JP2001198982A - Method for manufacturing decorative plastic molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a decorative plastic molding by which this molding can be bonded to another molding such as an enclosure by irradiating the surface of a panel with a laser beam. SOLUTION: A decorative transparent resin panel 1 with a colored layer 2 showing 70.0-100% transmittance of the laser beam and 60% or less transmittance of the total light by Japan Industrial Standard(JIS) K7361-1, is placed in contact on a colored resin molding 7 whose transmittance of the laser beam 5 is 0-10%. Further, the laser beam 5 is applied on the colored layer 2 of the decorative transparent resin panel 1 and thereby an interface between the back of the decorative transparent resin panel 1 and the surface of the colored resin molding 7 is welded. Thus the decorative transparent resin panel 1 and the colored resin molding 7 are welded in one piece together.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a decorative plastic molded article suitable for joining a panel and a casing used for automobile parts, home electric appliances and the like.

[0002]

2. Description of the Related Art Conventionally, when bonding panels for home appliances such as televisions and audio products and automobiles and housings and other molded products, a method of applying an adhesive uniformly and then bonding the two together, There has been a method using a double-sided adhesive tape having adhesive properties on both sides of the body. However, in the former method, the handling of the adhesive is troublesome, and the adhesive surface sometimes becomes dirty due to excess adhesive protruding.
In the latter method, a satisfactory adhesive strength may not be obtained.

Further, when the adhesive cannot be applied over the entire surface, a gap is formed between the back surface of the panel and the housing, and the waterproof property is sometimes poor. In addition, in the case of a small lot, there is a problem in terms of cost to mechanize the bonding process, and there is a problem in that the uniformity is poor for manual processing.

In order to solve such problems, recently, a high frequency welding process or an ultrasonic process for efficiently fusing the interface between the back surface of the panel and the housing has appeared. These are used to bond a portion where the panel and the housing are in contact with each other by heat generated by vibration. In the case of these methods, it is necessary to create a vibrator called a horn along the surface shape of the panel, and there is a problem that the adhesion of the horn is poor due to the condition of the horn, and the horn vibrates against the panel surface, There was a problem that the panel surface was damaged to some extent.

Therefore, a welding technique using a laser has recently been proposed (see Japanese Patent Application Laid-Open No. 11-170371). This is to bring the colorless transparent resin panel into contact with the colored opaque housing and irradiate a laser from the surface of the colorless transparent resin panel to heat and heat the surface of the colored opaque housing,
This is a technique in which both interfaces are fused and bonded.

[0006]

However, in this case, when viewed from the colorless and transparent resin panel side, the welded portion is different in color and smoothness from the unwelded portion, resulting in a poor design appearance. was there.

There is a demand that the panel surface be colored to make it invisible in order to hide the poor design of the back surface. However, if the front side is colored with a conventional ink, there is a problem that laser light is absorbed and the back side cannot be welded only by melting the front side.

Accordingly, the present invention solves the above-mentioned problems and applies decorative laser molding to a molded article such as a housing by applying a laser beam from a panel surface with a laser beam so that a welded portion is inconspicuous. An object of the present invention is to provide a method for manufacturing a product.

[0009]

Means for Solving the Problems A method for manufacturing a decorative plastic molded product according to the present invention is constituted as follows in order to achieve the above objects.

That is, according to the method for producing a decorative plastic molded product of the present invention, the transmittance of laser light is 70.0 to 10
A decorative transparent resin panel provided with a colored layer having a total light transmittance of 60% or less according to Japanese Industrial Standard (JIS) K7361-1 at 0% is colored with a laser light transmittance of 0 to 10%. Decorating by placing it on the resin molded product and irradiating laser light from above the colored layer of the decorative transparent resin panel, and welding the interface between the back surface of the decorative transparent resin panel and the surface of the colored resin molded product The transparent resin panel and the colored resin molded product were welded and integrated.

Further, in the above invention, the decorative transparent resin panel may be formed such that another colored layer having a transmittance of 70% or less for a laser beam is formed.

In the above invention, the laser light is preferably a YAG laser having a wavelength of 1.063 to 1.066 μm, a CO ₂ laser having a wavelength of 10.6 μm, or a semiconductor laser having a wavelength of 938 to 942 nm. You may.

In the above invention, the coloring component of the coloring layer may be constituted mainly by a dye.

Further, in the above invention, the decorative transparent resin panel may be formed by a simultaneous molding and decorating method.

