JPH10278197A - Decorative sheet and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate reversion of uneven design and remaining of the air, and to make laminated layers uniform by forming an ultraviolet-curing adhesive layer, and a transparent polyolefin resin layer formed by melt extrusion coating on decorative surface provided on a sheet composed of polyolefin resin, and by providing unevenness on the transparent resin surface. SOLUTION: An ultraviolet curable resin-applied sheet is formed by providing an adhesive layer 3 at least composed of ultraviolet curable resin on the surface of a decorative design 2 provided on a base sheet 1 composed of polyolefin resin. Polyolefin resin (a transparent resin layer 4) is formed by melt extrusion coating on the adhesive layer 3 for shaping an uneven design 5 by an embossing roller. And the adhesive layer 3 composed of ultraviolet curable resin is cured. The transparent resin layer 4 is treated by corona discharging and/or treated by ozone gas blowing from an ozone gas supplying pipe. At this time, a colored design and a protective layer can be arranged on recessed parts formed on the surface of the transparent resin layer 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides furniture, walls, home appliances, floor materials and the like with a surface design having an uneven feeling, excellent surface protection performance, and a low molecular organic material such as a plasticizer on the sheet surface. The present invention belongs to a plastic decorative sheet for lamination that does not separate compounds and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, as a decorative sheet of thermoplastic resin having excellent surface design and suitability for post-processing, a sheet mainly comprising polyvinyl chloride has been marketed. this is,
A pattern layer is provided on a colored soft polyvinyl chloride sheet, and a vinyl chloride / vinyl acetate copolymer serving as an ink binder for the pattern layer is used as a heat-sensitive adhesive layer. This is a decorative sheet composed of doubling embossing that forms an uneven pattern on the side of polyvinyl chloride.

The decorative sheet made of polyvinyl chloride is laminated on a wood plywood, a metal plate or the like with an adhesive, and is subjected to a bending process such as a so-called V-cut. However, decorative sheets based on polyvinyl chloride are
Low molecular organic compounds such as plasticizers were included to accommodate the cutting process. There is a problem that it is difficult to solve the problem that the plasticizer is separated on the surface of the decorative sheet and contaminates the surface of the decorative sheet.

[0004] In recent years, attempts have been made to use a polyolefin resin as a resin in place of polyvinyl chloride. However, when attempting doubling embossing in the same manner as conventional polyvinyl chloride using a polyolefin-based resin, the work cannot proceed due to fusing of the film due to the high molding temperature of the uneven pattern, and when the processing temperature is lowered, In addition to the problem that the uneven pattern cannot be formed, there is a problem that "air remains", that is, bubbles are trapped between the films, resulting in poor appearance.

[0005] Attempts have also been made to laminate a non-imprinted surface of a transparent polyolefin film in which a concavo-convex pattern has been formed as a protective layer in advance and a printed polyolefin sheet by dry lamination using a reactive adhesive such as polyurethane. However, since the transparent film has an uneven pattern, there is a problem that the two films do not adhere to each other uniformly and embrace bubbles.

[0006]

