JP2003326597A - Decorative transparent molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To render a weld line developed in transparent injection molded article such as a front panel of an audio product inconspicuous in appearance and to avoid a lowering in inherent transparency. <P>SOLUTION: A transparent printing ink prepared by mixing and dispersing a matting powder such as silica powder or alumina powder in an acrylic resin, a polyester resin or the like is printed on the outer surface of a transparent injection molded article of an acrylic resin, an AS resin or the like by screen printing or the like. A matte finishing transparent print layer 4 is provided thereon to prepare a decorative transparent molded article 1 having on its surface fine concaves and convexes. A specular print layer 6 may be provided on the backside of the outer surface of the molded article to further impart metallic feeling to the decorative transparent molded article. Even after the specular printing, the weld line is not conspicuous. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decorative transparent molded product such as a front panel used in audio products such as amplifiers, receivers, tuners, and CD players, and the weld line inevitably generated in an injection molded product is inconspicuous. It was done.

[0002]

2. Description of the Related Art Injection-molded resin moldings are used in an extremely large number of fields, and synthetic resin such as acrylic resin, acrylonitrile-styrene copolymer resin, polycarbonate resin, etc. are used for the front panel of the above audio products. Often made by injection molding.

However, a molded product produced by the injection molding method has an essential problem that a weld line peculiar to this molding method is inevitably generated. Weld lines are often generated around the portion where the molten resin such as the through hole formed in the molded product flows separately at the time of molding and joins again. This weld line can be somewhat reduced by devising injection molding conditions such as increasing the molten resin temperature during injection molding and increasing the injection pressure, but it is impossible to completely eliminate this. It is said that there is.

Since the weld line generated in the molded product by this injection molding greatly impairs the appearance of the molded product, the user or the like may recognize the molded product as a defective product and may be the subject of the complaint. In order to prevent this, various methods have been conventionally proposed to make the weld line inconspicuous.

For example, Japanese Unexamined Patent Publication (Kokai) No. 58-42438 discloses a method of screen-printing a non-aqueous printing ink on the surface of an injection molded product to make the weld line inconspicuous. Further, in Japanese Patent Application Laid-Open No. 8-187732, as a mold for injection molding, a mold in which a heat insulating layer of polyimide is formed on the surface of the main mold and a skin-textured metal layer is provided on the heat insulating layer is used. Then, a method is disclosed in which fine unevenness is transferred and formed on the surface of the molded product, thereby making the weld line inconspicuous.

However, in these prior inventions, the weld line generated in the molded product cannot be made completely inconspicuous, and particularly when the molded product is a transparent product, the weld line generated in the transparent molded product is It is more difficult to make the appearance inconspicuous, and if the weld line is made inconspicuous, there is a major drawback that the original transparency of the transparent molded product is impaired.

[0007]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to make weld lines generated in a transparent injection-molded article inconspicuous in appearance and not to impair its transparency.

[0008]

In order to solve such a problem, the invention according to claim 1 is characterized in that a matte finish transparent printing or a matte finish transparent printing is applied to an outer surface of a transparent injection molded article. It is a decorated transparent molded product. The invention according to claim 2 is the decorative transparent molded article according to claim 1, characterized in that the outer surface of the back surface is mirror-printed.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. In the following embodiments, as an example of a decorative transparent molded article,
The transparent front panel of an audio product will be described as an example.

FIG. 1 shows an audio product equipped with this transparent front panel. The transparent front panel 1 is made of a synthetic resin having excellent transparency such as polymethylmethacrylate resin, acrylonitrile-styrene copolymer resin, polycarbonate resin, polystyrene resin, etc., and is molded by an injection molding method, and its shape is rectangular. It is a plate-shaped one having a thickness of about 2 to 8 mm.

In the present invention, the term "transparent" is not limited to being colorless and transparent, but includes colored and transparent, and is transparent to the extent that characters can be read through it. In particular, a so-called "blueing" in which a very small amount of a blue colorant is added to the transparent front panel 1 so that the transparent front panel 1 is colored in a very thin blue color to enhance the apparent transparency is preferable.

Further, the transparent front panel 1 has through holes 2 and 2 such as button holes and cable insertion holes.
.. are formed in large numbers, and the window portion 3 is formed substantially in the center thereof. A display surface of the fluorescent display tube is arranged in the window portion 3. Weld lines (not shown) are formed around some of the through holes 2, 2 ,.

Then, as shown in FIG. 2, on the outer surface (front surface) of the transparent front panel 1, matte finish transparent printing or matte transparent printing is applied to a portion other than the window portion 3 to form a printing layer. 4 is provided, and the surface thereof is transparent and has a fine grain shape, in other words, a state where fine irregularities are formed. The thickness of the printed layer 4 is preferably 2 to 10 μm after drying.

As a printing ink used for the transparent printing or matte transparent printing for matte finish, a transparent synthetic resin such as acrylic resin, urethane resin or polyester resin is used as a vehicle, and a matting agent such as silica powder or alumina powder is used. An evaporative drying type or ultraviolet curing type transparent printing ink in which a powder for use is mixed and dispersed is preferable. Specific examples of such a transparent printing ink include "Super gloss (100 series)" (trade name, manufactured by Jujo Chemical Co., Ltd.).

