JPWO2014129415A1 - Exterior cover manufacturing method, exterior cover, and electronic apparatus including the same - Google Patents

Abstract

The manufacturing method of the cover glass (6) as an exterior cover includes a substrate (12) having a main surface (12a) and a standing wall (13) extending from an end of the substrate (12), and the main surface (12a). And bonding the decorative film (14) on which the window frame portion (14a) is printed to the main surface (12a) of the cover body (11) to which the inner wall surface (13a) of the standing wall (13) is connected. And forming a mask (15) inside the outer shape of the decorative film (14) so as to cover the window portion (14R) inside the window frame portion (14a) of the decorative film (14), Forming a coating film (16) on the decorative film (14), on the main surface (12a) outside the decorative film (14) and on the inner wall surface (13a) of the standing wall (13); 15).

Description

  The present invention relates to an exterior cover that covers interior components such as a touch panel and a display panel, a method for manufacturing the exterior cover, and an electronic device including the exterior cover.

  FIG. 10 is an exploded sectional view showing a schematic configuration of a portable terminal 100 as a conventional tablet terminal. The portable terminal 100 is formed by housing interior components such as a circuit board 102, a liquid crystal panel 103, and a touch panel 104 in a housing 101, and further covering these interior components with a cover glass 105 as an exterior cover. The cover glass 105 is made of a transparent glass substrate having a constant thickness, for example. For convenience of explanation below, the surface on the interior component housing side of the cover glass 105 is referred to as a main surface 105a, and the surface opposite to the interior component housing side is referred to as an outer surface 105b.

  On the main surface 105a of the cover glass 105, a window frame portion 106 whose periphery is bordered with a predetermined color or pattern is formed by printing (for example, screen printing), and is decorated. Display information on the liquid crystal panel 103 is visually recognized from the outer surface 105 b side of the cover glass 105 through the inside of the frame of the window frame portion 106.

  The liquid crystal panel 103 is bonded to the touch panel 104 via an optical tape 107 made of, for example, OCA (Optical Clear Adhesive) or OCR (Optical Clear Resin). The touch panel 104 is bonded to the main surface 105a of the cover glass 105 and the window frame portion 106 through an optical tape 108 made of, for example, OCA or an OCR.

  Here, the cover glass 105 having a constant thickness is sometimes called 2D glass because both the main surface 105a and the outer surface 105b are flat. Further, as shown in FIG. 11, a cover glass 105 in which the main surface 105a is a flat surface and the end of the outer surface 105b is a curved surface has been proposed in the past in order to emphasize designability. The 2D glass is sometimes called 2.5D glass. In 2D glass or 2.5D glass, since the surface to be decorated (hereinafter also referred to as a surface to be decorated) is a single plane (only the main surface 105a), the decoration on the surface to be decorated can be performed as described above. As can be easily done by printing.

  However, instead of a cover glass having a constant thickness, for example, when a cover glass having a concave cross section is used and the concave surface inside the glass is used as the surface to be decorated, the surface to be decorated is not a flat surface (covered) Because the decoration surface is a combination of a flat surface and a flat surface, or a combination of a flat surface and a curved surface (concave surface), it is difficult to decorate the surface to be decorated by printing, and decorate by other methods. Is required. As described above, a cover glass having a combination of two or more different surfaces to be decorated is referred to as 3D glass here.

  FIG. 12 is a cross-sectional view showing a manufacturing process in the case where conventional spray coating is applied to decorating the surface to be decorated in the production of the cover glass 201 made of 3D glass. In this manufacturing method, first, a masking film 203 having a size corresponding to a window frame to be formed is bonded to the inner main surface 202a of the cover body 202 having a concave cross section. Then, spray coating is performed on the main surface 202a from the top of the masking film 203, and spray coating is performed on the inner wall surface 204a (connected to the main surface 202a) of the standing wall 204 at the end of the cover body 202. Do. Thereafter, the masking film 203 is peeled off. Thereby, the cover glass 201 in which the coating film 205 is formed on the main surface 202a other than the mask region and the inner wall surface 204a is completed. In addition, the part which forms a window frame on the main surface 202a among the coating films 205 is also called the window frame part 205a.

