JP2010146849A - Member for push-button switch, key panel, and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a push-button switch member which has a metallic luster feeling with high luminance and has excellent adhesion between a keytop or a member on keytop side and a layer to give the metallic luster feeling. <P>SOLUTION: The push-button switch member 100 is provided with at least a keytop 10 of light-transmission property and a metallic luster sheet 30 of semi-light transmission property installed on single face side of the keytop 10. The metallic luster sheet 30 has a resin substrate, a metal layer of semi-light transmission property installed on single face of the resin substrate, and an adhesive layer which covers the metal layer and is adhered to the keytop 10 side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a member for a push button switch, a key panel, and an electronic device.

As a member for the push button switch, a member made of rubber or resin is widely used. In recent years, a metallic luster is often given to a part or almost the entire surface of the key panel in order to emphasize the high-quality feeling of products using the pushbutton switch member. As a pushbutton switch member having a metallic luster, (1) a type in which a printing layer in which a glittering pigment made of scale-like particles having metallic luster such as aluminum foil is dispersed in a binder resin is provided on the key top side (See Patent Documents 1 and 2), and (2) a type (Patent Documents 3 and 4) in which a sheet including a metal vapor deposition layer is thermally transferred to the key top side by a hot stamp method.
JP 2002-210907 A JP 2005-5237 A JP 2001-312933 A JP 2002-298681 A

  In addition to having a metallic luster, the pushbutton switch member as described above is individually illuminated in a dark place such as outdoors at night or when illuminated by a backlight such as an LED, or outdoors in the daytime or in a place with illumination. Of course, it is also important that the characters, symbols, etc. of the push buttons can be visually recognized. And in order to balance such visibility with a metallic luster feeling in a balanced manner, it is important to control the light transmittance of the layer exhibiting the metallic luster. However, in the type provided with the printing layer in which the glitter pigment is dispersed, there is a limit to the amount of the glitter pigment that can be dispersed and contained in the printing layer. For this reason, even if visibility can be secured, it is difficult to obtain a metallic luster with high brightness.

  On the other hand, in a type in which a sheet including a metal vapor deposition layer is thermally transferred by a hot stamp method, thermal deformation of the key top occurs at the time of thermal transfer of the sheet, and a part between the sheet and the key top (or a member on the key top side) is generated. Adhesion failure is likely to occur.

  The present invention has been made in view of the above-described circumstances, and has a metallic luster with high luminance, and also has excellent adhesion between a key top or a member on the key top side and a layer imparting metallic luster. Another object is to provide a pushbutton switch member, and a key panel and an electronic device using the same.

The above-mentioned subject is achieved by the following present invention.
That is, the pushbutton switch member of the present invention includes at least a light transmissive key top and a light translucent metallic glossy sheet provided on one side of the key top, and the metallic glossy sheet is a resin. And a light semi-transparent metal layer provided on one side of the resin base material, and an adhesive layer that covers the metal layer and adheres to the key top side. To do.

  In one embodiment of the member for a push button switch of the present invention, the metal layer is preferably a discontinuous metal layer in which metal films are discretely formed on the surface of the resin base material.

  In another embodiment of the member for a pushbutton switch of the present invention, it is preferable that the discontinuous metal layer includes at least one metal selected from Sn and In.

  In another embodiment of the member for a pushbutton switch of the present invention, the key top is provided on the surface of the sheet-like base material opposite to the side of the key top on which the metallic glossy sheet is provided. It is preferable that the sum total of the thickness of the said sheet-like base material and the thickness of the said protrusion part exists in the range of 50 micrometers-500 micrometers.

  Another embodiment of the member for a pushbutton switch of the present invention is at least selected from the side between the key top and the metallic glossy sheet and the side opposite to the side where the keytop is provided of the metallic glossy sheet. On one side, a decorative layer is preferably provided.

  The key panel of the present invention is characterized by including the push button switch member of the present invention.

  An electronic apparatus according to the present invention includes the key panel according to the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, while having the metallic luster which has a high brightness | luminance, the member for pushbutton switches excellent also in the adhesiveness of the key top or the key top side member, and the layer which provides a metallic luster feeling, and this are used. Provided key panels and electronic equipment.

<Push button switch member>
The member for a push button switch of the present embodiment includes at least a light transmissive key top and a light semi-transmissive metallic glossy sheet provided on one side of the key top, and the metallic gloss sheet is made of resin. It has a base material, a light semi-transmissive metal layer provided on one side of the resin base material, and an adhesive layer that covers the metal layer and adheres to the key top side. .

  In the member for a push button switch according to the present embodiment, the layer that imparts a metallic luster is a metal layer composed of only a metal material. For this reason, a metallic luster with high luminance can be obtained. Further, in the push button switch member of the present embodiment, the metallic glossy sheet is bonded to the key top side without using the hot stamp method. For this reason, at the time of bonding, the key top is not thermally deformed, and partial adhesion failure does not occur between the metallic glossy sheet and the key top side. The “key top side” means a key top when no other layer is provided between the key top and the metallic glossy sheet, and there is another layer between the key top and the metallic glossy sheet. When provided, it means the other layer.