[0015]

Embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view showing one step of the method for manufacturing a decorative plastic molded product according to the present invention. FIG. 2 is a plan view showing one step of the method for manufacturing a decorative plastic molded product of the present invention. 3 and 4 are graphs each showing an example of a transmittance curve of a yellow dye. FIG. 5 is a graph showing an example of a transmittance curve of a yellow dye. FIG. 6 is a graph showing an example of the transmittance curve of the magenta dye. FIG. 7 is a graph showing an example of a transmittance curve of a cyan dye. In the figure, 1 is a decorative transparent resin panel, 2 is a colored layer, 3 is a transparent resin panel, 4 is a welded portion, 5 is a laser beam, 6 is a decorative plastic molded product, 7 is a colored resin molded product, 8 is another. The colored layer 9 is a transparent window portion.

According to the method of manufacturing the decorative plastic molded product 6 of the present invention, the transmittance of the laser light 5 is 70.0 to 100%.
The decorative transparent resin panel 1 provided with the colored layer 2 having a total light transmittance of 60% or less according to Japanese Industrial Standard (JIS) K7361-1 has a laser light 5 transmittance of 0 to 10%. Laser light 5 is applied from above the colored layer 2 of the decorative transparent resin panel 1 to be in contact with the colored resin molded article 7, and an interface between the back surface of the decorative transparent resin panel 1 and the surface of the colored resin molded article 7 is formed. In this method, the decorative transparent resin panel 1 and the colored resin molded product 7 are welded and integrated by welding.
reference).

In the decorative transparent resin panel 1, the transmittance of the laser beam 5 is 70.0 to 100% on the transparent resin panel 3.
The coloring layer 2 having a total light transmittance of 60% or less according to JIS K7361-1 is provided (see FIG. 1).

The resin used for the transparent resin panel 3 includes
Specifically, acrylic, acrylonitrile styrene (A
S), polycarbonate (PC), styrene (GP),
It is preferable to use a transparent resin mainly composed of methacryl-styrene (MS), transparent ABS, lactic acid-based biodegradable plastic, or the like.

The coloring layer 2 is provided on or in the transparent resin panel 3. The colored layer 2 has a laser beam 5
Has a transmittance of 70.0 to 100% and JIS K7
361-1 has a total light transmittance of 60% or less. Specifically, the colored layer 2 having such properties is obtained by performing coloring using an ink in which a dye such as an oil-soluble dye, a gold-containing dye, or an acid dye, or a finely powdered pigment is dissolved in a resin binder. be able to. If the transmittance of the laser beam 5 is less than 70.0%, the laser beam 5 is absorbed and generates heat, so that a problem occurs that the transparent resin panel 3 is melted and deformed. When the total light transmittance exceeds 60%, the welded portion 4 becomes conspicuous.

In particular, the total light transmittance of JIS K7361-1 is preferably 10% or less. In this range, the surface of the transparent resin panel 3 can be completely hidden by the colored layer 2. Also, it is easy to form an illuminated panel in which the colored layer 2 is patterned to form a blank character, and the back side is illuminated with an LED or the like so that only the blank character in the pattern portion shines.

In particular, it is preferable that the coloring component of the coloring layer 2 is mainly composed of a dye. When the dye is dissolved in a resin binder and a solvent, the dye does not disperse while maintaining the particle diameter like a pigment but dissolves without maintaining the particle diameter, and thus does not hinder the transmission of the laser light 5. In addition, although it absorbs in the wavelength region of visible light, it does not absorb heat in the wavelength region of laser, so it does not generate heat. FIG.
FIG. 5 shows an example of the transmittance curve of the yellow dye. FIG.
Shows an example of the transmittance curve of the magenta dye. FIG. 7 shows an example of the transmittance curve of the cyan dye.

The decorative transparent resin panel 1 may be provided with another colored layer 8 having a transmittance of the laser beam 5 of less than 70%. As the other colored layer 8, it is also possible to decorate with a metallic thin film layer of aluminum, chromium, or the like, or a metallic color with an aluminum pigment, a pearl pigment, or the like.

The decorative transparent resin panel 1 may have a transparent layer. The transparent layer can function as a protective layer for the transparent window portion 9 of the decorative plastic molded product 6.

In order to form the colored layers 2 and 8 and the transparent layer on the decorative transparent resin panel 1, a method of directly decorating the transparent resin panel 3, a transfer method, and a simultaneous transfer method by molding are used. is there.

As a method of directly decorating, there are a printing method such as a screen printing method and a coating method such as a spray coating method.