  In addition to spray coating, decorate the concave surface of the object to be decorated by using the conventional TOM method (Three dimension Overlay Method) and the decoration method of Patent Document 1. Is also possible. Hereinafter, the conventional TOM method and the decoration method of Patent Document 1 will be briefly described.

  FIG. 13: is sectional drawing which shows the flow of the decoration by the conventional TOM construction method. First, the base material 303 to be decorated is set on the table 302 in the lower chamber box 301. Subsequently, a film-like skin material 304 for decorating the base material 303 is set above the base material 303. Thereafter, the upper chamber box 305 is lowered to bring the inside of the lower chamber box 301 and the inside of the upper chamber box 305 into an airtight state (here, still an atmospheric pressure state).

  Next, the inside of the lower chamber box 301 and the inside of the upper chamber box 305 are evacuated by the vacuum tank 306 to make a vacuum state. Then, the heater 307 is turned on to heat the skin material 304. Thereafter, the internal pressures of the lower chamber box 301 and the upper chamber box 305 are adjusted, and the sag of the skin material 304 is corrected. That is, the skin material 304 hangs down by its own weight when heated, but the skin material 304 is brought into a substantially horizontal state by changing the degree of vacuum in the lower chamber box 301 and the upper chamber box 305.

  Subsequently, the table 302 in the lower chamber box 301 is raised. Then, the skin material 304 is brought into close contact with the surface of the base material 303 by bringing only the upper chamber box 305 into an atmospheric pressure state. At this time, by putting compressed air into the upper chamber box 305, the skin material 304 can be brought into close contact with the base material 303 with a larger force. Finally, the inside of the lower chamber box 301 is returned to the atmospheric pressure state, and the upper chamber box 305 is raised to take out the base material 303 to which the skin material 304 is bonded.

  FIG. 14 is a cross-sectional view showing a schematic configuration of a shrink transfer material 401 used in the decorating method of Patent Document 1. The shrink transfer material 401 is configured by laminating a release layer 403, a pattern layer 404, and an adhesive layer 405 in this order on a shrink base material 402. When decorating the three-dimensional decoration object 406 using the shrink transfer material 401 described above, first, as shown in FIG. 15, the adhesive layer 405 (see FIG. 14) is in contact with the decoration object 406. As described above, the decoration target object 406 is wrapped with the shrink transfer material 401, and the shrink transfer material 401 is heated and shrunk to be in close contact with the surface to be decorated of the decoration target object 406.

  Subsequently, as shown in FIG. 16, the decoration object 406 is moved below the rubber 407, the rubber 407 is lowered, and the shrink transfer material 401 is pressed against the decoration object 406 and heated. By this heating, the adhesive layer 405 is fused to the surface of the decoration object 406. Finally, by peeling the shrink base material 402 of the shrink transfer material 401, a decoration object 406 in which each layer of the peeling layer 403, the pattern layer 404, and the adhesive layer 405 is transferred to the surface to be decorated is obtained.

Japanese Patent No. 2753678 (see claim 1, paragraphs [0007] to [0020], FIGS. 1 to 3 etc.)

  However, when 3D glass is manufactured by the method shown in FIG. 12, when the touch panel or the display panel is bonded, the linearity of the edge of the window frame portion is deteriorated or the appearance quality is deteriorated. More specific description will be given below.

  FIG. 17 is an enlarged cross-sectional view of a part of the cover glass 201 finally obtained by the method shown in FIG. 12, and FIG. 18 is a diagram in which the touch panel 207 is attached to the main surface 202a via the adhesive layer 206. It is sectional drawing which expands and shows a part of cover glass 201 when it joins. When the masking film 203 is peeled off after spray coating, as shown in FIG. 17, the edge portion 205b of the coating film 205 (window frame portion 205a) is stretched due to the peeling of the masking film 203 (ink fogging). Occurs).

