and has completed the present invention.

That is, the present invention relates to the following decorative sheet.
JIS described in this specification refers to Japanese Industrial Standards.
1. A decorative sheet formed by laminating at least a transparent resin layer having a thickness of 40 to 500 μm on a base sheet,
(1) The transparent resin layer contains a random polypropylene copolymer as a resin component,
(2) A transparent surface protective layer is further laminated on the transparent resin layer,
(3) A synthetic resin layer having a thickness of 1 to 5 mm is further laminated on the back surface of the base sheet,
(4) the synthetic resin layer comprises a polyethylene as a resin component, and, seen containing an inorganic filler 20 to 80 wt%,
The random polypropylene copolymer is a propylene-ethylene random copolymer,
The propylene-ethylene random copolymer has a copolymerization ratio of propylene and ethylene of 99/1 to 94/6.
Makeup sheet.
2. Item 2. The decorative sheet according to Item 1, wherein a pattern layer, a transparent adhesive layer, the transparent resin layer, and the transparent surface protective layer are sequentially laminated on the base sheet.
3 . Item 3. The decorative sheet according to Item 1 or 2 , wherein the transparent resin layer has a tensile elastic modulus of 500 to 1200 MPa measured according to JIS K6734.
4 . Item 4. The decorative sheet according to any one of Items 1 to 3 , wherein the decorative sheet has a tensile elastic modulus of 400 to 1500 MPa measured according to JIS K6734.
5 . The transparent surface protective layer is formed of a composition containing an ionizing radiation polymerizable oligomer, and the ionizing radiation polymerizable oligomer is:
(A) 60 to 80% by weight of urethane (meth) acrylate oligomer having 2 radically polymerizable unsaturated groups in one molecule and (B) 3 to 15 radically polymerizable unsaturated groups in one molecule It is a mixture comprising 20 to 40% by weight of an aliphatic urethane (meth) acrylate oligomer,
Item 5. The decorative sheet according to any one of Items 1 to 4 .

When the decorative sheet of the present invention is cut according to the product size, the cut surface is hardly whitened.

  Moreover, the decorative sheet of the present invention is excellent in scratch resistance. For example, even if embossing is performed, cracks hardly occur on the surface. In particular, the decorative sheet of the present invention comprises (A) 60 to 80% by weight of a urethane (meth) acrylate oligomer having two radical polymerizable unsaturated groups in one molecule and (B) 1 as a transparent surface protective layer. It has a layer formed by a composition containing an ionizing radiation polymerizable oligomer which is a mixture of 20 to 40% by weight of an aliphatic urethane (meth) acrylate oligomer having 3 to 15 radically polymerizable unsaturated groups in the molecule. In this case, it is possible to further improve the scratch resistance. Moreover, the decorative sheet of the present invention having the transparent surface protective layer is also excellent in stain resistance.

  Furthermore, when the decorative sheet of the present invention has a synthetic resin layer (also called a backer layer) having a thickness of 1 to 5 mm on the back surface of the base sheet, a random polypropylene copolymer is formed on the back surface of the synthetic resin layer. Of the transparent resin layer having a thickness of 40 to 500 μm (that is, a resin layer having the same quality as the transparent resin layer laminated on the front surface side of the base sheet). The shrinkage and warpage of the decorative sheet can be prevented.

  The decorative sheet of the present invention can be suitably used as a decorative sheet for floors.

The decorative sheet of the present invention is a decorative sheet obtained by laminating at least a transparent resin layer having a thickness of 40 to 500 μm (hereinafter abbreviated as “first transparent resin layer”) on a base sheet,
(1) The transparent resin layer contains a random polypropylene copolymer as a resin component,
(2) A transparent surface protective layer is further laminated on the transparent resin layer.

  The configuration of the decorative sheet of the present invention is not particularly limited as long as the first transparent resin layer is laminated on the base sheet (the front surface of the base sheet). For example, a decorative sheet formed by sequentially laminating a pattern layer, a transparent adhesive layer, the first transparent resin layer, and a transparent surface protective layer on a base sheet is exemplified.

