JP7533091B2 - Manufacturing method and manufacturing device for decorative sheet - Google Patents

Description

The present invention relates to a method and an apparatus for manufacturing decorative sheets.

When decorating building materials, furniture, home appliances, and other components, decorative panels with decorative sheets attached to them are commonly used.

In order to impart visual design to such decorative sheets, embossing or other processes may be used to form recesses, creating a three-dimensional visual effect.

For example, Patent Document 1 discloses a decorative floor sheet that is attached to the surface of a veneer decorative floor board in which veneer is attached to a base material, and is characterized in that a transparent protective layer is formed on the surface of a transparent or translucent synthetic resin film, and that the synthetic resin film and the transparent protective layer are provided with an uneven shape by embossing.

In recent years, there has been a demand for decorative sheets with even more visually superior three-dimensionality, and the decorative floor sheet of Patent Document 1 is still not sufficient, leaving room for further improvement.

JP 2019-60159 A

The present invention aims to solve the above-mentioned problems and provide a manufacturing method and manufacturing device for decorative sheets that have a visually excellent three-dimensional effect by harmonizing the pattern of the design layer with the recesses.

The manufacturing method for a decorative sheet of the present invention is a manufacturing method for a decorative sheet having a recess, and is characterized by having a preparation step of preparing a substrate having a pattern layer having a characteristic portion and a non-characteristic portion on one side thereof, a lamination step of laminating a transparent resin layer onto the pattern layer, and a shaping step of shaping a recess that coincides with the characteristic portion of the pattern layer from the side of the transparent resin layer opposite to the side having the pattern layer.
In the decorative sheet manufacturing method of the present invention, after the shaping process, it is preferable to further include a detection process for detecting positional information between the characteristic portion of the pattern layer and the recesses synchronized with the characteristic portion of the pattern layer, and to feed back the positional information to a feed-out adjustment mechanism provided before the shaping process to adjust the position of the characteristic portion of the pattern layer and the position of the recesses synchronized with the characteristic portion of the pattern layer.
It is also preferable to have a coating step of coating a surface protective layer on the transparent resin layer between the laminating step and the shaping step.
In addition, the decorative sheet manufacturing apparatus of the present invention is a decorative sheet manufacturing apparatus that forms recesses while heating a decorative sheet that has a pattern layer having characteristic and non-characteristic portions, and a transparent resin layer on one side of a substrate, and is characterized in that it is equipped with a shaping mechanism that forms recesses that are synchronized with the characteristic portion of the pattern layer from the side of the transparent resin layer opposite to the side having the pattern layer, a detection mechanism at the rear of the shaping mechanism that detects positional information between the characteristic portion of the pattern layer and the recesses that are synchronized with the characteristic portion of the pattern layer, and a feed adjustment mechanism that feeds back the positional information to the front of the shaping mechanism to adjust the feed of the decorative sheet.

The present invention can provide a manufacturing method and manufacturing device for decorative sheets that have a visually excellent three-dimensional effect by harmonizing the pattern of the design layer with the recesses.

1(a) to 1(c) are cross-sectional views showing schematic examples of recesses in a decorative sheet produced by the decorative sheet production method of the present invention. 3 is a diagram illustrating a detection step in the manufacturing method of the decorative sheet of the present invention. FIG. 1 is a cross-sectional view showing a schematic diagram of an example of a decorative sheet produced by the decorative sheet production method of the present invention.

<Method of manufacturing decorative sheet>
The method for producing the decorative sheet of the present invention will now be described.
In the following description, the lower and upper limits of a numerical range expressed by "to" means "greater than or equal to" (for example, if α to β, then α is greater than or equal to β).

The manufacturing method for a decorative sheet of the present invention is a manufacturing method for a decorative sheet having a recess, and is characterized by having a preparation step of preparing a substrate having a pattern layer having a characteristic portion and a non-characteristic portion on one side thereof, a lamination step of laminating a transparent resin layer onto the pattern layer, and a shaping step of shaping a recess that coincides with the characteristic portion of the pattern layer from the side of the transparent resin layer opposite to the side having the pattern layer.
In the method for producing a decorative sheet of the present invention, all steps are preferably carried out by roll-to-roll.
Each step constituting the method for producing a decorative sheet of the present invention will be described below.

[Preparation process]
The method for producing a decorative sheet of the present invention includes a preparation step of preparing a substrate having on one side a pattern layer having a characteristic portion and a non-characteristic portion.
The substrate and the design layer used in the preparation step will be described below.

