JP5499430B2 - Decorative sheet for flooring and method for producing the same - Google Patents

Description

  The present invention relates to a decorative sheet for flooring and a method for producing the same.

  As a decorative sheet for flooring using a polyolefin resin, for example, in Patent Documents 1 and 2, a decorative sheet laminated on a thick synthetic resin layer (so-called backer layer) made of a polyolefin resin is disclosed. Yes. Such a decorative sheet for flooring is made into a flooring decorative material by sticking a backer layer to various adherends. The backer layer is a thick synthetic resin layer (reinforcing layer) provided for imparting hardness, strength and the like to the decorative sheet for flooring.

  Conventionally, the decorative sheet for flooring having a backer layer is manufactured by pasting a backer layer on the back side of a decorative sheet by dry lamination or the like. There is a problem that it takes time for the above work and a curing time is required to wait for a curing reaction after bonding. Further, in the case of dry lamination, the adhesion may not be sufficient. In addition, in order to improve adhesiveness, there is an attempt to further laminate a primer layer on the adhesive surface, but this makes the production process longer.

Therefore, it is desired to develop a decorative sheet for flooring that can be produced by a simple method and that the backer layer and the decorative sheet are sufficiently bonded.
JP-A-8-13740 JP-A-8-1883

  The present invention relates to a decorative sheet for flooring obtained by bonding a synthetic resin layer (backer layer), which is a polypropylene resin layer, and a decorative sheet (decorative sheet intermediate), which is obtained by a simple method, and is also a backer layer. An object of the present invention is to provide a decorative sheet for flooring in which a decorative sheet and a decorative sheet are sufficiently bonded, and a simple manufacturing method thereof.

  As a result of intensive research, the present inventor can achieve the above-mentioned object when the base material and the synthetic resin layer of the decorative sheet contain a polypropylene resin and the decorative sheet and the synthetic resin layer are further bonded by thermal lamination. As a result, the present invention has been completed.

That is, this invention relates to the following decorative sheet for flooring, and its manufacturing method.
1. A decorative sheet for flooring, comprising a decorative intermediate sheet in which one or more layers are laminated on the surface of the base sheet, and a synthetic resin layer having a thickness of 150 μm or more laminated on the back surface of the base sheet. There,
(1) The base sheet and the synthetic resin layer both contain a polypropylene resin,
(2) The decorative sheet for flooring is obtained by heating the synthetic resin layer to 150 to 300 ° C., and closely laminating the base sheet of the decorative sheet intermediate therewith ,
(3) The base sheet is obtained by using the base sheet having a width of 5 mm, a length of 10 mm, and a thickness of 0.06 mm as a sample, and according to the provisions of JIS K0129 (TMA: thermomechanical analysis). The temperature when the sample was stretched 1.7 mm in the length direction when the temperature of the sample was changed from 30 to 180 ° C. at a rate of 5 ° C./min while applying a tensile load of 5 gf in the length direction of Is 120-140 ° C.,
A decorative sheet for flooring.
2. The decorative sheet for flooring according to Item 1, wherein the decorative sheet intermediate has a pattern layer, a transparent adhesive layer, a transparent resin layer, and a transparent surface protective layer in this order on the base sheet.
3. Item 3. The decorative sheet for flooring according to Item 2, wherein a colored concealing layer is further formed between the base sheet and the pattern layer.
4). Item 4. The decorative sheet for flooring according to Item 2 or 3, wherein embossing is applied from the front surface of the transparent surface protective layer.
5 . A decorative sheet for flooring comprising a decorative intermediate sheet in which one or more layers are laminated on the surface of the base sheet, and a synthetic resin layer having a thickness of 150 μm or more laminated on the back surface of the base sheet. A manufacturing method comprising:
(1) The base sheet and the synthetic resin layer both contain a polypropylene resin,
(2) The base sheet is a sample obtained by forming the base sheet into a shape having a width of 5 mm, a length of 10 mm, and a thickness of 0.06 mm, and the sample according to JIS K0129 (TMA: thermomechanical analysis). The temperature when the sample was stretched 1.7 mm in the length direction when the temperature of the sample was changed from 30 to 180 ° C. at a rate of 5 ° C./min while applying a tensile load of 5 gf in the length direction of Is 120-140 ° C,
(3) The manufacturing method which adheres by heating the said synthetic resin layer to 150-300 degreeC, making the said base material sheet of the said decorative sheet intermediate body contact | adhere there, and carrying out heat lamination.
6 . Item 5. A flooring decorative material obtained by adhering a back surface of a synthetic resin layer and an adherend to the flooring decorative sheet according to any one of Items 1 to 4 .