In order to solve the above-mentioned problems caused by the plasticizer, a substrate sheet made of a polyolefin resin and a protective layer were printed by using an adhesive without a return of an uneven pattern. It is an object of the present invention to provide a decorative sheet having no air residue and a method for producing the same, wherein a laminate of a polyolefin sheet and a transparent polyolefin film having an embossed pattern is uniformly adhered.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an adhesive layer made of at least a UV-curable resin on a surface of a decorative pattern provided on a base sheet made of a polyolefin resin, and melt extrusion. The decorative sheet is a transparent polyolefin-based resin layer by coating (hereinafter, referred to as a transparent resin layer) and the surface of the transparent resin layer has an uneven pattern. Then, at least the surface of the decorative pattern provided on the base sheet made of a polyolefin-based resin, an adhesive layer made of an ultraviolet curable resin, a transparent resin layer, and a decorative sheet having a colored pattern on the surface recesses of the transparent resin layer. is there. Further, at least the surface of the decorative pattern provided on the base sheet made of a polyolefin-based resin, an adhesive layer made of an ultraviolet curable resin, a transparent resin layer, and a concave-convex pattern on the surface of the transparent resin layer, or a concave portion thereof. It is a decorative sheet having a colored pattern and a protective layer. Then, an adhesive layer made of at least an ultraviolet curable resin is provided on the surface of the decorative pattern provided on the base sheet made of the polyolefin resin, a transparent resin layer is formed by melt extrusion coating, and the concave and convex pattern is formed by a cooling roll. And a method for producing a decorative sheet for curing the ultraviolet-curable resin. Further, the present invention is a method for producing a decorative sheet in which the polyolefin resin formed by melt extrusion coating is bonded to the adhesive layer side by performing a treatment by corona discharge and / or an ozone gas treatment.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As shown in FIG.
The surface of a decorative pattern 2 provided on a base sheet 1 made of a polyolefin-based resin comprises at least an adhesive layer 3 made of an ultraviolet curable resin and a transparent resin layer 4, and the transparent resin layer 4
Is a decorative sheet 10 whose surface is an uneven pattern 5. As shown in FIGS. 2 and 3, at least a surface of a decorative pattern 2 provided on a base sheet 1 made of a polyolefin-based resin is composed of an adhesive layer 3 made of at least an ultraviolet curable resin, a transparent resin layer 4, and A decorative sheet 11 or 12 having a colored pattern 6 in a concave portion formed on the surface of the transparent resin layer 4 and a protective layer 7 if necessary. Then, as shown in FIG. 4, an adhesive layer 3 made of at least an ultraviolet-curable resin is provided on the surface of the decorative pattern 2 provided on the base sheet 1 made of the polyolefin-based resin to form an ultraviolet-curable resin-coated sheet 13. I do. Then, a polyolefin-based resin (transparent resin layer 4) is formed on the adhesive layer 3 by melt-extrusion coating, and the concavo-convex pattern 5 is shaped by an emboss roll 55. This is a method for producing a decorative sheet for curing the adhesive layer 3. Moreover, although not shown, the transparent resin layer 4 is subjected to a treatment by corona discharge and / or a treatment by an ozone gas 36 blown out from an ozone gas supply pipe 35 as shown in FIG.

The base sheet of the present invention is a polymer mainly composed of polyolefin, such as polyethylene, polypropylene, ethylene / propylene copolymer, ethylene / butene-1 copolymer, propylene / butene-1 copolymer, and polyolefin. Stretching and unstretching of methylpentene, olefinic elastomer, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / acrylic acid ester copolymer, ionomer, saponified ethylene / vinyl acetate copolymer The sheet has a thickness of 50 to 500 μm.
In particular, an unstretched sheet that is easily stretched is preferably subjected to a bending process such as a V-cut process. When providing a decorative pattern, coloring corresponding to a solid printing layer can be colored with high density and high hiding power (opaque).

The pigment used for coloring the base sheet is titanium white, red iron oxide, carbon black, ultramarine blue, navy blue, quinacridone red, isoindoline yellow, phthalocyanine blue, aniline black, aluminum powder, copper powder, metal-deposited synthetic resin film. And a coloring agent such as organic pigments or dyes such as pearl-like luster such as titanium dioxide-coated mica and fish scale foil. In addition, fillers such as calcium carbonate, silica, alumina, and barium sulfate are added as necessary.

In order to make the base sheet flame-retardant, magnesium hydroxide, aluminum hydroxide, antimony trioxide or the like is used, and a resin 100 is used in accordance with a desired degree of flame retardancy.
It is added in the range of 10 to 100 parts by weight with respect to parts by weight in consideration of the suitability for post-processing such as film formation. (If the amount is small, there is no flame-retardant effect, and if the amount is excessive, suitability for film formation and post-processing is reduced.) An ultraviolet absorber and / or a light stabilizer for improving light resistance can also be added.