  As described above, when the push button switch member of the present embodiment is manufactured, the key top side and the metallic glossy sheet are not particularly limited as long as they are bonded by a non-hot stamp method. However, bonding may be performed while heating or pressurizing at a level lower than the temperature and pressure (generally, the temperature is 170 to 220 ° C. and the pressure is 0.2 to 0.5 MPa) similar to the hot stamp method. As temperature at the time of adhesion, 40 ° C or less is preferred, and a normal temperature range (15-35 ° C) which does not need a heating operation using a heating device is more preferred. When it exceeds 40 degreeC, the adhesiveness between a keytop side and a metallic luster sheet may become inadequate. Moreover, as a pressure at the time of adhesion | attachment, when pressurizing using a roll, 0.05-0.3 MPa is preferable. When the pressure at the time of bonding exceeds 3.0 MPa, when the heating is also performed to some extent, the key top is thermally deformed, and as a result, the adhesion between the key top side and the metallic glossy sheet is insufficient. There is a case.

  Hereinafter, the layer configuration of the push button switch member of the present embodiment, the specific configuration of each layer, the manufacturing method, and the like will be described in more detail.

-Layer structure-
The push button switch member of the present embodiment is a laminate of at least a key top and a metallic glossy sheet, but other layers can be provided as necessary. For the purpose of improving the color tone and design of the members for pushbutton switches, and displaying characters, symbols, figures, etc. other than each key and key, between the key top and the metallic glossy sheet, and the key top of the metallic glossy sheet It is particularly preferable to provide a decorative layer on at least one selected from the side opposite to the side on which is provided. Moreover, the presser sheet | seat which has a presser can be provided in the opposite side to the side in which the key top of a metallic glossy sheet is provided. In addition, when a decoration layer is provided in the side by which the key top of a metal glossy sheet is provided, a presser sheet | seat is arrange | positioned on this decoration layer surface. FIG. 1 is a schematic cross-sectional view showing an example of a layer structure of a member for a push button switch according to this embodiment. The pushbutton switch member 100 shown in FIG. 1 has a configuration in which a decorative layer 40, a metallic glossy sheet 30, a decorative layer 20, and a key top 10 are laminated on a pusher sheet 50 in this order. Details of each layer and specific configuration examples will be described later.

-Metal gloss sheet-
The metallic glossy sheet has a resin base material, a light translucent metal layer provided on one side of the resin base material, and an adhesive layer that covers the metal layer and adheres to the key top side. It is. The adhesive layer has two functions, ie, a function of adhering (or sticking) to the key top side and a function of covering the metal layer. Therefore, the adhesive layer may be composed of two layers specialized for each function. Good. In this case, a coating layer specialized for the function of coating the metal layer and an adhesive layer specialized for the function of adhering to the key top side can be laminated in this order on the metal layer. The metallic gloss sheet is light semi-transmissive (that is, semi-light reflective) and imparts metallic gloss to the push button switch member. Here, in the present specification, “light translucency” means that the transmittance for light having a wavelength in the visible light range (about 400 to 800 nm) is in the range of 0.5% to 60%. It is preferably within the range of 40% to 40%. If the transmittance is less than 0.5%, sufficient visibility cannot be ensured even if the push button switch member is illuminated from the back side by a backlight such as an LED in a dark place such as outdoors at night. Moreover, when the transmittance exceeds 60%, visibility in the daytime outdoors or in places with illumination cannot be ensured. The thickness of the metallic glossy sheet is not particularly limited, but it is preferably 30 μm to 100 μm from the viewpoint of practical use such as reduction in thickness of the pushbutton switch member and securing of the strength of the metallic glossy sheet itself.

  A known resin film can be used as the resin substrate. Examples of the resin material constituting the resin film include PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PBT (polybutylene terephthalate), PC (polycarbonate), PMMA (polymethyl methacrylate), and the like. The thickness of the resin film is not particularly limited, but is preferably in the range of 5 μm to 125 μm, preferably in the range of 20 μm to 75 μm, from the viewpoint of reducing the thickness of the pushbutton switch member and securing the strength of the metallic glossy sheet itself. More preferred.

  The adhesive layer may have a single layer structure, but is preferably composed of a coating layer and an adhesive layer. Here, as a material constituting the coating layer, acrylic resin, acrylic resin mixed with ion exchange resin, fluorine resin, polyester resin, epoxy resin, vinyl chloride resin, urethane resin, acrylic urethane Resin, vinyl acetate resin, melamine resin and the like can be used. Among these materials, it is preferable to use a photocurable acrylic resin and an acrylic urethane resin when producing a metallic glossy sheet. The reason for this is that the photocurable acrylic resin can be cured immediately after the coating treatment, and also requires no solvent such as an organic solvent or heat treatment during the coating treatment. This is because erosion and deterioration of the metal layer can be reliably suppressed. In addition, as needed, you may perform a basecoat process using the same kind of material as a coating layer as a base layer between a resin-made base material and a metal layer. Thereby, the adhesion stability between the resin substrate and the metal layer can be further improved. As the adhesive layer, acrylic adhesives, acrylic urethane adhesives, polyester adhesives, epoxy adhesives, vinyl chloride adhesives, urethane adhesives, vinyl acetate adhesives, silicone adhesives A butadiene adhesive can be used. Although the thickness of a coating layer is not specifically limited, From the viewpoint of corrosion prevention of a metal layer, the inside of the range of 0.2 micrometer-10 micrometers is preferable, and the inside of the range of 0.5 micrometer-1.5 micrometers is more preferable. The thickness of the adhesive layer is not particularly limited, but from the viewpoint of preventing corrosion of the metal layer, it is preferably in the range of 5 μm to 75 μm, and more preferably in the range of 10 μm to 50 μm.