  Hereinafter, the decorative sheet for flooring of this invention and its manufacturing method are demonstrated.

The decorative sheet for flooring The decorative sheet for flooring of the present invention has a decorative sheet intermediate in which one or more layers are laminated on the surface of the base sheet, and a thickness laminated on the back surface of the base sheet. A decorative sheet for flooring having a synthetic resin layer (backer layer) of 150 μm or more,
(1) The base sheet and the synthetic resin layer both contain a polypropylene resin,
(2) The decorative sheet for flooring can be obtained by heat laminating the decorative sheet intermediate and the synthetic resin layer.

  In the decorative sheet for flooring of the present invention having the above characteristics, since the base sheet and the backer layer contain polypropylene resin, both are firmly bonded by thermal lamination. For this reason, sufficient adhesive strength can be obtained by simple thermal lamination as compared with dry lamination.

(Synthetic resin layer)
The decorative sheet for flooring of the present invention has a synthetic resin layer (so-called backer layer) having a thickness of 150 μm or more on the back surface of the base material sheet.

  The backer layer contains a polypropylene resin. The polypropylene resin may be not only a homopolymer mainly composed of polypropylene but also a copolymer. Examples thereof include homopolypropylene resins, random polypropylene resins, block polypropylene resins, and α-olefins having a polypropylene crystal part and having 2 to 20 carbon atoms other than propylene. 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 included.

  The backer layer may be a laminate of two or more layers. For example, a laminate of two or more polypropylene resin layers may be used.

  The thickness of the backer layer should just be 150 micrometers or more, and about 250-400 micrometers is preferable.

  The backer layer can be easily formed by, for example, extrusion of molten resin. When the coextrusion method is used, a backer layer made of a laminate can be easily formed. For coextrusion film formation, for example, a multi-manifold type or feed block type T-die can be used.

(Makeup sheet intermediate)
The decorative sheet intermediate has one or more layers laminated on the surface of a base material sheet containing a polypropylene resin.

  As a decorative sheet intermediate, for example, a layer structure in which at least a pattern layer, an adhesive layer, a transparent resin layer, and a transparent surface protective layer are provided on a base sheet, and the transparent surface protective layer is the outermost surface layer. Is mentioned as a preferred embodiment. The outermost surface layer of the decorative sheet may be provided with an uneven pattern by embossing.

  The formation method of each layer is not limited, for example, printing such as gravure printing, flexographic printing, silk screen printing, offset printing, transfer printing; application of spray, roller, brush, etc .; Any of these can be employed. What is necessary is just to select combining suitably from these methods according to the characteristic, raw material, etc. of each layer.

  The thickness of each layer is not limited, and can be determined as appropriate according to the use and characteristics of the final product. Usually, it can be in the range of about 0.1 to 500 μm.

  Hereinafter, each layer will be described using the above embodiment as a representative example.

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

  As the substrate sheet, a sheet containing a polypropylene resin is used. The polypropylene resin may be not only a homopolymer mainly composed of polypropylene but also a copolymer. Examples thereof include homopolypropylene resins, random polypropylene resins, block polypropylene resins, and α-olefins having a polypropylene crystal part and having 2 to 20 carbon atoms other than propylene. 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 included.

  The base sheet preferably contains about 10 to 60% by weight (preferably about 20 to 40% by weight) of a thermoplastic elastomer component. Thereby, the adhesiveness of a base material sheet and a synthetic resin layer can be improved more.

  The base sheet is a sample of the base sheet having a width of 5 mm, a length (= distance between chucks) of 10 mm, and a thickness of 0.06 mm. According to the provisions of JIS K0129 (TMA: thermomechanical analysis), When the temperature of the sample is changed from 30 to 180 ° C. at a rate of 5 ° C./min while applying a tensile load of 5 gf in the length direction of the sample (starting from 30 ° C. to 180 ° C. at the rate) Furthermore, it is preferable that the temperature when the sample is stretched 1.7 mm in the length direction is 140 ° C. or less. Among these, 130-140 degreeC is more preferable, and a lower limit is about 120 degreeC. On the other hand, when the temperature exceeds 140 ° C., there is a possibility that the heat laminating characteristics are deteriorated. In addition, the sample used for the said thermomechanical analysis uses what was fully heat-dried at the temperature of about 110 degreeC.

  In the case of having the above temperature characteristics, particularly the adhesive strength between the base sheet and the backer layer can be increased.