(Substrate)
Examples of the substrate include polyolefin resins such as low-density polyethylene (including linear low-density polyethylene), medium-density polyethylene, high-density polyethylene, ethylene-α-olefin copolymer, homopolypropylene, polymethylpentene, polybutene, ethylene-propylene copolymer, propylene-butene copolymer, ethylene-vinyl acetate copolymer, saponified ethylene-vinyl acetate copolymer, and mixtures thereof; thermoplastic ester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene naphthalate-isophthalate copolymer, polycarbonate, and polyarylate; thermoplastic acrylic resins such as polymethyl methacrylate, polyethyl methacrylate, polyethyl acrylate, and polybutyl acrylate; thermoplastic polyamide resins such as nylon-6 and nylon-66; and polyimide, polyurethane, polystyrene, and acrylonitrile-butadiene-styrene resins.
These may be used alone or in combination of two or more.
Among these, olefin resins are preferred because they are excellent in printability for the design layer and inexpensive.

The substrate may be colored. In this case, a colorant (pigment or dye) may be added to the substrate to color it.
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 may be selected from known or commercially available materials, and the amount of colorant added may be appropriately determined according to the desired color tone, etc.

The above-mentioned base material may contain various additives such as fillers, matting agents, foaming agents, flame retardants, lubricants, antistatic agents, antioxidants, UV absorbers, and light stabilizers, as necessary.

The thickness of the substrate is not particularly limited, but is preferably 40 μm or more and 200 μm or less.
The substrate may be constructed as either a single layer or multiple layers.

(Pattern layer)
The design layer is a layer that imparts decorativeness to the decorative sheet.

The design layer may be, for example, a design layer formed by printing various patterns using ink and a printing machine, or it may be a layer that combines a concealing layer and a design layer.

By providing the concealing layer, when the above-mentioned base material is colored or has color unevenness, it is possible to impart an intended color and adjust the color of the surface.
Furthermore, by providing a pattern layer, it is possible to impart to the decorative sheet a pattern such as a wood grain pattern, a marble pattern (e.g., travertine marble pattern) or other stone pattern that imitates the surface of rock, a fabric pattern that imitates a cloth grain or cloth-like pattern, a tiled pattern, a brickwork pattern, or a combination of these, such as inlay or patchwork.
These design patterns are formed by multi-color printing using the usual process colors of yellow, red, blue, and black, as well as by multi-color printing using special colors in which the individual colors that make up the pattern are prepared.

The ink composition used for the design layer is a suitable mixture of binder resin, pigment, colorant such as dye, extender pigment, solvent, stabilizer, plasticizer, catalyst, hardener, etc.

The binder resin is not particularly limited, and examples of preferred binder resins include urethane resin, acrylic resin, urethane-acrylic resin, urethane-acrylic copolymer resin, vinyl chloride/vinyl acetate copolymer resin, vinyl chloride/vinyl acetate/acrylic copolymer resin, acrylic resin, polyester resin, and nitrocellulose resin. Any of these binder resins can be used alone or in combination of two or more.

Preferred examples of the colorant include inorganic pigments such as carbon black (ink), iron black, titanium white, antimony white, yellow lead, titanium yellow, red iron oxide, cadmium red, ultramarine blue, and cobalt blue; organic pigments such as quinacridone red, isoindolinone yellow, and phthalocyanine blue; metal pigments consisting of scaly flakes of dyes, aluminum, brass, and the like; and pearlescent (pearl) pigments consisting of scaly flakes of titanium dioxide-coated mica, basic lead carbonate, and the like.
These may be used alone or in combination of two or more.

The design layer has feature portions and non-feature portions.
The characteristic parts refer to parts having features that allow the pattern of the pattern layer to be recognized. For example, if the pattern layer has a wood grain pattern, these would be the vessels, knots, annual rings and spots in the wood grain, and if the pattern layer has a stone grain pattern, these would be the pattern (crack pattern) expressed by the stripes and cracks of different crystal components in the rock.
Also, a marking pattern may be added to the end of the design layer, and this may be used as the characteristic portion.
The non-characteristic portion refers to a portion other than the characteristic portion.

The thickness of the design layer is not particularly limited, but is preferably 0.1 μm or more, and more preferably 0.5 μm or more and 600 μm or less. If the thickness of the design layer is within the above range, the resulting decorative sheet can be given an excellent design and can also be given hiding properties.

Methods for forming the above-mentioned pattern layer include, for example, gravure printing, offset printing, screen printing, flexographic printing, electrostatic printing, inkjet printing, etc. In addition, when forming a concealing layer, various coating methods such as roll coating, knife coating, air knife coating, die coating, lip coating, comma coating, kiss coating, flow coating, and dip coating can also be used.

[Lamination process]
The method for producing a decorative sheet of the present invention includes a laminating step of laminating a transparent resin layer onto the design layer.
First, the transparent resin layer laminated in the lamination step will be described.