The base sheet is preferably subjected to a corona discharge treatment on both sides thereof.
Adhesive strength between the adhesive and the plywood or the like can be increased.

For the decorative pattern of the picture layer including the solid print layer, a usual printing method such as gravure printing, silk screen printing, letterpress printing or the like can be used. In addition, it can be performed by drawing and transfer printing. In addition, the base sheet of polyolefin,
Since the colorant contained in the ink may cause uneven adhesion of the ink, it is advantageous to provide a primer layer prior to printing the ink to stabilize the adhesion.

For the primer layer, a varnish of an ink containing no particles such as pigments can be used. The primer layer is made of a thermoplastic resin such as linear polyester or urethane, polyol / isocyanate, polyester / isocyanate, epoxy / acryl etc. It can be selected from compositions having reactivity. And, when the primer layer and the solid printing layer are performed in the same process, immediately after coating or even after the primer layer has some tackiness after the reaction, because the solid printing layer does not block, Materials that remain somewhat sticky can also be used.

The transparent resin layer formed by the melt-extrusion coating of the present invention is a polymer mainly composed of polyolefin similar to that of the base sheet, such as polyethylene, polypropylene,
Ethylene / propylene copolymer, propylene / butene
1 copolymer, polymethylpentene, olefin-based elastomer, ethylene / acrylic acid copolymer, ethylene / acrylic ester copolymer, ionomer, ethylene
And saponified vinyl acetate copolymer. And it can be selected from those having melt flow aptitude that can be melt-extruded and that can form a concave and convex pattern.

The polyolefin resin constituting the transparent resin layer by coating can be formed not only by a single layer but also by a multilayer melt extrusion coating. In the case of multi-layer melt extrusion coating, a material having good suitability for melt extrusion coating (melt flow, adhesion to a base sheet or an ultraviolet curable resin, etc.) and surface characteristics (abrasion resistance, moldability of uneven pattern) , Gloss, etc.). For example, on the base sheet side,
It can be selected from low-density polyethylene, ethylene-vinyl acetate copolymer, etc., which have excellent suitability for melt extrusion coating. On the surface side, not only polypropylene, ethylene / acrylic acid copolymer, ethylene / acrylic acid ester copolymer, and ionomer, but also polyamide and polyester can be selected as the surface modifying material. Then, an adhesive resin is inserted between these layers of the material to be melt-extruded and coated as required.

In order to improve the light fastness of the decorative sheet (discoloration of the decorative pattern and prevention of deterioration of the transparent resin layer by light), an ultraviolet absorber and / or a light stabilizer is added.

When forming the resin layer, the concave and convex pattern of the transparent resin layer is formed by embossing a molten polyolefin resin with a concave and convex pattern and an unreacted ultraviolet curable resin coated with an ultraviolet curable resin. (Adhesive layer) and can be processed by the usual method of melt extrusion coating. In order to stabilize the adhesion, the polyolefin-based resin containing polyolefin as a main material is subjected to a corona discharge treatment on the bonding surface, or in the atmosphere of ozone gas 36 as shown in FIG. It is preferable to perform the coating while bringing the ozone gas into contact with the resin. As a result, the temperature required for bonding the molten resin is increased from 310 to 320 ° C to 20 to 50 ° C.
By lowering by ° C., not only the adhesion can be firmly stabilized, but also the melting of the base sheet and the thermal decomposition of the resin can be prevented.

The UV-curable resin constituting the adhesive layer between the face of the decorative pattern of the substrate sheet and the transparent resin layer is composed of a prepolymer, a polymer and a polymer having a polymerizable unsaturated bond or a cationically polymerizable functional group in the molecule. A UV curable composition in which a monomer is appropriately mixed is preferably used. The ultraviolet curable resin has a radical polymerizable polymer such as a (meth) acryloyl group (in the present application, an acryloyl group and a methacryloyl group are simply referred to as a (meth) acryloyl group) and a (meth) acryloyloxy group in a molecule. A cationic polymerizable functional group such as a saturated group or an epoxy group or a thiol group
It is composed of a monomer, prepolymer or polymer having more than one. These monomers, prepolymers or polymers are used alone or as a mixture of two or more.

