JP2002103515A - Decorative sheet for molding processing, method for manufacturing the same and molded article using decorative sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decorative sheet for molding processing usable as a base film for injection molding and becoming an inner surface embossed sheet high in design effect, a method for manufacturing the same and a molded article using the decorative sheet. SOLUTION: Shrink ink is applied to a sheet base material by solid printing using a screen printing process and irradiated with ultreaviolet rays to be cured to form a resin layer to which irregular unevenness processing is applied. The solid printing of ink, in which metal pigment is dispersed, is applied to the resin layer to form a layer having metal gloss.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decorative sheet for molding formed by forming an irregular pattern by ultraviolet curing with a shrink ink, a method for producing the same, and a molded article using the decorative sheet.

[0002]

2. Description of the Related Art Conventionally, there is a chimney printing method as a method for producing a decorative sheet. The stencil printing is obtained by printing stencil ink by screen printing, and curing the ink by irradiation of ultraviolet rays so as to generate unevenness of the squeezed pattern on the surface. The shrinking pattern refers to an irregular wrinkle pattern on the ink surface.
In general, chimprinting is often performed on gold paper, silver paper, or the like. In addition, there is a fogged glass using a transparent sheet, and a colored sheet having a decorative effect such as stained glass.

[0003] Conventional printing will be described with reference to FIG. First, monochromatic offset printing is performed on gold paper or silver paper. Here, a transparent sheet may be used instead of gold paper or silver paper. On top of that, the entire surface is printed with a screen printing device using a fine ink. When using a transparent medium for coloring and adding a color paste, 1-3% of a color paste is added.

[0004] Then, ultraviolet rays are irradiated from above by a shrinking device. The shrinking device is a UV irradiation device that cuts a long wavelength and irradiates a short wavelength. Irradiation of ultraviolet light of such a wavelength causes unevenness in light absorption between the surface and the inside of the applied ink, resulting in unevenness in the curability and curing shrinkage of the surface and the inside. A pattern is formed.

Next, when a dust pattern is formed on the surface,
The UV curing device irradiates ultraviolet rays without further defining the wavelength range. By irradiating ultraviolet rays using a UV curing device that does not define the wavelength range, the inside of the applied ink is sufficiently cured, and the adhesion of the coating film to the object to be coated, or the physical properties and durability are improved. .

[0006] Through the above steps, a shrinking pattern is formed on gold paper, silver paper, or a transparent sheet. As described above, when a decorative sheet is formed by ultraviolet curing, the decorative sheet is glossy and has excellent abrasion resistance, heat resistance, and chemical resistance.

[0007] However, as described above, a decorative sheet formed by conventional shrink printing is an external embossed sheet having irregular irregularities on the surface. Therefore, it is not suitable for a base material of a molded product that does not function unless the surface is flat like a ruler.

That is, when a molding process is performed using a decorative sheet formed by the conventional stencil printing, for example, the decorative sheet is used as a base film (insert member) for injection molding, and synthetic resin is injected into the base film to be integrated therewith. When formed, because it is an external embossed sheet with irregularities on the surface,
Adhesion of each layer is deteriorated, resulting in defective products. In addition, since the adhesion of each layer is poor, wrinkles and turbidity are generated, and the decorative pattern of the decorative sheet as an insert member is impaired.

Therefore, conventionally, an independent coating step is provided after the injection molding step, and surface decoration such as coating is performed as secondary processing. In addition, in-mold coating injection molding has been performed to create a decorated molded product.
In-mold coat injection molding is a molding method for performing surface decoration such as painting on a molded product at the same time as injection molding.

[0010]

However, in the above-mentioned method, the number of steps during the molding process increases, and the manufacturing apparatus has a complicated structure. On the other hand, insert injection molding using a pre-painted sheet as a base film requires a small number of steps, and the manufacturing apparatus can be simplified.

[0011] However, when a decorative sheet provided with a dimpled pattern is used as a base film for insert injection molding, a problem occurs because of the outer surface embossed sheet as described above.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and is intended to be used as a base film for injection molding, and has a high designability. It is an object to provide a molded product using a decorative sheet.

