JP2016207200A - Touch panel and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a touch panel that stably maintains a three-dimensionally molded shape of a laminated film, and a manufacturing method of the same.SOLUTION: A touch panel comprises: a panel material; and a multi-layer film 10 that is joined to a surface of the panel material, and includes conductive films 1, 2 having conductive layers 1a, 2a and a protective film 4. The multi-layer film 10 has the respective films laminated via adhesive layers 5-7 formed of a thermosetting adhesive, and is molded to have a three-dimensional shape extending along the surface.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a touch panel and a manufacturing method thereof.

  Conventionally, touch panels have been used as input devices in automobile audio equipment, home appliances, electronic devices, and the like. The touch panel is usually formed by printing and laminating a conductive layer for detecting a change in capacitance and a decorative layer for decoration on the surface of an insulating film. By using the touch panel, there are advantages that the operation surface can be flattened and various switch parts for input operation can be omitted.

  The decoration layer provided in the touch panel is selected from various types according to the use and preference of the touch panel. However, if a decorative layer and a conductive layer are printed and laminated on a single film, various combinations of the conductive layer and the decorative layer cannot be easily realized. For this reason, the touch panel which joins the decorating film provided with the decorating layer, and the electrically conductive film provided with the electroconductive layer with an adhesive agent etc. exists (for example, patent document 1). By providing the decorative film and the conductive film separately, various combinations of the conductive layer and the decorative layer can be easily realized.

JP 2014-2450 A

  Depending on the installation location, the touch panel may preferably have a three-dimensional shape such as a curved surface for design or visual reasons. In the touch panel of Patent Document 1, a decorative film is bonded to a conductive film through an adhesive layer using an adhesive using a film insert method, a TOM method (Three Dimension Overlay Method), or the like. When a touch panel is formed into a three-dimensional shape using a film insert method or the like, both films are bent and deformed after being joined by an adhesive layer. For this reason, the cured adhesive layer may break during deformation. In order to prevent breakage of the adhesive layer, various film materials can be easily bonded together by using an adhesive tape instead of the adhesive layer. However, since the adhesive force of the pressure-sensitive adhesive tape is generally smaller than that of the adhesive, for example, there is a possibility that each film may be peeled off from the pressure-sensitive adhesive tape in a three-dimensional molded part having a large undulation. For this reason, the freedom degree of the film shape laminated | stacked in the touch panel was restrict | limited.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a touch panel in which the shape is stably maintained even when the laminated film is formed into a three-dimensional shape, and a method for manufacturing the touch panel. .

  A characteristic configuration of a touch panel according to the present invention includes a panel material, and a multilayer film including a conductive film and a protective film which are bonded to the surface of the panel material and have a conductive layer, and the multilayer film includes each film. Are laminated via an adhesive layer formed of a thermosetting adhesive and are formed into a three-dimensional shape along the surface.

  In this configuration, the multilayer film includes a conductive film and a protective film, and since each film is laminated via an adhesive layer made of a thermosetting adhesive, the adhesive layer is not cured at room temperature before heating. . Therefore, the multilayer film can be deformed without breaking the adhesive layer, and the adhesive layer can be cured during or after molding into a three-dimensional shape while heating the multilayer film. For this reason, the multilayer film containing a conductive film and a protective film can be shape | molded in a three-dimensional shape in the state which each film contact | adhered through the contact bonding layer. Thereby, when a multilayer film is shape | molded by a three-dimensional shape, a shaping | molding distortion does not generate | occur | produce easily and the internal stress which induces peeling with each film and an adhesive layer falls. As a result, the three-dimensional shape of the multilayer film is stably maintained on the touch panel.

  Another characteristic configuration of the touch panel according to the present invention is that the protective film is a decorative film having a decorative layer.

  As in this configuration, when the protective film is a decorative film having a decorative layer in the multilayer film, various combinations of the conductive layer and the decorative layer can be easily realized on the touch panel by selecting the decorative film. be able to.