Examples of the prepolymer having a radical polymerizable unsaturated group include polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, melamine (meth) acrylate, triazine (meth) acrylate, and silicon (meth). Acrylate and the like can be used. Those having a molecular weight of 250 to 10,000 are used. As the polymer having a radically polymerizable unsaturated group, those having a degree of polymerization of about 1000 formed above are used.

Examples of the prepolymer having a cationically polymerizable functional group include prepolymers of epoxy resins such as bisphenol epoxy resins and novolak epoxy resins, and vinyl ether resins such as aliphatic vinyl ethers and aromatic vinyl ethers. Examples of the monomer having a radical polymerizable unsaturated group include methyl (meth) acrylate, monofunctional monomer of (meth) acrylate compound,
-Ethylhexyl (meth) acrylate, phenoxy (meth) acrylate and the like.

Examples of the polyfunctional monomer having a radical polymerizable unsaturated group include diethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and trimethylolpropane. Examples include ethylene oxide tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate.

As examples of the monomer having a cationically polymerizable functional group, the above-mentioned prepolymeric monomer having a cationically polymerizable functional group can be used. Examples of the monomer having a thiol group include trimethylolpropane trithioglycolate and dipentaerythritol tetraglycolate.

In order to cure the above composition with ultraviolet light or visible light, a photopolymerization initiator is added. As the photopolymerization initiator in the case of a resin composition having a radical polymerizable unsaturated group, acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether, and the like can be used alone or in combination. Further, the photopolymerization initiator in the case of a composition having a cationically polymerizable functional group, an aromatic diazonium salt, an aromatic sulfonium salt, an aromatic iodonium salt, a metallocene compound, a benzoin sulfonic acid ester or the like is used alone or as a mixture. be able to.

If necessary, a thermoplastic resin such as a vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, an acrylic resin, or a cellulose derivative may be used as a plasticizer or anti-adhesive, calcium,
An extender made of fine powder such as barium sulfate, silica, and alumina, and a coloring agent such as a dye and a pigment can be used.

When applying the above-mentioned UV-curable resin to a decorative pattern, a gravure coat or a roll coat capable of uniformly coating a usual coating amount can be used. The coating amount (in this specification, the coating amount is described in g / m ² ) is 0.5 to 3
0 g / m ² . High amounts not only waste resources, but also may cause cracks in the decorative sheet due to the cured adhesive layer. Also, if it is less than 0.5 g / m ² ,
In some cases, it is not possible to prevent the deformation of the concavo-convex pattern that occurs when the base sheet is deformed.

Light sources for curing the ultraviolet-curable resin layer include:
Light sources such as ultra-high pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, carbon arc lamps, and metal halide lamps can be used.
Ultraviolet light, usually in the wavelength range of 1900 to 3800 °, is used. In addition, as long as the polyolefin-based resin does not deteriorate, curing can be performed by irradiation with a light electron beam.

The colored pattern of the concave portion on the surface is a pattern in which the concave portion is filled with a coloring ink and only the concave portion is colored. The surface of the transparent resin layer on which the uneven pattern is formed is subjected to an easy adhesion treatment such as a corona discharge treatment as necessary, and an ink using, for example, a urethane-based resin as a binder is used on the entire surface. Then
The substrate is wiped with a doctor blade, an air knife or a sponge, a roller having a cloth or the like as a surface, and the ink in the convex portions is removed, and the image is formed by wiping processing in which only the concave portions are filled with the ink. To form. Further, if necessary, a slight amount of ink other than the concave portions may be left to assist the coloring of the surface.

A surface protective layer can be provided for the purpose of protecting the colored layer in the wiping portion and improving the scratch resistance of the transparent resin layer. The surface protective layer can be appropriately selected from conventionally known ones corresponding to the transparent resin layer. For example, two-component curable polyurethane, polyester, urethane acrylate, ionizing radiation curable resin (ultraviolet curable resin, electron beam curable resin) using a curing agent such as isocyanate or amine
Etc. can be used. For coating, conventionally known methods such as roll coating, gravure reverse coating, and spray coating can be used.