  When ink scuffing occurs, as shown in FIG. 18, when the touch panel 207 is pasted so as to overlap the window frame part 205 a, the edge part 205 b of the window frame part 205 a is crushed by the touch panel 207. As a result, large jaggedness or rattling occurs in the straight lines constituting the window frame, making it difficult to visually recognize the straight lines as if they were straight lines. Further, when the edge portion 205b is crushed and the ink piece 208 is generated, the ink piece 208 is visually recognized as dust from the outer surface side of the cover glass 201, so that the appearance quality is deteriorated. Further, the height of the ink burrs is, for example, 50 μm or more reflecting the thickness of the masking film 203, and the level difference between the cover body 202 and the edge portion 205 b of the coating film 205 is increased. Bubbles 209 are caught in the adhesive layer 206. The entrainment of the bubbles 209 causes the glare to be visually recognized, and the quality of the appearance is also lowered in this respect.

  On the other hand, when the conventional TOM method described above is applied to the production of 3D glass, the following problems occur. FIG. 19 is a cross-sectional view of the cover glass 501 to which the decorative film 502 is bonded. The decorative film 502 corresponds to the skin material 304 described above. When the TOM method is applied to manufacture of the cover glass 501 that is 3D glass, the decorative film 502 is bonded over two or more surfaces that form the concave shape of the cover glass 501 that is a decoration object.

  In the TOM method, bonding is performed while stretching the decorative film 502 by introducing atmospheric pressure or compressed air, but the decorative film 502 is made to follow corners of two surfaces (for example, the surfaces 501a and 501b) forming a concave shape. There is a limit, and it is difficult to make it stick together completely. For example, when the angle formed by the two surfaces is 90 degrees, the decorative film 502 must have an R shape with a radius of 3 mm or more. When an R shape that does not completely follow the corners of the two surfaces is generated in the decorative film 502, the frame shape of the window frame portion 503 printed on the decorative film 502 is distorted as shown in FIG. End up.

  A method of canceling the distortion of the frame shape by measuring the amount of distortion of the window frame portion 503 in advance and causing the window frame portion 503 to have distortion in the reverse direction in advance is also conceivable. However, with this method, it is very difficult to stably ensure the quality (shape, linearity) required for the window frame of a general mobile terminal.

  Moreover, when the decoration method of patent document 1 is applied to manufacture of 3D glass, in patent document 1, in order to utilize the heat shrink of a decorative film (equivalent to the shrink transfer material 401), it is connected to form a concave shape. In addition, it is more difficult to bond the decorative film to the corners of the two surfaces completely than in the case of the TOM method. As a result, similarly to the above, the frame shape of the window frame portion printed on the decorative film is distorted, and it is difficult to ensure the quality required for the window frame of the portable terminal.

  In the above, a cover glass having a concave cross section is considered as the 3D glass. However, in the exterior cover having at least one standing wall at the end of the substrate having the main surface, the main surface and the standing wall connected to each other are connected. When decorating at least two surfaces with the inner wall surface, the same problem as described above may occur.

  The present invention was made to solve the above-described problems, and its purpose is to suppress distortion of the window frame to be decorated on the main surface when decorating the main surface and the inner wall surface of the standing wall. The manufacturing method of the exterior cover that can stably ensure the linearity of the edge of the window frame and suppress the deterioration of the appearance due to the ink pieces and bubbles, the exterior cover, and the exterior cover are provided. To provide electronic equipment.

