JPH11176273A - Manufacture of fancy and lucent key top - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the manufacturing time and simplify the work process by dripping a liquid resin on the surface and/or the rear face of a die molded resin key top and a substrate made of a polymer material, curing the resin by reaction, and transferring a hot stamp foil including an inorganic thin film layer having a specified film thickness and light transmittance. SOLUTION: This key top is manufactured by transferring a hot stamp foil including an inorganic thin film having 1-500 nm film thickness and 70% or higher transmittance to the surface of a key top made of resin. The hot stamp foil is provided with a hologram color due to birefringence by forming a decorative layer as a protective layer on a heat resistant plastic film by finely and geometrically cut or applying a coating material containing an acrylic resin and further forming can inorganic thin film layer by vacuum evaporation. Titanium oxide is preferably used for the inorganic thin film layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high quality decorative translucent key top which is used for a cellular phone, a portable information terminal, a remote controller for various home appliances, a card remote controller and various keyboards. It relates to a manufacturing method.

[0002]

2. Description of the Related Art Conventionally, as a method of decorating a key top portion of a push button switch with a metallic luster or a pearly luster, a method of mixing a metal powder or a pearl pigment into a resin or rubber component, and molding a metal powder or a pearl pigment. Known methods include screen printing or spray coating of paint containing pearl pigments, method of providing a metal thin film layer of aluminum or chromium on the surface of key top by vacuum evaporation method or sputtering method, method of plating, and each configuration. I have.

[0003]

However, in the method of molding by mixing a metal powder or a pearl pigment with a resin or rubber, it is difficult to uniformly disperse the powder, so that a stripe pattern or uneven color tone is generated due to the segregation of the powder. There is a problem that characters and symbols are difficult to see. Further, even with a method of printing a paint containing a metal powder or a pearl pigment, a translucent decorative key top having a uniform and high-quality iris gloss has not been obtained. On the other hand, a key top obtained by depositing a metal thin film of aluminum, chromium, or the like on the surface of a molded body by a vacuum evaporation method, a sputtering method, or metal plating has a metallic luster, but is not a translucent material having an iris luster. Also,
A thin film of a metal oxide such as titanium oxide, tungsten oxide, silicon oxide or the like is formed by the present applicant using Japanese Patent Application No. 9-111741.
A decorative key top having an iris gloss can be obtained by laminating to an arbitrary film thickness by the method described in (1). There is a problem that a complicated jig is required for film formation.
Further, the inorganic foil layer in the key top described in JP-A-8-11419 does not have translucency and iris gloss.

However, recent mobile phones, mobile terminal devices,
For resin key tops such as remote controllers for various home electric appliances, card remote controllers, and various keyboards, demands for highly luxurious ones having an iris-colored luster, which are excellent in aesthetic appearance, are becoming very strong.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a uniform and high-quality iris gloss by laminating an inorganic thin film by a vacuum evaporation method or a sputtering method. By stacking the inorganic thin film while winding it up and transferring it to the key top, it takes no time to manufacture, and furthermore, a method for manufacturing a decorative translucent key top that simplifies the working process. To provide.

That is, according to the present invention, an uncured liquid resin is dropped on the surface and / or the back surface of a resin key top formed by molding, or on a base material made of a polymer material, and after reaction-curing, And a film thickness of 1 μm to 500 μm on its surface.
m, and a method for producing a decorative translucent keytop, characterized by exhibiting translucent iris luster by transferring a hot stamp foil including an inorganic thin film layer having a total light transmittance of 70% or more. It is.

Further, the present invention is a method for producing a decorative translucent key top, characterized by further laminating a polymer protective film having a thickness of 5 μm to 60 μm on the transferred hot stamp foil. .

[0008] The total light transmittance of the present invention is JIS
It means the value measured by K-7105.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail.

According to the present invention, a resin key top molded in advance or a resin key top formed by dropping an uncured liquid resin and curing by reaction is used.