  The metal layer preferably has a thickness in the range of 3 nm to 70 nm, and more preferably in the range of 5 nm to 50 nm. When the thickness is out of the above range, it may be difficult to make the metallic glossy sheet semi-transparent. Although it does not specifically limit as a metal material which comprises a metal layer, Metals, such as Al, Sn, In, Pb, Au, Ag, Fe, Pt, and these alloys are mentioned. This metal layer is formed on the surface of the resin substrate by using a known metal film forming method such as a vacuum film forming method such as an evaporation method or a sputtering method, or a plating method.

  The metal layer is particularly preferably a discontinuous metal layer in which metal films are discretely formed on the surface of a resin base material. The discontinuous metal layer has a structure in which a large number of metal films are dispersed in an island shape on the surface of a resin base material. For this reason, unlike the metal layer (continuous metal layer) which consists of a metal film which coat | covers the resin-made base-material whole surface continuously, it has electrical insulation. In addition to this, corrosion deterioration due to moisture in the atmosphere does not substantially occur. This is because even if moisture enters the metal layer from the end face of the metallic glossy sheet, the metal film exists discretely with respect to the plane of the resin substrate, and the upper and lower surfaces of the metal layer are adhesive layers. This is because the metal layer is completely covered with the (or coating layer) and the resin base material, so that the corrosion of the metal layer does not proceed gradually from the end face side to the inside, but is limited to the vicinity of the end face.

  For this reason, compared with the member for pushbutton switches which has a continuous metal layer, the member for pushbutton switches which has a discontinuous metal layer has the following characteristics. That is, (1) since the discontinuous metal layer has insulating properties, it does not shield electromagnetic waves. For this reason, when the electronic device using the push button switch member receives radio waves from the outside or performs wireless communication with the outside, the push button switch member does not hinder reception or communication. Further, (2) since the corrosion of the metal layer does not substantially occur even when the push button switch member is exposed to a high humidity environment or used for a long time, the discoloration of the push button switch member due to the corrosion of the metal layer. Can be suppressed.

  When the discontinuous metal layer is formed on the surface of the resin substrate, the thickness is preferably in the range of 3 nm to 50 nm, and more preferably in the range of 5 nm to 40 nm. If the thickness is less than 3 nm, it may be difficult to make the metallic glossy sheet semi-permeable. Further, when the thickness exceeds 50 nm, it may be difficult to form the discontinuous metal layer itself. In addition, “the thickness of the discontinuous metal layer” means that the portion where the metal film on the surface of the resin base is present is averaged so as to be extended to the portion where the metal film does not exist, thereby forming a single flat film. It means the thickness of the case.

  Among the metal materials listed above, Sn (melting point: 231.9 ° C.), In (melting point: 156.4 ° C.), or an alloy thereof is preferable as the metal material constituting the discontinuous metal layer. Examples of the method for forming the discontinuous metal layer include a vacuum deposition method and a sputtering method.

  Unlike other metals such as Al (melting point: 600 ° C.), Sn and In have a melting point as low as about 200 ° C., and a sheet having a metal layer containing Sn or In is used as a transfer foil for hot stamping. Similarly to the above, it is extremely difficult to perform thermal transfer by a hot stamp method in which thermal transfer is performed at a high temperature of about 200 ° C. This is because the metal layer containing Sn or In is softened or melted by heating during hot stamping. For this reason, there is a possibility that the film thickness of the metal layer may be partially changed, or if the metal layer is a discontinuous metal layer, electrical conduction may occur. However, since the hot stamp is not used in manufacturing the push button switch member of the present embodiment, the above-described problem can be reliably generated even if a metal layer using a low melting point metal material such as Sn or In is used. Can be prevented.

  FIG. 2 is a schematic cross-sectional view showing an example of a metallic glossy sheet used for the pushbutton switch member of the present embodiment, and is a cross-sectional view showing a case where the metal layer is a discontinuous metal layer. The metallic glossy sheet 30U shown in FIG. 2 includes a resin base material 32 and a plurality of convex metal films 33 that are discretely formed so as to form convex portions on one surface of the resin base material 32. The discontinuous metal layer 34U, the convex metal film 33 and the coating layer 36 that covers the surface of the resin base material 32 not covered with the convex metal film 33, and the adhesive layer provided on the surface of the coating layer 36 38. When the metallic glossy sheet 30U shown in FIG. 2 is used as the metallic glossy sheet 30 of the pushbutton switch member 100 shown in FIG. 1, the key top 10 is positioned on the peak side of the convex metal film 33. .

-Key top-
The key top is light transmissive. Here, “light transmittance” means that the transmittance for light having a wavelength in the visible light region (about 400 to 800 nm) is in the range of 60% to 100% in the present specification, and 80% to 100%. % Is preferable. When the transmittance is less than 60%, sufficient visibility cannot be ensured even when the push button switch member is illuminated from the back side by a backlight such as an LED in a dark place such as outdoors at night.

  The thickness of the key top is not particularly limited. However, when producing a key top by resin injection molding, it is preferable that the lower limit of thickness exceeds 500 micrometers. When the thickness is 400 μm or less, it is difficult to produce a key top using an injection molding method. Moreover, the upper limit of thickness is not specifically limited. In addition, the key top produced using such an injection molding method is usually composed of a member corresponding to one key. Examples of the resin material used for producing the key top include polycarbonate resin, ABS resin (acrylonitrile / butadiene / styrene copolymer resin), PMMA resin, PBT resin, and PA resin (polyamide resin).

