JP2008123896A - Manufacturing method and molding die of push-button switch member with resin film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a push-button switch with resin film having a high dimension accuracy at a low cost, and a molding die for molding a resin film. <P>SOLUTION: This is the manufacturing method of a push-button switch member 1 with resin film which has a configuration to cover the surface of a core material with a resin film 10. The method includes a process of drawing forming the resin film 10 by using a molding die 20 which is provided with a metallic convex die 26 and a metallic concave die 22 and in which an elastic body 30 is arranged on a base face 27 adjoining a convex part 25 in the convex die 26. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a manufacturing method of a member for a push button switch with a resin film suitable for a push button switch of an electronic device or the like, and a molding die used in the manufacturing process.

2. Description of the Related Art In recent years, in electronic devices such as mobile phones and personal digital assistants, the configuration of push button switch members used for input units has been diversified. Among a wide variety of push button switch members, the push button switch member with a resin film whose core material is covered with a resin film has a wide variety of appearance designs and can be manufactured at low cost. Is becoming extremely expensive.

  Conventionally, a member for a pushbutton switch with a resin film has been manufactured by, for example, the following method. First, a resin film on which a printing layer is formed in advance is prepared. Next, the resin film is drawn using a molding die composed of a metal concave mold having a concave portion and a metal convex mold having a convex portion. Then, resin used as a core material is injected into the concave portion of the resin film to obtain a core material with a resin film. Finally, it decorates with the printing and / or hot stamp on the back surface side of this core material with a resin film (for example, refer patent document 1).

A member for a pushbutton switch with a resin film manufactured by the following method is also known. First, when using a molding die composed of a convex mold made of an elastic material and a metal concave mold, a flexible film is sandwiched between the concave mold and the convex mold, and then drawn. The convex mold is brought into close contact with the concave mold through the flexible film. Next, the concave mold is heated to manufacture a member for a pushbutton switch with a resin film (see, for example, Patent Document 2).
JP 2002-197933 A (Claims) JP 2002-011729 A (Claims)

  However, the conventional member for a pushbutton switch with a resin film has the following problems. When manufacturing the member for a pushbutton switch with a resin film disclosed in Patent Document 1, by closing the metal concave mold and the metal convex mold constituting the molding mold, A resin film having a printed layer is drawn. However, the force applied to the resin film often becomes non-uniform due to an error in dimensional accuracy between the convex mold and the concave mold or non-uniform thickness of the resin film. For this reason, wrinkles are likely to occur between a portion where a large force is applied for stretching and a portion where a small force is not applied. When such wrinkles occur, this leads to a problem that the drawn resin film cannot be accurately set on the mold or jig in the next process such as injection molding or bonding of the core material. In order to solve this problem, a method of cutting off the wrinkled portion of the resin film after drawing is also conceivable. However, if the wrinkles generated on the outer periphery of the key top part can be cut off, this problem can be solved if wrinkles are present in a portion that cannot be cut off, for example, in the gap between the key top parts. Can not. In addition, if a step of cutting is introduced when cutting off the wrinkle portion, there is a problem that the manufacturing cost increases.

  In addition, when manufacturing a member for a pushbutton switch with a resin film disclosed in Patent Document 2, a convex mold made of an elastic material is used, so even if there is some error in dimensional accuracy, it is applied to the resin film. The force is almost uniform and the molded resin film is less likely to wrinkle. However, when a resin film having a higher rigidity than the elastic material constituting the convex mold is formed, there is a problem that the outer periphery of the key top portion is deformed and rounded more than a desired shape. In order to solve such a problem, the material of the resin film to be drawn must be a material having a lower rigidity than the elastic material constituting the convex mold. If such a restriction exists, it becomes impossible to increase the rigidity of the key top surface.

  Therefore, in order to solve the above-described problem, a resin film molded using a metal molding die disclosed in Patent Document 1 is molded including a convex mold made of an elastic material disclosed in Patent Document 2. A method of forming using a metal mold is also conceivable. However, it is difficult to solve the problem that the outer periphery of the key top portion of the push button switch member with a resin film becomes round. In addition, when a thin and highly rigid resin film is used, there is a high possibility that the periphery of the molded part is broken. Furthermore, if molding is performed twice, a lot of time is required for molding, the manufacturing process becomes complicated, and there is a problem that the cost is increased and productivity is lowered.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a method for manufacturing a member for a pushbutton switch with a resin film having a high dimensional accuracy at a low cost and a resin film. An object of the present invention is to provide a molding die for molding a mold.

