JP2003103674A - Embossed sheet, method for manufacturing the same, and embossed sheet manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an embossed sheet dispensing with the formation of a hot press mold and a hot press roll, capable of altering an embossed pattern easily, having economical efficiency, retaining fine protruded and recessed patterns without resuming flat surface and capable of arbitrarily regulating the depth of the unevenness of the embossed pattern, to provide a method for manufacturing the same and an embossed sheet manufacturing apparatus. SOLUTION: Drops of a photosetting resin is fallen or discharged on a substrate sheet and irradiated with light before or after bonded to the substrate sheet to be cured to form unevenness on the substrate sheet by the adhesion of cured drops.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concavo-convex sheet that can be used as a member for forming concavities and convexities on a decorative sheet, a method for manufacturing the same, and a concavo-convex sheet manufacturing apparatus.

[0002]

2. Description of the Related Art Conventionally, a concave-convex sheet has been used to obtain a decorative sheet or the like having a three-dimensional effect such as wood grain conduits and streaks. This concavo-convex sheet has concavities and convexities formed on the base sheet, and the following methods have been used to form the concavities and convexities on the base sheet.

(1) As a method of heating and pressing, a hot press die or a hot press roll is pressed against the surface of a base sheet made of a smooth thermoplastic resin sheet to soften the surface of the base sheet and at the same time hot press it. There is a method of copying the unevenness (embossing) pattern on the surface of the mold or the heat press roll.

(2) As a printing method using a gravure plate, a liquid photocurable resin is provided on a base sheet by gravure printing, and then a light ray is irradiated to cure the photocurable resin, and the unevenness of the gravure plate is obtained. There is a method of forming an (emboss) pattern on the surface of the base sheet.

[0005]

According to the method (1), a hot press die and a hot press roll are required to be manufactured in many steps, and a high production cost is required. Further, it is not possible to easily change the concavo-convex pattern of the hot press mold or the hot press roll, and a new hot press mold or hot press roll must be prepared every time a change request is made, which is uneconomical. It was Since the thermoplastic resin sheet is softened and a hot press die or a heat press roll is pressed to copy the uneven pattern, it is easy to return to a flat surface when the hot press die or the heat press roll is released from the pressing in a fine convex portion or a concave portion. It was

In the method (2), the height of the convex portion of the unevenness of the gravure plate can be at most about 40 μm,
There were restrictions on the degree of unevenness. Further, since the light curable resin is a liquid having a low degree of viscosity, ink dripping occurs on the surface of the substrate sheet after gravure printing, and the concavo-convex pattern collapses, so that the concavo-convex pattern having the intended shape cannot be obtained.

[0007]

The concavo-convex sheet of the present invention is characterized in that concavities and convexities are formed on a base sheet by cured light-curable resin droplets.

According to the method for producing a concavo-convex sheet of the present invention, a light-curable resin droplet is dropped or released onto a base sheet,
A feature of the present invention is that the light-curable resin droplets are adhered to the base sheet and then the light-curable resin droplets are cured to form irregularities on the base sheet.

According to the method for producing a concavo-convex sheet of the present invention, a light curable resin droplet is dropped or released onto a base sheet,
Before the light-curable resin droplets adhere to the base sheet, the light-curable resin droplets are semi-cured by irradiating the light rays, and after the light-curable resin droplets adhere to the base sheet, the light rays are re-irradiated to the light rays. It is characterized in that unevenness is formed by curing a curable resin droplet.

According to the method for producing a concavo-convex sheet of the present invention, a light curable resin droplet is dropped or released onto a base sheet, and a light beam is irradiated before the light curable resin droplet adheres to the base sheet to apply the light curable resin. The resin droplets are semi-cured, the irradiation state is maintained, and after the light-curable resin droplets adhere to the base sheet, the light-curable resin droplets are cured to form irregularities.

In the method for manufacturing the uneven sheet, the light curable resin droplets dropped or emitted may be separately irradiated with light rays. Alternatively, a plurality of light-curable resin droplets that have been dropped or emitted may be simultaneously irradiated with light rays.

The concavo-convex sheet manufacturing apparatus of the present invention includes a light-curable resin dropping / releasing device capable of dropping or releasing a light-curable resin droplet onto a base sheet, and dropping or releasing onto a base sheet. And a light irradiation device capable of curing the light curable resin droplets.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to the drawings.