  On the other hand, in order to cope with the thinning of the pushbutton switch member, the thickness of the key top is preferably 500 μm or less, and preferably 400 μm or less. In addition, the lower limit value of the thickness is preferably 100 μm or more, and more preferably 150 μm or more, from the viewpoint of securing strength and the like. Examples of such a key top include a key top having a sheet-like base material made of a resin film such as PET resin or polycarbonate resin, and two or more protrusions provided on one surface of the sheet-like base material. . In this type of key top, a protrusion corresponding to each key is formed by molding a UV curable resin on one side of a sheet-like substrate by mold transfer. In this case, the sum of the thickness of the sheet-like base material and the thickness of the protrusion corresponds to the thickness of the key top. Therefore, the thickness of the sheet-like substrate is preferably in the range of 50 μm to 100 μm. In addition, the thickness of the protrusion is preferably 10 μm or more, more preferably 30 μm or more, from the viewpoint of ensuring the recognition of unevenness. On the other hand, the upper limit of the thickness is preferably 400 μm or less from the viewpoint of reducing the thickness.

  In addition, since the thin key top as described above uses a UV curable resin, shrinkage deformation easily occurs during UV curing, and the sheet-like base material is also very thin. For this reason, irregularities are likely to occur on the surface (back surface) opposite to the side on which the key top protrusions are provided, resulting in poor smoothness. Further, when heated (the heat capacity is small because the thickness is small), the temperature easily rises. Therefore, as a result, thermal deformation is more likely to occur as compared with an injection molding type key top having a thickness exceeding 400 μm. Therefore, even if a sheet including a metal vapor deposition layer is transferred to the back side of such a key top by a hot stamp method as disclosed in Patent Documents 3 and 4, etc., a portion between the key top side and the sheet Inadequate adhesion tends to occur. In addition, even when a metal layer is formed on the back side of the key top by vapor deposition, the key top side is heated to a greater or lesser extent during film formation, and heat shrinkage of the key top occurs. Cracks and wrinkles are likely to occur in the metal layer due to differences in heat shrinkage with the key top side. Accordingly, even in this case, sufficient adhesion cannot be ensured.

  However, the push button switch member of the present embodiment suppresses the above-mentioned poor adhesion because the metallic gloss sheet with the metal layer formed in advance is bonded to the key top side member without using the hot stamp method. Can do.

-Decorative layer-
The decorative layer is provided between the key top and the metallic glossy sheet and on the opposite side of the metallic glossy sheet from the side on which the key top is provided, and is configured by a combination of one layer or two or more printing layers. . As a printing layer constituting the decorative layer, display of light transmissivity (or light impermeability, light shielding property), color tone, characters / symbols / graphics, etc. according to the contents to be displayed on the surface of the pushbutton switch member Therefore, whether or not it is partially provided on the plane (whether the printing layer is partially missing corresponding to the character or the like, or the printing layer exists only corresponding to the character or the like Is appropriately selected, and two or more printed layers are combined as necessary. The light-impermeable or light-shielding printing layer is partially provided so as not to obstruct the light reflection of the backlight light or the external light by the metal layer. Note that “light-opaque” or “light-shielding” means that all the layers constituting the member for a push button switch have a transmittance with respect to light having a wavelength in the visible light region (about 400 to 800 nm) in the present specification. In the state, it means 0.5% or less in an area where “light-opaque” or “light-shielding” is required.

  For example, a printing layer (light-shielding printing layer) provided so as to shield the backlight and to remove a portion corresponding to a character or the like displayed on the surface of the pushbutton switch member is made of a metallic glossy sheet of resin. It can be provided on the side surface. Further, a colored printing layer partially provided so as to correspond to characters or the like displayed on the surface of the pushbutton switch member can be disposed between the keypad and the metallic glossy sheet. The colored print layer may be light transmissive or light opaque. However, in the case of providing a light-shielding print layer, a light-transmitting colored print layer is disposed so as to correspond to all or a part of a region where a portion corresponding to characters or the like is missing. In addition, when it is desired that the substantially entire surface of the pushbutton switch member has a predetermined pastel color, a light-transmitting light-colored printing layer can be disposed between the keypad and the metallic glossy sheet. In addition, when a some printing layer exists between a keypad and a metallic glossy sheet | seat, it is preferable that this light-transmitting light-colored printing layer is arrange | positioned most on the key top side. For the purpose of expressing characters and the like, when one or more printing layers are disposed between the keypad and the metallic glossy sheet, the colorless and transparent printing layer or the light colored printing layer is replaced with the keypad and the metallic glossy sheet. It is preferable that it is located between the metallic glossy sheets and between them.

-Manufacturing method of pushbutton switch member-
The member for a push button switch of the present embodiment can be manufactured as follows, for example. First, prepare a key top. As described above, the key top may be formed by injection molding, or may be a sheet-like base material formed by projecting a protrusion on a UV curable resin. In addition, you may provide the transparent resin sheet which consists of thermoplastic urethane elastomer, PET resin, etc. on the back surface side of a keytop as needed. Subsequently, a decorative layer is formed on the back side of the key top as necessary. When the decorative layer is composed of two or more printed layers, these printed layers are sequentially laminated. As a method for forming the print layer, known printing methods such as screen printing and offset printing can be used.