  Hereinafter, the decorative sheet of the present invention will be specifically described with the decorative sheet having such a configuration as a representative example.

Although it does not specifically limit as a base material sheet Base material sheet, The film containing polyolefin resin as a resin component is preferable. 90-100 weight% is preferable and, as for content of polyolefin resin in a base material sheet, 95-100 weight% is more preferable.

  The polyolefin resin is not particularly limited, and those usually used in the field of decorative sheets 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. These can be used alone or in combination of two or more. Among these, polyethylene, polypropylene, polyolefin-based thermoplastic elastomers and the like are particularly preferable.

  The polyolefin resin is preferably a homopolymer or a copolymer mainly composed of polypropylene. For example, a homopolypropylene resin, a random polypropylene resin, a block polypropylene resin, and a copolymer of a crystalline part of polypropylene and an α-olefin having 2 to 20 carbon atoms other than propylene can be given. 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 a block polymer using isotactic polypropylene for the hard segment and atactic polypropylene for the soft segment. In particular, an elastomer obtained by mixing a hard segment made of isotactic polypropylene and a soft segment made of atactic polypropylene at a weight ratio of 80:20 is preferable.

  A well-known 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). These can be used alone or in combination of two or more. About the compounding quantity of the said additive, it can set suitably according to a product characteristic.

  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. These can be used alone or in combination of two or more. The coloring mode of the base sheet includes transparent coloring and opaque coloring (hiding coloring), and these can be arbitrarily selected. For example, when the ground color of the adherend (base material to which the decorative sheet is bonded) is concealed, opaque coloring may be selected. On the other hand, in order to make the ground pattern of the adherend visible, transparent coloring may be selected.

  The base sheet is obtained by forming a resin composition containing the resin component or the like into a film by, for example, a calendar method, an inflation method, a T-die extrusion method, or the like.

  The thickness of the said base material sheet is not specifically limited, Usually, 50-150 micrometers, Preferably it is about 60-80 micrometers.

  The front surface of the base sheet may be subjected to surface treatment such as corona discharge treatment, ozone treatment, plasma treatment, ionizing radiation treatment, or dichromic acid treatment as necessary. For example, when the corona discharge treatment is performed, the surface tension of the substrate sheet surface may be 35 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 the front surface of the base sheet, if necessary. By providing the primer layer, the interlayer adhesion with the pattern layer (or colored hiding layer) can be increased.

The primer layer can be formed by applying a known primer agent to the front surface of the substrate sheet. As the primer agent, for example, an acrylic-urethane resin-based primer agent made of an acrylic-modified urethane resin or the like is preferable in that it has weather resistance. The application amount of the primer agent is not particularly limited, but is usually 0.1 to 100 g / m ² , preferably about 0.1 to 50 g / m ² .

  Although the thickness of a primer layer is not specifically limited, Usually, 0.01-10 micrometers, Preferably it is about 0.1-1 micrometer.

A pattern layer is formed on the pattern pattern layer base sheet (front surface).

  The design pattern layer imparts design properties with a desired design to the decorative sheet, 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 etc.

  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 resins, styrene resins, polyester resins, urethane resins, acrylic-urethane resins, chlorinated polyolefin resins, vinyl chloride-vinyl acetate copolymer resins, polyvinyl butyral resins. Alkyd resins, petroleum resins, ketone resins, epoxy resins, melamine resins, fluorine resins, silicone resins, fiber derivatives, rubber resins, 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.

  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.

A colored concealment layer may be further formed between the colored concealment layer base sheet and the pattern layer, if necessary. The colored masking layer is provided when it is desired to mask the ground color of the adherend (base) from the front surface of the decorative sheet. Of course, when the base sheet is transparent, even when the base sheet is concealed, it may be formed to stabilize the concealment.