  A method of manufacturing an exterior cover according to an aspect of the present invention includes a substrate having a main surface and a standing wall extending from an end portion of the substrate, wherein the main surface and the inner wall surface of the standing wall are connected. The process of bonding the decorative film which printed the window frame part to the said main surface of a main body, and the window part inside the said window frame part of the said decorative film are covered inside the external shape of the said decorative film. Forming a mask, forming a coating film on the decorative film, on the main surface outside the decorative film and on the inner wall surface of the standing wall, and peeling the mask And have.

  An exterior cover according to another aspect of the present invention includes a substrate having a main surface and a standing wall extending from an end portion of the substrate, wherein the main surface and the inner wall surface of the standing wall are connected to each other. From the surface of the window frame portion of the decorative film, the decorative film on which the window frame portion is printed, which is bonded to the main surface of the cover body, and the main surface outside the window frame portion and the surface And a coating film formed over the inner wall surface.

  An electronic device according to still another aspect of the present invention includes the exterior cover and a touch panel or a display panel covered with the exterior cover.

  According to the above manufacturing method and configuration, the distortion of the window frame to be decorated on the main surface of the exterior cover can be suppressed, and the linearity of the edge of the window frame can be stably secured, so that a high-quality window frame can be obtained. Can be realized. In addition, it is possible to suppress deterioration in appearance quality due to ink pieces and bubbles.

It is sectional drawing which decomposes | disassembles and shows the structure of the outline of the portable terminal to which the cover glass as an exterior cover which concerns on embodiment of this invention is applied. It is sectional drawing which shows the manufacturing process of the said cover glass. It is sectional drawing which shows the structure of the outline of the decorating film bonded by the main surface of the said cover glass. It is sectional drawing of the said cover glass in the state which adhere | attached the touchscreen, without overlapping with the edge part of a coating film. It is sectional drawing of the said cover glass in the state which adhered the touch panel so that it might overlap with the edge part of a coating film. It is sectional drawing which shows the other structure of the said decorating film. It is sectional drawing which shows other structure of the said decorating film. It is sectional drawing which shows other structure of the said decorating film. It is a perspective view which shows one method of spray coating typically. It is sectional drawing which decomposes | disassembles and shows the structure of the outline of the conventional portable terminal. It is sectional drawing of the cover glass applicable to the said portable terminal. It is sectional drawing which shows the manufacturing process of the cover glass including the decorating process by spray coating. It is sectional drawing which shows the flow of the decoration by the conventional TOM construction method. It is sectional drawing which shows the structure of the outline of the shrink transfer material used with the conventional decorating method. It is sectional drawing which shows a mode that the said shrink transfer material is heat-shrinked, and it adheres to the surface of a decorating target object. It is sectional drawing which shows a mode that the said shrink transcription | transfer material is pressed against a decoration target object with a rubber. It is sectional drawing which expands and shows a part of cover glass obtained by the manufacturing process of FIG. It is sectional drawing which expands and shows a part of said cover glass which bonded the touch panel. It is sectional drawing of the cover glass with which a decorating film is bonded by the TOM construction method. It is a top view which shows distortion of the window frame part of the said decoration film.

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

(Configuration of mobile device)
FIG. 1 is an exploded cross-sectional view showing a schematic configuration of a mobile terminal 1 as an electronic apparatus to which the exterior cover of the present embodiment is applied. The mobile terminal 1 is formed by housing interior parts such as a circuit board 3, a display panel 4, and a touch panel 5 in a housing 2 and further covering these interior parts with a cover glass 6 as an exterior cover. . The cover glass 6 is 3D glass, and its inner surface is decorated. The display panel 4 includes a liquid crystal panel, an organic EL (Electro-Luminescence) display element, and the like, and is bonded to the touch panel 5 via an optical tape 7 (for example, OCA). The touch panel 5 is bonded to the cover glass 6 via an optical tape 8 (for example, OCA).

  The mobile terminal 1 may have a configuration including an operation unit (input unit) including various buttons (including a numeric keypad) instead of the touch panel 5. In this case, the display panel 4 is directly bonded to the cover glass 6 via the optical tape 7, and the cover glass 6 functions as an exterior cover for the display panel 4.