  In order to achieve the above object, the present invention provides a method for manufacturing a pushbutton switch member with a resin film having a form in which the surface of a core material is covered with a resin film, the metal convex mold and the metal concave mold. And a member for a pushbutton switch with a resin film, including a step of drawing a resin film using a molding die in which an elastic body is disposed on a base surface adjacent to a convex portion in the convex die It's a way.

  By adopting such a manufacturing method, a member for a push button switch with a resin film having high dimensional accuracy can be manufactured easily and at low cost. Furthermore, by placing an elastic body on the surface of the base part of the metal convex mold, when the resin film is drawn, the force applied to the resin film is almost uniform, and the load concentration is concentrated on a part of the resin film. Less likely to occur. Accordingly, the resin film can be sufficiently adhered to the elastic body disposed on the base portion of the convex mold and the metal surface of the concave mold. As a result, in the base part adjacent to the key top part in the molded resin film, wrinkles are unlikely to occur, and a resin film drawn molded body having a smooth surface form is obtained. In addition, since the key top portion is formed through a metal mold, even when a highly rigid resin film is formed, the shape of the key top portion is not deformed and high-precision molding can be performed. In addition, since the resin film drawn molded body can be molded at a time, the cost can be reduced by saving labor in the manufacturing process.

  Another aspect of the present invention is a molding die including a metal convex die and a metal concave die, and an elastic body is disposed on a base surface adjacent to the convex portion in the convex die. This is a molding die.

  When the molding die having such a configuration is adopted, the resin does not cause wrinkles or breakage in the concave portion (base portion) adjacent to the key top portion in the molded resin film, as described above. Film drawing can be performed with high accuracy. In addition, since the key top portion can be accurately formed into a desired shape by a metal portion, the outer periphery of the key top portion is not deformed, and a highly rigid resin film can be used.

  In another aspect of the present invention, in the previous invention, a molding die in which the durometer hardness (type A) of the elastic body is in the range of 30 degrees or more and 90 degrees or less. The durability can be secured by setting the hardness to 30 degrees or more. Moreover, by making the said hardness into 90 degrees or less, shape followability can be improved and generation | occurrence | production of wrinkles can be prevented effectively. For this reason, the resin film can be sufficiently adhered to the elastic body disposed on the base portion of the convex mold and the metal surface of the concave mold. As a result, the surface of the base portion around the key top of the resin film becomes smooth.

  The material of the resin film used in the method for manufacturing a pushbutton switch member with a resin film according to the present invention is not particularly limited as long as it can be drawn. Resins such as polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polypropylene, vinyl chloride, polyethylene, polyamide, polyurethane, acrylic, polyester elastomer, and polyurethane elastomer can be suitably used. Of these resins, polycarbonate resin or polyethylene terephthalate resin is particularly preferable from the viewpoints of translucency, easy moldability, availability, good surface condition, and good decorative processability after molding. Can be used. However, the above-mentioned resin material is only an example, and other resin materials may be adopted. The resin material may be one kind of resin material as described above or a mixture of two or more kinds of resin materials. Moreover, if the resin film has transparency, a light-transmitting pushbutton switch member with a resin film configured to illuminate an arbitrary portion can be obtained by arranging a light source on the back surface. In addition, additives such as a heat stabilizer, a UV absorber, an antioxidant, a light stabilizer, and a colorant can be added to the resin film as long as the effects of the present invention are not impaired. Moreover, the thickness of the resin film can be appropriately selected depending on the application and the like. In general, the thickness is preferably 25 μm to 200 μm, particularly preferably 75 μm to 150 μm. Furthermore, the resin film may be a laminate in which a plurality of layers are laminated.

  As the elastic body disposed on the base surface of the convex mold, a thermoplastic elastomer typified by urethane elastomer or a vulcanized rubber typified by silicone rubber is suitable, but is not limited thereto.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing die of the manufacturing method of the member for pushbutton switches with a resin film with high dimensional accuracy at low cost and the molding die for shape | molding a resin film can be provided.

  Hereinafter, preferred embodiments of a method for producing a pushbutton switch member with a resin film and a molding die according to the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the preferred embodiments described below.