(Transparent Resin Layer)
The transparent resin layer is preferably a layer formed from a thermoplastic resin.
The transparent resin layer is not particularly limited as long as it allows the design layer to be seen, and includes any of colorless transparent, colored transparent, translucent, and the like.

Examples of the thermoplastic resin include olefin resins such as polyethylene, polypropylene, polybutene, polymethylpentene, and olefin thermoplastic elastomers; polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, ethylene glycol-terephthalic acid-isophthalic acid copolymer resin, terephthalic acid-ethylene glycol-1,4 cyclohexane dimethanol copolymer resin, and polyester thermoplastic elastomers; acrylic resins such as polymethyl (meth)acrylate, methyl (meth)acrylate-butyl (meth)acrylate copolymer resin, and methyl (meth)acrylate-styrene copolymer resin; polycarbonate resin, polyvinyl chloride, polystyrene, and ionomers.
Among these, polyethylene or polypropylene is more preferred because of its high tensile strength, excellent chemical resistance, and excellent production process.
In this specification, (meth)acrylate means acrylate or methacrylate.

The polyethylene may be a homopolymer of ethylene or a copolymer of ethylene and another comonomer copolymerizable with ethylene (for example, an α-olefin such as propylene, 1-butene, 1-hexene, or 1-octene, vinyl acetate, or vinyl alcohol).
Examples of polyethylene resins include high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), very low density polyethylene (VLDPE), ultra high molecular weight polyethylene (UHMWPE), and cross-linked polyethylene (PEX).
These polyethylenes may be used alone or in combination of two or more.

The polypropylene may be a homopolymer of propylene, or a copolymer of propylene and another comonomer copolymerizable with propylene (e.g., α-olefins such as ethylene, 1-butene, 1-hexene, and 1-octene; vinyl acetate, vinyl alcohol, etc.).
These polypropylenes may be used alone or in combination of two or more.
In the present invention, a homopolymer of propylene (homopolypropylene) is particularly preferred from the viewpoint of excellent scratch resistance and bending processability.

The transparent resin layer may be composed of one layer, or may be composed of two or more layers.

From the viewpoint of obtaining excellent scratch resistance and bending workability, the thickness of the transparent resin layer is preferably 30 μm or more and 200 μm or less, more preferably 40 μm or more and 180 μm or less, and even more preferably 60 μm or more and 120 μm or less.

When the transparent resin layer is composed of two or more layers, the total thickness of the transparent resin layer is preferably 30 μm or more and 200 μm or less, more preferably 40 μm or more and 180 μm or less, and even more preferably 60 μm or more and 120 μm or less.

When the transparent resin layer is composed of a plurality of layers, the resins may be the same or different in type, and the thicknesses of the substrates made of a plurality of resins may be the same or different.
The method for laminating two or more transparent resin layers is not limited as long as it is a common method, and examples thereof include a dry lamination method and an extrusion heat lamination method.

The transparent resin layer may be subjected to surface treatments such as saponification treatment, glow discharge treatment, corona discharge treatment, plasma discharge treatment, ultraviolet (UV) treatment, and flame treatment, without departing from the spirit of the present invention.

(Lamination mechanism)
The lamination step can be carried out, for example, by a lamination mechanism described below.
The lamination mechanism may be a dry lamination method or an extrusion heat lamination method.

The adhesive used in the dry lamination method may be appropriately selected from, for example, a water-based adhesive, a heat-sensitive adhesive, a pressure-sensitive adhesive, a hot melt adhesive, and the like.
The method for applying the adhesive is not particularly limited, and may be appropriately selected from the following methods: roll coating, comma coating, curtain coating, squeeze coating, blade coating, gravure coating, and the like.

As the above-mentioned extrusion heat lamination method, in addition to the method of pressing metal plates together with a flat pressure, it is also possible to use a continuous lamination method using a roll press. In particular, the continuous lamination method using an endless metal belt or a metal or hardening resin heat drum has the advantage that there is no warping or waviness on the surface, there is good adhesion between the layers, they can be hardened and integrated densely, and they can be manufactured continuously at high speed.

[Shaping process]
The method for producing a decorative sheet of the present invention includes a shaping step of shaping recesses in line with characteristic portions of the design layer from the side of the transparent resin layer opposite to the side having the design layer.
First, the recesses formed in the forming step will be described.

(recess)
The recesses formed in the forming step have a shape that matches the characteristic portions of the design layer.
The recess may have a shape that is modeled after the outline of a characteristic part of the pattern of the picture layer, a simplified shape of the outline of the characteristic part of the pattern of the picture layer, or a similar shape that is a reduced or enlarged version of the outline of the characteristic part.