[0013]

In order to achieve the above object, according to the present invention, a resin layer formed on a sheet substrate by at least a resin curable by ultraviolet rays, and a resin layer formed on the resin layer are formed. Characterized in that it comprises a layer having a metallic luster.

According to a second aspect of the present invention, in the first aspect of the present invention, the sheet substrate is made of any one of a polyethylene terephthalate sheet and a polypropylene sheet.

The third aspect of the present invention provides the first or second aspect.
In the invention described, after irradiating only the short wavelength portion of ultraviolet light, the resin layer is again irradiated with ultraviolet light without defining the wavelength range, whereby the resin layer can be subjected to irregular asperity processing. It is characterized by being made of a possible ultraviolet-curable resin material.

According to a fourth aspect of the present invention, in the first, second or third aspect, the metallic glossy layer is
It is characterized by being formed by vapor deposition of an ink or metal in which a metal pigment is dispersed.

According to a fifth aspect of the present invention, there is provided a step of coating an ultraviolet-curable resin on a sheet substrate, and a step of irradiating the coated ultraviolet-curable resin with only a short wavelength portion of ultraviolet light. After the step of irradiating only the short wavelength portion of the ultraviolet light, again, by irradiating the ultraviolet light without defining the wavelength range, a step of applying irregular irregularities to the resin layer, and a metal pigment on the resin layer Characterized by comprising a step of forming a layer having a metallic luster by applying an ink in which is dispersed or vapor-depositing a metal.

According to a sixth aspect of the present invention, there is provided a decorative sheet for molding comprising a resin layer formed on a sheet substrate by a resin curable by ultraviolet rays, and a layer having a metallic luster formed on the resin layer. Wherein the decorative sheet is integrally formed as a base film of an injection-molded product.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the decorative sheet according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view showing a decorative sheet according to an embodiment of the present invention. First of all, a screen printing device with a transparent sheet that can be formed and processed with ink
The whole surface is printed.

The shrinking ink is a UV (ultraviolet curing type) ink. A UV ink is an ink that undergoes a photochemical reaction with the energy of ultraviolet light, cures from a liquid to an individual in seconds, and forms a film.

Next, the transparent sheet, which has been solid-printed on the entire surface, is passed through a packing device. The shrinking device is a UV irradiation device that irradiates ultraviolet rays to cure the surface of the ink on the transparent sheet.

The UV irradiation device has a UV lamp. As the lamp, a high-pressure mercury lamp or a metal halide lamp is used. Further, a xenon lamp may be used.

The chopping device cuts a long wavelength among ultraviolet wavelengths and irradiates a short wavelength. When irradiating ultraviolet light of such a wavelength, the unevenness of the light absorbing ability between the surface and the inside of the applied ink causes the curability of the surface and the inside and the non-uniformity of the curing accommodating rate, thereby causing the ink surface to bleed. A printing layer is formed. At this stage, since the long wavelength is cut and irradiated, the ink inside does not cure.

Next, when a dust pattern is formed on the surface,
Irradiation with ultraviolet rays is performed by a UV curing device without further defining the wavelength range. Here, the inside of the applied ink is cured by irradiating without defining the wavelength range. At this stage, the ink is completely cured.

Next, the entire surface is solid-printed with an ink in which a metal pigment is dispersed on the resin layer on which the irregular uneven pattern is formed,
Allow to air dry (20 ° C / 20-30 minutes). Alternatively, metal deposition is performed instead. Metal deposition involves evaporating the metal in a high vacuum and depositing it as a thin film on a solid surface.

The decorative sheet produced by the above steps is used in an inverted manner. In the inverted state, the see-through pattern is seen through the transparent sheet, and the design looks deep and three-dimensional. This is because the reflected light reflected on the metallic glossy layer through the transparent sheet is seen. Further, as compared with a decorative sheet formed by the conventional shrink printing, the surface has no irregularities and is suitable for forming processing.

<Example 1> The present invention will be described in more detail with reference to examples, but the present invention is not construed as being limited to these examples. The screen version of chumi printing has a mesh number of 100 to 150 and a film pressure of 30 to 50 um. Ink: manufactured by Seiko Advance Co., Ltd., trade name: TJN Medium A

The shrinking pattern is basically a random pattern, but the size of the shrinkage can be changed by changing the amount of ink applied (the number of meshes of the screen plate, etc.). The number of meshes is 1 inch (2.54
cm). When the number of meshes is 100, it becomes a rough pattern, and the number of meshes is 1
In the case of 50, it becomes a fine pattern. When the film pressure is large, the pattern becomes rough, and when the film pressure is small, the pattern becomes fine.