  Next, a metallic glossy sheet is bonded and bonded to the back surface of the key top (or the decoration layer surface when a decoration layer is provided). Bonding in this case is performed by laminating a metallic glossy sheet using a roller. The pressure and temperature at this time are as described above.

  Next, a decoration layer is formed on the surface of the metallic glossy sheet as necessary. Also in this case, when the decorative layer is composed of two or more print layers, these print layers are sequentially laminated. As a method for forming the print layer, known printing methods such as screen printing and offset printing can be used. Finally, the presser sheet is bonded to the surface of the metallic glossy sheet (or the decoration layer surface when the decoration layer is laminated). An adhesive can be used for this bonding, but a double-sided tape is preferably used.

-Specific examples of pushbutton switch members-
Next, a more specific configuration example of the push button switch member of the present embodiment will be described with reference to the drawings. 3 and 4 are schematic cross-sectional views showing other examples of the push button switch member of the present embodiment. The push button switch member 110 shown in FIG. 3 is the same as the push button switch member 110 shown in FIG. However, the push button switch member 110 shown in FIG. 3 is shown in a form in which the layers are partially separated in order to facilitate understanding of the arrangement relationship in the thickness direction of each layer. The push button switch member 110 shown in FIGS. 3 and 4 is similar to the push button switch member 100 shown in FIG. 1 on the pusher sheet 50, on the decorative layer 40A, the metallic glossy sheet 30, the decorative layer 20A, and the key. The top 10 has a configuration in which the top 10 is laminated in this order.

  Here, the key top 10 is provided with a sheet-like substrate 12 made of a resin film, a plurality of protrusions 14 provided on one surface of the sheet-like substrate 12, and the protrusions 14 of the sheet-like substrate 12. And a resin sheet 16 provided on the opposite side. The protrusions 14 are formed by transferring a UV curable resin on one side of the sheet-like substrate 12 by mold transfer. Each member is made of a light transmissive resin material. Moreover, as the resin sheet 16, a PET resin sheet can be used, for example.

  The decorative layer 20A is, in order from the resin sheet 16 side of the key top 10, a light-impermeable colored printing layer 23 provided for displaying characters and a light-transmitting colored printing layer 22 provided for displaying characters. And the light-color printing layer 21 are stacked in this order. The light-impermeable colored printing layer 23 and the light-transmissive colored printing layer 22 are partially provided so as not to overlap each other with respect to the planar direction of the pushbutton switch member 110, and both are provided for each key. It is provided in a region where the corresponding protrusion 14 exists.

  The metallic glossy sheet 30 is formed by laminating a resin base material 32, a metal layer 34, a coating layer 36, and an adhesive layer 38 in this order. For example, as shown in FIG. It may be a discontinuous metal layer. The metallic gloss sheet 30 is bonded to the decorative layer 20 </ b> A via the adhesive layer 38.

  The decorative layer 40A is obtained by laminating a light semi-transmissive white print layer 42 and a light-shielding light-shielding print layer 41 in this order on the surface of the resin base material 32 of the metallic gloss sheet 30. The two print layers 41 and 42 are formed so that portions corresponding to areas where the print layers 22 and 23 provided partially with respect to the plane direction of the push button switch member 110 are present for character display are removed. Is provided.

  The pusher sheet 50 is composed of a resin sheet 56 provided with a pusher 54 made of a UV curable resin on one side so as to correspond to the protrusions 14. As the resin sheet 56, for example, a PET resin can be used. This pusher sheet 50 is bonded to the decorative layer 40A by a double-sided tape 60 through the surface on which the resin sheet 56 is provided.

  5 and 6 are schematic cross-sectional views showing other examples of the push button switch member of the present embodiment. The push button switch member 120 shown in FIG. 5 is the same as the push button switch member 120 shown in FIG. However, the pushbutton switch member 120 shown in FIG. 5 is shown in a form in which the layers are partially separated in order to facilitate understanding of the arrangement relationship in the thickness direction of each layer. The push button switch member 120 shown in FIGS. 5 and 6 has basically the same layer structure as the push button switch member 110 shown in FIGS. 3 and 4, but the push button switch member 110 shown in FIGS. On the other hand, it is different in that the layer configuration of each printing layer constituting the decorative layer 20 and the decorative layer 40 is changed.

  Here, the decorative layer 20B has a configuration in which a light-impermeable black print layer 27, a light-color print layer 26, and a colorless transparent print layer 25 are laminated in this order from the resin sheet 16 side of the key top 10. . The light-impermeable black print layer 27 is provided so that a part of the area where the protrusions 14 corresponding to the respective keys are partially removed with respect to the planar direction of the pushbutton switch member 110. Yes. In addition, the light-colored print layer 26 includes an opaque black print layer so as to include a region where the light-impermeable black print layer 27 is partially removed with respect to the planar direction of the pushbutton switch member 110. 27 and partially overlapping.

  The decorative layer 40 </ b> B includes a light-shielding light-shielding print layer 43 formed on the surface of the resin base material 32 of the metallic glossy sheet 30. The light-shielding print layer 43 is provided in an area where the opaque black print layer 27 is partially removed with respect to the planar direction of the pushbutton switch member 110 or in an area where the light-color print layer 26 exists. It is provided so that the corresponding part can be removed.