Specifically, using a mold having a desired key top shape, injection molding, compression molding, transfer molding,
It is manufactured by filling a mold with a resin or a liquid uncured resin heated and melted by rotational molding or the like and then solidifying the resin. Although there is no particular limitation on the composition and type of the resin, the elastic modulus, and the color tone, polymethyl methacrylate, polycarbonate, silicone resin, amorphous polyester, polyvinyl chloride, polystyrene, polyarylate, amorphous polyolefin, amorphous polyolefin, polymethylpentene, which have good transparency, are used. , Amorphous nylon, polyurethane, ester-based thermoplastic elastomer, styrene-based thermoplastic elastomer, and nylon-based thermoplastic elastomer are particularly preferable.

Further, polyethylene, polypropylene, A
BS resin, crystalline polyester such as PET and PBT,
Crystalline nylon, polyphenylene ether, polyacetal, polyacetal, polysulfone, polyethersulfone, polyphenylene sulfide, polyimide, polyether, polyketone, polyetherketone, polyetheretherketone, polyethernitrile, polyetherimide, liquid crystal polymer, fluorine resin Translucent or slightly colored resin such as may be used. Furthermore, known resins such as thermosetting, photo-curing, and moisture-curing resins such as silicone resin, epoxy resin, phenol resin, unsaturated polyester, diallyl phthalate, acrylic resin, and urethane resin can also be used. is there.

According to the present invention, in addition to resin key tops formed of synthetic rubber such as silicone rubber having characters and symbols printed thereon or thermoplastic elastomers, films and sheet-like polymer materials such as polyester, polyamide and polyurethane Resin key tops that have been reacted and cured by dropping an uncured liquid resin onto a substrate made of, for example, can be used. According to this, it is possible to obtain a translucent key top and a push button switch having an iris-colored luster excellent in beauty.

These resin key tops are bonded to a base member of a push button switch having a working portion and a non-working portion formed of a synthetic rubber such as silicone rubber or ethylene-propylene rubber or a thermoplastic elastomer polymer material. A push button switch structure can be obtained by attaching the device with a double-sided tape or the like.

Further, a known resin key top structure and a push button switch by two-color molding of a known thermoplastic elastomer and a hard resin or a thermoplastic elastomer are also included.

The base material made of a polymer material may have a structure in which the operating portion and the non-operating portion of the switch are provided in advance by press molding or the like.

The method of dropping the resin is not limited to a potting method, a dispenser method, a pad printing method, and a transfer method.
Further, the resin key top can be formed without using the above-described mold. Examples of the liquid resin at this time include thermosetting, photo-curing, and moisture-curing resins such as acrylic resins, urethane resins, silicone resins, epoxy resins, and diallyl phthalate. In order to improve the adhesion between the base material made of a polymer material and these liquid resins, it is preferable to subject the surface of the base material to short-wavelength ultraviolet irradiation, corona treatment, plasma treatment, coupling agent treatment, or the like. For example, a method according to a method for manufacturing a silicone key switch with a resin keytop described in JP-A-6-5150, and a method according to a method for manufacturing a key sheet with a transparent resin keytop described in JP-A-6-5151. It can also be applied.

The decorative translucent key top of the present invention may have a thickness of 1 nm to 5 nm on the front surface, the back surface, or both surfaces of the above-mentioned resin key top, or the surface of a polymer material base material.
It is characterized by transferring a hot stamp foil containing an inorganic thin film having a thickness of 00 nm and a total light transmittance of 70% or more.

The hot-stamp foil is printed or coated in a fine and geometric shape or uniformly coated with a resin such as an acrylic resin or a rubber-based resin such as a urethane or silicone as a protective layer on a heat-resistant plastic film. The decorative layer is formed by partially forming a fine geometric pattern by laser cutting the resulting material, and the inorganic thin film layer is laminated by vacuum evaporation or sputtering, and the hologram coloring is performed by birefringence of light. It is a hot stamp foil to be presented.

