JP4485019B2 - Key sheet manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a key sheet for various push button switches used in various mobile communication terminals such as a mobile phone and a car phone, a fixed telephone, a personal computer keyboard, a remote controller, and an AV device, and a manufacturing method thereof.
[0002]
[Prior art]
Conventionally, for pushbutton switches used in portable devices, a key sheet in which a resin film with a display portion printed on the back surface is curved in the same shape as the upper surface side of a button made of a thermoplastic resin and integrated with the button has been used. Attention has been paid to the reduction in thickness and weight. As shown in FIG. 8, the key sheet is formed by integrating a resin film 1 provided with a display portion 2 with predetermined characters, numbers, symbols, symbols and the like on the back surface and a button 3 made of a thermoplastic resin. It is common.
[0003]
The colors of the display are various, such as black, gray, etc., chromatic colors such as red, green, blue, etc., gold, silver, etc. There is also a type. As a manufacturing method of these key sheets, a method of integrally forming a resin film on which a display portion is printed and a thermoplastic resin by injection molding is disclosed in JP-A-54-154461 and JP-B-7-54656. Are listed.
[0004]
In recent years, many key-sheets for cellular phones and the like have been demanded to have a mirror-like metallic luster design that can be obtained by metal plating. As a configuration of a key sheet having a mirror-like metallic luster, there is a configuration in which a metallic luster layer 5 is formed by vapor-depositing metal on the back surface of the resin film 1 as shown in FIG.
[0005]
As shown in FIG. 10, a method for forming a blank character display portion with this configuration forms a metallic gloss layer 5 by vapor-depositing a metal on the back surface of the resin film 1, and further on the back surface of the metallic gloss layer. After the printed layer 11 was formed, the metallic gloss layer in the blank was removed by etching to form the display portion 2 with the metallic gloss layer of the blank. For example, gold was vapor-deposited to obtain a golden mirror-like metallic luster layer, or aluminum was vapor-deposited to obtain a silver-like mirror-like metallic luster layer.
[0006]
[Problems to be solved by the invention]
However, the display part with the metallic glossy layer of the blank letters formed by the above method can only embody the color tone of the metal deposited on the resin film, and there are rich variations such as red, green, blue etc. in the mirror-like metallic gloss I could n’t.
[0007]
As a key sheet for adding a color tone to the metallic gloss layer of the blank character, as shown in FIG. 12, after forming the colored layer 6 for the metallic gloss layer on the back surface of the resin film 1, the metallic gloss layer 5 is further formed. There is a key sheet in which the printed layer 11 of the cut character is formed on the back surface of the glossy metal layer, and then the metal gloss layer in the cut character is removed by etching to form the display portion 2 by the glossy metal layer of the cut character.
[0008]
However, in this key sheet, when the metallic gloss layer in the blank characters of the blank character printed layer is removed by etching, the colored layer 6 for the metallic gloss layer in the blank characters cannot be removed, as shown in FIG. The display layer colored layer 7 is not visible from the surface side because it is blocked by the metallic gloss layer 6 and the color tone of the display unit cannot be set arbitrarily, and the operator cannot easily see the character display part. was there.
[0009]
[Means for Solving the Problems]
SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and provides a key sheet that allows a variety of variations in the metallic gloss layer of a letter to be drawn and allows the operator to easily see the letter display part at a low cost. It is.
[0010]
In other words, the stamped character display part is formed on a resin film by transfer, then the resin film is bent and deformed in the same shape as the upper surface of the button, and the resin is filled into the bent deformation by injection molding to integrally form the button. This is a method for manufacturing a key sheet.
[0011]
Further, a metallic gloss layer is formed on the release layer formed on the release film by vapor deposition, and a translucent colored layer of a letter is formed on the metallic gloss layer by coating, and then the colored layer This is a method for manufacturing a key sheet in which the metallic gloss layer in the extracted characters is removed by etching to form a display portion of the extracted characters, and the display portion of the extracted characters is transferred to a resin film.
Further, the present invention provides a method for manufacturing a key sheet in which a display portion of a letter is transferred to a resin film through a translucent adhesive layer.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in further detail.