The manufacturing process of the decorative sheet is as follows.
Add a color paste to Chimi Ink (transparent medium).
Add ~ 3% and color. If it is added in an amount of 3% or more, poor packing and poor curing will occur. The medium is a clear used to lighten the color of the ink. The medium is used in the gloss type ink, and the extender is used in the mat type ink. Used as a mixing base for special colorants such as color pastes.

Transparent sheet that can be formed (processed PE
T, PP, etc.), and the entire surface is solid-printed by a screen printing device, and then a fine pattern is formed through a fine device. Thereafter, the ink is completely cured through a UV curing device. After the printing, the whole surface is solid-printed with metallic glossy silver ink and dried naturally (20 ° C / 20-30 minutes)
Or aluminum vapor deposition (500 °) to complete.

<Embodiment 2> Next, an embodiment of manufacturing a molded article using the decorative sheet according to the present invention will be described.
In a second embodiment, an example will be described in which a ruler is formed by a multi-cavity mold. Film base resin: PET (polyethylene terephthalate) Molded resin: PMMA (methacrylic resin) Product name: Ruler Molding machine: Injection 130t Resin temperature: Nozzle 250 ° C Front 240 ° C Central 230 ° C Rear 210 ° C Injection pressure: (130t) 78-80% (150t) 50% Injection speed (time): 6-7 seconds Cooling time: 13 seconds Molding cycle: 30 seconds Number of molds: 4

FIG. 2 is a plan view of a ruler forming die. FIG. 3 is a cross-sectional view taken along line AA ′ of the ruler forming die of FIG. 2. FIG. 4 is a cross-sectional view of BB ′ of the ruler forming die of FIG. 2. The mold according to the present embodiment can form and process four rulers per cycle.

FIG. 5 shows a ruler forming die of FIG.
FIG. 3 is a plan view showing a mold cavity 33 of one ruler. FIG. 6 is a side view of the mold cavity 33 of FIG. 5 as viewed from the longitudinal direction. FIG. 7 shows the mold cavity 33 of FIG.
Is a side view as viewed from the gate port 34 side. FIG. 8 shows FIG.
FIG. 4 is an enlarged side view of the vicinity of a gate port 34 of the mold cavity 33 of FIG.

First, as shown in FIG. 2, four films are loaded on a mold so as to be adhered to the surface of the mold cavity 33. Here, the film uses the decorative sheet according to the present invention. This decorative sheet can be manufactured according to Example 1. As shown in FIG. 2, there is a runner 30 at the center of the mold according to the present embodiment, and the resin is supplied to each mold cavity through the runner 30.

Next, a resin is injected into the mold cavity 33 loaded with the film. As the resin, PMMA (methacrylic resin) is used. In this example, the resin is injected at 78-80% using a 130 ton injection. When a 150 ton machine is used, the resin is injected at 50%. As shown in FIG. 5, there is a gate port 34 between the runner 30 and each cavity 33, from which resin is supplied to each mold cavity 33. The resin is filled into the mold cavity in 6 to 7 seconds including the opening time of the gate port 34. The temperature of the resin is 250 ° C. at the nozzle portion before the resin enters the gate port 34, 240 ° C. at the portion in front of the mold cavity 33 through the gate port 34, 230 ° C. at the middle portion, and the gate port 34. 2 at the back
10 ° C.

The gate opening 34 shown in FIG. 5 has a width of 3.5 m.
m, height 1.5 mm. The resin flowing from the gate port 34 is filled up to a height of 2.5 mm of the mold cavity 33. At the same time as the molding of this resin, it is thermally fused with the loaded film. Thereby, the film position 31
Is the position of 2.5 mm in the mold cavity 33.

As shown in FIGS. 3 and 4, in the mold cavity 33, a molded article integrally formed by heat fusion is cooled with cooling water. The cooling time is 13 seconds.
The four holes shown in FIG. 3 are drain holes 32 for cooling water.