1(a) to (c) are cross-sectional views that typically show one example of recesses in a decorative sheet produced by the decorative sheet production method of the present invention.
The positional relationship between the recess (D) and the characteristic portion of the design layer may be any one of those shown in Figs. 1(a) to (c).
That is, as shown in FIG. 1(a), in the stacking direction, the characteristic portion 2a of the pattern layer 2 and the recess (D) may be positioned so as to overlap, as shown in FIG. 1(b), the characteristic portion 2a of the pattern layer 2 and the recess (D) may be positioned so as to partially overlap, or as shown in FIG. 1(c), the characteristic portion 2a of the pattern layer 2 and the recess (D) may be positioned so as not to overlap.
1(c), in plan view, the recess (D) is located in the vicinity of the characteristic portion 2a of the pattern layer 2. The above-mentioned vicinity means that in plan view, the distance between the position of the characteristic portion 2a and the position of the recess (D) having a shape corresponding to the characteristic portion 2a is 70 mm or less.
These can be appropriately set depending on the design of the pattern layer 2.
In addition, the harmonious relationship between the recess (D) and the characteristic portion 2a does not necessarily have to be established over the entire surface of the design, and there may be some areas that are not harmonious as long as it does not impair the overall design feel.

(Shaping mechanism)
The shaping mechanism may, for example, be a method in which the transparent resin layer is embossed from the side opposite to the side having the pattern layer to form recesses that correspond to the characteristic portions of the pattern layer.

The embossing may be carried out, for example, by a known sheet-type or rotary embossing machine.
As the pattern used in the embossing process, a design that matches the above-mentioned design layer can be appropriately selected and used.

When the embossing is performed, it is preferable to adjust the position of the characteristic portion of the design layer and the position of the recess of the embossing that corresponds to the characteristic portion of the design layer.
The positions of the recesses corresponding to the characteristic parts of the pattern layer of the embossed processing include, for example, in the case of a wood grain pattern, the vessels, knots, annual rings and spots of the wood grain, and in the case of a stone grain pattern, the patterns (crack patterns) expressed by the stripes and cracks of different crystal components in the rock.
In addition, a marking pattern may be added to the end of the design used in the embossing process, and the position may be adjusted to correspond to the marking pattern added to the end of the design layer described above.

The temperature at which the embossing process is carried out is not particularly limited, but a temperature at which the disappearance of recesses during thermocompression molding, that is, so-called emboss return, is reduced is preferred.
The heating method is not particularly limited, and for example, an infrared heater or the like can be used.

[Detection step]
In the decorative sheet manufacturing method of the present invention, after the shaping process, it is preferable to further include a detection process for detecting positional information between the characteristic portion of the pattern layer and the recesses synchronized with the characteristic portion of the pattern layer, and to feed back the positional information to a feed-out adjustment mechanism provided before the shaping process to adjust the position of the characteristic portion of the pattern layer and the position of the recesses synchronized with the characteristic portion of the pattern layer.

FIG. 2 is a diagram for explaining an example of the detection step in the method for producing a decorative sheet of the present invention.
2, the unshaped sheet 11 is transported by a transport mechanism 20, heated, and then a shaping mechanism 40 forms recesses in sync with the characteristic portions of the picture layer to obtain a decorative sheet 10. Thereafter, a detection mechanism 50 detects positional information of the characteristic portions of the picture layer and the recesses in sync with the characteristic portions of the picture layer (detection step), and the positional information is fed back to a feed-out adjustment mechanism 30 to adjust the positions of the characteristic portions of the picture layer and the recesses in sync with the characteristic portions of the picture layer.

In the detection process, position information between the characteristic parts of the pattern layer obtained in the shaping process and the recesses synchronized with the characteristic parts of the pattern layer, i.e., the positional relationship in the actual decorative sheet, is detected, and the position information is fed back to a feed adjustment mechanism provided before the shaping process to adjust the positions of the pattern layer and the recesses. Therefore, it has superior position adjustment capabilities compared to methods that adjust the stretch of the decorative sheet using information before the recesses are formed.

The positions of the characteristic portions of the design layer and the positions of the recesses that are in sync with the characteristic portions of the design layer may be appropriately adjusted according to the desired product.
For example, if a positional misalignment of several mm is detected, the positional relationship between the characteristic parts of the pattern layer and the recesses may be adjusted, and if a positional misalignment of several μm is detected, the positional relationship between the characteristic parts of the pattern layer and the recesses may be adjusted.