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

  In the case of coloring the base sheet, the base sheet has a three-layer structure, and the intermediate layer contains a colorant, whereby the adhesive strength when the base sheet and the backer layer are thermally laminated is further increased. It can be improved and contributes to pollution prevention.

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

  Although the thickness of a base material sheet can be suitably set with the use of a final product, a usage method, etc., generally 50-250 micrometers is preferable.

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

≪Pattern pattern layer (pattern layer) ≫
The pattern layer provides a desired pattern (design) to the decorative sheet, and the type of the pattern is not 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, printing using ink 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 in the base-material sheet | seat surface by a method.

  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.

  As binder resin, polyester urethane resin, polyester urethane resin with hydrophilic treatment, polyester, polyacrylate, polyvinyl acetate, polybutadiene, polyvinyl chloride, chlorinated polypropylene, polyethylene, polystyrene, polystyrene-acrylate A polymer, a rosin derivative, an alcohol adduct of a styrene-maleic anhydride copolymer, a cellulose resin, or the like can be used in combination.

  More specifically, for example, polyurethane-polyacrylic resin, polyacrylamide resin, poly (meth) acrylic acid resin, polyethylene oxide resin, poly N-vinylpyrrolidone resin, water-soluble polyester resin, water-soluble Polyamide resins, water-soluble amino resins, water-soluble phenol resins, other water-soluble synthetic resins; water-soluble natural polymers such as polynucleotides, polypeptides, polysaccharides, etc. can be used. Further, for example, natural rubber, synthetic rubber, polyvinyl acetate resin, (meth) acrylic resin, polyvinyl chloride resin, polyurethane-polyacrylic resin modified or mixed resin, and other resins can also be used. The binder resin can be used alone or in combination 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. In addition, when further forming a solid colored layer (also referred to as a colored concealing layer) between the base sheet and the pattern layer, a roll coating method, a knife coating method, an air knife coating method, a die coating method, a lip Examples of the coating method include a coating method, a comma coating method, a kiss coating method, a flow coating method, and a dip coating method.

  In addition to the above, for example, 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. are used or combined with other forming methods. It may be used.

  The thickness of the pattern layer is not particularly limited and can be appropriately set 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. The thickness of the colored hiding layer after drying is preferably about 0.1 to 10 μm.

≪Adhesive layer≫
The adhesive layer exists between the pattern layer and the transparent resin layer. The adhesive used in the adhesive layer can be appropriately selected depending on the components constituting the pattern layer or the transparent resin layer. For example, various adhesives including polyurethane resin, polyacrylic resin, polycarbonate resin, epoxy resin and the like can be used. In addition to the reactive curing type, an adhesive such as a hot melt type, an ionizing radiation curing type, and an ultraviolet curing type may be used.

  In the present invention, an adhesive capable of thermocompression bonding is used, and the pattern layer and the transparent resin layer can be laminated by thermocompression bonding.

  The adhesive layer may be transparent or translucent as long as the pattern layer can be recognized.

  In the present invention, a known easy adhesion treatment such as a corona discharge treatment, a plasma treatment, a degreasing treatment, a surface roughening treatment or the like can be applied to the adhesion surface as necessary.

  The thickness of the adhesive layer varies depending on the transparent resin layer, the type of adhesive to be used, and the like, but is generally about 0.1 to 30 μm.

≪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 include polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyamide, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, and ionomer. , Polymethylpentene, acrylic acid ester, methacrylic acid ester, polycarbonate, cellulose triacetate and the like. Among the above, 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 generally about 10 to 150 μm.

≪Transparent surface protective layer≫
A transparent surface protective layer is formed on the transparent resin layer. The transparent surface protective layer is not limited, but preferably contains an ionizing radiation curable resin or a two-component curable urethane resin as a resin component. Substantially those formed from these resins are preferred. When forming a transparent surface protective layer with ionizing radiation curable resin or two-component curable urethane resin, it is easy to improve the abrasion resistance, impact resistance, contamination resistance, scratch resistance, weather resistance, etc. of the decorative sheet. .

  The ionizing radiation curable resin is not particularly limited, and prepolymers (including oligomers) and / or monomers containing radically polymerizable double bonds capable of undergoing a crosslinking reaction upon irradiation with ionizing radiation such as ultraviolet rays and electron beams. A transparent resin containing as a main component can be used. These prepolymers or monomers can be used alone or in combination. The curing reaction is usually a cross-linking curing reaction.