  FIG. 1 is a view showing the structure of a pushbutton switch member 1 with a resin film manufactured by the manufacturing method according to the embodiment of the present invention. FIG. 1 (A) shows the pushbutton switch member 1 with a resin film on the front side. FIG. 2B is a schematic perspective view of the push button switch member 1 with a resin film as viewed from the back side, and FIG. 3C is a push button switch member with a resin film shown in FIG. It is AA sectional view taken on the line of 1. FIG.

  As shown in FIG. 1C, the pushbutton switch member 1 with a resin film is filled in a resin film 10 having a plurality of key top portions 11 and recesses formed on the back surfaces of the key top portions 11. A key top core portion 15. A printed layer 31 is provided on the back side of the resin film 10, that is, on the contact surface side with the key top core portion 15. As shown in FIG. 1A, at the top surface position of each key top 15 in the printing layer 31, patterns such as letters, numbers, designs, and the like indicating the type of each key are drawn. Further, as shown in FIG. 1B, a presser 16 that is convex in the back direction is formed on the back side of the key top core portion 15. The presser 16 is a part for turning on / off a switch disposed on the back side of the key top core part 15.

  FIG. 2 is a cross-sectional view of the molding die 20 used for drawing the resin film 10 of the member 1 for a pushbutton switch with a resin film shown in FIG.

  As shown in FIG. 2, the molding die 20 includes a metal concave die 22 having a concave portion 21 and a convex die 26 having a convex portion 25. An elastic body 30 is disposed on the base surface 27 around the convex portion 25 in the convex mold 26. The concave mold 22 and the convex mold 26 are closed so that the concave portion 21 and the convex portion 25 are aligned with each other when used.

  The concave mold 22 and the convex mold 26 of the molding mold 20 are formed of a metal material. As the metal material, iron, stainless steel, aluminum, tungsten alloy or the like may be employed. In particular, it is more preferable to use stainless steel in terms of high hardness and high corrosion resistance. However, the above metal material is only an example, and other metal materials may be adopted. Each corner of the concave portion 21 of the concave mold 22 is chamfered to prevent cracking or cracking during molding. The concave portion 21 of the concave mold 22 and the convex portion 25 of the convex mold 26 are fitted to each other. Moreover, the height of the recessed part 21 of the concave mold 22 can be processed according to the dimension of the molding object.

  The elastic body 30 disposed on the base surface 27 of the convex mold 26 is made of an elastically deformable material, for example, a cured rubber such as a thermoplastic elastomer or a fluorine rubber. When the resin film 10 is drawn using the molding die 20, the concave portion 21 of the concave die 22 and the convex portion 25 of the convex die 26 are fitted through the resin film 10, and the resin film 10 is Accordingly, the convex portion around the concave portion 21 of the concave mold 22 and the elastic body 30 of the convex mold 26 can be fitted. The durometer hardness (type A) of the elastic body 30 is preferably in the range of 30 degrees to 90 degrees. If the elastic body 30 within this hardness range is employed, the resin film 10 can be sufficiently adhered to the metal surface of the elastic body 30 and the concave mold 22 due to the excellent shape following ability of the elastic body 30. As a result, wrinkles are unlikely to occur in the molded resin film 10 and the molding accuracy can be improved. As a method for measuring the hardness of the elastic body 30, a durometer hardness (type A) test method based on JIS K6253 is employed. As a method for forming the elastic body 30, for example, a method in which the elastic body 30 formed in the same shape as the base surface 27 is fitted into the convex mold 26, or the elastic body 30 is welded or bonded to the convex mold 26. A method is mentioned. However, the formation method of the elastic body 30 is not limited to these methods, and another method may be used.

  Next, the manufacturing method of the member for pushbutton switches with a resin film which concerns on embodiment of this invention is demonstrated.

  FIG. 3 is a flowchart showing a manufacturing process of the member for a push button switch with a resin film according to the embodiment of the present invention. FIG. 4 is a view showing a part of the manufacturing process of the pushbutton switch member 1 with a resin film in a stepwise manner.