The above-mentioned feed-out adjusting mechanism is not particularly limited as long as it can adjust the feed-out of the unshaped sheet, and for example, a feed roll or the like can be used.
As a method for adjusting the position of the characteristic part of the pattern layer and the position of the recess synchronized with the characteristic part of the pattern layer (feed-out adjustment mechanism), the position can be adjusted, for example, by changing the speed of the feed-out adjustment mechanism and correcting the tension of the pre-shaped sheet 11.

The detection mechanism is not particularly limited, and for example, position information may be detected using a camera, laser sensor, etc.

[Coating process]
The method for producing a decorative sheet of the present invention preferably includes a coating step of coating a surface protective layer onto the transparent resin layer between the laminating step and the shaping step.
First, the surface protective layer will be described.

(Surface protection layer)
The surface protective layer is a layer that imparts durability (scratch resistance, contamination resistance, weather resistance, etc.) to the resulting decorative sheet, and by having the surface protective layer, it is possible to more effectively protect the pattern layer, and it is possible to effectively prevent deterioration of the design due to scratches.
The surface protective layer may be a single layer, or may be a multi-layer structure made of the same or different materials, or may be a suitable mixture of the materials shown below.

The surface protective layer is not particularly limited, but examples thereof include those made of a two-component curing resin or a crosslinked cured product of an ionizing radiation curable resin composition.
The crosslinked and cured product is preferably transparent, and may be translucent or colored so long as it is transparent to the extent that the design layer can be visually recognized.

As the two-component curing resin, the binder resin of the adhesive primer layer may be used.
As the ionizing radiation curable resin, for example, an oligomer (hereinafter, so-called prepolymer, macromonomer, etc. are also included) having a radical polymerizable unsaturated bond or a cationic polymerizable functional group in the molecule and/or a monomer having a radical polymerizable unsaturated bond or a cationic polymerizable functional group in the molecule is preferably used. Here, ionizing radiation means electromagnetic waves or charged particles having energy capable of polymerizing or crosslinking molecules, and generally includes electron beams (EB) or ultraviolet rays (UV).

The above oligomers or monomers include, for example, compounds having radically polymerizable unsaturated groups such as (meth)acryloyl groups and (meth)acryloyloxy groups, and cationic polymerizable functional groups such as epoxy groups in the molecule. These oligomers and monomers can be used alone or in combination. In this specification, the above (meth)acryloyl group means an acryloyl group or a methacryloyl group.

As the oligomer having a radically polymerizable unsaturated group in the molecule, for example, oligomers such as urethane (meth)acrylate, polyester (meth)acrylate, epoxy (meth)acrylate, melamine (meth)acrylate, and triazine (meth)acrylate can be preferably used, and urethane (meth)acrylate oligomers are more preferable. As for the molecular weight, those having a molecular weight of about 250 to 100,000 are usually used.

The monomer having a radically polymerizable unsaturated group in the molecule is preferably, for example, a polyfunctional monomer, and more preferably a polyfunctional (meth)acrylate.
Examples of the polyfunctional (meth)acrylate include diethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, bisphenol A ethylene oxide modified di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane ethylene oxide tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate {pentafunctional (meth)acrylate}, dipentaerythritol hexa(meth)acrylate {hexafunctional (meth)acrylate}, etc. Here, the polyfunctional monomer refers to a monomer having a plurality of radically polymerizable unsaturated groups.

It is more preferable that the ionizing radiation curable resin composition contains an ionizing radiation curable resin component consisting of a urethane acrylate oligomer and a polyfunctional monomer, and it is particularly preferable that the ionizing radiation curable resin component has a urethane acrylate oligomer/polyfunctional monomer (mass ratio) of 6/4 to 9/1. This mass ratio range allows the composition to have better scratch resistance.
If necessary, a monofunctional monomer may be appropriately used in addition to the ionizing radiation curable resin component.
Examples of the monofunctional monomer include methyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and phenoxyethyl (meth)acrylate.

When the ionizing radiation curable resin composition is crosslinked by ultraviolet light, it is preferable to add a photopolymerization initiator to the ionizing radiation curable resin composition.
When the ionizing radiation curable resin composition is a resin system having a radically polymerizable unsaturated group, acetophenones, benzophenones, thioxanthones, benzoin, and benzoin methyl ethers can be used alone or in combination as the photopolymerization initiator.
When the ionizing radiation curable resin composition is a resin system having a cationically polymerizable unsaturated group, the photopolymerization initiator may be an aromatic diazonium salt, an aromatic sulfonium salt, an aromatic iodonium salt, a methacerone compound, a benzoin sulfonate ester, or the like, either alone or in combination. The amount of these photopolymerization initiators to be added is about 0.1 to 10 parts by mass per 100 parts by mass of the ionizing radiation curable resin component.