The inorganic thin film layer is made of aluminum, chromium,
Nickel, titanium, tungsten, silicon, magnesium, cobalt, tantalum, germanium, indium,
Manganese, zirconium, bell, lead, zinc, iron, gold, silver,
Any one of a thin film of a metal such as platinum or copper, or an oxide, nitride, fluoride, or carbide of the above-described metal, or a laminated thin film thereof may be used. Particularly preferably, chemically stable metal nitrides, metal carbides, and metal sulfides are used.

Further, a hot stamp foil having an iris gloss can be obtained by laminating a specific material as an inorganic thin film layer of the hot stamp foil without processing the printing layer. After laminating the inorganic thin film layer, a resin-based resin such as acrylic or a rubber-based hot melt adhesive such as urethane or silicone is uniformly applied and cured to form an adhesive layer. It is preferable to select a material of the key top as an adherend and a material having good adhesiveness for the adhesive layer.

Further, a protective layer for protecting the inorganic substance may be provided between the inorganic thin film layer and the adhesive layer.

Specifically, the inorganic thin film layer is made of titanium oxide, silicon oxide, iron oxide, magnesium oxide, tungsten oxide, aluminum oxide, chromium oxide, cobalt oxide, tantalum oxide, indium oxide, tin oxide, manganese oxide, Metal oxides such as zirconium, vanadium oxide, cerium oxide, bismuth oxide, antimony oxide, zinc oxide and hafnium oxide; metal nitrides such as silicon nitride, aluminum nitride and titanium nitride; metal carbides such as silicon carbide and titanium carbide; sulfides Metal sulfides such as zinc are preferred. Above all, when a single thin film of titanium oxide, iron oxide, tungsten oxide, silicon oxide, magnesium fluoride, and zinc sulfide or a laminated thin film layer of two or more of these is used, an extremely aesthetically pleasing transparent film having an iris gloss is obtained. A light decorative key top and a push button switch are obtained.

These inorganic thin films are formed by physical vapor deposition such as vacuum vapor deposition, sputtering, or ion plating, or thermal CVD (Chemical Vapor Deposition).
A uniform and uniform film can be formed by a chemical vapor deposition method such as a plasma CVD method or a photo CVD method. For an inorganic material having a high deposition temperature, it is preferable to use a deposition apparatus having an electron beam heating source.

Furthermore, a vapor deposition apparatus including an ion assist mechanism may be used in various ways to enhance the adhesion between the decorative layer of the hot stamp foil and the inorganic thin film.

Further, there are materials having different oxidation numbers in the metal oxide. For example, in the case of titanium oxide, in addition to TiO ₂ , TiO, Ti ₂ O ₃ , TiO ₃ O ₅ , Ti ₄ O _7, etc. Materials are known. By using these materials,
It is possible to suppress problems such as the decomposition of oxygen gas from the material when the material is heated to lower the deposition pressure, and such a material may be used for performing continuous and stable deposition.

Further, when laminating a metal oxide or a metal nitride, a gas such as oxygen or nitrogen, which is considered to be insufficient, may be introduced into the apparatus for vapor deposition.

When the total light transmittance of the inorganic thin film as one of the constituent layers of the hot stamp foil is less than 70%, the light transmittance becomes insufficient, and the characters and symbols printed on the base are recognized. Becomes difficult. A preferred total light transmittance is 75
%, More preferably 80% or more. On the other hand, if the film thickness is thinner than 1 nm, the iris gloss becomes thin, and
If it exceeds nm, the light transmittance is inferior. Actually, depending on the type of resin used, the refractive index, the shape, and the material, refractive index, color tone, etc. of the inorganic thin film, the range of 2 nm to 300 nm is red, yellow, blue, An aesthetically pleasing one having an iris gloss mainly of purple or the like is obtained.