(Method for manufacturing cover glass)
Next, a method for manufacturing the cover glass 6 will be described. FIG. 2 is a cross-sectional view showing the manufacturing process of the cover glass 6. First, the cover body 11 made of transparent glass is prepared (preparation process). Since the cover body 11 is transparent, the display information on the display panel 4 can be viewed from the outer surface side of the cover body 11, and the decorative portion (color, pattern, character, etc.) on the inner surface side can be viewed. Can do. That is, the cover body 11 is an object (decoration object) to be decorated.

  The cover body 11 includes a substrate 12 having a main surface 12a and a standing wall 13 extending perpendicularly from the end of the substrate 12 to the main surface 12a. Here, the standing walls 13 are provided at both ends of the substrate 12 in one direction, and as a result, the cross-sectional shape of the cover body 11 is concave. The main surface 12a of the substrate 12 and the inner wall surface 13a of the standing wall 13 are connected. That is, the concave inner surface of the cover body 11 is constituted by the main surface 12a and the inner wall surface 13a.

  Next, after washing the cover body 11, the decorative film 14 on which the window frame portion 14a is printed is bonded to the main surface 12a of the cover body 11 (bonding step). As shown in FIG. 3, the decorative film 14 has a decorative layer 22 (thickness is, for example, 1 to 20 μm) constituting the window frame portion 14 a on a film base 21 (thickness is, for example, 30 to 500 μm). The adhesive layer 23 (having a thickness of, for example, 3 to 30 μm) is laminated. The decorative layer 22 (window frame portion 14a) is formed by high-quality printing such as gravure printing or screen printing, thereby ensuring high quality (shape and edge linearity) of the window frame portion 14a. Has been.

  Then, the mask 15 is formed so that the window part 14R of the decorating film 14 may be covered inside the external shape of the decorating film 14 (mask formation process). In addition, said window part 14R is an area | region inside the window frame part 14a of the decorating film 14, ie, the area | region enclosed by the frame of the window frame part 14, Comprising: It is an area | region which permeate | transmits light. . The mask 15 may be formed by bonding a masking film 15a as shown in the figure, or by applying a resist in a photolithography technique. The mask 15 is larger than the outer shape of the touch panel 5 or the display panel 4 to be covered by the cover glass 6, and is formed to have a size that overlaps the window frame portion 14 a of the decorative film 14.

  Subsequently, the coating ink is sprayed from the top of the mask 15 toward the main surface 12a, and the coating ink is sprayed onto the inner wall surface 13a (spray coating process). Thereby, the coating film 16 is formed on the inner surface of the cover body 11, that is, on the decorative film 14, on the main surface 12 a outside the decorative film 14 (window frame portion 14 a), and on the inner wall surface 13 a of the standing wall 13. The Thereafter, the mask 15 is peeled off (peeling step). Thereby, the coating film 16 on the mask 15 is removed together with the mask 15, and the coating film 16 other than the mask region remains. That is, the cover glass 6 in which the coating film 16 is formed from the surface of the window frame portion 14a of the decorative film 14 to the outer main surface 12a and the inner wall surface 13a of the window frame portion 14a is completed.

  As mentioned above, in this embodiment, in decorating the inner surface of the cover glass 6 which is 3D glass, both bonding of the decorating film 14 and spray coating are used together. Here, the decorative film 14 is bonded only to the main surface 12a of the cover glass 6, and is not bonded over two or more different surfaces. For this reason, pasting of the decoration film 14 is easy. And since the bonding of the decorating film 14 is only 1 surface, the decorating film 14 does not round in the corner | angular part where the main surface 12a and the inner wall surface 13a are connected. Therefore, the frame shape of the window frame portion 14a printed on the decorative film 14 is not distorted, and it is not necessary to add correction for canceling the distortion to the shape of the window frame portion 14a in advance. Therefore, in the cover glass 6 before adhesion of the touch panel 5, the quality (shape, linearity) required for a window frame of a general mobile terminal can be stably secured.

