JP4992564B2 - Decorative sheet - Google Patents

Description

  The present invention relates to a decorative sheet used for floor tiles for interiors in buildings, and particularly relates to a decorative sheet that does not use vinyl chloride and has no problems such as warping and peeling.

  Conventionally, as floor tiles for interiors of houses, stores, office buildings, etc., decorative sheets made of polyvinyl chloride resin that are flexible, easy to process, and inexpensive have been frequently used. However, polyvinyl chloride resin may generate toxic substances such as hydrogen chloride and dioxin during combustion. Problems such as fire and environmental pollution caused by incineration after use are pointed out. Became a problem.

  In order to solve such a problem, as a non-halogen type decorative sheet instead of a polyvinyl chloride resin decorative sheet, an ionomer resin is sandwiched between a pattern layer on a backer layer mainly composed of an acrylate copolymer resin. A decorative sheet formed by laminating layers made of is proposed and has already been put into practical use.

  This ionomer resin-based decorative sheet is superior in flexibility and easy to construct even when compared with a decorative sheet made of polyvinyl chloride resin, but on the other hand, because the thermal stretchability of the resin is large, Depending on the construction environment, problems such as gaps and warping due to thermal expansion and contraction may occur, which is a problem.

Therefore, the present inventors attempted to prevent these warpages by providing an intermediate resin layer made of a polyester resin between the ionomer resin layers sandwiching the pattern layer, particularly below the pattern layer. However, when an inorganic filler is further added to the intermediate layer to suppress thermal stretchability and biaxial stretching is performed, a slight void is generated around the inorganic filler in the resin layer due to stretching, and the entire resin layer is It becomes fragile. As a result, there has been a problem of peeling from the intermediate resin layer in a peel test of the decorative sheet.
JP 2004-223823 A

  The present invention has been made to solve such problems, and the problem is that the ionomer resin-based decorative sheet has no problem of warping and is peeled from the resin layer provided in the middle. It is to provide a decorative sheet without any problems.

  The present invention solves this problem, that is, the invention according to claim 1 is characterized in that a first ionomer resin is formed on a backer layer mainly composed of an ethylene-vinyl acetate copolymer resin containing an inorganic filler. A decorative sheet comprising a layer, a non-stretched amorphous polyethylene terephthalate resin layer containing an inorganic filler, a pattern layer, a second ionomer resin layer, and a third ionomer resin layer at least in this order. .

  Further, the invention according to claim 2 is a non-stretched amorphous material in which the thickness of the backer layer is 1 to 5 mm, the thickness of the first ionomer resin layer is 40 to 60 μm, and the inorganic filler is contained. The layer thickness of the conductive polyethylene terephthalate resin layer is 50 to 70 μm, the layer thickness of the second ionomer resin layer is 40 to 60 μm, and the layer thickness of the third ionomer resin layer is 200 to 500 μm. The decorative sheet according to claim 1.

From the inventions according to claims 1 and 2 of the present invention, since it is a decorative sheet using an ionomer resin as a main layer constituent material, harmful substances such as hydrogen chloride gas and dioxin are present at the time of incineration at the time of disposal or at the time of fire. Needless to say, it has the same performance as a conventional decorative sheet made of polyvinyl chloride resin in terms of flexibility, surface hardness, abrasion resistance and the like.
In addition, while providing a non-stretched amorphous polyethylene terephthalate resin layer containing an inorganic filler below the pattern layer between the ionomer resin layers provided across the pattern layer, while suppressing thermal stretchability There is an effect of preventing a warp and preventing a problem of peeling without causing a decrease in strength in the layer, and providing an excellent practical decorative sheet.

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 shows a cross-sectional structure of one embodiment of the decorative sheet of the present invention. On the backer layer 1 mainly composed of an ethylene-vinyl acetate copolymer resin containing an inorganic filler, a first ionomer resin layer 2 and an unstretched amorphous polyethylene terephthalate resin layer 3 containing an inorganic filler The pattern layer 4, the second ionomer resin layer 5, and the third ionomer resin layer 6 are laminated at least in this order.
In addition, the surface of the third ionomer resin layer 6 may be embossed to give a desired design.