The present invention further provides an iris color by forming a polymer protective film having a thickness of 5 μm to 60 μm obtained by laminating and curing an uncured liquid resin on the transferred hot stamp foil. Can be physically and chemically stabilized. The type, application and curing method of the liquid resin are not specified, but monomers and oligomers such as acrylic, urethane, silicone, epoxy and ester such as thermosetting, photo-curing and moisture-curing types Can be laminated and cured by a method such as spray coating, various printings, and potting to form a polymer protective film of 5 μm to 60 μm. This polymer protective film may be colorless, but if a colored material such as red, blue, or yellow is used, the color tone further changes, so that any color can be applied. When the film thickness is less than 5 μm, the mechanical properties of the polymer protective film are weak and it is impossible to sufficiently protect the inorganic thin film. On the other hand, when the film thickness is more than 60 μm, the iris gloss becomes less sharp. It detracts from aesthetics. The more preferable thickness of the polymer protective film is in the range of 15 μm to 45 μm. Further, a plurality of polymer protective films can be laminated.

Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples. However, the present invention is not limited to the following examples.

[0031]

Embodiment 1 FIG. 1 is a longitudinal sectional view showing a hot stamp foil of Embodiment 1.

Commercially available PET film 1 having a thickness of 20 μm
Then, a silicone release coating is applied to a thickness of 0.5 μm and dried by heat treatment to form a release layer 2. An acrylic coating is applied and dried to form a protective layer 3. A part of this protective layer is laser-cut with a YAG laser to form a decorative layer 4 for providing a hologram decorative effect. This was vacuum-deposited with aluminum in a vacuum deposition apparatus at a deposition pressure of 5 × 10 ⁻⁴ torr and a deposition rate of 5 nm / min for 2 minutes to form an aluminum thin film layer 5 having a thickness of 5 nm. An acrylic hot-melt adhesive is applied to this hologram foil and dried to a thickness of 2 μm.
m of the adhesive layer 6 (hereinafter referred to as “hologram hot stamp foil”). Hereinafter, this is referred to as “hologram hot stamp foil”. The measured total line transmittance of the hologram foil was 82%.

Separately from this, a push button switch provided with a translucent resin key top was manufactured. FIG. 2 is a longitudinal sectional view showing a push button switch provided with a translucent resin key top according to the first and second embodiments of the present invention and a method for manufacturing the same.

In FIG. 2, the base member 7 has a non-operating portion 7a and an operating portion 7b formed of transparent silicone rubber.
A predetermined character or symbol printing layer 8 is screen-printed on the top surface. The top surface is irradiated with short-wavelength ultraviolet rays by the same manufacturing method as in the invention described in JP-A-6-5150, treated with a silane coupling agent, then dropped with an acrylic ultraviolet curable resin, and irradiated with ultraviolet rays. After curing, a resin key top 9 made of a transparent acrylic resin was formed. Then, the molded pushbutton switch was fixed with a dedicated fixing jig 11, and the film with the hologram foil layer of FIG. 1 was arranged on the top surfaces of the plurality of key tops of the molded pushbutton. Next, the film with the hologram foil is pressed for 2 seconds with a key top-shaped silicone rubber foil pressing body 12 heated to 160 ° C. for 2 seconds.
Was removed from the top surface of the key top 9, and the translucent hot stamp foil layer 10 having an iris color by a hologram was transferred to the top surface of the key top 9.

Since the key top of the produced push button was translucent, the character printed portion located under the transparent acrylic resin could be clearly seen from the outside, and the appearance was excellent.

[0036]

Example 2 As in Example 1, a light-transmitting hologram hot stamp foil (Laser Multi TS-SK manufactured by Kurz Japan Co., Ltd.) was disposed on the top surfaces of a plurality of key tops of the molded push button body. . Next, the film with the hologram foil was pressed with a key top-shaped silicone rubber foil pressing body 12 heated to 160 ° C. for 2 seconds, and then the foil pressing body and the film were removed from the top of the key top. A translucent hot stamp foil layer 10 having an iris color by a hologram was transferred to the surface.

Since the key top of the produced push button was translucent, the character printed portion located under the transparent acrylic resin could be clearly seen from the outside, and the appearance was excellent.

[0038]

Third Embodiment FIG. 3 is a longitudinal sectional view showing a hot stamp foil of a second embodiment.