According to the manufacturing method of the present invention, a light-curable resin droplet is dropped or released onto a base sheet, and a light beam is irradiated before or after the droplet adheres to the base sheet to cure the droplet. A method for manufacturing a concavo-convex sheet, characterized by forming concavities and convexities on a base sheet by adhesion.

First, the base sheet 1, the light curable resin droplets 2 and the uneven sheet manufacturing apparatus used in the method for manufacturing the uneven sheet according to the present invention will be described.

The material of the base sheet 1 is polyester resin, polypropylene resin, polyurethane resin, acrylic resin, fluorine resin, vinyl resin, polyethylene resin or the like. The thickness of the base sheet 1 is
It is preferably 0.01 to 3 mm. If it is thinner than 0.01 mm, wrinkles are likely to occur, and if it is thicker than 3 mm,
It is bulky and difficult to handle as a sheet.

As the light curable resin, a liquid of a resin (oligomer, prepolymer) which is cured by being irradiated with a light ray such as an ultraviolet ray, an electron beam or a laser beam is used. As the light curable resin, ultraviolet curable resin, electron beam curable resin, α
There are ray curable resins, β ray curable resins, γ ray curable resins, laser light curable resins and the like. Specific examples of the light curable resin include ester acrylate-based resin, urethane acrylate-based resin, epoxy acrylate-based resin, amino acrylate-based resin, unsaturated polyester-based resin, etc., each of which is 1) radical polymerization type and 2) cation. Polymerization type and 3) thiol / ene addition type are available.

Further, when a high-viscosity light-curable resin is used, a diluent can be used. As the diluent, an organic solvent or a reactive diluent (photopolymerizable monomer) can be used. Examples of the reactive diluent include monofunctional compounds such as 2-ethylhexyl acrylate, ethoxydiethylene glycol acrylate, phenoxyethyl acrylate, 2hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, dicyclopentenyl acrylate, vinylcyclohexene monooxide, and hydroxybutyl vinyl ether. , Neopentyl glycol diacrylate, 1.6 hexanediol diarylate, hydroxypivalic acid neopentyl glycol diacrylate, polyethylene glycol diacrylate, bis (acryloxyethyl) bisphenol A, and other bifunctional compounds, merimethylolpropane Triacrylate, pentaerythritol triacrylate, dipentaerythritol hexacrylate Include the polyfunctional etc., it can be used as these alone or composite. In addition to these, a photopolymerization initiator, a sensitizer, a filler, a coating additive (a leveling agent, an antifoaming agent), a non-reactive resin, a colorant, and the like can be added, if necessary. Examples of the filler include inorganic substances such as silica and calcium carbonate, and organic substances such as acrylic beads and urethane beads. By adding these fillers, the surface of the light-curable resin droplets that are dropped or released can be made into a matte shape or the like. Examples of colorants include dyes, pigments, and aluminum paste. These fillers have such a size that the light-curable resin droplets that are dropped or emitted are not destroyed.

The concavo-convex sheet manufacturing apparatus includes a light-curable resin dropping / releasing device capable of dropping or discharging the light-curable resin droplets 2 onto the base sheet 1, and the base sheet 1.
It is provided with a light beam irradiation device capable of curing the light beam curable resin droplets 2 dropped or emitted onto the above.

The light curable resin dropping / releasing device is a device for dropping or releasing the light curable resin droplet 2. The light curable resin dropping / releasing device basically has a mechanism for dropping or ejecting a light curable resin droplet from the tip of the nozzle 4 (capillary tube) in response to an electric signal. Examples include a dispenser 3, an inkjet printer, a bubble jet (registered trademark) printer, and the like. As a general dispenser 3, there is a dispenser 3 of a type in which a liquid light curable resin in a syringe is pushed out from a tip of a nozzle 4 by applying pressure by hydraulic pressure or air pressure (see FIGS. 1 and 2).
reference). By adjusting the size of the opening of the nozzle 4 and the oil pressure or air pressure, the size of the light curable resin droplet 2 to be dropped or emitted can be adjusted. A general inkjet printer refers to a printer of a type that prints by ejecting ink onto paper by heat or pressure. There are a method of ejecting ink by utilizing expansion by heat, a method of utilizing foaming of ink by heat, a method of flying ink by utilizing an electrostrictive effect, and the like. Bubble Jet (registered trademark)
As a general printer, a printer is used in which the ink on the heater surface causes film boiling due to a heating heater installed in the nozzle to generate bubbles, and the ejected ink equivalent amount is used as an ink droplet for recording. I mean.