  The backer layer 1 in the present invention contains an ethylene-vinyl acetate copolymer resin as a main component and contains an inorganic filler in order to reduce thermal stretchability. As the inorganic filler, for example, silica, alumina, calcium carbonate, barium sulfate, titanium oxide, zinc oxide, kaolin, talc and the like can be used singly or in combination of two or more, but the heat stretchable From the viewpoint of the reduction effect, it is most desirable to use talc as the main component. In general, the content of the inorganic filler needs to be at least 20 parts by weight or more per 100 parts by weight of the resin component, and it is desirable to design appropriately within the range of about 50 to 500 parts by weight.

  As the resin component of the backer layer 1, in addition to the ethylene-vinyl acetate copolymer resin, which is the main component, any thermoplastic resin compatible with the resin may be used. However, in consideration of combustion problems, it is desirable to use a non-halogen thermoplastic resin. Specifically, for example, polyolefin resin, polyester resin, polystyrene resin, acrylic resin, and the like. Furthermore, in order to improve the compatibility, for example, a compatibilizing agent such as an acid-modified polyolefin resin grafted with an unsaturated carboxylic acid such as maleic acid or an anhydride thereof may be added.

  In order to color the backer layer 1 in a desired color tone, a colorant such as an inorganic pigment or an organic pigment may be added. In addition, various additives such as an ultraviolet absorber, a light stabilizer, an antioxidant, an internal mold release agent, an antistatic agent, and an antibacterial agent may be appropriately added as necessary. The thickness of the backer layer 1 is usually designed in the range of about 1 to 5 mm.

  The ionomer resin used in the decorative sheet of the present invention is generally a resin in which organic and inorganic components are bonded by covalent bond and ionic bond. As the ionomer resin particularly preferably used in the present invention, Examples include resins in which the molecules of the coalescence are crosslinked with metal ions. Examples of the copolymer in this case include an acrylate copolymer, such as an ethylene-methacrylic acid copolymer. Examples of the metal ion include sodium, potassium, magnesium, zinc and the like.

  In order to obtain an ionomer resin, for example, an ethylene polymer obtained by copolymerizing a monomer having a carboxyl group in the side chain (for example, acrylic acid), a metal hydroxide such as sodium, potassium, magnesium, or zinc, A method of neutralizing an acid group by adding an appropriate amount of alkoxide or a lower fatty acid salt can be mentioned. As a result, the carboxyl anions distributed along the molecular chain are electrostatically combined with the metal cations existing between the molecular chains to form a kind of cross-linking, and the inter-copolymer molecules are completely bonded with the metal ions. Alternatively, an ionomer resin having a partially crosslinked structure is obtained.

  Since the ionomer resin preferably used in the present invention is the above-described copolymer resin, the hardness of the sheet can be arbitrarily selected depending on the copolymer composition, and the cross-linking bond by metal ions is weakened by heating. It has properties very similar to those of polyvinyl chloride resin, in which the bonding strength is restored upon cooling. Therefore, the decorative sheet of the present invention using the above-mentioned ionomer resin can be manufactured in a conventional process using, for example, a conventional vinyl chloride decorative sheet manufacturing facility manufactured by thermal lamination and embossing. There is an advantage of being.

The ionomer resin used in the ionomer resin layers 2, 5, and 6 in the present invention can be added with appropriate additives such as an ultraviolet absorber, a light stabilizer, and a heat stabilizer as necessary.
As a method for forming the ionomer resin layer, the ionomer resin layer is formed into a film shape or a sheet shape by an appropriate method such as an extrusion method, a calendar method, or an inflation method.