In addition, various additives may be further added to the ionizing radiation curable resin composition as necessary. Examples of these additives include thermoplastic resins such as urethane resin, polyvinyl acetal resin, polyester resin, polyolefin resin, styrene resin, polyamide resin, polycarbonate resin, acetal resin, vinyl chloride-vinyl acetate copolymer resin, vinyl acetate resin, acrylic resin, and cellulose resin; lubricants such as silicone resin, wax, and fluorine resin; ultraviolet absorbers such as benzotriazole, benzophenone, and triazine; light stabilizers such as hindered amine radical scavengers; and colorants such as dyes and pigments.

As the electron beam source of the ionizing radiation, for example, various electron beam accelerators such as Cockcroft-Walton type, Van de Graft type, resonant transformer type, insulating core transformer type, or linear type, dynamitron type, high frequency type, etc. can be used, which irradiate electrons having an energy of 70 to 1000 keV. The exposure dose of the ionizing radiation is preferably, for example, about 1 to 10 Mrad.
As the ultraviolet ray source of the ionizing radiation, for example, a light source such as an extra-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, etc. can be used, and the wavelength of the ultraviolet ray is usually in the wavelength range of 190 to 380 nm.

The thickness of the surface protective layer is not particularly limited, but a preferred lower limit is 1 μm, a preferred upper limit is 50 μm, a more preferred lower limit is 10 μm, a more preferred upper limit is 40 μm, a still more preferred lower limit is 13 μm, and a still more preferred upper limit is 35 μm.
If the thickness of the surface protection layer is less than 1 μm, it may not be possible to provide sufficient durability (scratch resistance, contamination resistance, weather resistance, etc.), and if it exceeds 50 μm, the transmittance may decrease and the visibility of the pattern in the pattern layer may decrease.

The coating step is not particularly limited, and may involve, for example, coating the ionizing radiation curable resin composition and irradiating the coating with ionizing radiation.
Examples of the coating method that can be used include roll coating, knife coating, air knife coating, die coating, lip coating, comma coating, kiss coating, flow coating, and dip coating.

[Decorative sheet]
The decorative sheet produced by the decorative sheet manufacturing method of the present invention comprises a substrate having a pattern layer having characteristic and non-characteristic portions on one side thereof laminated to a transparent resin layer, and has a recess on the side of the transparent resin layer opposite to the side having the pattern layer.
FIG. 3 is a cross-sectional view that illustrates a schematic example of a decorative sheet produced by the decorative sheet production method of the present invention.
In one example of a decorative sheet shown in FIG. 3, a decorative sheet 10 has a design layer 2 on one surface of a substrate 1 , and a transparent resin layer 3 on the design layer 2 .
The pattern layer 2 has a characteristic portion 2a and a non-characteristic portion 2b.
Moreover, the transparent resin layer 3 has a recess (D) on the side opposite to the side having the pattern layer 2, the recess (D) being in sync with a characteristic portion of the pattern layer 2. The pattern layer 2 has a recess on the side opposite to the side having the substrate 1, the recess (D) being located in the lamination direction.
Although not shown in FIG. 3, the decorative sheet 10 preferably has a surface protective layer on the transparent resin layer 3 .
The recesses located in the stacking direction of the recesses (D) may be present as shown in FIG. 3, but are not necessarily required.

(Other layers)
The decorative sheet 10 may have a primer layer and an adhesive layer, if necessary.
The primer layer and adhesive layer can be provided between layers, for example, between the substrate and the pattern layer, between the pattern layer and the transparent resin layer, or between the transparent resin layer and the surface protective layer.

The primer layer can be formed by applying a known primer agent. Examples of primer agents include urethane resin-based primer agents made of acrylic-modified urethane resin (acrylic urethane-based resin), urethane-cellulose-based resin (for example, a resin obtained by adding hexamethylene diisocyanate to a mixture of urethane and soluble cellulose), and resin-based primer agents made of acrylic and urethane block copolymers. Additives may be blended into the primer agent as necessary. Examples of additives include fillers such as calcium carbonate and clay, flame retardants such as magnesium hydroxide, antioxidants, lubricants, foaming agents, ultraviolet absorbers, and light stabilizers. The amount of additives blended can be set appropriately depending on the product characteristics.

The primer layer may contain an ultraviolet absorbing agent, if necessary.
As the ultraviolet absorbing agent, any known ultraviolet absorbing agent can be appropriately selected and used.

The thickness of the primer layer is not particularly limited, but is preferably 0.01 to 10 μm, and more preferably 0.1 to 1 μm.

The primer layer may be formed by coating the resin-based primer agent and curing it with ionizing radiation or the like.
The above coating method and curing method may be appropriately selected from known methods.