In the present invention, as shown in FIG. 1, a translucent colored layer 4 of a blank character is formed on the back surface of a resin film 1, and a metallic gloss layer 5 is laminated on the back surface of the colored layer. The resin film 1 having the character display portion 2 formed with the color layer 7 for the display portion is a key sheet that is curved in the same shape as the upper surface side of the resin button and is integrated with the button. It is a metallic glossy layer of colorful drawn characters by the translucent colored layer of the drawn characters, and is a key sheet that allows the operator to easily see the drawn character display.
Further, according to the present invention, as shown in FIG. 2, the translucent colored layer 4 of the extracted characters can be made into a plurality of colors so as to have different colors for each button.
[0013]
The metallic luster layer of the present invention is formed of a mirror-like metallic luster metal or metal compound, and the material is not particularly limited, but aluminum that can be deposited at a relatively low temperature when depositing the metallic luster layer, A metal such as chromium is preferred.
[0014]
The optical density of the metallic gloss layer is preferably 0.35 or more. When the optical density is less than 0.35, the mirror-like metallic gloss is lost. When the optical density range is 0.35 to 2, the metallic gloss layer also has a translucent function, and when the key sheet is illuminated from the back side, the entire surface becomes a bright key sheet. At this time, since the color of transmitted light is different between the display portion of the extracted character and the periphery thereof, a colorful display can be obtained without impairing the visibility of the display portion.
[0015]
The definition of the optical density of the present invention is represented by a common logarithm of the reciprocal of the transmittance, which is the ratio of the projection light L ₀ incident on the sample and the transmitted light L that has passed through the sample, and the relationship between the optical density and the transmittance is Is as shown in the following equation.
Optical density D = log (L / T) = log (L ₀ / l) Expression (1) Transmittance T = L / L ₀ (2) Expression For example, when optical density D is 1, transmission When the rate T is 0.1 or 10% and the optical density is 2, the transmittance is 0.01 or 1%. The transmittance when the optical density is 0.35 is about 45%.
[0016]
The translucent colored layer of the extracted letters of the present invention can visually recognize a colorful mirror surface even if the metallic luster layer is silver. For example, if the color of the translucent colored layer of the extracted characters is red, yellow, green, blue, purple, the key sheet is red metallic, golden metallic, green metallic, blue metallic, purple metallic. Can be visually recognized.
[0017]
The resin film of the present invention is preferably a resin film having a thickness of 50 to 200 μm and excellent transparency. Since the surface of the key sheet is the resin film surface and the colorful display part exists on the back surface of the resin film, transparency of the resin film is required, and haze (cloud value: JIS K 7105 compliant) is 15% or less The material is preferably a polyethylene terephthalate resin film, a polycarbonate resin film, a polyamide resin film having excellent transparency, or an alloy film containing at least one of these.
[0018]
The resin used for the button of the present invention may be a thermoplastic resin or a thermosetting resin as long as it can be molded into the curved deformation of the resin film. In consideration of productivity, a thermoplastic resin that can be integrally molded with a resin by injection molding is preferable. In the case of an illuminated key sheet, a transparent thermoplastic resin is preferable. For example, polyethylene resin, polypropylene resin, polystyrene resin, polycarbonate resin, polyacrylic acid resin, polymethacrylic acid resin, polyamide resin and the like can be mentioned.
[0019]
The key sheet manufacturing method of the present invention is a key sheet manufacturing method in which a resin film having a display portion is curved in the same shape as the upper surface side of a button made of resin and integrated with the button, and is formed on a release film. A metallic gloss layer is formed on the released release layer by vapor deposition, and after forming a translucent colored layer of the extracted characters on the metallic gloss layer, the metallic gloss in the extracted characters of the colored layer is formed. The layer is removed by etching to form a letter display.
[0020]
As shown in FIG. 3 (1), the resin character 1 is transferred by transferring the extracted character display portion 2 of the metallic gloss layer 5 formed on the release film 8 and the transparent colored layer 4 of the extracted character. Then, as shown in FIG. 3 (2), the display portion colored layer 7 is formed on the back surface of the metallic glossy layer of the blank character by coating. Next, this is a key sheet manufacturing method in which the resin film is curved and deformed in the same shape as the upper surface side of the button, and the button 3 is integrally molded by filling the resin into the curved deformation by injection molding.