The transfer method is to use a transfer material having a transfer layer comprising a release layer, a coloring layer, an adhesive layer, etc. formed on a base sheet, and to apply heat and pressure to bring the transfer layer into close contact with the object to be transferred. This is a method in which the base sheet is peeled off, and only the transfer layer is transferred to the surface of the transfer object to perform decoration. Also, the simultaneous molding transfer method
After sandwiching the transfer material in the molding die, injecting and filling the resin in the mold, cooling and bonding the transfer material to the surface of the molded product at the same time as obtaining the resin molded product, peeling the base sheet, This is a method in which the transfer layer is transferred to the surface of the transfer object to perform decoration.

As a material of the base sheet, a base sheet of a usual transfer material such as a resin sheet of a polypropylene resin, a polyethylene resin, a polyamide resin, a polyester resin, an acrylic resin, a polyvinyl chloride resin or the like is used. Things can be used. Further, when the surface of the base sheet has fine irregularities, the irregularities are transferred to the transfer layer, and the surface shape such as matting and hair lines can be expressed.

When the transfer layer has good releasability from the base sheet, the transfer layer may be provided directly on the base sheet. In order to improve the releasability of the transfer layer from the base sheet, a release layer may be formed before providing the transfer layer on the base sheet.

The release layer is formed on a base sheet or a release layer. When the base sheet is separated after the transfer or after the simultaneous transfer of the molding, the release layer is separated from the base sheet or the release layer and becomes the outermost surface of the transfer object. Examples of the material of the release layer include acrylic resin, polyester resin, polyvinyl chloride resin, cellulose resin, rubber resin, polyurethane resin, polyvinyl acetate resin, and the like, as well as vinyl chloride-vinyl acetate copolymer. It is preferable to use a resin or a copolymer such as an ethylene-vinyl acetate copolymer resin. When the release layer requires hardness, a photocurable resin such as an ultraviolet curable resin, a radiation curable resin such as an electron beam curable resin, or a thermosetting resin may be selected and used. The release layer may be colored or uncolored. As a method of forming the release layer, a gravure coating method, a roll coating method, a coating method such as a comma coating method, a gravure printing method,
There are printing methods such as a screen printing method.

The coloring layer is formed on the release layer, usually as a printing layer. As a material of the printing layer, a resin such as a polyvinyl resin, a polyamide resin, a polyester resin, an acrylic resin, a polyurethane resin, a polyvinyl acetal resin, a polyester urethane resin, a cellulose ester resin, and an alkyd resin is used as a binder. ,
It is preferable to use a coloring ink containing a pigment or dye of an appropriate color as a coloring agent. As a method for forming the printing layer, a normal printing method such as a gravure printing method, a screen printing method, and an offset printing method may be used. In particular, an offset printing method or a gravure printing method is suitable for performing multicolor printing and gradation expression. In the case of a single color, a coating method such as a gravure coating method, a roll coating method, and a comma coating method can be adopted. The printing layer may be provided entirely or partially depending on the design to be expressed.

The coloring layer may be formed of a metal thin film layer or a combination of a printing layer and a metal thin film layer. The metal thin film layer is for expressing metallic luster as a colored layer, and is formed by a vacuum evaporation method, a sputtering method, an ion plating method, a plating method, or the like. Metals such as aluminum, nickel, gold, platinum, chromium, iron, copper, tin, indium, silver, titanium, lead, and zinc, and alloys or compounds thereof are used according to the metallic luster color to be expressed. The metal thin film layer may be partially formed. When providing the metal thin film layer, a front anchor layer or a rear anchor layer may be provided in order to improve the adhesion between another transfer layer and the metal thin film layer.

The adhesive layer is for bonding each of the above layers to the surface of the object to be transferred. As the adhesive layer, a heat-sensitive or pressure-sensitive resin suitable for the material of the material to be transferred is appropriately used. For example, when the material of the transfer object is an acrylic resin, an acrylic resin may be used. When the material to be transferred is a polyphenylene oxide / polystyrene resin, a polycarbonate resin, a styrene copolymer resin, or a polystyrene blend resin, an acrylic resin, a polystyrene resin, or a polyamide having an affinity for these resins. A system resin or the like may be used. Further, when the material of the transfer object is a polypropylene resin, chlorinated polyolefin resin, chlorinated ethylene-vinyl acetate copolymer resin, cyclized rubber, and coumarone indene resin can be used. As a method of forming the adhesive layer, a gravure coating method, a roll coating method, a coating method such as a comma coating method, a gravure printing method,
There are printing methods such as a screen printing method.