  As the ink for forming the colored masking layer, an ink for forming a pattern layer and capable of masking coloring can be used.

  The method for forming the colored concealment layer is preferably a method that can be formed so as to cover the entire base sheet (entirely solid). For example, the 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 method and the like described above are preferable.

  The thickness of the colored concealing layer is not particularly limited and can be set as appropriate according to the product characteristics. The layer thickness during coating is about 0.2 to 10 μm, and the layer thickness after drying is about 0.1 to 5 μm.

Transparent adhesive layer A transparent adhesive layer is formed on the pattern layer. The transparent adhesive layer is not particularly limited as long as it is transparent, and includes any of transparent and colorless, colored and translucent. This adhesive layer is formed in order to bond the pattern layer and the transparent resin layer.

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

  The transparent adhesive layer can be formed, for example, by applying an adhesive on the pattern layer and drying / curing it. Conditions such as drying temperature and drying time are not particularly limited, and may be set as appropriate according to the type of adhesive. The method of applying the adhesive is not particularly limited, and examples thereof include roll coating, curtain flow coating, wire bar coating, reverse coating, gravure coating, gravure reverse coating, air knife coating, kiss coating, blade coating, smooth coating, and comma coating. The method can be adopted.

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

A first transparent resin layer having a thickness of 40 to 500 μm is formed on the first transparent resin layer and the transparent adhesive layer. The first transparent resin layer is not particularly limited as long as it is transparent, and includes any of colorless and transparent, colored and transparent, translucent and the like.

  The thickness of the first transparent resin layer is 40 to 500 μm, preferably 80 to 400 μm. By setting the thickness of the first transparent resin layer to 40 to 500 μm, it is possible to obtain a decorative sheet having excellent wear resistance while suppressing cost.

  The first transparent resin layer includes a random polypropylene copolymer as a resin component. By including a random polypropylene copolymer as a resin component, whitening of the cut surface of the decorative sheet can be prevented. Moreover, the impact resistance excellent in the decorative sheet can be provided.

  The random polypropylene copolymer means a copolymer obtained by randomly copolymerizing propylene and a monomer other than propylene.

  Examples of the monomer other than propylene include ethylene and 1-butene. These monomer components are contained alone or in combination of two or more. Among the monomers, ethylene is particularly preferable. When the polypropylene is a copolymer of propylene and ethylene, whitening of the cut surface of the decorative sheet can be more effectively prevented.

  The copolymerization ratio of propylene and the monomer may be appropriately set according to the type of the monomer, etc. For example, when the monomer is ethylene, the copolymerization ratio of propylene and ethylene is 99 to 94: 1. ~ 6 is preferred. When the copolymerization ratio of propylene and ethylene is 99 to 94: 1 to 6, whitening of the cut surface of the decorative sheet can be more effectively prevented.

  The content of the random polypropylene copolymer in the first transparent resin layer is preferably 90 to 100% by weight, and more preferably 95 to 100% by weight.

  The first transparent resin layer may contain a resin other than the random polypropylene copolymer such as homopolypropylene as long as the effects of the present invention are not hindered.

  The first transparent resin layer preferably has a tensile modulus measured according to JIS K6734 of 500 to 1200 MPa, and more preferably 600 to 900 MPa. When a tensile elasticity modulus is 500-1200 MPa, the whitening phenomenon of a cut surface can be suppressed more reliably.

  In addition, the tensile elasticity modulus in this specification is a value measured in accordance with the provisions of JIS K6734 “Plastics—Hard Polyvinyl Chloride Sheet—Dimensions and Properties—Part 2: Sheet with a Thickness of Less than 1 mm”.

  Specifically, using a tensile tester (Tensilon universal tester RTC-1250A), a test sample punched into the shape of FIG. 1 (synthetic resin layer, and selected from the group consisting of a base sheet and a transparent resin layer) When the both ends (A and B in FIG. 2) are pulled at a speed of 50 mm / min., The tensile elastic modulus (MPa) is measured when the test sample is cut at the central portion. It is the value obtained by doing.