  The characteristic means of the manufacturing method of the touch panel according to the present invention includes a film creation step of creating a multilayer film by laminating a conductive film having a conductive layer and a protective film via an adhesive layer formed of a thermosetting adhesive. A film forming step of deforming the multilayer film into a three-dimensional shape while heating, placing the multilayer film after molding in a mold for injection molding, and injecting molten resin into the mold to form a panel And a panel integration step of forming the material and integrating the multilayer film and the panel material.

  According to this characteristic means, a touch panel is manufactured by forming a multilayer film by a film forming process, placing the film in a mold, and performing injection molding. Here, a multilayer film is created by the film creation process which laminated | stacked the conductive film and protective film which have a conductive layer through the contact bonding layer formed with the thermosetting adhesive. Although the adhesive layer of the multilayer film is not cured at the completion of the film production process, the conductive film and the protective film are bonded together due to the viscosity. When the temperature of the multilayer film exceeds the curing temperature of the thermosetting adhesive during or after the molding of the three-dimensional shape by heating in the film molding process, the adhesive layer is cured. In this way, since the adhesive layer of the multilayer film is cured in the film forming process, distortion generated in each film during the forming is suppressed. Thereby, the touch panel with which the stable three-dimensional multilayer film and panel material were integrated can be manufactured. Moreover, even if it is a case where hardening of an adhesive layer is not completed by the heating of a film formation process, hardening of an adhesive layer can be completed by heating a multilayer film in a panel integration process.

It is a figure which shows the structure of a multilayer film. 1 is a perspective view of a touch panel according to a first embodiment. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. It is a figure which shows the multilayer film after preforming. It is a figure which shows the shaping | molding process of a touchscreen. It is a figure which shows the shaping | molding process of a touchscreen. It is a figure which shows the shaping | molding process of a touchscreen. It is a figure which shows another form of the shaping | molding process of a touchscreen. It is a figure which shows another form of the shaping | molding process of a touchscreen. It is a perspective view of the touch panel which concerns on 2nd Embodiment. It is XI-XI sectional view taken on the line of FIG. It is a perspective view of the touch panel concerning other embodiments.

  Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment]
As shown in FIGS. 1 to 3, the touch panel 20 is configured by laminating a multilayer film 10 on the surface of the panel material 11. Both the panel material 11 and the multilayer film 10 are formed in a three-dimensional shape. In the present embodiment, the surface of the touch panel 20 is formed in a three-dimensional curved surface shape. An opening 12 serving as an operation screen of the touch panel 20 is formed in the center of the panel material 11.

  As shown in FIG. 1, as for the multilayer film 10, the conductive films 1 and 2 which have the conductive layers 1a and 2a, the contact bonding layer 6, and the decorating film 3 which has the decorating layer 3a are laminated | stacked in order. A protective film 4 having a protective layer 4 a is further laminated on the surface side of the decorative film 3 (upper side in FIG. 1) via an adhesive layer 7.

  The first conductive film 1 and the second conductive film 2 include a first conductive layer 1a and a second conductive layer 2a on the surface side of the base film, respectively. The first conductive film 1 and the second conductive film 2 are laminated via an adhesive layer 5. For example, the first conductive layer 1a detects a coordinate position in one predetermined direction, and the second conductive layer 2a detects a coordinate position in a direction crossing the one direction. Therefore, the first conductive film 1 and the second conductive film 2 are detected. In combination with a touch sensor. In the present embodiment, the touch sensor is constituted by two conductive films 1 and 2, but the touch sensor may be constituted by one conductive film.

  The decorative film 3 has a decorative layer 3a on the back side of the base film. The decorative layer 3a is formed by screen printing or transfer. The decorative layer 3a is non-translucent and has a design and color tone according to the touch panel 20, for example.

The protective film 4 has a protective layer 4a on the surface side of the base film. For example, a hard coat material is applied as the protective layer 4a, thereby having functions such as scratch resistance, low reflection, anti-glare, anti-fingerprint, scratch repair, refractive index adjustment, and retardation adjustment.
The protective film 4 may be comprised only of the following base films which do not have the protective layer 4a.

  Although the base film of each film 1-4 is not specifically limited, For example, polyethylene terephthalate (PET), polycarbonate (PC), acrylic (PMMA), cycloolefin trimer (COP), polypropylene (PP), polyethylene naphthalate (PEN) , Triacetyl cellulose (TAC), polyimide (PI) and the like are used. The base films of the films 1 to 4 may all be the same type of material or different materials.