  The first ionomer resin layer 2 is provided in consideration of the thermal adhesiveness between the thick and hard backer layer 1 and the non-stretched amorphous polyethylene terephthalate resin layer 3 containing an inorganic filler described later. . Since the backer layer 1 is bonded by applying a certain amount of pressure, it also serves as a buffer layer at that time. Therefore, it may be thinner than the backer layer 1, and the layer thickness is preferably about 40 to 60 μm.

  The second ionomer resin layer 5 is provided in consideration of the thermal adhesiveness between the non-stretched amorphous polyethylene terephthalate resin layer 3 containing the inorganic filler described later and the third ionomer resin layer 6. . Since the third ionomer resin layer 6 is bonded by applying a certain pressure, it also serves as a buffer layer at that time. Therefore, it may be thinner than the third ionomer resin layer 6, and usually about 40 to 60 μm.

  The non-stretched amorphous polyethylene terephthalate resin layer 3 containing an inorganic filler, which is a feature of the present invention, is used in the decorative sheet of the present invention in order to reduce thermal expansion and contraction and warpage. Between the layer 6 and between the first ionomer resin layer and the second ionomer resin layer sandwiching the pattern layer 4, it is provided below the pattern layer 4.

  In order to suppress the thermal expansion and contraction of the flexible third-side ionomer resin layer 6, the backer layer 1 is mainly composed of an ethylene-vinyl acetate copolymer resin containing an inorganic filler and having a low thermal expansion and contraction. However, since the warp is likely to occur due to the difference in thermal expansion and contraction, the third ionomer resin layer 6 has a thermal stretchability sandwiched between the backer layer 1 and an approximate intermediate resin layer. This offsets the thermal expansion and contraction effect, further reducing the thermal stretchability of the decorative sheet as a whole, and reducing warpage due to thermal expansion and contraction. And in the biaxially stretched polyester resin previously used as the intermediate resin layer, the strength of the layer may be reduced due to the biaxial stretching with the inorganic filler added for adjustment. A non-stretched amorphous polyethylene terephthalate resin containing an inorganic filler was used. Thereby, it became possible to adjust the content of the inorganic filler and the layer thickness of each layer to further prevent warpage and to optimize the peelability.

  The thickness of the non-stretched non-crystalline polyethylene terephthalate resin layer 3 containing an inorganic filler is designed in consideration of the balance of thermal stretchability of the entire decorative sheet described above. In general, good results are obtained within a range of about 50 to 70 μm.

  As the inorganic filler used for the non-stretched amorphous polyethylene terephthalate resin layer 3 containing an inorganic filler, the same filler as that contained in the above-described backer layer 1 can be used. The content of the inorganic filler is preferably about 1% by weight to 20% by weight. In addition to the inorganic filler, a colorant and other additives may be appropriately added as necessary.

  The amorphous polyethylene terephthalate resin used in the present invention can be produced by copolymerizing terephthalic acid (TPA) and 1,4 cyclohexanedimethanol (CHDM).

  Since the inorganic filler is contained, the non-stretched amorphous polyethylene terephthalate resin layer 3 containing the inorganic filler is low in transparency, so that the pattern layer 4 is at least non-stretched amorphous containing the inorganic filler. It will be provided above the conductive polyethylene terephthalate resin layer 3. On the contrary, the non-stretched non-crystalline polyethylene terephthalate resin layer 3 containing an inorganic filler was colored white or chromatic in order to conceal the color variation of the backer layer 1 and stabilize the design. It is preferable to use an opaque one.

  The pattern layer 4 is provided to give a desired pattern design by printing or the like. The type of the pattern formed by the pattern layer 4 is not particularly limited. For example, a wood grain pattern, a stone pattern, a cloth pattern, a grain pattern, an abstract pattern, a geometric figure, a character or a symbol, or a combination thereof may be arbitrarily selected as desired. is there.