  First, the printing layer 31 is formed on the back surface of the resin film 10 (the surface opposite to the top surface of the key top) (step S101). In this embodiment, as shown in FIG. 4 (A), patterns such as letters, numbers or designs are formed at predetermined positions on the back surface of the resin film 10. Examples of the method for forming the printing layer 31 include a normal printing method such as an offset printing method, a gravure printing method, a screen printing method, or a coat printing method. In particular, when performing multicolor printing or gradation expression, a screen printing method, an offset printing method, or a gravure printing method can be suitably used. In the case of a single color, it is preferable to employ a coating method such as a gravure coating method, a roll coating method, or a comma coating method. Moreover, the printing layer 31 can also be provided in the whole surface or partially according to the design to represent. For the purpose of protecting the printing layer 31 when the key top portion 11 of the molded resin film 10 is filled with molten resin, the surface of the printing layer 31 is subjected to various known surface treatments in advance to improve it. You may make it quality. If such a protective layer is formed, the printing layer 31 can be effectively protected from the heat generated when the molten resin is injected.

  Next, as shown in FIG. 4B, the resin film 10 is set in the molding die 20 (step S102). In this embodiment, the resin film 10 is disposed between the convex mold 26 and the concave mold 22 of the molding mold 20 of the present invention.

  Subsequently, the resin film 10 is drawn (step S103). Specifically, as shown in FIG. 4C, the mold is closed with the resin film 10 interposed between the heated convex mold 26 and the heated concave mold 22. As a result, the key top portion 11 protruding from the front surface of the resin film 10 is formed. Further, when the portion other than the key top portion 11 of the resin film 10 is in close contact with the elastic body 30 disposed on the base surface 27, the portion other than the key top portion 11 becomes smooth. This is because a portion other than the key top portion 11 is pressed with a substantially uniform pressure, so that partial concentration of weight does not occur.

  Next, as shown in FIG. 4D, molten resin is injected into the back side of the key top portion 11 of the resin film molded body 35 taken out from the molding die 20 (step S104). Specifically, the resin film molded body 35 is taken out from the molding die 20 of the present invention and placed in another mold (not shown) having the same shape at the same position as the key top portion 11. Thereafter, the molten resin is filled into the space on the back side of the key top portion 11 using a pin gate or the like, and then cured. As a result, a pushbutton switch member 1 with a resin film as shown in FIG. 4 (E) is obtained.

  Then, the unnecessary part of the member 1 for pushbutton switches with a resin film is removed. In this embodiment, for example, the obtained pushbutton switch member 1 with a resin film is cut by using a precision press machine or a laser processing apparatus to obtain the pushbutton switch member 1 with a resin film. It is done. However, the method for removing unnecessary portions is not particularly limited.

  As mentioned above, although the manufacturing method of the member for pushbutton switches with a resin film which concerns on this invention, and embodiment of the metal mold | die were demonstrated, this invention is not limited to each above-mentioned embodiment, It is in various deformation | transformation form. Can be implemented.

  For example, the molding die 20 of the present invention is opened, the resin film molded body 35 is taken out, and the resin film molded body 35 can be fixed to the surface of the molded body to be a key top core with an adhesive. That is, step S104 shown in FIG. 3 can be a key top core attaching step. Even if such a process is adopted, the member 1 for a push button switch with a resin film is obtained. However, if the injection process of the molten resin is not performed, it is difficult to accurately form the corner of the resin film molded body 35 by the injection pressure. It is suitable when manufacturing what you have.

  In addition, for example, by using a photocurable resin or the like, a convex push button shape portion is formed on the surface, and the resin film 10 with the push button shape portion is drawn to form a push button with a resin film having a desired shape. The switch member 1 may be formed. The push button shape portion is preferably smaller than the convex surface of the resin film 10. Specifically, it is preferable that the push button shape portion has a size such that the edge is 0.2 mm or more inward from the edge of the convex surface of the resin film 10. This is because, as the size of the push button shape portion is smaller than the size of the convex surface of the resin film 10, the push button shape portion is less likely to be deformed even with a slight extension of the convex surface generated during the drawing process.

  Next, each example of the present invention will be described. However, this invention is not limited by each Example illustrated below.

(Example 1)
First, a printed layer (decorative layer) having a pattern such as letters, numbers or a pattern was formed on the back surface of a polycarbonate film having a thickness of 100 μm (trade name: Iupilon, manufactured by Mitsubishi Engineering Plastics Co., Ltd.). As printing ink, IPS ink (trade name) manufactured by Teikoku Ink Manufacturing Co., Ltd. was used. Next, the printed polycarbonate film was placed in the molding die of the present invention (a die having a urethane elastomer attached to the base surface of the convex die). Subsequently, the heated convex mold having the convex portions and the heated concave mold having the concave portions were closed, and the polycarbonate film was molded so as to adhere to the surface of the urethane elastomer. The temperature of the molding die was 120 ° C. As a result, the polycarbonate film was drawn and a polycarbonate film molded body having a desired shape was obtained.