Printing methods of such printing inks include screen printing, offset printing, gravure printing,
Printing methods such as flexographic printing are used, and among them, screen printing is suitable for this application because the thickness of the printing layer 4 can be easily changed.

Further, around the through holes 2 such as button holes and cable insertion holes on the printed layer 4 for matte transparent printing or matte transparent printing, characters, marks, etc. indicating their names, applications, etc. are provided. The display 5 is formed by printing characters using colored ink. To print this character,
A method of slightly thicker printing by screen printing using colored inks of various tones is used.

Further, as shown in FIG. 2, a mirror surface printing layer 6 is provided on the rear surface of the outer surface of the transparent front panel 1 in a part other than the window portion 3 by mirror surface printing. This mirror surface printing provides a mirror surface effect (mirror effect) to give the transparent front panel 1 a good metallic feeling, further enhances the transparent feeling, gives excellent designability, and gives a high-class feeling. The thickness of the printing layer 6 is in the range of 3 to 20 μm.

The printing ink used for this mirror surface printing uses a synthetic resin such as acrylic resin, urethane resin or polyester resin as a vehicle, to which a metal powder such as aluminum powder or silver powder is mixed and dispersed, or an evaporation drying type or An ultraviolet-curable silver printing ink is used, and specific examples thereof include "mirror surface ink series (silver)" (trade name, manufactured by Seiko Advance Co., Ltd.).

Printing methods of such printing inks include screen printing, offset printing, gravure printing,
Printing methods such as flexographic printing are used, and screen printing is preferable among them.

Further, a white printing layer 7 is provided on the mirror printing layer 6 by white printing. This white printing is intended to stop the slight pinholes slightly left on the inner mirror surface printing layer 6 and prevent the transmission of light so as to prevent the metallic feeling obtained by the mirror surface printing from being deteriorated by the pinholes. The ordinary printing ink containing a white colorant is used and is printed by screen printing or the like.

In addition, the infrared transmission window for the remote controller of the transparent front panel 1 is not subjected to the above-mentioned mirror surface printing and white printing, but is subjected to medium printing which transmits infrared rays well.

Such a transparent front panel 1 is composed of an acrylonitrile-butadiene-styrene copolymer resin (AB
The transparent front panel 1 is mechanically fixed to a box-shaped panel 8 made of a synthetic resin having high mechanical strength such as S resin), and the panel 8 is attached so as to cover the front surface of the housing 9 of the audio product. Is attached to the front surface of the housing 9.

In such a transparent front panel 1, a weld line may run from the through hole 2 in the molded product after injection molding. Since the eraser transparent printing is applied, the light rays are diffusely reflected by the fine irregularities on the surface of the printing layer 4, which makes the weld line inconspicuous and the irregularities are not very fine, so that the transparent feeling of the transparent molded article is originally intended. It is not so damaged.

When the back surface is mirror-printed to give a metallic feel, the weld line usually tends to be more prominent, but since the matte transparent print or the matte transparent print is made on the external surface. , The weld line is not conspicuous, and an excellent metallic feeling can be obtained.

Further, the cavity surface of the injection molding die is embossed, and injection molding is performed using this die, and fine unevenness is transferred to the outer surface of the panel to form a welded line as compared with a transparent front panel. Was found to be less noticeable. Also, because it is printed, it is possible to adjust the finished surface condition of the appearance surface to some extent compared to the case of using a mold, and if the weld line is tight, increase the thickness of the plate for screen printing, This can be dealt with by increasing the addition amount of the matting powder.

The decorative transparent molded product of the present invention is not limited to the above-mentioned front panel of audio products, but can be widely used for various applications such as panels of various electric devices, decorative plates and front panels of automobiles.

[0027]

As described above, the decorative transparent molded article of the present invention is a transparent injection molded article having a matte transparent print or a matte transparent print on its outer surface.
The weld line generated in the injection-molded product is hardly noticeable, and the original transparency is not impaired.

Further, in the case where the back surface is mirror-printed, the decorated transparent molded article has an excellent metallic feeling,
It will be more luxurious. Further, conventionally, the mirror surface printing tends to make the weld line on the appearance surface more noticeable, but in the present invention, since the matte transparent printing or the matte transparent printing is applied to the appearance surface, the weld line Is almost inconspicuous even with mirror printing.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of an audio product equipped with a transparent front panel as an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing an example of a transparent front panel as an embodiment of the present invention.

[Explanation of symbols]

1 ... Transparent front panel, 4 ... Matt finished transparent printing layer or matte transparent printing layer, 6 ... Mirror surface printing layer.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4F206 AA21 AA28 AF14 AF15 AF16                       AG03 AH42 AM32 JA07 JQ81                       JW50                 4F209 AA13 AA21 AA28 AF00 AF01                       AF16 AG05 AG26 AH33 AH42                       PA01 PB01 PC03 PC05 PG01                       PH27 PJ06 PJ08 PN01 PN20                       PQ20

Claims (2)

[Claims] 1. A decorated transparent molded article, characterized in that the transparent surface of the transparent injection molded article is subjected to matte transparent printing or matte transparent printing. 2. The decorated transparent molded article according to claim 1, wherein mirror-like printing is applied to the back surface of the exterior surface.