Next, the present invention will be described in more detail based on examples. (Example 1) As shown in FIG.
Thickness of linear polyethylene treated with double-sided corona discharge treatment at a density of 0.920 g / cm ³ and colored with a red pigment, carbon black and a mixed pigment mainly containing isoindolinone
On one surface of the 50 μm base sheet 1, a decorative pattern 2 composed of a solid print layer 22 and a picture layer 21 was formed with an ink using polyurethane as a binder. Then, an ultraviolet curable resin coated sheet 13 shown in FIG. 3 was formed by applying 5 g / m ² of an adhesive layer 3 made of an ultraviolet curable resin (Diabond DA885 manufactured by Nogawa Chemical Co., Ltd.). Further, as shown in FIG. 4, a TPX for coating: DX-810 (trade name, manufactured by Mitsui Petrochemical Industries, Ltd.) having a thickness of 50 μm was melt-extruded under the following ozone treatment conditions from a molten resin extruder 45. Then, it was shaped and cooled by the embossing roll 55 to form the uneven pattern 5. Then, an ultraviolet ray was irradiated under the condition of 160 W / cm to cure the ultraviolet curable resin, thereby producing a decorative sheet 10 of the present invention shown in FIG. The ozone treatment conditions in the present embodiment are such that the ozone concentration is 20 g /
In m ³ or more, was supplied at a rate of 160 ml / m ^2, the ozone gas-containing gas 36 is provided between the ultraviolet curable resin 3 of the substrate film 1 of the coating resin 4. The formed decorative sheet 10 did not have a heating history required for the bonding / curing step, so that the curing of the adhesive could be completed without deformation and deterioration of the sheet.

(Example 2) A low-density polyethylene was melt-extruded and coated to a thickness of 50 µm on the ultraviolet-curable resin-coated sheet 13 prepared in Example 1 without using an ozone gas generator. A transparent resin layer 4 having a concavo-convex pattern 5 on which a corona discharge treatment was applied was formed on a surface opposite to the surface. Then, ultraviolet rays were irradiated under the conditions of Example 1,
The ultraviolet curing resin was cured to prepare a decorative sheet of the present invention. Further, the surface of the transparent resin layer 4 provided with the concavo-convex pattern 5 is subjected to a wiping process using a colored urethane-based ink to prepare the decorative sheet 11 of Example 2 having the colored pattern 6 in the concave portion shown in FIG. did.

(Example 3) On the surface of the transparent resin layer having the concave coloring pattern 6 of the decorative sheet 11 prepared in Example 2,
A decorative sheet 12 of Example 3 shown in FIG. 3 was prepared by applying a urethane-based varnish at 5 g / m ² to provide a surface protective layer 7.

(Comparative Example 1) An ionizing radiation-curable resin coated sheet obtained by applying the same resin composition as in Example 1 and applying a composition prepared by removing the photosensitizer from the ultraviolet-curable resin 3 prepared by the same method was used. Created. And the thickness 50 provided with the uneven pattern
The low-density polyethylene film of μm was brought into close contact with the non-imprinted surface of the transparent resin film 4 and the electron beam was applied at 250 KV, 5 Mr
The decorative sheet of Comparative Example 1 was prepared by curing the ionizing radiation-curable resin by irradiating ad.

Comparative Example 2 A polyester-isocyanate-based adhesive layer was applied to the surface of a decorative pattern 2 provided on a base sheet 1 prepared in the same manner as in Example 1 by gravure coating at 5 g / m ^2.
After coating and drying the solvent, the transparent resin layer 4 of Comparative Example 1 was rolled up by pressing against the non-imprinting surface. And 7 at 40 ° C
Aging was performed for 2 hours to complete the curing of the adhesive layer, and a decorative sheet of Comparative Example 2 was produced.