  The adhesive layers 5 to 7 are all formed of a thermosetting adhesive. The thermosetting adhesive preferably has tackiness at room temperature. Although the kind of thermosetting adhesive is not specifically limited, For example, when a thermosetting optical transparent adhesive (Optical Clear Adhesive; OCA) is used, it is preferable.

  The thermosetting adhesive may have some viscoelasticity after curing. There may be subtle differences in formability and physical properties such as thermal shrinkage and linear expansion coefficient between adjacent films 1 to 4. In such a case, if the thermosetting adhesive has viscoelasticity, the adhesive layers 5 to 7 serve as a buffer and can absorb differences in formability and physical properties of the films 1 to 4. Thereby, peeling of each film 1-4 can be prevented.

  The thermosetting adhesive may have rigidity after curing. In this case, peeling of each film 1-4 can be prevented because the interaction of the distortion which generate | occur | produces in each film 1-4 is interrupted | blocked by the rigidity of the adhesive layers 5-7.

  The multilayer film 10 is formed by applying the adhesive layers 5 to 7 on the surface side of the first conductive film 1, the second conductive film 2, and the decorative film 3, respectively, and laminating the films 1 to 4. Note that a binder 1 b suitable for bonding to the panel material 11 is applied to the back side of the conductive film 1.

[Manufacturing method of touch panel]
Next, the manufacturing method of the touch panel 20 by the film insert method will be described.
As shown in FIGS. 4 to 7, the manufacturing method of the touch panel 20 includes a film creation process for creating the multilayer film 10, a film molding process for transforming the multilayer film 10 into a three-dimensional shape while heating, and after molding The multilayer film 10 is placed in a mold 30 for injection molding, a molten resin is injected into the mold 30 to mold the panel material 11, and the molded multilayer film 10 and the panel material 11 are integrated. A panel integration step.

  In the film creation process (not shown), the conductive films 1 and 2 having the conductive layers 1a and 2a, the decorative film 3 having the decorative layer 3a, and the protective film 4 having the protective layer 4a are formed by a thermosetting adhesive. It laminates | stacks through the formed adhesive layers 5-7. Although the adhesive layers 5-7 are not hardened | cured at the time of completion of a film preparation process, each film 1-4 is joined by the viscosity. In the multilayer film 10 shown in FIG. 2, the decorative layer 3 a is not formed at least in the translucent region 15 that overlaps the opening 12 of the panel material 11. Instead of the form of FIG. 2, the decorative layer 3 a may be formed in a part of the light-transmitting region 15 in the multilayer film 10.

  In the film forming step, as shown in FIG. 4, the multilayer film 10 is preformed into a three-dimensional shape while being heated. The preforming of the multilayer film 10 is performed by hot pressing, vacuum forming, pressure forming, or the like. When the temperature of the multilayer film 10 exceeds the curing temperature of the thermosetting adhesive of the adhesive layers 5 to 7 by heating in the film forming step, the adhesive layers 5 to 7 are cured.

  Next, as shown in FIG. 5, the multilayer film 10 after the pre-molding is arranged along the inner surface of one molding die 31 of the mold 30 for injection molding. As shown in FIG. 6, when the mold 30 is closed, the convex portion 33 of the other mold 32 abuts on the multilayer film 10, and a cavity 34 is formed around the convex portion 33.

  Thereafter, as shown in FIG. 7, the panel material 11 is molded by injecting molten resin into the cavity 34 from the gate 35, and the three-dimensional multilayer film 10 and the panel material 11 are integrated. The touch panel 20 is manufactured by this panel integration process.