  The kind of printing ink used for the pattern layer 4 is not specifically limited, Arbitrary printing ink conventionally used for the decorative sheet which concerns can be used. Specifically, for example, binder resins such as butyral, acrylic, urethane, polyester, epoxy, alkyd, and polyamide, organic or inorganic dyes or pigments, and extenders and fillers as necessary Any conventionally known printing ink prepared by appropriately adding a tackifier, a dispersant, an antifoaming agent, a stabilizer and other additives and adjusting the viscosity to a desired level with an appropriate dilution solvent can be used.

  A primer layer (not shown) may be provided on the upper side and / or the lower side of the pattern layer 4 as necessary in order to ensure interlayer adhesion with each resin layer. Examples of the material for the primer layer include isocyanate curable urethane resins, ethylene-vinyl acetate copolymer resins, modified polyolefin resins in which a functional group such as a hydroxyl group, an amino group, or a carboxyl group is introduced into a side chain or a terminal. These can be used alone or in admixture of two or more.

  The thickness of the third ionomer resin layer 6 needs to be appropriately designed in consideration of appropriate flexibility, surface hardness, abrasion resistance, durability, etc. of the surface of the decorative sheet, and is particularly limited in the present invention. However, a thickness of about 200 to 500 μm is usually appropriate.

Hereinafter, the manufacturing method of the decorative sheet of this invention is demonstrated.
As in the case of a conventional decorative sheet made of polyvinyl chloride resin, it can be produced by a thermal lamination method. First, a first ionomer resin layer 2, an unstretched non-crystalline polyethylene terephthalate resin layer 3 containing an inorganic filler, a pattern layer 4, and a second ionomer resin layer 5 are laminated to form a sheet body, and a backer is formed on the lower surface thereof. The layer 1 is provided with a third ionomer resin layer 6 on its upper surface, and these three layers are simultaneously bonded and integrated by a thermal laminating method.

  Regarding the lamination between the respective layers of the sheet body, a dry lamination method using an adhesive for dry lamination such as polyester or polyurethane between the layers (not shown), ethylene-vinyl acetate copolymer system, acrylic, polyester Laminating with heat-sensitive adhesive such as heat-sensitive adhesives such as polyurethane, modified polyolefin, polyamide, etc., and simultaneously laminating an ionomer resin on the surface of non-stretched amorphous polyethylene terephthalate resin layer 3 containing an inorganic filler while heating and melting. However, the dry lamination method is the most common.

  As a heat laminating method of the sheet body, the backer layer 1, and the third ionomer resin layer 6, generally, a multi-stage press method using a single wafer or a continuous heat laminating method using a heat roll is adopted. Any method can be applied to the production of the decorative sheet, but the continuous heat laminating method is preferable because of its superior productivity.

  The surface of the laminated body from the backer layer 1 to the third ionomer resin layer 6 thus obtained, that is, the surface of the third ionomer resin layer 6 is embossed to form concave portions for the purpose of improving the design or preventing slipping. It may be formed. As a method for embossing, a conventionally known embossing method of applying pressure while heating using an embossing plate or an embossing roll having an uneven surface can be used.

  Note that embossing can be performed in a separate process from the thermal lamination described above, but when performed at the same time as thermal lamination, the manufacturing process can be shortened, waste of thermal energy can be reduced, productivity is improved, and manufacturing costs are reduced. This is advantageous.

  As described above, the decorative sheet of the present invention can be easily manufactured by the thermal laminating method. As the manufacturing equipment, for example, a conventional decorative sheet made of polyvinyl chloride resin manufactured by thermal lamination and embossing is used. The manufacturing equipment can be applied as it is, and there is no major change in the manufacturing process, so that it is possible to manufacture easily and inexpensively without the need for new equipment investment.