As the light beam irradiation device, an ultraviolet light irradiation device 5, an electron beam irradiation device, an α-ray irradiation device, a β-ray irradiation device, γ
There are a line irradiation device and a laser light irradiation device. Examples of the ultraviolet irradiation device and the electron beam irradiation device include a high pressure mercury lamp, a metal halide lamp, a xenon lamp, and a low pressure mercury lamp. When irradiating pinpoint ultraviolet rays, the ultraviolet rays are sent to the glass fiber 6 and the glass fiber 6
Ultraviolet rays radiated from the diameter of can be applied to the light-curable resin droplet 2 dropped or emitted (see FIG. 1).
As the laser beam irradiation device, carbon dioxide laser device, YAG laser device, ruby laser device, VYO
There are ₄ laser devices.

Next, a method of manufacturing the uneven sheet will be described.

First, the light curable resin droplets 2 are dropped or discharged onto the base sheet 1.

As the base sheet 1, the above-mentioned ones can be used. The above-mentioned light-curable resin dropping / releasing device can be used to drop or release the light-curable resin droplet 2.

The dropping or releasing of the light curable resin droplet 2 is
Dispenser 3 as a light-curable resin dropping / releasing device
When using, the tip of the dispenser 3 is attached to the base sheet 1.
The surface can be moved by drawing an arbitrary concave-convex pattern with a light-curable resin toward the surface of. The movement of the dispenser 3 can be performed by a three-axis control robot. The base sheet 1 can be moved using an XY table.

Next, a light-curable resin droplet is dropped on or discharged from the base sheet, and after the light-curable resin droplet adheres to the base sheet, a light beam is irradiated to cure the light-curable resin droplet. The unevenness is formed on the sheet.

The types of irregularities to be formed on the base sheet 1 include irregularities corresponding to a matte pattern, irregularities corresponding to mats, wood grain conduits and lines, irregularities corresponding to woven patterns, and leather patterns. There are irregularities, and irregularities corresponding to the hairline pattern. Light-curable resin droplets 2 dropped or emitted
The height of the convex portion of the unevenness formed by
Some are 0 μm.

In the present invention, the number of the light-curable resin droplets 2 dropped or emitted on the base sheet is changed, or the light-curable resin droplets 2 dropped or emitted are changed.
The width of the design can be widened by changing the size of (see FIG. 3).

In the case of changing the number of the light-curable resin droplets 2 dropped or emitted that are stacked on the substrate sheet, three-tiered pyramidal projections (see FIG. 3) are used.
(A)) and four-tiered pyramid-shaped protrusions (see FIG. 3).
(B)) There is a convex portion (FIG. 3C) composed of a three-tiered portion and a one-tiered portion. In these cases, the height of the convex and concave portions can be finely adjusted.

As a case of changing the size of the light-curable resin droplet 2 to be dropped or emitted, the above-mentioned FIG.
A protrusion having a pyramid shape in which two or more droplets larger than those described in (c) are formed (FIG. 3D), and a protrusion formed by combining light curable resin droplets 2 having different sizes (FIG. 3).
(E)) etc. In these cases, it is economical because the number of times of dropping or discharging is small.

As described above, when the dropped or released light-curable resin droplets 2 are stacked to form the unevenness, the unevenness having a so-called undercut can also be formed (see FIG. 4). In this case, it is possible to enhance the design effect such that the distinction between the concave portion and the convex portion becomes clear.

Further, in the present invention, the plurality of light-curable resin droplets 2 may be integrated before or during curing to form irregularities (see FIG. 5). Only a few large light-curable resin droplets 2 may be integrated (see FIG. 5 (a)), or a large number of small light-curable resin droplets 2 may be used so that they are stacked so as to be uneven. You may make it (refer FIG.5 (b)). It should be noted that the reason why the light-curable resin droplets 2 are integrated before or during curing is that the plurality of light-curable resin droplets 2 are still in a liquid state, and thus they are easily integrated.