  Thus, the adhesive layers 5 to 7 are cured by heating the multilayer film 10 in the film forming step. For this reason, the multilayer film 10 can be shape | molded in the three-dimensional shape in the state which each film 1-4 contact | adhered through the adhesive layers 5-7. Thereby, when the multilayer film 10 is shape | molded by a three-dimensional shape, a shaping | molding distortion does not generate | occur | produce easily and the internal stress which induces peeling with each film 1-4 and the adhesive layers 5-7 falls. As a result, the touch panel 20 in which the stable three-dimensional multilayer film 10 and the panel material 11 are integrated can be manufactured. Moreover, even if it is a case where hardening of the adhesive layers 5-7 is not completed by the heating of a film formation process, the hardening of the adhesive layers 5-7 is performed by heating the multilayer film 10 in a panel integration process. Can be completed.

When preforming the multilayer film 10 in the film forming step, the multilayer film 10 is usually heated to 60 ° C to 100 ° C. For this reason, if the curing start temperature of the thermosetting adhesive is different, different actions are generated accordingly.
As the thermosetting adhesive for the adhesive layers 5 to 7, for example, an adhesive whose curing starts at 60 ° C. or higher can be used. In this case, the adhesive layers 5 to 7 are not cured in the film making process, but the curing of the adhesive layers 5 to 7 is started by heating when preforming in the film forming process.

  The thermosetting adhesive may start curing at 100 ° C. or higher. In this case, the adhesive layers 5-7 harden | cure by setting the heating temperature of the multilayer film 10 in a film formation process to a high area | region. For this reason, before performing a film forming process, for example, when performing an autoclave (sterilization) process or an annealing (annealing) process on the multilayer film 10, the film forming process is performed without curing the adhesive layers 5-7. Only occasionally the curing of the adhesive layers 5-7 can be started. Moreover, the start of hardening of the adhesive layers 5-7 of the multilayer film 10 is suppressed in the film forming step by setting the heating temperature in the film forming step low, and the adhesive layers 5-7 are cured in the panel integration step. be able to.

  The thermosetting adhesive may start curing at 250 ° C. or higher. In this case, the curing start temperature of the thermosetting adhesive is higher than the heating temperature in the preliminary molding in the film molding process. Therefore, when the multilayer film 10 is disposed in the mold 30, the adhesive layers 5 to 7 are not yet cured. For this reason, even if the multilayer film 10 preformed with respect to the mold 30 is arranged with a gap in the panel integration step, the multilayer film 10 is formed on the mold 30 by the injection pressure of the molten resin. The adhesive layers 5 to 7 can be cured by correcting the shape and heating the multilayer film 10 to the molten resin in this state.

[Other touch panel manufacturing methods]
As shown in FIGS. 8 to 9, a flat multilayer film 10 may be inserted into a mold 30 and the multilayer film 10 may be molded inside the mold 30. The multilayer film 10 is deformed along the mold 31 while being heated by, for example, a heat source (not shown). Thereafter, the mold 30 is closed, and molten resin is injected from the gate 35 into the cavity 34 to mold the panel material 11. Thereby, the touch panel 20 in which the panel material 11 is integrated with the three-dimensional multilayer film 10 is manufactured.

  The multilayer film 10 inserted into the mold 30 may be subjected to injection molding with a molten resin after being deformed into a shape along which at least a part is aligned with the mold 30 by a pressing force when the mold 30 is closed. If it carries out like this, while the multilayer film 10 receives the pressure of molten resin and deform | transforms, the adhesive layers 5-7 will be heated with molten resin, and will be hardened | cured.

[Second Embodiment]
In 2nd Embodiment, as shown in FIGS. 10-11, the touchscreen 21 is comprised by laminating | stacking the multilayer film 10 on the whole surface of the panel material 11 which does not have opening. Both the panel material 11 and the multilayer film 10 are formed in a three-dimensional shape. The panel material 11 is made of a transparent resin such as polycarbonate and is configured in substantially the same shape as the multilayer film 10. In the multilayer film 10 shown in FIG. 10, the decorative layer 3a is not formed in the translucent area | region 15 used as an operation screen. Instead of the form of FIG. 10, the decorative layer 3 a may be formed on a part of the translucent region 15 in the multilayer film 10. The touch panel 21 can be manufactured by the same manufacturing method as in the first embodiment.