  Specifically, as the prepolymer or monomer, a compound having in the molecule a radically polymerizable unsaturated group such as a (meth) acryloyl group or (meth) acryloyloxy group, or a cationically polymerizable functional group such as an epoxy group. Is mentioned. Further, a polyene / thiol prepolymer based on a combination of polyene and polythiol is also preferable. Here, the (meth) acryloyl group means an acryloyl group or a methacryloyl group.

  Examples of the prepolymer having a radically polymerizable unsaturated group include polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, melamine (meth) acrylate, triazine (meth) acrylate, and silicone (meth) acrylate. Etc. These molecular weights are usually preferably about 250 to 100,000.

  As a monomer which has a radically polymerizable unsaturated group, methyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, phenoxyethyl (meth) acrylate etc. are mentioned as a monofunctional monomer, for example. Examples of the polyfunctional monomer include diethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethylene oxide tri (meth) acrylate, dipentaerythritol tetra ( And (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate.

  Examples of the prepolymer having a cationic polymerizable functional group include prepolymers of epoxy resins such as bisphenol type epoxy resins and novolac type epoxy compounds, and vinyl ether type resins such as fatty acid type vinyl ethers and aromatic vinyl ethers. Examples of the thiol include polythiols such as trimethylolpropane trithioglycolate and pentaerythritol tetrathioglycolate. Examples of the polyene include those in which allyl alcohol is added to both ends of polyurethane by diol and diisocyanate.

  As the ionizing radiation used for curing the ionizing radiation curable resin, electromagnetic waves or charged particles having energy capable of causing a curing reaction of molecules in the ionizing radiation curable resin (composition) are used. Usually, ultraviolet rays or electron beams may be used, but visible light, X-rays, ion rays, or the like may be used.

  As the ultraviolet light source, for example, 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, a metal halide lamp can be used. As a wavelength of ultraviolet rays, 190 to 380 nm is usually preferable.

  As the electron beam source, for example, 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. Among them, those capable of irradiating electrons having energy of 100 to 1000 keV, preferably 100 to 300 keV are preferable.

  The two-component curable urethane resin is not particularly limited. Among them, a polyol component (acrylic polyol, polyester polyol, polyether polyol, epoxy polyol, etc.) having an OH group as a main component and an isocyanate component (tolylene diene) which is a curing agent component. Isocyanate, hexamethylene diisocyanate, metaxylene diisocyanate and the like) can be used.

  These transparent surface protective layers may contain a plasticizer, a stabilizer, a filler, a dispersant, a dye, a pigment, and the like, if necessary.

  For example, the transparent surface protective layer is formed by applying an ionizing radiation curable resin or a two-component curable urethane resin on the transparent resin layer by a known coating method such as gravure coating or roll coating, and then curing the resin. Can be formed. In the case of an ionizing radiation curable resin, the resin is cured by electron beam irradiation.

  The thickness of the transparent surface protective layer is not particularly limited and can be appropriately set according to the properties of the final product, but is usually about 0.1 to 50 μm, preferably about 1 to 20 μm.

≪Embossing≫
The decorative sheet intermediate may be embossed from the transparent surface protective layer side. Furthermore, it is preferable to perform a wiping process of filling ink into the recesses by embossing and to coat the surface with a two-component curable urethane resin (overcoat treatment).

  Embossing is performed to give a desired texture such as a wood grain pattern to the decorative sheet. For example, after heating and softening the transparent surface protective layer on a heating drum, it is further heated to 140 to 170 ° C. with an infrared radiation heater, pressed and shaped with an embossed plate having a desired shape of uneven pattern, and cooled. A texture is given by fixing. Embossing can be performed with a known single wafer or rotary embossing machine.

  Examples of the embossed concavo-convex pattern include a wood grain conduit groove, a float pattern (a concavo-convex pattern of a raised annual ring), a hairline, a grain, and a satin texture.

  The wiping process is a process of filling the embossed recess with ink while scratching the surface with a doctor blade. As the wiping ink, an ink having a two-component curable urethane resin as a binder can be used. In the wiping process, the product value can be increased by expressing the design closer to the actual wood grain, particularly by performing on the wood grain conduit groove unevenness.

  In the present invention, the transparent surface protective layer may contain other components. For example, additives such as a solvent, an ultraviolet absorber, an antioxidant, a dispersant, a light stabilizer, a gloss adjusting agent, an antiblocking agent, and a lubricant can be blended.