With respect to the samples of Examples and Comparative Examples, air remaining, deterioration of the decorative sheet, change in the shape of the uneven pattern, and scratch resistance were evaluated by the following evaluation methods. Table 1 shows the results. Air remaining: Evaluate visually. ：: No hug. Δ: There is some hugging. Deterioration of decorative sheet: Illuminance 60mw / c using an ice par UV tester (trade name, manufactured by Iwasaki Electric Co., Ltd.)
After irradiating for 400 hours under the conditions of m ² , a distance from the light source of 240 mm, and a black panel temperature of 63 ° C., the decorative sheet is folded and the change in appearance is visually evaluated. ：: good without cracks Δ: Cracking is observed. Change in uneven pattern: The sample is left in an oven at 100 ° C. for 1000 hours, and the change in the uneven pattern is visually evaluated. ：: No change. Δ: There is some return. Surface strength: Abrasion resistance is evaluated by rubbing the surface 10 times with a nail. ：: No change. Δ: The gloss changes.

[0036]

[Table 1] *: The surface protective layer needs to be cured with temperature and time.
Poor productivity.

As described in detail above, according to the present invention, an ultraviolet-curable resin is applied as an adhesive layer to a decorative pattern of a substrate sheet having no uneven pattern, and is further subjected to melt extrusion coating to form a transparent resin layer. Because of the provision, there is an effect of preventing air remaining, deterioration of the film, return of the uneven pattern, etc., which are conventionally observed in the laminate of the polyolefin resin. And the thing by the wiping process which comprised the surface layer is excellent in abrasion resistance, and can comprise a decorative sheet.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a decorative sheet of the present invention.

FIG. 2 is a schematic sectional view of a decorative sheet subjected to wiping processing according to the present invention.

FIG. 3 is a schematic sectional view of a decorative sheet provided with a protective layer in the wiping process of the present invention.

FIG. 4 is a schematic sectional view showing a step of providing a transparent resin layer by coating.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base sheet 2 Decorative pattern 21 Picture layer 22 Solid printing layer 3 Adhesive layer made of UV curable resin 4 Transparent resin layer 5 Irregular pattern 6 Concave coloring pattern 7 Surface protective layer 10, 11, 12 Decorative sheet 13 UV curable Resin coating sheet 35 Ozone gas supply pipe 36 Ozone gas 45 Molten resin extruder 55 Emboss roll

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29K 23:00 B29L 9:00

Claims (5)

[Claims] 1. A decorative pattern provided on a base sheet made of a polyolefin resin, comprising at least an adhesive layer made of an ultraviolet curable resin, a transparent polyolefin resin layer formed by melt extrusion coating, and said transparent polyolefin resin. A decorative sheet, characterized in that the surface of the layer has an uneven pattern. 2. The transparent polyolefin resin, comprising: an adhesive layer made of at least an ultraviolet-curable resin; and a transparent polyolefin resin layer formed by melt extrusion coating on a face of a decorative pattern provided on a base sheet made of a polyolefin resin. A decorative sheet having a colored pattern in a concave portion on the surface of the layer. 3. A transparent polyolefin resin, comprising an adhesive layer made of at least an ultraviolet curable resin and a transparent polyolefin resin layer formed by melt extrusion coating on the surface of a decorative pattern provided on a base sheet made of a polyolefin resin. A decorative sheet having a colored pattern and a protective layer in a concave portion on the surface of the layer. 4. An adhesive layer made of at least a UV-curable resin is provided on the face of a decorative pattern provided on a base sheet made of a polyolefin resin, and the polyolefin resin layer is formed by melt extrusion coating, and the uneven pattern is cooled. The method for producing a decorative sheet according to any one of claims 1 to 3, wherein the molding is performed by a roll, and the ultraviolet curable resin is further cured. 5. The method for producing a decorative sheet according to claim 4, wherein the polyolefin resin formed by melt extrusion coating is adhered to the adhesive layer side by a treatment by corona discharge and / or an ozone gas treatment. .