  As a method for forming the first transparent resin layer, for example, a resin composition containing the resin component or the like is laminated on the transparent adhesive layer by, for example, a calendar method, an inflation method, a T-die extrusion method, or the like. The method of doing is mentioned.

  Corona discharge treatment, ozone treatment, plasma treatment, ionizing radiation treatment, dichromic acid treatment, etc., as necessary, on the surface of the first transparent resin layer, on which the transparent surface protective layer described later is formed. The surface treatment may be performed. The surface treatment may be performed according to a conventional method for each treatment.

  Moreover, you may provide a primer layer (primer layer for making formation of a surface protective layer easy) on the surface as needed.

  The primer layer can be formed by applying a known primer agent to the surface of the first transparent resin layer. As the primer agent, those exemplified above can be used.

The application amount of the primer agent is not particularly limited, but is usually 0.1 to 100 g / m ² , preferably about 0.1 to 50 g / m ² .
Although the thickness of a primer layer is not specifically limited, Usually, 0.01-10 micrometers, Preferably it is about 0.1-1 micrometer.

Transparent surface protective layer A transparent surface protective layer is formed on the first transparent resin layer. By forming the transparent surface protective layer, excellent scratch resistance is imparted to the decorative sheet.

  In particular, in the present invention, the transparent surface protective layer is preferably formed of a composition containing an ionizing radiation polymerizable oligomer. The ionizing radiation polymerizable oligomer includes (A) 60 to 80% by weight of a urethane (meth) acrylate oligomer having two radical polymerizable unsaturated groups in one molecule and (B) 3 to 15 in one molecule. A mixture composed of 20 to 40% by weight of an aliphatic urethane (meth) acrylate oligomer having a radically polymerizable unsaturated group is preferable. This surface protective layer can further improve the scratch resistance of the decorative sheet of the present invention.

  The urethane (meth) acrylate oligomer (A) is one having two radical polymerizable unsaturated groups in one molecule (so-called bifunctional urethane acrylate oligomer). This includes, for example, a) a diisocyanate, b) a polyhydric alcohol having two or more hydroxyl groups in one molecule (preferably a weight average molecular weight of 500 to 2000), c) a hydroxyl group at the terminal and a radically polymerizable unsaturated group. An oligomer formed by bonding a (meth) acrylate compound to be included is mentioned. The oligomer preferably has a weight average molecular weight of 1000 to 4000. When the molecular weight is 1000 or more, the flexibility of the urethane (meth) acrylate can be sufficiently exerted in the cured resin layer, and workability during embossing can be improved. Moreover, when the molecular weight is 4000 or less, various properties such as contamination resistance can be improved.

  The diisocyanate a) is an aliphatic, alicyclic or aromatic isocyanate having two or more isocyanate groups in one molecule, such as 2,4-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 1 , 6-hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and the like.

  Examples of the polyhydric alcohol b) include polyester polyols having a hydroxyl group at both ends, polyether polyols, polycarbonate polyols, and acrylic polyols. Examples of the polyester polyol include (a) an addition reaction product of a diol compound having an aromatic or spiro ring skeleton and a lactone compound or a derivative thereof or an epoxy compound, and (b) a condensation product of a polybasic acid and an alkylene glycol. And (c) a ring-opening polyester compound derived from a cyclic ester compound, and these can be used alone or in admixture of two or more. For example, a polyester diol having a hydroxyl group at both ends (particularly a weight average molecular weight of 500 to 2000) obtained as a condensation product with an alkylene glycol using adipic acid as the polybasic acid of (b) above has various physical properties. Therefore, it is preferably used. As the alkylene glycol, ethylene glycol is preferable. Examples of the polyether polyol include polytetramethylene ether glycol, polyethylene glycol, and polypropylene glycol.