Production method of decorative sheet for flooring The decorative sheet for flooring is produced by bonding a base sheet of a decorative sheet intermediate and a backer layer by thermal lamination. Since both the base sheet and the backer layer contain polypropylene, they can be sufficiently adhered by heat lamination. The description of the base sheet and the backer layer is as described above.

  The conditions for thermal lamination are not particularly limited as long as the two are bonded. For example, the backer layer is heated to about 150 to 300 ° C. (preferably about 240 to 280 ° C.), and the decorative sheet intermediate (base sheet side) is brought into close contact therewith for thermal lamination.

  Moreover, you may heat laminate by the method of forming a backer layer directly on the back surface of a base material sheet by melt extrusion. In this case, the melt flow rate (MFR) of the polypropylene resin subjected to melt extrusion is preferably 2 to 20 g / 10 minutes (230 ° C. extrusion), and more preferably 2 to 15 g / 10 minutes. The MFR is a value measured by the method of JIS-K7210.

Flooring decorative material The flooring decorative sheet of the present invention can be made into a flooring decorative material by bonding with various adherends. The material of the adherend is not particularly limited, and examples thereof include inorganic non-metallic materials, metallic materials, wood materials, and plastic materials.

  Specifically, in inorganic non-metallic systems, for example, papermaking cement, extruded cement, slag cement, ALC (lightweight cellular concrete), GRC (glass fiber reinforced concrete), pulp cement, wood chip cement, asbestos cement, calcium oxalate, Non-ceramic ceramic materials such as gypsum and gypsum slag, ceramic materials such as earthenware, ceramics, porcelain, setware, glass, and glazing.

  In a metal system, metal materials (metal steel plate), such as iron, aluminum, and copper, are mentioned, for example.

  In the wood system, for example, a single board, plywood, particle board, fiber board, laminated timber and the like made of cedar, straw, firewood, lauan, teak and the like can be mentioned.

  In the plastic type, for example, a single plate or a plywood made of a resin material such as polypropylene, ABS resin, or phenol resin can be used. A foamed resin material obtained by foaming the above resin can also be used. Such plastic materials may include inorganic fillers such as calcium carbonate, titanium oxide, clay and the like.

  The shape of such an adherend is not particularly limited, and may be a flat plate in consideration of installation on a flooring or the like.

  After joining with the adherend, for example, according to the characteristics of the final product, cutting, use of a tenor, sag processing, provision of V-shaped grooves, chamfering on four sides, etc. may be performed.

  In the decorative sheet for flooring of the present invention, since the base sheet and the backer layer contain polypropylene resin, both are firmly bonded by heat lamination. For this reason, sufficient adhesive strength can be obtained by simple thermal lamination as compared with dry lamination. In particular, the advantage is high in that application of an adhesive and formation of a primer layer can be omitted.

  Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples.

Example 1
(Preparation of decorative sheet for flooring)
A colored polypropylene (base material sheet) having a thickness of 0.06 mm was prepared. A pattern layer (2 μm) was formed on the base sheet by printing. Next, a 0.08 mm thick transparent polypropylene resin film (transparent resin layer) was adhered onto the pattern layer using a urethane dry laminate adhesive. The thickness of the transparent adhesive layer was 3 μm. Next, an electron beam curable transparent surface protective layer (15 μm) was formed on the transparent resin layer. Next, embossing was performed from the transparent surface protective layer side to produce a decorative sheet intermediate. In embossing, a grain conduit pattern with a depth of about 30 μm was applied.

Finally, a resin melted at 260 ° C. (two types and three layers) was coextruded to form a backer layer, and the base sheet side of the decorative sheet intermediate was placed thereon, and both were adhered by thermal lamination. The backer layer was a laminate formed of 30 μm homopolypropylene (MFR: 6 g / 10 min) / 190 μm homopolypropylene (MFR: 2 g / 10 min) / 30 μm homopolypropylene (MFR: 6 g / 10 min).
(Preparation of decorative materials for floors)
A 12 mm lauan plywood was stuck to the back surface (backer layer side) of the produced decorative sheet for flooring to prepare a flooring decorative material. A urethane-modified ethylene-vinyl acetate emulsion adhesive (9 g / scale ² wet) was used for pasting.

Comparative Example 1
A flooring decorative material was produced in the same manner as in Example 1 except that the adhesion between the decorative sheet intermediate and the backer layer was performed by dry lamination instead of thermal lamination. The backer layer was prepared in advance and used at room temperature.

The adhesive used for the dry lamination was a two-component thermosetting urethane adhesive, and the coating amount was about 2 g / m ² .