As a non-stretched amorphous polyethylene terephthalate resin layer 3 containing an inorganic filler, a sheet of rivester “PETG” (about 14% by weight of inorganic filler) manufactured by Riken Technos Co., Ltd. was used, and this surface was subjected to corona treatment. Thereafter, a two-component urethane printing ink (“Lamister” manufactured by Toyo Ink Manufacturing Co., Ltd.) was used as the pattern layer 4 to print a stone pattern by a gravure printing method. Then, a transparent ionomer resin film having a thickness of 50 μm (“Himiran 1652” manufactured by DuPont Co., Ltd.) as a first ionomer resin layer 2 and a second ionomer resin layer 5 on both the front and back surfaces is used. Ink Manufacturing Co., Ltd. “TM593”) was laminated by a dry laminating method with a coating amount of about 5 g / m ² to obtain a sheet body.

  On the back surface of this sheet body, the backer layer 1 mainly composed of an ethylene-vinyl acetate copolymer resin containing an inorganic filler has a thickness of 1.5 mm containing an equal weight of ethylene-vinyl acetate copolymer resin and talc. A sheet is arranged, and a transparent ionomer resin film having a thickness of 300 μm (“HIMILAN” manufactured by DuPont Co., Ltd.) is arranged as the third ionomer resin layer 6 on the surface of the sheet body, and the lamination temperature is about 120 ° C. At the same time as laminating and laminating by the continuous laminating method, the embossing roll is pressed on the surface of the resulting laminate at 120 ° C. which is the same as the laminating temperature to give embossing and imparting a concavo-convex pattern. Produced.

<Comparative Example 1>
In Example 1, makeup was applied in the same manner as in Example 1 except that biaxially stretched polyethylene terephthalate containing no inorganic filler was used instead of the non-stretched amorphous polyethylene terephthalate resin layer 3 containing inorganic filler. A sheet was produced.

<Comparative example 2>
In Example 2, instead of the non-stretched amorphous polyethylene terephthalate resin layer 3 containing an inorganic filler, a biaxially stretched polyethylene terephthalate containing an inorganic filler (the content is the same as in Example 1) was used. A decorative sheet was prepared in the same manner as Example 1 except for the above.

<Performance evaluation>
The decorative sheet prepared as described above was bonded to a decorative board made of a wood resin, and a peel test and curl evaluation were performed. The results are shown in Table 1.
Curling is evaluated by cutting the laminated sheet into floor tiles, laying them on the floor, checking the condition after curing, and having poor contact with the ground surface due to gaps or warping between adjacent floor tiles. The quality of the land, steps, etc. was judged visually by ○ △ ×.
In the peel test, the interlayer strength was measured, and those showing an interlayer strength of 10 N / 25 mm or more were evaluated as “○”, the results below that as “Δ”, and those resulting in cohesive failure of polyethylene terephthalate.

  The decorative sheet of the present invention can be used particularly for floor tiles for interiors in buildings.

It is explanatory drawing which shows the structure of the cross section of one Example of the decorative sheet of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Backer layer 2 ... 1st ionomer resin layer 3 ... Non-stretched non-crystalline polyethylene terephthalate resin layer containing an inorganic filler 4 ... Picture layer 5 ... 2nd ionomer resin layer 6 ... 3rd ionomer resin layer

Claims (2)

  On a backer layer mainly composed of an ethylene-vinyl acetate copolymer resin containing an inorganic filler, a first ionomer resin layer, an unstretched amorphous polyethylene terephthalate resin layer containing an inorganic filler, a pattern layer, A decorative sheet comprising a second ionomer resin layer and a third ionomer resin layer at least in this order. The layer thickness of the backer layer is 1 to 5 mm, the layer thickness of the first ionomer resin layer is 40 to 60 μm, and the layer thickness of the non-stretched amorphous polyethylene terephthalate resin layer containing the inorganic filler is The decorative sheet according to claim 1, wherein the decorative sheet has a thickness of 50 to 70 µm, a layer thickness of the second ionomer resin layer of 40 to 60 µm, and a layer thickness of the third ionomer resin layer of 200 to 500 µm.

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