A method of decorating the surface of an object to be transferred by using the transfer material having the above-described layer configuration and utilizing the transfer method will be described. First, the adhesive layer side of the transfer material is brought into close contact with the transfer object surface. Next, using a transfer machine such as a roll transfer machine or an up-down transfer machine having a heat-resistant rubber-like elastic body such as silicon rubber, a temperature of about 80 to 260 ° C. and a pressure of 490 to 1960
Heat and pressure are applied from the base sheet side of the transfer material via the heat-resistant rubber-like elastic body set to a condition of about Pa. By doing so, the adhesive layer adheres to the surface of the transfer object. Finally, when the base sheet is peeled off after cooling, peeling occurs at the interface between the base sheet and the release layer, and the transfer is completed.

Next, a method of decorating the surface of a resin molded product as an object to be transferred by using the above-described transfer material and by using a molding simultaneous transfer method by injection molding will be described. First, a transfer material is fed into a molding die including a movable die and a fixed die. At this time, the sheet transfer material may be fed one by one, or a necessary portion of a long transfer material may be sent intermittently. When a long transfer material is used, it is advisable to use a feeding device having a positioning mechanism so that the register between the colored layer of the transfer material and the molding die coincides with each other. In addition, when the transfer material is intermittently fed, if the transfer material is fixed by the movable type and the fixed type after the position of the transfer material is detected by the sensor, the transfer material can always be fixed at the same position. This is convenient because there is no displacement of the colored layer. After the molding die is closed, the molten resin is injected and filled into the die from the gate, and the transfer material is adhered to the surface of the transfer material simultaneously with the formation of the transfer object. After cooling the resin molded product as the transfer object, the molding die is opened and the resin molded product is taken out. Finally, the transfer is completed by removing the base sheet.

As described above, the decorative transparent resin panel 1 can be obtained.

The colored resin molded product 7 includes a laser beam 5
Is used, whose transmittance is as low as 0 to 10% and which can convert the energy of the laser beam 5 into heat on its surface. Specifically, a resin molded product colored with a black pigment, aluminum powder, pearl pigment, or the like may be used.

It is preferable to use a resin of the same type as the transparent resin panel 3 from the viewpoint of easy welding. That is,
When the same type of resin is used, when both surfaces are melted and integrated, the compatibility is high and the two are not separated, so that the adhesive strength is further increased.

The decorative transparent resin panel 1 is formed into a colored resin molded product 7.
On top of Next, a laser beam 5 is irradiated from above the colored layer 2 of the decorative transparent resin panel 1.

The laser beam 5 has a wavelength of 0.2-2.
Those having a thickness of 0 μm can be used. Examples of the type of laser include a ruby laser, an Ar laser, an excimer laser, a YAG laser, a CO ₂ laser, and a semiconductor laser. In consideration of heat generation and damage due to absorption of the colored layer 2, a YAG laser, a CO ₂ laser, and a semiconductor laser are used. It is preferable to use a laser or the like.

Particularly, a YAG laser having a wavelength of 1.063 to 1.066 μm, a CO ₂ laser having a wavelength of 10.6 μm,
Alternatively, it is preferable to use a semiconductor laser having a wavelength of 938 to 942 nm. These are easy to obtain the amount of heat for melting the surface of the colored resin molded product 7, and are relatively easy to handle as a laser.

The welding process is as follows. First, the decorative transparent resin panel 1 is placed in contact with the colored resin molded product 7, and the colored transparent resin panel 1 is irradiated with a laser beam 5 from above the colored layer 2. The surface is melted to have an adhesive strength to the decorative transparent resin panel 1. Since the colored layer 2 and the transparent resin panel 3 of the decorative transparent resin panel 1 transmit the laser beam 5,
It does not melt at this point. Further, when the laser beam 5 is continuously irradiated, the heat of the melting portion of the colored resin molded product 7 increases, and the back surface of the decorative transparent resin panel 1 that is in contact with the colored resin molded product 7 by heat conduction is also melted. Become. By melting and integrating the two surface portions, the adhesive force is further increased (see FIGS. 2 and 3). In FIG. 2, the welded portion 4 is shown by a solid line for easy understanding, but is actually hidden by the colored layer 2 and cannot be seen.

As described above, by welding the interface between the back surface of the decorative transparent resin panel 1 and the surface of the colored resin molded product 7, the decorative transparent resin panel 1 and the colored resin molded product 7 are welded and integrated. The decorative plastic molded product 6 can be obtained.