  The (meth) acrylate c) is an ester compound of acrylic acid or methacrylic acid or a derivative thereof, and has a hydroxyl group at the terminal. Specifically, 2-hydroxyethyl (meth) acrylate, 2-hydroxylpropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxycyclohexyl (meth) acrylate, 5-hydroxycyclooctyl (meth) acrylate , (Meth) acrylic acid ester compounds having one polymerizable unsaturated group such as 2-hydroxy-3-phenyloxypropyl acrylate, etc., or having two or more polymerizable unsaturated groups in one molecule (meth) Examples include acrylic ester compounds.

  As the urethane (meth) acrylate oligomer (A), the polyhydric alcohol component is a polyester polyol having a weight average molecular weight of 500 to 2000 formed from alkylene glycol and adipic acid, the diisocyanate component is isophorone diisocyanate, and the acrylate component is An oligomer having a weight average molecular weight of 1000 to 3000 obtained by reacting these with hydroxyethyl (meth) acrylate is desirable.

  The aliphatic urethane (meth) acrylate oligomer (B) has a radically polymerizable unsaturated group such as 3 to 15 (meth) acryloyl groups in one molecule. This is obtained by reacting a) an aliphatic diisocyanate, b) a polyfunctional polyol, c) a (meth) acrylate having a hydroxyl group at the terminal and having a radically polymerizable unsaturated group. ) Urethane acrylate.

  Examples of the aliphatic diisocyanate a) include 1,6-hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and the like.

  As the polyfunctional polyol b), those having the polyhydric alcohol as a basic skeleton and having a plurality of functional groups can be used.

  Examples of the (meth) acrylate c) include 2-hydroxyethyl (meth) acrylate, 2-hydroxylpropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxycyclohexyl (meth) acrylate, and 5-hydroxycyclohexane. Examples include (meth) acrylic acid ester compounds having one polymerizable unsaturated group such as octyl (meth) acrylate and 2-hydroxy-3-phenyloxypropyl acrylate.

  As the ionizing radiation polymerizable oligomer, a mixture composed of 60 to 80% by weight of the urethane (meth) acrylate oligomer (A) and 20 to 40% by weight of the aliphatic urethane (meth) acrylate oligomer (B) is used. When said (A) is 60 weight% or more, a surface protective layer has sufficient flexibility, malleability, etc., and can improve the impact resistance of the decorative sheet of this invention. Moreover, when said (A) is 80 weight% or less, sufficient scratch resistance, abrasion resistance, and stain resistance can be provided to the decorative sheet of the present invention. In addition, the compounding quantity of said (A) and said (B) is the weight% of each component with respect to the total weight of said oligomer (A) and oligomer (B) in the coating composition which forms a curable resin layer. To express.

  The composition containing the ionizing radiation polymerizable oligomer may contain additives such as a matting agent and a matting agent, if necessary.

  The composition can be prepared by mixing these components uniformly. The formation method of the transparent surface protection layer by this composition may follow a well-known method, for example, if a coating film by the above-mentioned composition is formed and the coating film is crosslinked and cured by irradiating with an electron beam under known use conditions good.

  As an electron beam source of ionizing radiation, various electron beam accelerators such as a cockcroft Walton type, a bandegraft type, a resonant transformer type, an insulated 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 usually 100 to 1000 keV, preferably 100 to 300 keV. The irradiation amount of the electron beam is usually 1 to 30 Mrad.

  The thickness of the transparent surface protective layer is usually 2 to 20 μm, preferably 5 to 15 μm.

Synthetic resin layer In the decorative sheet of the present invention, it is preferable to further laminate a synthetic resin layer having a thickness of 1 to 5 mm on the back surface of the base sheet. Since the synthetic resin layer absorbs the unevenness of the adherend (base), the smoothness of the decorative material obtained using the decorative sheet of the present invention can be improved.
Although the thickness of the said synthetic resin layer should just be 1-5 mm, Preferably it is 2-3 mm.
As the synthetic resin layer, a known synthetic resin layer (backer layer) may be used. In particular, (1) polyethylene is included as a resin component, and (2) inorganic filler is 20 to 80% by weight, It is preferable to use a layer containing 20 to 50% by weight.