Test example 1
The interlayer strength between the base sheet and the backer layer of the floor decorative material produced in Examples and Comparative Examples was measured and evaluated.

  The interlayer strength was measured according to JIS-K6854. Specifically, a 25 mm width cut is made on the decorative sheet side of the decorative material for flooring and peeled between the base sheet and the backer layer in accordance with the above-mentioned JIS regulations. I investigated. The wet heat test was conducted under the conditions of a temperature of 80 ° C. and a humidity of 90% for leaving the floor decorative material to stand for 200 hours. The results are shown in Table 1 below.

  As can be seen from Table 1, the floor decorative material of the present invention bonded by thermal lamination has higher interlayer strength between the base sheet and the backer layer than the conventional product bonded by dry lamination. Particularly in dry laminate products, strength reduction due to the wet heat test is remarkable, but in the heat laminate products, sufficient interlayer strength is maintained even after the wet heat test.

Reference Examples 1-3
In Example 1, the interlayer strength (normal strength) between the base sheet and the backer layer when the TMA tensile properties of the base sheet were changed as shown in Table 2 below was measured and evaluated. The method for measuring the normal strength is the same as described above. The base sheet used in Example 1 had a TMA tensile property of 138 ° C.

  The above TMA tensile properties are obtained by using a base sheet having a width of 5 mm, a length of 10 mm, and a thickness of 0.06 mm as a sample, and in the length direction of the sample in accordance with JIS K0129 (TMA: thermomechanical analysis). This is the temperature when the sample is stretched 1.7 mm in the length direction when the temperature of the sample is changed from 30 to 180 ° C. at a rate of 5 ° C./min while applying a tensile load of 5 gf. In addition, the sample used what was fully heat-dried at 110 degreeC.

  From the results in Table 2, it can be seen that the use of a base sheet having a TMA tensile property of 140 ° C. or lower is effective in developing the interlayer strength.

Claims (6)

A decorative sheet for flooring, comprising a decorative intermediate sheet in which one or more layers are laminated on the surface of the base sheet, and a synthetic resin layer having a thickness of 150 μm or more laminated on the back surface of the base sheet. There,
(1) The base sheet and the synthetic resin layer both contain a polypropylene resin,
(2) The decorative sheet for flooring is obtained by heating the synthetic resin layer to 150 to 300 ° C., and closely laminating the base sheet of the decorative sheet intermediate therewith ,
(3) The base sheet is obtained by using the base sheet having a width of 5 mm, a length of 10 mm, and a thickness of 0.06 mm as a sample, and according to the provisions of JIS K0129 (TMA: thermomechanical analysis). The temperature when the sample was stretched 1.7 mm in the length direction when the temperature of the sample was changed from 30 to 180 ° C. at a rate of 5 ° C./min while applying a tensile load of 5 gf in the length direction of Is 120-140 ° C.,
A decorative sheet for flooring.   The decorative sheet intermediate for flooring according to claim 1, wherein the decorative sheet intermediate has a pattern layer, a transparent adhesive layer, a transparent resin layer, and a transparent surface protective layer in this order on the base sheet.   The decorative sheet for flooring according to claim 2, wherein a colored concealing layer is further formed between the base sheet and the pattern layer.   The decorative sheet for flooring according to claim 2 or 3, wherein embossing is applied from the front surface of the transparent surface protective layer. A decorative sheet for flooring comprising a decorative intermediate sheet in which one or more layers are laminated on the surface of the base sheet, and a synthetic resin layer having a thickness of 150 μm or more laminated on the back surface of the base sheet. A manufacturing method comprising:
(1) The base sheet and the synthetic resin layer both contain a polypropylene resin,
(2) The base sheet is a sample obtained by forming the base sheet into a shape having a width of 5 mm, a length of 10 mm, and a thickness of 0.06 mm, and the sample according to JIS K0129 (TMA: thermomechanical analysis). The temperature when the sample was stretched 1.7 mm in the length direction when the temperature of the sample was changed from 30 to 180 ° C. at a rate of 5 ° C./min while applying a tensile load of 5 gf in the length direction of Is 120-140 ° C,
(3) The manufacturing method which adheres by heating the said synthetic resin layer to 150-300 degreeC, making the said base material sheet of the said decorative sheet intermediate body contact | adhere there, and carrying out heat lamination. The flooring decorative material formed by sticking the back surface of the synthetic resin layer in the decorative sheet for flooring in any one of Claims 1-4 , and a to-be-adhered material.