<Key panels, electronic devices>
The key panel of this embodiment includes at least the push button switch member of this embodiment. Here, in the present specification, the “key panel” refers to an operation panel having an operation switch. The key panel may be provided integrally with the electronic device main body to be operated by the switch operation, or physically separated from the electronic device main body to be operated by the switch operation. There may be. In the latter case, the key panel and the electronic device may be a wired type, or the key panel and the electronic device may be a wireless type capable of exchanging signals by infrared communication or the like. Good. Typical examples include an operation panel used for an air conditioner, an interphone, a remote controller such as a television, a keyboard of a desktop type personal computer, and the like. In addition, electronic devices equipped with a key panel (an electronic device in which the key panel is integrated with the electronic device main body) can be used for music reproduction such as an electronic dictionary, a mobile phone, a calculator, a notebook computer, a personal digital assistance (PDA), and an MP3 player. For example, a portable player having a function.

  When the member for a push button switch of this embodiment is used as a key panel, a light source is further provided on the back surface (the surface on the side where the key gloss metallic sheet is provided) or the side surface of the member for the push button switch. Here, the “light source” means a light source that emits light to irradiate the back side. When the light source is disposed on the side surface of the push button switch member, a member that guides light emitted from the light source to the back side, such as a light guide plate, is provided on the back side of the push button switch member. And a light source is arranged on the side of the member. Here, as a light source that emits light, an LED, an electroluminescence sheet (EL sheet), or the like can be used.

  The use of the electronic device of the present embodiment is not particularly limited as long as it has the above-described key panel integrally with the main body of the electronic device, but is not limited to a portable electronic device; for example, a mobile phone, an electronic dictionary, a PDA, A notebook computer or the like is preferable, and a mobile phone is particularly preferable.

  Hereinafter, the push button switch member of the present embodiment will be described in more detail with reference to examples.

<Preparation of key top A>
Using key mold for mold formation and polycarbonate resin (Mitsubishi Engineering Plastics Co., Ltd., H3000R), a key top A is produced in which a sheet-like substrate and a plurality of protrusions are integrally formed by injection molding. did. The thickness of this key top A was 530 μm.

<Preparation of key top B>
An acrylic urethane-based ultraviolet curable resin was applied to the surface of a mold provided with a recess corresponding to the protrusion of the key top. Thereafter, the upper surface was covered with a transparent PET sheet (Lumirror, manufactured by Toray Industries, Inc.) corresponding to a sheet-like substrate while extruding with a roller so that air bubbles do not enter between the UV curable resin and the PET sheet. Subsequently, the ultraviolet curable resin was cured by irradiating ultraviolet rays from the surface side on which the PET sheet was provided. Finally, by peeling from the mold, a key top B was obtained in which a plurality of acrylic urethane resin protrusions were formed on a transparent PET sheet. The key top B has the same shape in the planar direction as the key top A. The thickness of the key top B was 400 μm (sheet-like base material thickness 50 μm + projection thickness 350 μm).

<Preparation of the pusher sheet>
The presser sheet was prepared in the same manner as the key top B, except that the mold type was changed to that for the presser sheet and Lumirror (thickness 50 μm) manufactured by Toray Industries, Inc. was used as a transparent PET sheet. The presser was 500 μm in height and 1500 μm in diameter, and was provided at a position corresponding to each protrusion when a pushbutton switch member was produced.

<Preparation of metal color sheet A>
An Sn layer was formed on one side of a transparent PET sheet (manufactured by Toray Industries Inc., Lumirror, thickness 25 μm) by vacuum deposition so that the film thickness was 10 nm. Subsequently, a UV curable acrylic coating agent was applied to the Sn layer surface by reverse roll coating so as to have a thickness of 1 μm, thereby forming a coating layer. Then, the acrylic urethane type adhesive was apply | coated to the coating layer surface by the laminating method so that thickness might be set to 25 micrometers, and the adhesive bond layer was formed. Thereby, a metallic color sheet A was obtained. In addition, when the cross section of this metal color sheet A was observed with the transmission electron microscope, it was confirmed that Sn layer has a discontinuous structure as FIG. 2 shows.

<Preparation of metal color sheet B>
An In layer was formed on one side of a transparent PET sheet (manufactured by Toray Industries Inc., Lumirror, thickness 25 μm) by a sputtering method so that the film thickness was 30 nm. Subsequently, a coating layer and an adhesive layer were sequentially formed in the same manner as the metal color sheet A. Thereby, a metallic color sheet B was obtained. When the cross section of the metallic color sheet B was observed with a transmission electron microscope, it was confirmed that the In layer had a discontinuous structure as shown in FIG.

<Preparation of metal color sheet C>
An Al layer was formed on one side of a transparent PET sheet (manufactured by Toray Industries, Inc., Lumirror, thickness 25 μm) by a sputtering method so that the film thickness was 30 nm. Subsequently, a coating layer and an adhesive layer were sequentially formed in the same manner as the metal color sheet A. Thus, a metal color sheet C was obtained. When the cross section of the metal color sheet C was observed with a transmission electron microscope, the Al layer was not a discontinuous structure as shown in FIG. 2, but a single continuous layer having a constant thickness in the plane direction of the sheet. It was confirmed that there was.