  By including polyethylene as a resin component, the synthetic resin layer can impart flexibility to the decorative sheet of the present invention and give excellent followability to the base shape. As the polyethylene, for example, at least one polyethylene selected from the group consisting of high-density polyethylene, medium-density polyethylene, and low-density polyethylene can be used.

  What is necessary is just to set suitably content of the said polyethylene in a synthetic resin layer in the range which does not impair the performance of the said synthetic resin layer, and 10 to 80 weight% is preferable.

  Examples of the inorganic filler include calcium carbonate, talc, silica, aluminum hydroxide, magnesium hydroxide, antimony trioxide, zinc borate, and a molybdenum compound. These can be used alone or in combination of two or more. Among the inorganic fillers exemplified above, calcium carbonate is particularly preferable.

  By making the content of the inorganic filler in the synthetic resin layer 20% by weight or more, the use ratio of the resin component is relatively reduced, and accordingly, the decorative sheet of the present invention can be produced at a low cost. it can.

  The synthetic resin layer may further include a resin other than polyethylene as a resin component.

  Examples of resins other than polyethylene include polypropylene (homopolypropylene, random polypropylene, block polypropylene), ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, and styrene copolymer. (For example, styrene-butadiene-styrene block copolymer, etc.).

  As a method for forming the synthetic resin layer, for example, a resin composition containing the above resin component or the like is formed into a sheet shape by, for example, a calendar method, an inflation method, a T-die extrusion method, etc., and then laminated on the back surface of the base sheet At the same time, a method of pressing from the transparent surface protective layer side at 100 to 130 ° C. using an embossing roll described later can be mentioned.

Second transparent resin layer In the decorative sheet according to the present invention, the back surface of the synthetic resin layer further contains a random polypropylene copolymer as a resin component, and has a thickness of 40 to 500 µm, preferably 80 to 400 µm. A conductive resin layer (second transparent resin layer) may be laminated. As said 2nd transparent resin layer, the thing similar to the said 1st transparent resin layer can be used. By laminating a resin layer of the same quality as the first transparent resin layer on the back surface of the synthetic resin layer, it is possible to prevent shrinkage and warpage of the decorative sheet of the present invention.

  As a method for forming the second transparent resin layer, for example, the resin composition used for forming the first transparent resin layer is formed on the back surface of the synthetic resin layer by a calendar method, an inflation method, a T-die extrusion method, or the like. And laminating method.

Primer layer A primer layer may be formed on the back surface (base bonding surface) of the decorative sheet of the present invention, if necessary. By forming the primer layer, the adhesion between the decorative sheet constituting the decorative material and the base can be improved. The primer layer can be formed by applying a known primer agent.
As the primer agent, those exemplified above can be used.

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

  Although the thickness of a primer layer is not specifically limited, Usually, 0.01-10 micrometers, Preferably it is about 0.1-1 micrometer.

Weathering agent At least one of the layers constituting the decorative sheet of the present invention may contain a weathering agent, if necessary. As the weathering agent, ultraviolet absorbers such as benzophenone, benzotriazole, and triazine, hindered amine light stabilizers, and the like are preferable. These weathering agents can be used alone or in admixture of two or more.

Embossing An embossed pattern may be applied to the front surface of the decorative sheet of the present invention as necessary. The embossed pattern can be applied by, for example, a known embossing roll. For example, a desired embossed pattern can be formed by pressing from 100 to 130 ° C. from the transparent surface protective layer side using an embossing roll. Embossed patterns include wood grain plate conduit grooves, stone plate surface irregularities, cloth surface textures, satin texture, sand texture, hair lines, and multi-line grooves.

  The decorative sheet of the present invention is used after being cut using a known cutter such as a guillotine cutter.