The above process can produce four rulers in one cycle of 30 seconds. Thus, when insert injection molding is performed using the decorative sheet according to the present invention as a base film, since the decorative sheet is an inner embossed sheet, a molded product is produced without damaging the resin layer having irregular irregularities. can do.

In the second embodiment, the example of the ruler is described as a molded product, but the present invention can be applied to various molded products such as combs and decorative boxes.

[0041]

As is clear from the above description, according to the present invention, it is possible to produce a chemical inner embossed sheet having a depth and a three-dimensional design with a shimmer pattern. This is different from the conventional decorative sheet with a fine pattern, in which a resin layer with irregular irregularities is formed on the back surface of the transparent sheet, and it is covered with a thin film with metallic luster, so that the mirror reflection is reduced. This is because you will use it to see the pattern.

Also, by using a transparent sheet that can be molded, an insert molded product is a painting method in which a film pre-printed at the time of molding is set in a mold and heat-sealed simultaneously with molding of the resin. It can be used for various applications. This is because the embossed sheet is not an outer embossed sheet but an inner embossed sheet, so that it can be processed in the same manner as a general molding base material.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a decorative sheet according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a mold for forming a ruler according to a second embodiment.

FIG. 3 is a cross-sectional view taken along line A-A 'of FIG.

FIG. 4 is a cross-sectional view taken along a line B-B 'of FIG.

5 is a plan view showing a mold cavity 33 of one ruler of the ruler forming die shown in FIG. 2;

6 is a side view of the mold cavity 33 of FIG. 5 as viewed from a longitudinal direction.

7 is a side view of the mold cavity 33 of FIG. 5 as viewed from the gate port 34 side.

8 is an enlarged side view of the vicinity of a gate port 34 of the mold cavity 33 of FIG.

FIG. 9 is a cross-sectional view showing a decorative sheet according to the related art.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 Transparent sheet 11 Fine print layer (fine ink) 12 Mirror thin film layer (silver ink) 20 Fine print layer (fine ink) 21 Monochromatic thin film layer 22 Silver paper 30 Runner 31 Film position 32 Cooling water outlet 33 Mold cavity 34 Gate mouth

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B05D 7/24 301 B05D 7/24 301T B32B 33/00 B32B 33/00 F-term (Reference) 4D075 BB42Z BB46Z BB85Y CB04 CB21 DA04 DB48 EA21 4F100 AK01B AK07A AK25 AK42A AT00A BA03 BA07 BA10A BA10C EH46 EH462 EH66 EH662 EJ54 EJ542 GB08 JB14B JN24C

Claims (6)

[Claims] 1. A decorative sheet for molding comprising a resin layer formed on a sheet substrate at least by a resin curable by ultraviolet rays, and a layer having a metallic luster formed on the resin layer. . 2. The decorative sheet according to claim 1, wherein the sheet base is made of one of a resin sheet of a polyethylene terephthalate sheet or a polypropylene sheet. 3. The resin layer may be irradiated with only short wavelength portions of ultraviolet rays and then again irradiated with ultraviolet rays without defining a wavelength range, thereby performing irregular asperity processing on the resin layers. The decorative sheet for molding according to claim 1, wherein the decorative sheet is made of a possible ultraviolet-curable resin material. 4. The decorative sheet according to claim 1, wherein the layer having a metallic luster is formed by depositing an ink or a metal in which a metallic pigment is dispersed. 5. A step of coating an ultraviolet-curable resin on a sheet substrate, a step of irradiating the applied ultraviolet-curable resin with only a short-wavelength portion of ultraviolet light, After the step of irradiating only
By irradiating ultraviolet rays without defining the wavelength region, a step of applying irregular irregularity processing to the resin layer, and by coating or depositing a metal with an ink in which a metal pigment is dispersed on the resin layer, the metal A method for producing a decorative sheet for molding, comprising a step of forming a glossy layer. 6. A molded product using a decorative sheet for molding comprising a resin layer formed on a sheet substrate by a resin curable by ultraviolet rays, and a layer having a metallic luster formed on the resin layer. A molded product, wherein the decorative sheet is integrally formed as a base film of an injection molded product.