  Thus, by laminating the multilayer film 10 and the panel material 11 in the same shape, the touch panel 21 can ensure a stable strength that satisfies the specifications over the entire surface. Thereby, the durability of the touch panel 21 is improved. Moreover, although not shown in figure, you may use the multilayer film 10 which does not have the decorating layer 3a for the touchscreen 21. FIG. In that case, the entire surface of the multilayer film 10 can be used as the operation screen of the touch panel 21.

[Other Embodiments]
(1) FIG. 12 shows a touch panel 22 of another embodiment. In the touch panel 22, the surface is formed in a three-dimensional curved surface shape, and the left and right end portions 13 are folded back at a substantially right angle. In addition, a partition section 14 that can be pressed is provided on the front surface side of the touch panel 22. You may provide the partition part 14 in the touchscreen 20 of 1st Embodiment, or the touchscreen 21 of 2nd Embodiment.

(2) In each of the above-described embodiments, the multilayer film 10 includes the conductive films 1 and 2, the decorative film 3, and the protective film 4. However, the multilayer film 10 does not include the protective film 4. May be. In this case, since the outermost layer of the multilayer film 10 is the decorative film 3, the decorative film 3 is also used as a protective film. That is, the protective film of the multilayer film 10 is constituted by the decorative film 3. Further, the multilayer film 10 may be constituted by the conductive films 1 and 2 and the protective film 4 without including the decorative film 3.

(3) In the multilayer film 10, a dummy film may be laminated between the conductive films 1 and 2 in order to adjust the sensitivity of the touch panel 20. The dummy film is composed of a single base film of each of the films 1 to 4. That is, the dummy film is a film that does not include the conductive layers 1a and 2a, the decorative layer 3a, the protective layer 4a, and the like. Further, only the dummy film may be laminated between the conductive films 1 and 2 and the protective film 4, or both the dummy film and the decorative film 3 may be laminated. By using a dummy film, the thickness of the multilayer film 10 can be easily adjusted. Each film (the conductive films 1 and 2, the decorative film 3, the protective film 4, and the dummy film) is laminated via an adhesive layer formed of a thermosetting adhesive.

(4) There may be a plurality of protective films 4, decorative films 3, and dummy films provided in the multilayer film 10. A plurality of the same type of films are also laminated through an adhesive layer formed of a thermosetting adhesive.

(5) In each of the above embodiments, an example in which the surfaces of the touch panels 20 to 22 have a three-dimensional curved surface shape has been described. However, the surface of the touch panel may have a three-dimensional shape, and may have a shape other than a curved surface. Good.

(6) In each of the above embodiments, the conductive layers 1 a and 2 a are formed on the front surface side of the conductive films 1 and 2, and the decorative layer 3 a is formed on the back surface side of the decorative film 3. However, the conductive layers 1 a and 2 a may be formed on the back side of the conductive films 1 and 2. Further, the decorative layer 3 a may be formed on the surface side of the decorative film 3.

(7) In each of the above embodiments, the example in which the multilayer film 10 and the panel material 11 are integrated using the film insert method has been shown, but the TOM method may be used instead of the film insert method.

  The present invention can be widely used for touch panels installed in automobiles, home appliances, electronic devices, and the like.

DESCRIPTION OF SYMBOLS 1, 2 Conductive film 1a, 2a Conductive layer 3 Decorative film 3a Decorative layer 4 Protective film 4a Protective layer 5, 6, 7 Adhesive layer 10 Multi-layer film 11 Panel material 20-22 Touch panel

Claims (3)

Panel material,
A multilayer film including a conductive film and a protective film bonded to the surface of the panel material and having a conductive layer;
The multilayer film is a touch panel in which each film is laminated through an adhesive layer formed of a thermosetting adhesive and is formed into a three-dimensional shape along the surface.   The touch panel according to claim 1, wherein the protective film is a decorative film having a decorative layer. A film forming step of forming a multilayer film by laminating a conductive film having a conductive layer and a protective film via an adhesive layer formed of a thermosetting adhesive;
A film forming step of deforming into a three-dimensional shape while heating the multilayer film;
A panel in which the multilayer film after molding is placed in a mold for injection molding, a molten resin is injected into the mold to mold a panel material, and the multilayer film and the panel material are integrated. A touch panel manufacturing method comprising: an integration step.

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