In the present invention, the light-curable resin droplets 2 that have been dropped or emitted can be individually cured by irradiation with light rays (see FIG. 1). In this case, the light-curable resin droplet 2 is generally dropped from the light-curable resin dropping / releasing device. Or, by irradiating a light beam,
It is also possible to simultaneously cure a plurality of the light-curable resin droplets 2 dropped or released (see FIG. 2). In this case, in general, the light-curable resin droplet 2 is the light-curable resin droplet
Emitted from the ejection device.

In the case of the former, the dripped light curable resin droplet 2 is hardened in a unit of one drop while keeping the outer shape of the drop as it is, so that it is possible to form fine irregularities with sharp edges.

In the latter case, the emitted light curable resin droplets 2 are simultaneously cured, so that it is possible to form unevenness with rounded edges.

In the present invention, the light-curable resin droplets are dropped or released onto the base sheet, and before the light-curable resin droplets are attached to the base sheet, light rays are irradiated to semi-cure the light-curable resin droplets. Then, after the light curable resin droplets adhere to the base sheet, the light rays may be re-irradiated to cure the light curable resin droplets to form the irregularities. Further, a light-curable resin droplet is dropped or released onto the base sheet, and before the light-curable resin droplet adheres to the base sheet, light rays are irradiated to semi-cure the light-curable resin droplet,
Irregularities may be formed by maintaining the irradiation state and then curing the light-curable resin droplet after the light-curable resin droplet has adhered to the base sheet.

In these cases, by semi-curing before adhering to the base sheet 1, the drop shape may be deformed or destroyed by the impact when the light curable resin 2 collides with the base sheet 1. It is effective because it can be avoided. Further, the semi-cured state is preferable because it is more likely to be firmly adhered to the base sheet 1 and the adjacent light curable resin droplets 2 are more easily bonded. The adjustment of the timing of irradiating the light beam can utilize the electric signal when the light-curable resin droplet 2 is dropped or emitted.

Regarding the extent to which the light-curable resin droplet 2 is cured, basically, the light-curable resin droplet 2 may be cured to such an extent that the surface of the light-curable resin droplet 2 does not become sticky (“touch-drying”).
Also called. ). For example, the light curable resin droplet 2 is JISA
It can be cured to a value of 30 to 60 by the hardness measurement method. When a colored layer of characters, figures, patterns, etc. is formed by printing on the surface of the base sheet 1 on the side where the light-curable resin droplets 2 are attached, the hardness of the light-curable resin droplets 2 depends on the solvent of the printing layer. Good not to be attacked.

The irregularities are formed by the cured light curable resin droplets 7 attached on the base sheet 1. The unevenness may be formed on the entire surface of the base sheet 1, or may be formed linearly only on a necessary portion. When forming a linear shape only in a necessary portion, the surface of the base sheet 1 is exposed except for the portion where the cured droplet 7 exists (see FIG. 3).

The concavo-convex sheet obtained as described above is
For example, it can be used as follows. Less than,
Described below is the case of using as a member for forming irregularities on a decorative sheet having a matte metallic design.

As an example, the colored layer 8 is formed of an ink containing an aluminum paste partially on the side of the uneven sheet on which the unevenness formed by the cured light-curable resin droplets 7 is formed.
Is formed by screen printing, and the adhesive layer 9 is formed by screen printing to obtain a decorative sheet (FIG. 6).
(A)). In this case, a release layer can be formed between the uneven sheet and the colored layer by printing to form a so-called transfer sheet. A transfer sheet is a sheet used to copy the unevenness of the uneven sheet onto the surface of the transferred object by peeling the uneven sheet after adhering the adhesive layer of the transfer sheet to the surface of the transferred object. Say.

As another example, a colored layer is formed by screen printing with an ink partially containing aluminum paste on the side of the base sheet 1 where the unevenness of the uneven sheet is not formed, and the adhesive layer is further screen printed. It can be formed to obtain a decorative sheet. In this case, the cured droplet 7 is exposed on the outermost surface of the decorative sheet (see FIG. 6B).

There is a method in which the uneven sheet is deformed into a three-dimensional shape if necessary, then placed in an injection molding die, and the uneven sheet is fused to the molded product by heat and pressure of the molding resin simultaneously with the injection molding. Examples of the material of the molded product include acrylic resin, polypropylene resin, ABS resin, polystyrene resin, polycarbonate resin, and noryl resin.