A silicone release coating is applied to a commercially available PET film 1 having a thickness of 20 μm to a thickness of 0.5 μm and dried by heat treatment to form a release layer 2. An acrylic coating is applied and dried to form a protective layer 3. In a vacuum deposition apparatus, titanium oxide is deposited over a period of 7 minutes at a deposition pressure of 5 × 10 ⁻⁴ torr and a deposition rate of 10 nm / min, and a titanium oxide thin film having a thickness of 70 nm and a total line transmittance of 88%. Layer 5 was formed. An acrylic hot melt adhesive was applied on the titanium oxide thin film and dried to form an adhesive layer 6 having a thickness of 2 μm. Hereinafter, this is referred to as “titanium oxide hot stamp foil”. Next, as in Example 1, this titanium oxide hot stamp foil was heated to 160 ° C.
2 for 2 seconds, and then the foil-pressed body and the film were removed from the top of the key top, and the translucent hot stamp foil layer 1 having an iris color mainly composed of yellow was placed on the top of the key top.
0 was transferred.

Since the key top of the produced push button was translucent, the character printed portion disposed under the transparent acrylic resin could be clearly seen from the outside, and the appearance was excellent.

[0041]

Fourth Embodiment FIG. 4 is a longitudinal sectional view showing a push button switch provided with a translucent decorative key top according to a fourth embodiment.

A transparent urethane-based paint (manufactured by Origin Plate Z Origin Electric Co.) was applied to a push button switch having a decorative translucent key top having an iris color formed by the hologram produced in Example 1, and dried and cured. A polymer protective layer 13 having a thickness of 30 μm was laminated.

The transferred hot stamp foil could be protected by this polymer protective layer.

[0044]

Fifth Embodiment FIG. 5 is a longitudinal sectional view showing a push button switch provided with a translucent decorative key top according to the fourth embodiment.

In FIG. 5, the non-operating portion 7 of the base member 7
a and the operating portion 7b were formed of transparent silicone rubber in the same manner as in Example 1. On the other hand, using a separate mold, polycarbonate (Panlite L1225L manufactured by Teijin Chemicals Ltd.)
Was injection molded to produce a resin key top 14 made of polycarbonate. Further, the hot stamp foil 10 of Example 1 was transferred to the back surface of the resin key top to obtain a translucent key top having hologram coloring. Further, a character or symbol printing layer 8 was formed thereon by screen printing of an acrylic ink. A thermosetting silicone adhesive 15 was applied to the printed surface of the characters or symbols, the above-mentioned base member 7 was bonded, and cured by heating to produce a push button switch provided with a decorative translucent key top having hologram coloring. .

[0046]

Comparative Example 1 In the same manner as in Example 1, a commercially available PET film 1 having a thickness of 20 μm was coated with a silicone release coating of 0.5 μm.
After forming a release layer 2 by heat treatment and drying, an acrylic paint is applied and dried to form a protective layer 3. A part of this protective layer is laser-cut with a YAG laser to form a decorative layer 4 for providing a hologram decorative effect. Then, a film thickness of 800 nm and a total light transmittance of 10% were formed by vacuum evaporation.
The inorganic thin film layer 5 made of aluminum was formed. An acrylic hot melt adhesive was applied to the hologram foil and dried to form an adhesive layer 6 having a thickness of 2 μm. This hot stamp foil was pressure-transferred to the surface of a resin key top made of a transparent acrylic resin.

The resin key top of the obtained push button switch had iris gloss but was inferior in transparency.

[0048]

Comparative Example 2 In the same manner as in Example 1, a commercially available PET film 1 having a thickness of 20 μm was coated with a silicone release coating of 0.5 μm.
After forming a release layer 2 by heat treatment and drying, an acrylic paint is applied and dried to form a protective layer 3. Then, a film thickness of 800 nm and a total light transmittance of 10% were formed by vacuum evaporation.
The inorganic thin film layer 5 made of aluminum was formed. An acrylic hot melt adhesive was applied to the hologram foil and dried to form an adhesive layer 6 having a thickness of 2 μm. This hot stamp foil was pressure-transferred to the surface of a resin key top made of a transparent acrylic resin.