[0021]
The method of forming the metallic luster layer of the present invention includes physical vapor deposition such as vacuum vapor deposition, ion plating, sputtering, chemical vapor deposition using thermal / plasma chemical reaction for particle generation, electroplating for depositing particles from a solution. In addition, there is a method such as thermal spraying using plasma discharge or the like, and a method of forming a layer includes an island-like growth method and a layer-like growth method. In particular, when the resin gloss film is drawn into a predetermined shape and integrally formed with a thermoplastic resin by growing the metal gloss layer in an island shape by vacuum deposition, the metal gloss layer is not preferable in terms of appearance such as cracks and cracks. There will be no defects.
[0022]
The display part of this invention can be formed in a letter by etching a metallic luster layer. Etching method can be used by printing a colored layer of the extracted character and then immersing it in an alkali or acid solution to remove the metallic luster layer in the extracted character, or incinerating the portion of the extracted character using a laser marker, etc. The method of doing is common.
[0023]
Hereinafter, the present invention will be described with reference to examples. In addition, all members, such as a resin film and an ink expressed in an Example, are typical, and are not this limitation.
[Example 1]
The manufacturing method of the key sheet of Example 1 of the present invention is shown in FIGS.
The surface of the release film 8 made of a polyethylene terephthalate resin film was completely removed of dust and foreign matters, and after the release layer 9 was printed, aluminum vapor deposition was performed by a batch type wind-up vapor deposition machine to provide the metallic gloss layer 5. . At this time, if the thickness of the metallic luster layer is adjusted to 10 nm to 20 nm, the optical density can be within the range of 0.35 to 0.85.
[0024]
Further, a translucent colored layer 4 with letters drawn thereon was screen-printed with a yellow vinyl chloride-based ink on the metallic gloss layer and dried (80 ° C. × 6 hours or more). As shown in FIG.
This is immersed in a 1% aqueous potassium hydroxide solution to remove the metallic luster layer at the portion in the extracted character, to form a display portion 2 for the extracted character, soaked in 1% sulfuric acid, neutralized, and then immersed in purified water. Washed and dried thoroughly. As shown in FIG.
[0025]
The character display portion 2 was transferred to a polycarbonate resin film 1 having a thickness of 100 μm by heat and pressure. As shown in FIG. Thereafter, the release film 8 was peeled off from the release layer 9. As shown in FIG.
Next, a translucent white colored portion 7 for display portion was screen-printed with urethane-based ink so as to cover the entire surface of the metallic gloss layer 5 including the display portion of the extracted characters. As shown in FIG.
[0026]
This was drawn with a compression molding die so that the colored layer side for the display portion was on the inside, and was bent and deformed in the same shape as the upper surface side of the button. As shown in FIG.
Next, a polycarbonate resin (“Iupilon” manufactured by Mitsubishi Engineering Plastics), which is a thermoplastic resin, is injection-molded into a concave portion of the resin film by an injection molding machine manufactured by Nissei Plastic Industry, and a button 3 made of the resin film and the resin is formed. Make it integral. As shown in FIG. 5, a golden-glossy letter-type key sheet with a predetermined shape and a mirror surface was obtained.
[0027]
[Example 2]
6 (1) to 6 (6) show a method for manufacturing a key sheet according to the second embodiment of the present invention.
In the same manner as in Example 1, a release layer 9 and a metallic luster layer 5 were provided on a release film 8 made of a polyethylene terephthalate resin film. On the metallic luster layer, unlike in Example 1, a translucent colored layer 4 with letters extracted with blue urethane ink was screen-printed and dried (80 ° C. × 6 hours or more). As shown in FIG.
[0028]
In the same manner as in Example 1, the metallic luster layer at the portion in the blank was removed, washed, and sufficiently dried. As shown in FIG.
The display portion of the extracted characters was transferred by heat and pressure to an unstretched polyamide resin film 1 having a thickness of 100 μm in which the adhesive layer 10 was previously formed. As shown in FIG.
Thereafter, the release film 8 was peeled off from the release layer 9. As shown in FIG.