[0044]

EXAMPLE A light-curable resin dropping / releasing device in which a dispenser equipped with a nozzle for dropping 0.01 ml as a drop is attached to a three-axis control robot capable of controlling in the XYZ axis directions, and this nozzle. An ultraviolet ray was sent by a glass fiber directed toward the tip of the glass fiber, and an ultraviolet ray was irradiated from the tip of the glass fiber to prepare a light ray irradiation device capable of curing the light ray curable resin droplet in a unit of one drop. As the resin supplied from the dispenser, a UV curable resin containing a urethane arylate resin and 2-ethylhexyl acrylate as a reactive diluent was used, and a 0.2 mm thick transparent base sheet made of polycarbonate was formed on the XY table. It was placed, and a transparent ultraviolet curable resin was dropped on it from the nozzle of the dispenser. XY the robot with the dispenser attached according to the grain pattern data.
Controlled in the direction, the convex portions of the wood-grained conduit were formed. The robot is controlled in the Z direction and dropped from the dispenser,
And the amount of photocurable resin drops that were stacked was controlled.
The ultraviolet curable resin dropped from the nozzle was irradiated with ultraviolet rays in a unit of 1 drop to be attached on the base sheet. In this way, an uneven sheet was obtained.

[0045]

Since the present invention has the above-mentioned structure, it has the following effects.

Since only the light-curable resin dropping / discharging device and the light-irradiating device are used, it is not necessary to prepare a heat press type or a heat press roll, and the concavo-convex pattern can be easily changed, which is economical. Is. Even fine protrusions and recesses do not return to flat. The depth of the unevenness of the uneven pattern can be arbitrarily adjusted. The light curable resin does not cause ink sagging, and it is possible to reliably obtain an uneven pattern having an intended shape.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing one step of a method for manufacturing an uneven sheet according to the present invention.

FIG. 2 is a cross-sectional view showing one step of a method for manufacturing an uneven sheet according to the present invention.

FIG. 3 is a sectional view showing an example of an uneven sheet of the present invention.

FIG. 4 is a sectional view showing an example of an uneven sheet of the present invention.

FIG. 5 is a cross-sectional view showing an example of an uneven sheet of the present invention.

FIG. 6 is a cross-sectional view showing an example of an uneven sheet of the present invention.

[Explanation of symbols]

1 Base sheet 2 Light-curable resin drops 3 dispensers 4 nozzles 5 UV irradiation device 6 glass fiber 7 hardened drops 8 colored layers 9 Adhesive layer

Claims (7)

[Claims] 1. A concavo-convex sheet, wherein concavities and convexities are formed by cured light-curable resin droplets on a base sheet. 2. A substrate sheet by dropping or releasing a light curable resin droplet onto a base sheet, irradiating a light ray after the light curable resin droplet adheres to the base sheet to cure the light curable resin droplet. A method for manufacturing a concavo-convex sheet, comprising forming concavities and convexities on the top. 3. A light-curable resin droplet is dropped or released onto the base sheet, and before the light-curable resin droplet adheres to the base sheet, a light beam is irradiated to semi-cure the light-curable resin droplet, and then the light-curable resin droplet is semi-cured. A method for producing a concavo-convex sheet, which comprises forming irregularities by re-irradiating light rays to cure the light-curable resin droplets after the light-curable resin droplets have adhered to the base sheet. 4. A light-curable resin droplet is dropped on or released from a base sheet, and before the light-curable resin droplet adheres to the base sheet, a light beam is irradiated to semi-cure the light-curable resin droplet and then irradiated. A method for producing a concavo-convex sheet, characterized in that the state is maintained, and after the light-curable resin droplets adhere to the base sheet, the light-curable resin droplets are cured to form irregularities. 5. The method for producing a concavo-convex sheet according to any one of claims 2 to 4, wherein each of the dropped or emitted light curable resin drops is separately irradiated with a light beam. 6. The method for producing a concavo-convex sheet according to claim 2, wherein a plurality of the light-curable resin droplets that have been dropped or emitted are simultaneously irradiated with a light beam. 7. A light-curable resin dropping / releasing device capable of dropping or releasing a light-curable resin droplet onto a base sheet, and a light-curable resin droplet dropped or released onto a base sheet. An uneven sheet manufacturing apparatus, which is provided with at least a light irradiation apparatus capable of curing the sheet.