The resin key top of the obtained push button switch had poor transparency and no iris gloss.

[0050]

Comparative Example 3 In the same manner as in Example 2, a commercially available PET film 1 having a thickness of 20 μm was coated with a silicone release coating of 0.5 μm.
After forming a release layer 2 by heat treatment and drying, an acrylic paint is applied and dried to form a protective layer 3. Then, a film thickness of 800 nm and a total light transmittance of 31% were formed by a vacuum evaporation method.
An inorganic thin film layer 5 made of titanium oxide was formed. An acrylic hot melt adhesive was applied on the titanium oxide thin film and dried to form an adhesive layer 6 having a thickness of 2 μm. Hereinafter, this is referred to as “titanium oxide hot stamp foil”. This hot stamp foil was pressure-transferred to the surface of a resin key top made of a transparent acrylic resin.

The resin key top of the obtained push button switch had poor transparency and no iris gloss.

[0052]

According to the present invention, it is possible to provide a high quality translucent decorative key top having an iris gloss on the surface and / or the back surface of the resin key top.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a hot stamp foil of Example 1.

FIG. 2 is a longitudinal sectional view showing a push button switch provided with a decorative translucent key top according to the first and second embodiments and a method for manufacturing the same.

FIG. 3 is a longitudinal sectional view showing a hot stamp foil of Example 3.

FIG. 4 is a longitudinal sectional view showing a push-button switch provided with a translucent decorative key top according to a fourth embodiment.

FIG. 5 is a longitudinal sectional view showing a push-button switch provided with a translucent decorative key top according to a fifth embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 PET film 2 Release layer 3 Protective layer 4 Decorative layer 5 Inorganic thin film layer 6 Adhesive layer 7 Base member 7a Non-operation part 7b Operation part 8 Character or symbol printing layer 9 Resin key top 10 Hot stamp foil layer 11 Fixing jig 12 Silicone Rubber Foil 13 Polymer Protective Film 14 Molded Polycarbonate Resin Key Top 15 Adhesive Layer

Claims (4)

[Claims] An uncured liquid resin is dropped on the surface and / or the back surface of a resin-molded resin key top or on a substrate made of a polymer material, and after reaction-curing,
By transferring a hot stamp foil including an inorganic thin film layer having a film thickness of 1 nm to 500 nm and a total light transmittance of 70% or more on the surface thereof, a translucent iris color is exhibited. Manufacturing method of optical key top. 2. The inorganic thin film contained in the hot stamp foil is made of titanium oxide, silicon oxide, iron oxide, magnesium oxide, tungsten oxide, aluminum oxide, chromium oxide, cobalt oxide, tantalum oxide, indium oxide, tin oxide, nickel oxide. , Manganese oxide, zirconium oxide, vanadium oxide, cerium oxide, bismuth oxide, antimony oxide, zinc oxide, oxidation is funium, silicon nitride, aluminum nitride, titanium nitride, magnesium fluoride, cerium fluoride, lead fluoride, silicon carbide, The method for producing a decorative translucent keytop according to claim 1, comprising a material selected from titanium carbide, zinc sulfide, silicon and germanium. 3. A hot stamp foil is printed or coated finely and geometrically on a heat-resistant plastic film as a protective film made of an acrylic resin or a urethane-based or silicone-based rubber, or uniformly. 2. The method according to claim 1, wherein the decorative layer is formed by partially forming a fine geometric pattern by laser cutting on the applied material, and the inorganic thin film layer is formed by laminating by a vacuum evaporation method or a sputtering method. The method for producing a decorative translucent keytop according to the above. 4. An uncured liquid resin is further laminated on the transferred hot stamp foil, and a polymer protective film having a film thickness of 5 μm to 60 μm is cured and formed. 4. The method for producing a decorative translucent keytop according to 3.