<Production of push button switch member>
Example 1
A member for a push button switch having a layer configuration substantially similar to that shown in FIG. 3 was prepared by the following procedure. First, the key top B is used as the key top 10, and the light-impermeable colored printing layer 23, the light-transmissive colored printing layer 22, and the light-colored printing layer 21 are arranged in this order on the back side as the decorative layer 20 </ b> A. Stacking was performed by sequentially repeating printing and hot air drying (80 ° C., 5 minutes (in the case of the light-impermeable colored printing layer 23 and the light-transmissive colored printing layer 22) or 30 minutes (in the case of the light-colored printing layer 21)). . A black ink was used to form the light-opaque colored printing layer 23, and a mixture of a plurality of colored inks and medium was used to form the light-transmitting colored printing layer 22 and the light-colored printing layer 21. The ink used is a two-component curable polyester ink (Seiko Advance, GAP new series).

  Subsequently, after using the metallic color sheet A as the metallic glossy sheet 30 and accurately positioning the decorative layer 20A and the adhesive layer 38 of the metallic color sheet A, a roller is used so that air bubbles are not mixed between the two. The laminate was pressure-bonded at a normal temperature (about 22 ° C.) at a pressure of 0.1 MPa.

  Next, as a decorative layer 40 on the surface of the metal color sheet A, a white printing layer 42 and a light shielding printing layer 41 are arranged in this order by screen printing and hot air drying (at 60 ° C. for 5 minutes (in the case of the white printing layer 42 ) Or 30 minutes (in the case of the light-shielding print layer 41)) The layers were formed by repeating sequentially. White ink was used to form the white print layer 42, and black ink was used to form the light-shielding print layer 41. The ink used is a two-component curable polyester ink (Seiko Advance, GAP new series).

Finally, the presser sheet 50 was adhered to the surface of the decorative layer 40A with a double-sided tape. Thus, a push button switch member was obtained.

(Example 2)
A push button switch member was obtained in the same manner as in Example 1 except that the key top B was used instead of the key top A as the key top 10 when the push button switch member of Example 1 was manufactured.

(Example 3)
In producing the push button switch member of Example 1, a push button switch member was obtained in the same manner as in Example 1 except that the metal color sheet 30 was replaced with the metal color sheet B instead of the metal color sheet A.

Example 4
In producing the push button switch member of Example 1, a push button switch member was obtained in the same manner as in Example 1 except that the metal color sheet 30 was replaced with the metal color sheet C instead of the metal color sheet A.

(Comparative Example 1)
The key top A was fixed to a key top fixing jig having a concave portion corresponding to the protruding portion with the protruding portion facing downward so that the sheet-like base material portion of the key top A was flat. Subsequently, a decorative layer (first decorative layer) similar to the decorative layer 20A formed in Example 1 was formed on the surface of the sheet-like base material portion of the key top A in the same manner as in Example 1. . Subsequently, an Al metal transfer foil sheet (Al metal layer thickness 100 nm (continuous layer)) composed of a carrier film and an Al metal layer was overlaid on the surface of the decorative layer so that the carrier film side was the upper surface. In this state, the Al metal layer was transferred onto the decorative layer surface by pressing the stamp surface of the elastic rubber stamp against the carrier film at a surface temperature of 200 ° C. for 3 seconds.

  Thereafter, a decorative layer (second decorative layer) was formed on the surface of the transferred Al metal layer. This decorative layer is composed of a white print layer, a light shielding print layer, and a transparent print layer. Here, the positional relationship of the white printing layer and the light-shielding printing layer with respect to the key top protrusions was the same as the layers indicated by reference numerals 42 and 41 in FIG. Moreover, the transparent printing layer was formed so that the opening part (equivalent to the opening part of the layer shown by the code | symbol 42 and the code | symbol 41 in FIG. 3) of a white print layer and a light-shielding print layer was embedded. These layers were laminated by screen printing and hot air drying (60 ° C., 5 minutes (in the case of a white printing layer), 30 minutes (in the case of a light-shielding printing layer) or 30 minutes (in the case of a transparent printing layer)). . In addition, CAV (made by Seiko Advance) was used for formation of a white printing layer, a light shielding printing layer, and a transparent printing layer.

  Thereafter, a member in which a first decorative layer, an Al metal layer, and a second decorative layer are laminated in this order on the surface of the sheet-like substrate portion, and a plurality of protrusions are integrally formed in the sheet-like substrate portion. Are cut with a blade jig so as to be separated and independent for each protrusion, so that individual keys in which a first decorative layer, an Al metal layer, and a second decorative layer are laminated in this order on one side Got the top.

  Next, the second decorative layer side surface of each individual key top is made to correspond to the position where the key top is provided on one side of a 50 μm-thick thermoplastic polyurethane sheet (Dus601, manufactured by Sea Dam Co., Ltd.). (Hitachi, manufactured by Hitachi Chemical Co., Ltd.) was bonded to the region where it was pasted. Finally, a push button switch member was obtained by adhering a pusher sheet to the other surface of the thermoplastic polyurethane sheet.

(Comparative Example 2)
A push button switch member was obtained in the same manner as in Comparative Example 1 except that the key top B was used instead of the key top A as the key top 10 when the push button switch member of Comparative Example 1 was manufactured.

(Comparative Example 3)
A first decorative layer was formed in the same manner as in Comparative Example 1 except that the key top B was used instead of the key top A. Subsequently, a mirror ink (MIR-9100, manufactured by Teikoku Ink Manufacturing Co., Ltd.) was printed on the surface of the first decorative layer by screen printing and dried at 80 ° C. for 30 minutes. This mirror ink is an ink in which Al flake powder is blended.