[0044]

EXAMPLE A 38 μm-thick polyester film was used as a base sheet, and a release layer, a colored layer and a transfer layer were formed thereon.
An adhesive layer was formed to obtain a transfer material. The design is the frame of the display window of the mobile phone. 5% by weight of VALIFAST BLACK 3810 as a black dye,
A black frame was printed on the outer periphery of the transparent window by using a resin containing 20% by weight of a polyester resin as a resin binder and 75% by weight of methyl ethyl ketone as a solvent.

The total light transmittance of the black portion according to JIS K7361-1 is 10%, and YAG having a wavelength of 1.064 nm is used.
The transmittance of the laser was 90%.

The transfer material having such a configuration was placed in a mold, and a transparent polycarbonate resin was injected to form a display cover panel of a mobile phone by a molding simultaneous transfer method, thereby obtaining a decorative transparent resin panel.

Next, using a polycarbonate resin colored black, a housing for a mobile phone having a hole-shaped display portion was formed to obtain a colored resin molded product.

Next, the decorative transparent resin panel is placed on the colored resin molded product so that the side other than the transfer layer is in contact with the colored resin molded product.
When irradiated with a 64 nm YAG laser, the colored resin molded product and the decorative transparent resin panel could be welded without damaging the black portion of the decorative transparent resin panel.

[0049]

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

The simultaneously decorated decorative sheet of the present invention has a colored layer having a laser light transmittance of 70.0 to 100% and a total light transmittance of 60% or less according to Japanese Industrial Standard (JIS) K7361-1. The decorative transparent resin panel provided is placed in contact with a colored resin molded product having a laser light transmittance of 0 to 10%, and the decorative transparent resin panel is irradiated with laser light from above the colored layer of the decorative transparent resin panel. The decorative transparent resin panel and the colored resin molded product are welded together by welding the interface between the back surface of the decorative transparent resin panel and the surface of the colored resin molded product, thereby integrating the decorative transparent resin panel and the colored resin molded product. Is welded and integrated, the back surface of the decorative transparent resin panel and the surface of the colored resin molded product can be welded without damaging the colored layer, and the welded portion is formed by the presence of the colored layer. Make it inconspicuous Can.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one step of a method for manufacturing a decorative plastic molded product according to the present invention.

FIG. 2 is a plan view showing one step of a method for manufacturing a decorative plastic molded product according to the present invention.

FIG. 3 is an AA sectional view showing one step of the method for manufacturing a decorative plastic molded product according to the present invention.

FIG. 4 is a graph showing an example of a transmittance curve of a yellow dye.

FIG. 5 is a graph showing an example of a transmittance curve of a yellow dye.

FIG. 6 is a graph showing an example of a transmittance curve of a magenta dye.

FIG. 7 is a graph showing an example of a transmittance curve of a cyan dye.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Decorative transparent resin panel 2 Colored layer 3 Transparent resin panel 4 Welding part 5 Laser light 6 Decorative plastic molded article 7 Colored resin molded article 8 Other colored layers 9 Transparent window part

Claims (5)

[Claims] 1. A laser beam having a transmittance of 70.0 to 100.
%, A decorative transparent resin panel provided with a colored layer having a total light transmittance of 60% or less according to Japanese Industrial Standards (JIS) K7361-1 is converted to a colored resin having a laser light transmittance of 0 to 10%. A laser beam is irradiated from above the colored layer of the decorative transparent resin panel by placing it on the molded product, and the interface between the back surface of the decorative transparent resin panel and the surface of the colored resin molded product is welded, so that the decorative transparent resin panel is welded. A method for producing a decorative plastic molded product, comprising: welding and integrating a resin panel and a colored resin molded product. 2. The method for producing a decorative plastic molded article according to claim 1, wherein another colored layer having a transmittance of 70% or less for a laser beam is formed on the decorative transparent resin panel. 3. A laser beam having a wavelength of 1.063 to 1.0.
66 μm YAG laser, 10.6 μm wavelength CO ₂
The method for producing a decorative plastic molded product according to claim 1, wherein the method is a laser or a semiconductor laser having a wavelength of 938 to 942 nm. 4. The method for producing a decorative plastic molded product according to claim 1, wherein the coloring component of the coloring layer mainly comprises a dye. 5. The method for producing a decorative plastic molded product according to claim 1, wherein the decorative transparent resin panel is produced by a simultaneous molding and decorating method.