  After cutting, the base sheet side (the opposite side of the first transparent resin layer) can be used by sticking it to the adherend (base). For example, when the decorative sheet of the present invention has the synthetic resin layer, the synthetic resin layer side is adhered to an adherend (base).

  The decorative sheet of the present invention can be used by sticking to various adherends (bases). In particular, the decorative sheet of the present invention is advantageous in that it can be used by directly sticking to a ground such as mortar or concrete. In sticking, a known adhesive such as vinyl copolymer resin, vinyl acetate resin, acrylic resin, synthetic rubber, urethane resin, or epoxy resin can be used. The said adhesive agent can be suitably selected according to a construction place etc. For example, when constructing the decorative sheet of the present invention in a place where water resistance is required, an epoxy resin adhesive can be suitably used.

  The decorative sheet of the present invention can be suitably used particularly as a decorative sheet for floors.

  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.

Example 1
A decorative sheet having the structure shown in FIG. 2 was produced by the following method.

An acrylic-urethane resin (a resin obtained by adding 5 parts by weight of hexamethylene diisocyanate to 100 parts by weight of an acrylic polyol) solution on a base sheet 1 made of a colored polyethylene film having a thickness of 80 μm is obtained by a gravure printing method. A primer layer for printing (not shown) was formed by coating so as to be ² g / m ² .

  By a gravure printing method using a printing ink with an acrylic-urethane resin (a resin obtained by adding 5 parts by weight of hexamethylene diisocyanate to 100 parts by weight of an acrylic polyol) on a printing primer layer (not shown). A woodgrain pattern layer 2 was formed.

A thermosetting urethane resin adhesive is applied onto the pattern layer 2 so that the solid content is 8 g / m ² , and a random polypropylene copolymer is heated and melt-extruded by a T-die extruder, and 8 μm. A thick transparent adhesive layer 3 and a first transparent resin layer 4 having a thickness of 300 μm were formed. The tensile modulus of the resin layer 2 alone was 600 MPa.

  The random polypropylene copolymer used was a copolymer of propylene and ethylene, and a copolymerization ratio of propylene and ethylene of 96: 4.

After the surface of the first transparent resin layer 4 is subjected to corona discharge treatment, an acrylic-urethane resin (resin obtained by adding 5 parts by weight of hexamethylene diisocyanate to 100 parts by weight of acrylic polyol) is applied to the corona discharge treatment surface. A primer layer (not shown) for forming a transparent surface protective layer was formed by applying a gravure printing method so that the solid content was 1 g / m ² .

Roll an ionizing radiation polymerizable oligomer composed of 80% by weight of bifunctional urethane acrylate oligomer (A) and 20% by weight of hexafunctional urethane acrylate oligomer (B) on a primer layer (not shown) for forming a transparent surface protective layer. The uncured electron beam curable resin layer was formed by coating and drying so that the solid content was 15 g / m ² by a coating method.

  The bifunctional urethane acrylate oligomer is formed by bonding a) isophorone diisocyanate, b) polyester diol (condensation product of adipic acid and ethylene glycol) and c) 2-hydroxyethyl acrylate, and has a weight average. The molecular weight is 1700.

  As the hexafunctional urethane acrylate oligomer, product name “UA306H” manufactured by Kyoeisha Chemical Co., Ltd. was used.

  After forming an uncured electron beam curable resin layer, in an environment with an oxygen concentration of 200 ppm, the uncured resin layer is irradiated with an electron beam under conditions of an acceleration voltage of 125 KeV and 5 Mrad to cure the resin to obtain a 15 μm thick electron. A line curable resin layer (transparent surface protective layer 5) was formed.

  Next, a synthetic resin layer 6 having a thickness of 2 mm is thermally laminated at 120 ° C. on the back surface of the substrate sheet (opposite side to the printing primer layer), and at the same time, a grainy pipe-like uneven pattern having a depth of 50 μm is formed by embossing. Formed.