  Subsequently, a second decorative layer was formed on the surface of the layer made of mirror ink. This second decorative layer has the same layer structure as the second decorative layer of Comparative Example 1 except that MIB (manufactured by Teikoku Ink Manufacturing Co., Ltd.) was used as the printing material. After that, as in Comparative Example 1, each key top was produced by cutting with a blade jig so as to be separated and independent for each protrusion, and this was attached to one side of the thermoplastic polyurethane sheet and the other side. A push button switch member was obtained by adhering a pusher sheet to the surface.

<Evaluation>
About the obtained member for pushbutton switches of each Example and a comparative example, adhesiveness, an external appearance, moisture resistance, and electromagnetic wave shielding property were evaluated. The results are shown in Table 1 below.

  The evaluation methods and evaluation criteria for adhesion, appearance, moisture resistance and electromagnetic wave shielding properties shown in Table 1 are as follows.

-Adhesion-
Adhesiveness was evaluated based on JIS K5600-5-6 (paint cross-cut method) in a state where the metal layer was exposed immediately after forming the metal layer of each example and comparative example. The evaluation criteria are as follows.
A: Classification 0, 1
○: Classification 2
Δ: Classification 3
×: Classification 4, 5

-Appearance-
The appearance was evaluated for the presence or absence and degree of appearance defects (metal layer cracks, undulations, unevenness) when the surface was visually observed for 100 samples. The evaluation criteria are as follows.
◎: Appearance defect is less than 3 ○: Appearance defect is 3 or more and less than 10 △: Appearance defect is 10 or more and less than 20 ×: Appearance defect is 20 or more

-Moisture resistance-
Moisture resistance is determined by leaving the pushbutton switch member in a high-temperature, high-humidity environment (60 ° C, 90RH%) for one month, and using the pushbutton switch member before leaving as a reference, the degree of discoloration of the surface of the left pushbutton switch member. Visual evaluation was made. The evaluation criteria are as follows.
(Double-circle): Discoloration is not observed at all before and after leaving.
○: Some discoloration is observed, although partially in the vicinity of the end face.
Δ: Discoloration is observed in the region with a width of around 1 mm over the entire periphery of the end face.
X: The occurrence of discoloration was confirmed not only near the end face but also near the center of the panel of the push button switch member.

-Electromagnetic wave shielding-
The electromagnetic wave shielding property was evaluated by measuring the surface resistance value in a state where the metal layer was exposed immediately after the formation of the metal layer of each example and comparative example. For measurement, a digital multimeter R8340 (manufactured by Advantest) was used. The evaluation criteria are as follows.
A: Surface resistance is 10 ⁵ Ω / cm ² or more ○: Surface resistance is 100 Ω / cm ² or more and less than 10 ⁵ Ω / cm ² Δ: Surface resistance is 30 Ω / cm ² or more and less than 100 Ω / cm ² ×: Surface resistance is 30 Ω Less than / cm ²

It is a schematic cross section which shows an example of the layer structure of the member for pushbutton switches of this embodiment. It is a schematic cross section which shows an example of the metallic glossy sheet used for the member for pushbutton switches of this embodiment. It is a schematic cross section which shows the other example of the member for pushbutton switches of this embodiment. It is a schematic cross section which shows the state of the finished product which has not isolate | separated the layers about the member for pushbutton switches shown in FIG. It is a schematic cross section which shows the other example of the member for pushbutton switches of this embodiment. It is a schematic cross section which shows the state of the finished product which has not isolate | separated the layers about the member for pushbutton switches shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Key top 12 Sheet-like base material 14 Protrusion part 16 Resin sheet | seat 20,20A, 20B Decorating layer 21 Light color printing layer 22 Light transmission colored printing layer 23 Light opaque color printing layer 25 Colorless transparent printing layer 26 Light color printing layer 27 Light-impermeable printing layer 30, 30 U Metal gloss sheet 32 Resin base material 33 Convex metal film 34 Metal layer 34 U Discontinuous metal layer 36 Cover layer 38 Adhesive layers 40, 40 A, 40 B Decorating layer 41 Light-shielding printing layer 42 White printing layer 43 Light-shielding printing layer 50 Presser sheet 54 Presser 56 Resin sheet 60 Double-sided tape 100, 110, 120 Pushbutton switch member

Claims (7)

A light-transmissive key top,
A light translucent metallic glossy sheet provided on one side of the key top, and at least
The metallic glossy sheet is
A resin substrate;
A light translucent metal layer provided on one side of the resin substrate;
A member for a push button switch, characterized by having an adhesive layer that covers the metal layer and adheres to the key top side.   2. The member for a push button switch according to claim 1, wherein the metal layer is a discontinuous metal layer in which metal films are discretely formed on the surface of the resin base material.   The member for a pushbutton switch according to claim 2, wherein the discontinuous metal layer contains at least one metal selected from Sn and In. The key top has a sheet-like base material, and two or more protrusions provided on the surface of the key-like side of the sheet-like base material opposite to the side where the metallic glossy sheet is provided,
The pushbutton switch member according to any one of claims 1 to 3, wherein the sum of the thickness of the sheet-like base material and the thickness of the protrusions is in the range of 50 µm to 500 µm.   A decorative layer is provided on at least one selected from the key top and the metallic glossy sheet and on the opposite side of the metallic glossy sheet from the side on which the keytop is provided. The member for pushbutton switches of any one of Claims 1-4.   A key panel comprising the push button switch member according to claim 1.   An electronic device comprising the key panel according to claim 6.

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