[0029]
Next, a translucent white colored portion 7 for display portion was screen-printed with urethane-based ink so as to cover the entire surface of the metallic gloss layer 5 including the display portion of the extracted characters. As shown in FIG.
This was drawn with a compression molding die so that the colored layer side for the display portion was on the inside, and was bent and deformed in the same shape as the upper surface side of the button. As shown in FIG.
[0030]
Next, a polycarbonate resin (“Iupilon” manufactured by Mitsubishi Engineering Plastics), which is a thermoplastic resin, is injection-molded into a concave portion of the resin film by an injection molding machine manufactured by Nissei Plastic Industry, and a button 3 made of the resin film and the resin is formed. Make it integral. As shown in FIG. 7, a blue-colored glossy letter-type key sheet having a predetermined shape and mirror surface was obtained.
[0031]
【The invention's effect】
In the display part of the key sheet of the present invention, a translucent colored layer is formed on the back surface of the resin film, and a metallic gloss layer is laminated on the back surface of the colored layer. Since the metallic luster is visually recognized through the translucent colored layer, a display portion having a mirror-like metallic luster of any color can be created, and the key sheet can be realized at low cost.
[0032]
Furthermore, it can also combine without impairing the illumination function by a backlight. Since the color tone of the colored layer for the display unit can be appropriately selected, the visibility of the display unit is high. The metallic gloss layer is provided on the back surface of the resin film and does not wear.
The translucent colored layer of the extracted letters of the present invention can be freely embodied by printing a mirror-like metallic luster color ordinarily used ink, and a plurality of colors of metal in the key sheet. It becomes possible to have gloss and is excellent in design.
[0033]
The key sheet manufacturing method of the present invention is a manufacturing method in which a character sheet display portion is formed on a resin film by transfer, and a key sheet having the above effects can be obtained at low cost.
[Brief description of the drawings]
1 is an embodiment of a key sheet of the present invention. FIG. 2 is another embodiment of a key sheet of the present invention. FIG. 3 is a manufacturing method of a key sheet of the present invention. FIG. 5 is a longitudinal sectional view of the key sheet of Example 1 of the present invention. FIG. 6 is a method of manufacturing the key sheet of Example 2 of the present invention. FIG. 7 is a key sheet of Example 2 of the present invention. Fig. 8 Conventional key sheet Fig. 9 Conventional key sheet Fig. 10 Conventional key sheet manufacturing method Fig. 11 Conventional key sheet Fig. 12 Conventional key sheet manufacturing method [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Resin film 2 Display part 3 Button 4 The translucent colored layer 5 of a drawing character The metallic gloss layer 6 The colored layer 7 for a metallic gloss layer The colored layer 8 for a display part Release film 9 Release layer 10 Adhesive layer 11 Print layer

Claims (5)

The display part of the letter is formed on the resin film by transfer from the release film ,
Next, in the key sheet manufacturing method in which the resin film is bent and deformed in the same shape as the upper surface side of the button, and the button is integrally formed by filling the resin into the curved deformation by injection molding .
The display part of the extracted character is
On the metallic luster layer formed on the release film,
After forming the translucent colored layer of the extracted characters,
By removing the metallic luster layer in the extracted letters of the colored layer by an etching method immersed in an alkali and an acid aqueous solution,
A method for producing a key sheet, which is obtained by forming a metallic gloss layer of a letter under a translucent colored layer of the letter. 2. The method for producing a key sheet according to claim 1 , wherein the display portion of the extracted characters is transferred to a resin film through a translucent adhesive layer. The key sheet according to claim 1 or 2, wherein the metallic gloss layer is formed on the release layer formed on the release film by vapor deposition so that the optical density is within a range of 0.35 to 2. Manufacturing method. The method for producing a key sheet according to any one of claims 1 to 3, wherein the translucent colored layer of the extracted character is formed by application by screen printing. It is characterized by using an etching method in which the metallic luster layer in the characters of the colored layer is removed by soaking in a 1% aqueous potassium hydroxide solution, further neutralizing by soaking in 1% sulfuric acid, and then soaking in purified water. The key sheet manufacturing method according to any one of claims 1 to 4.

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