  Next, the polycarbonate film molded body was taken out from the molding die and placed in a separately prepared die (a die having the same position as the key top portion and a concave portion having the same shape). Next, the molten polycarbonate resin was injection-filled into a recess formed on the back side of the key top portion of the polycarbonate film molded body. Thereafter, the base material of the cured pushbutton switch member with the polycarbonate film was taken out of the mold. Finally, unnecessary parts were removed using a punching die to obtain a pushbutton switch member with a polycarbonate film. Since the polycarbonate film molded body constituting the obtained pushbutton switch member with the polycarbonate film was manufactured by one-time drawing, the base surface around the key top portion had a good surface form without wrinkles. Had.

(Example 2)
First, a photocurable resin was formed in a push button shape on the surface of a 75 μm thick polyethylene terephthalate film (trade name: Lumirror, manufactured by Toray Industries, Inc.). Next, a printing layer having a pattern such as letters, numbers or a pattern was formed at a position corresponding to the key top portion on the surface opposite to the push button-shaped resin in the polyethylene terephthalate film. HIPET ink (trade name) manufactured by Jujo Chemical Co., Ltd. was used as the printing ink. Subsequently, the printed polyethylene terephthalate film was drawn using the same molding die as the molding die used in Example 1. As a result, a polyethylene terephthalate film was drawn and a polyethylene terephthalate film molded body having a desired shape was obtained.

  Next, a photo-curing resin protrusion (a member serving as a presser) is pasted on a 50 μm thick polyethylene terephthalate film (trade name: Lumirror, manufactured by Toray Industries, Inc.) so that it fits the inner bottom surface of the film on the back side of the key top. Cut into a simple shape. Next, the cut resin was stuck on the bottom surface of the film. Finally, unnecessary portions were removed using a punching die to obtain a pushbutton switch member with a polyethylene terephthalate film. Since the polyethylene terephthalate film molded body constituting the obtained pushbutton switch member with the polyethylene terephthalate film was manufactured by one-time drawing, the base surface around the key top portion has a good surface form without wrinkles. Had.

  INDUSTRIAL APPLICABILITY The present invention can be used in industries that manufacture or use a pushbutton switch member with a resin film, for example, electronic device industries such as portable information terminals and various OA equipment.

It is a figure which shows the structure of the member for pushbutton switches with a resin film manufactured with the manufacturing method which concerns on embodiment of this invention, (A) is the schematic perspective view which looked at the member for pushbutton switches with a resin film from the front side (B) is a schematic perspective view of a member for a pushbutton switch with a resin film as seen from the back side, and (C) is a cross-sectional view taken along line AA of the member for a pushbutton switch with a resin film shown in (A). It is. It is sectional drawing of the metal mold | die used for drawing-molding the resin film of the member for pushbutton switches with a resin film shown in FIG. It is a flowchart which shows the manufacturing process of the member for pushbutton switches with a resin film which concerns on embodiment of this invention. It is a figure which shows a part of manufacturing process of the member for pushbutton switches with a resin film which concerns on embodiment of this invention in steps.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Member for pushbutton switches with a resin film 10 Resin film 11 Key top part 15 Key top core part (core part)
16 Presser 20 Molding Mold 21 Concave 22 Concave Mold 25 Convex 26 Convex Mold 27 Base Surface 30 Elastic Body 31 Printed Layer 35 Resin Film Molded Body

Claims (3)

A method for manufacturing a pushbutton switch member with a resin film having a form in which the surface of a core material is covered with a resin film,
The resin film is squeezed using a molding die having a metal convex die and a metal concave die and having an elastic body disposed on a base surface adjacent to the convex portion of the convex die. The manufacturing method of the member for pushbutton switches with a resin film characterized by including the process to shape | mold. A molding die comprising a metal convex mold and a metal concave mold,
A molding die, wherein an elastic body is disposed on a base surface adjacent to a convex portion in the convex die.   The molding die according to claim 2, wherein the durometer hardness (type A) of the elastic body is in a range of 30 degrees or more and 90 degrees or less.

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