The adhesive layer is not particularly limited, and any known adhesive may be used. Examples include polyurethane, acrylic, polyolefin, polyvinyl acetate, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ionomer, butadiene-acrylonitrile rubber, neoprene rubber, natural rubber, etc. These adhesives may be used alone or in combination of two or more.

The thickness of the adhesive layer after drying is preferably about 0.1 to 30 μm, and more preferably about 1 to 5 μm.

The adhesive layer may be formed by coating the adhesive and curing it with ionizing radiation or heat.
The above coating method and curing method may be appropriately selected from known methods.

The decorative sheet 10 may have a backer layer as the bottom layer (the side opposite to the side on which the design layer is laminated) of the base material in order to impart scratch resistance and impact resistance.
As the backer layer, a known backer layer disclosed in JP-A-2014-188941 or the like can be appropriately selected and used.
When providing the backer layer, the backer layer may be laminated on the side of the substrate opposite to the side on which the pattern layer is laminated after the shaping process or the detection process, or a substrate having a backer layer laminated on the side opposite to the side on which the pattern layer is laminated may be prepared in the preparation process.

<Decorative sheet manufacturing equipment>
The decorative sheet manufacturing apparatus of the present invention is a decorative sheet manufacturing apparatus that forms recesses in a decorative sheet having a pattern layer having characteristic and non-characteristic portions, and a transparent resin layer on one side of a substrate, while heating the decorative sheet, and is characterized in that it is equipped with a shaping mechanism that forms recesses in sync with the characteristic portions of the pattern layer from the side of the transparent resin layer opposite to the side having the pattern layer, a detection mechanism at the rear of the shaping mechanism that detects positional information between the characteristic portions of the pattern layer and the recesses in sync with the characteristic portions of the pattern layer, and a feed adjustment mechanism that feeds back the positional information to the front of the shaping mechanism to adjust the feed of the decorative sheet.

The shaping mechanism, detection mechanism, and adjustment mechanism can be appropriately selected from those described in the decorative sheet manufacturing method described above.

<Decorative board>
The decorative sheet produced by the method for producing a decorative sheet of the present invention can be laminated on an adherend to produce a decorative board that has a visually excellent three-dimensional effect and is also highly durable.

Examples of the adherend include wood boards such as wood veneer, wood plywood, particle board, and MDF (medium density fiberboard); gypsum-based boards such as gypsum boards and gypsum slag boards; cement boards such as calcium silicate boards, asbestos slate boards, lightweight foamed concrete boards, and hollow extruded cement boards; fiber cement boards such as pulp cement boards, asbestos cement boards, and wood chip cement boards; ceramic boards such as pottery, porcelain, earthenware, glass, and enamel; metal boards such as iron boards, galvanized steel boards, polyvinyl chloride sol-coated steel boards, aluminum boards, and copper boards; polyolefin resin boards, polyvinyl chloride resin boards, acrylic resin boards, A Examples of such resins include thermoplastic resin plates such as BS plates and polycarbonate plates; thermosetting resin plates such as phenolic resin plates, urea resin plates, unsaturated polyester resin plates, polyurethane resin plates, epoxy resin plates and melamine resin plates; and so-called FRP plates obtained by impregnating and curing a resin such as phenolic resin, urea resin, unsaturated polyester resin, polyurethane resin, epoxy resin, melamine resin, diallyl phthalate resin, into a glass fiber nonwoven fabric, cloth, paper, or other various fibrous base material. These may be used alone, or two or more of these may be laminated to form a composite substrate.
In addition, the thermoplastic resin board or thermosetting resin board may contain various additives, such as coloring materials (pigments or dyes), fillers such as wood powder or calcium carbonate, matting agents such as silica, foaming agents, flame retardants, lubricants such as talc, antistatic agents, antioxidants, ultraviolet absorbers, and light stabilizers, as necessary.
The thickness of the adherend is not particularly limited.

The method for laminating the decorative sheet of the present invention to the above-mentioned adherend is not particularly limited, and examples include laminating via the above-mentioned primer layer or via the above-mentioned adhesive layer.

Next, the present invention will be described in more detail using examples, but the present invention is not limited to these examples.