  The synthetic resin layer 6 comprises 50% by weight of polyethylene and 50% by weight of calcium carbonate, and was prepared by heat-melting and extruding a composition comprising polyethylene and calcium carbonate with a T-die extruder.

  A decorative sheet was prepared by the above process.

  The thickness of the produced decorative sheet was about 2.4 mm.

  The decorative sheet obtained above was cut into single sheets with a guillotine cutter.

Comparative Example 1
A flooring decorative material was produced in the same manner as in Example 1, except that the first transparent resin layer was formed using homopolypropylene instead of the random polypropylene copolymer. The tensile elastic modulus of the first transparent resin layer alone was 1500 MPa.

Comparative Example 2
In the formation of the uncured electron beam curable resin layer, the content of the bifunctional urethane acrylate oligomer in the ionizing radiation polymerizable oligomer is 50% by weight, and the content of the hexafunctional urethane acrylate oligomer is 50% by weight. A flooring decorative material was produced in the same manner as in Comparative Example 1.

Test Example 1 (Cutability)
The presence or absence of whitening of the cut surface of the decorative sheet of the floor decorative material obtained in Examples and Comparative Examples was confirmed by visual observation.
The case where the cut surface was not whitened was evaluated as ○, and the case where the cut surface was whitened was evaluated as ×.
The results are shown in Table 1.

Test Example 2 (Scratch Resistance (Embossing Suitability))
It was confirmed by visual observation whether cracks were generated on the surface (transparent surface protective layer side) of the floor decorative material obtained in Examples and Comparative Examples.
The case where no crack was generated on the surface was evaluated as ◯, and the case where a crack was generated was evaluated as ×.
The results are shown in Table 1.

FIG. 1 is a top view of a test sample to be measured when measuring a tensile elastic modulus in accordance with the provisions of JIS K6734 “Plastic—Rigid polyvinyl chloride sheet—Dimensions and characteristics—Part 2: Sheet having a thickness of less than 1 mm”. It is. 2 is a conceptual diagram (cross-sectional view) of the decorative sheet produced in Example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Base material sheet 2 ... Pattern pattern layer 3 ... Transparent adhesive layer 4 ... 1st transparent resin layer 5 ... Transparent surface protection layer 6 ... Synthetic resin layer

Claims (5)

A decorative sheet formed by laminating at least a transparent resin layer having a thickness of 40 to 500 μm on a base sheet,
(1) The transparent resin layer contains a random polypropylene copolymer as a resin component,
(2) A transparent surface protective layer is further laminated on the transparent resin layer,
(3) A synthetic resin layer having a thickness of 1 to 5 mm is further laminated on the back surface of the base sheet,
(4) the synthetic resin layer comprises a polyethylene as a resin component, and, seen containing an inorganic filler 20 to 80 wt%,
The random polypropylene copolymer is a propylene-ethylene random copolymer,
The propylene-ethylene random copolymer has a copolymerization ratio of propylene and ethylene of 99/1 to 94/6.
Makeup sheet.   The decorative sheet according to claim 1, wherein a pattern layer, a transparent adhesive layer, the transparent resin layer, and the transparent surface protective layer are sequentially laminated on the base sheet. The decorative sheet according to claim 1 or 2 , wherein the transparent resin layer has a tensile elastic modulus of 500 to 1200 MPa measured according to JIS K6734. The decorative sheet, the tensile modulus was measured in accordance with the provisions of JIS K6734 is 400～1500MPa, decorative sheet according to any one of claims 1-3. The transparent surface protective layer is formed of a composition containing an ionizing radiation polymerizable oligomer, and the ionizing radiation polymerizable oligomer is:
(A) 60 to 80% by weight of urethane (meth) acrylate oligomer having 2 radically polymerizable unsaturated groups in one molecule and (B) 3 to 15 radically polymerizable unsaturated groups in one molecule It is a mixture comprising 20 to 40% by weight of an aliphatic urethane (meth) acrylate oligomer,
The decorative sheet according to any one of claims 1 to 4 .

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