(Example)
A substrate (60 μm thick, colored polypropylene sheet) was prepared which had been subjected to a corona discharge treatment on both sides. An ink consisting of 100 parts by mass of a urethane-nitrocellulose mixed resin to which 5 parts by mass of hexamethylene diisocyanate had been added was applied to one side to form a 2 μm thick primer layer, and an ink consisting of 100 parts by mass of an acrylic urethane resin to which 8 parts by mass of hexamethylene diisocyanate and 70 parts by mass of titanium oxide had been applied to the other side to form a 2 μm thick concealing layer (non-characteristic portion).
Next, an ink containing an acrylic urethane resin with added coloring pigment was applied onto the concealing layer to form a 1 μm-thick pattern layer (wood grain pattern, characteristic parts), thereby preparing a substrate having a pattern layer on one side having characteristic and non-characteristic parts (preparation process).
Next, an ink containing 11 parts by mass of hexamethylene diisocyanate added to 100 parts by mass of an acrylic polyol-urethane mixed resin was applied to form an adhesive layer having a thickness of 2 μm, and a polypropylene resin was hot-melt extruded onto the adhesive layer using a T-die extruder to form a transparent resin layer having a thickness of 100 μm (lamination process).Furthermore, an ink containing 6 parts by mass of hexamethylene diisocyanate added to 100 parts by mass of an acrylic polyol-urethane mixed resin was applied onto the transparent resin layer to form a primer layer having a thickness of 2 μm.
Thereafter, an acrylate-based electron beam curable resin was applied onto the primer layer by a gravure coating method so that the solid content was 30 g/ ^m2 , followed by drying. After that, an electron beam was irradiated under conditions of an oxygen concentration of 200 ppm, an acceleration voltage of 165 KeV, and 5 Mrad to form a surface protective layer made of the electron beam curable resin (coating process).
Furthermore, the surface protective layer was embossed to form recesses in accordance with the design layer (shaping step), thereby producing a decorative sheet.
When the produced decorative sheet was checked, it was found that the picture pattern of the picture layer was in harmony with the recesses, and the sheet had a visually excellent three-dimensional effect.

The laminating, coating and shaping processes were carried out continuously by roll-to-roll, and after the shaping process, a detection mechanism (camera) was used to confirm the positional relationship between the position of the characteristic part of the design layer and the position of the recess that was synchronized with the characteristic part of the design layer. If a positional misalignment between the characteristic part of the design layer and the recess was detected, the speed of the delivery adjustment mechanism was changed to correct the tension of the sheet before shaping, thereby adjusting the position.

The present invention provides a manufacturing method and manufacturing device for decorative sheets that have a visually excellent three-dimensional effect by harmonizing the pattern of the design layer with the recesses.

Reference Signs List 1: Substrate 2: Design layer 2a: Characteristic portion 2b: Non-characteristic portion 3: Transparent resin layer 10: Decorative sheet 11: Pre-shaping sheet 20: Conveying mechanism 30: Feed-out adjustment mechanism 40: Shaping mechanism 50: Detection mechanism

Claims (3)

A method for producing a decorative sheet having a recess, comprising the steps of:
A preparation step of preparing a substrate having a design layer on one side thereof, the design layer having a feature portion and a non-feature portion;
a lamination step of laminating a transparent resin layer on the pattern layer; and
A forming step of forming a recess in accordance with a characteristic portion of the pattern layer from the side of the transparent resin layer opposite to the side having the pattern layer ,
The method further includes a detection step of detecting position information of the characteristic portion of the pattern layer and the recesses synchronized with the characteristic portion of the pattern layer after the shaping step, and feeding back the position information to a feed adjustment mechanism provided before the shaping step to adjust the position of the characteristic portion of the pattern layer and the position of the recesses synchronized with the characteristic portion of the pattern layer,
The substrate is at least one selected from the group consisting of polyolefin resins, thermoplastic ester resins, acrylic thermoplastic resins, polyamide thermoplastic resins, polyimides, polyurethanes, polystyrenes, and acrylonitrile-butadiene-styrene resins.
A method for producing a decorative sheet comprising the steps of: 2. The method for producing a decorative sheet according to claim 1 , further comprising a coating step of coating a surface protective layer on the transparent resin layer between the laminating step and the shaping step. A manufacturing apparatus for a decorative sheet, which forms recesses while heating a decorative sheet having a pattern layer having characteristic and non-characteristic parts and a transparent resin layer on one side of a substrate, comprising:
a shaping mechanism for shaping a recess in accordance with a characteristic portion of the pattern layer from the side of the transparent resin layer opposite to the side having the pattern layer;
A detection mechanism for detecting position information of a characteristic portion of the pattern layer and a recess synchronized with the characteristic portion of the pattern layer, the detection mechanism being disposed behind the shaping mechanism;
a feed-out adjustment mechanism that feeds back the position information to the front part of the shaping mechanism to adjust the feed-out of the decorative sheet ;
The decorative sheet manufacturing apparatus is characterized in that the substrate is at least one selected from the group consisting of polyolefin resins, thermoplastic ester resins, acrylic thermoplastic resins, polyamide thermoplastic resins, polyimides, polyurethanes, polystyrene, and acrylonitrile-butadiene-styrene resins .

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