  Moreover, in order to perform decoration by combining bonding of the decorative film 14 and spray coating, the color tone of the window frame part 14a of the decorative film 14 and the color tone of the coating film 16 formed by spray coating are matched. In this case, it is possible to make it difficult to visually recognize the boundary line on the appearance between the window frame portion 14 a and the coating film 16.

  FIG. 4 is a cross-sectional view of the cover glass 6 in a state where the touch panel 5 is bonded. As the mask 15 is peeled off, the edge portion 16a of the coating film 16 extends in the peeling direction of the mask 15 (caking ink). However, as described above, when the mask 15 is formed inside the outer shape of the decorative film 14 so as to cover the window portion 14R of the decorative film 14, when the mask 15 is peeled off after spray coating, FIG. As described above, the edge portion 16 a of the coating film 16 can be positioned on the window frame portion 14 a of the decorative film 14. In particular, by forming the mask 15 in a size that overlaps the window frame portion 14a of the decorative film 14 and performing spray coating, the edge portion 16a is reliably positioned on the window frame portion 14a after the mask 15 is peeled off. Can do.

  In addition, by adjusting the size of the mask 15, the position of the edge portion 16 a on the window frame portion 14 a can be adjusted, so that the touch panel 5 can be positioned without overlapping the edge portion 16 a or the touch panel 5 can be It can be positioned overlapping the portion 16a. That is, if the mask 15 is formed larger than the outer shape of the touch panel 5 to be covered by the cover glass 6 as in the present embodiment, after the mask 15 is peeled off, the touch panel is placed inside the edge portion 16a as shown in FIG. 5 can be located. On the other hand, if the mask 15 is formed to be smaller than the outer shape of the touch panel 5, the touch panel 5 can be positioned so as to cover the edge portion 16a as shown in FIG.

  In the case of FIG. 4, since the touch panel 5 does not crush the edge portion 16a from above, no ink piece is generated due to the crushing of the edge portion 16a. Therefore, the ink piece is not visually recognized as dust from the outer surface side of the cover glass 6, and it is possible to avoid a deterioration in appearance due to the ink piece. Further, since the touch panel 5 is bonded to the inner side of the edge portion 16a, the step of the edge portion 16a does not affect the entrainment of bubbles in the adhesive layer (optical tape 8) when the touch panel 5 is bonded. Furthermore, the level difference generated in the decorative film 14 is only the thickness (for example, 1 to 20 μm) of the decorative layer 22 shown in FIG. 3, and is sufficiently smaller than the height of the ink burrs. Occasionally, bubbles can be reduced from being caught in the adhesive layer. Therefore, it can also be suppressed that the glare caused by the bubbles is visually recognized from the outer surface side of the cover glass 6 and the appearance quality is lowered.

  On the other hand, in the case of FIG. 5, since the touch panel 5 crushes the edge portion 16a from above, there is a concern that an ink piece due to the crushing of the edge portion 16a occurs in the vicinity of the edge portion 16a. However, since the vicinity of the edge portion 16a is hidden by the window frame portion 14a, the generated ink piece is also hidden by the window frame portion 14a, and the appearance of the ink piece is reduced by reducing the visibility of the ink piece from the outside. Can be suppressed. Further, even when bubbles are wound around the edge portion 16a when the touch panel 5 is attached, the bubbles are hidden by the window frame portion 14a, so that glare caused by the bubbles is not visually recognized from the outside.

  Further, in both cases of FIG. 4 and FIG. 5, the edge portion 16a is hidden by the window frame portion 14a, so that it is not visually recognized from the outer surface side of the cover glass 6, and the edge portion of the window frame portion 14a. 14b is visually recognized as an edge of the window frame. As described above, since the quality of the edge portion 14b is secured in advance by high-quality printing on the decorative film 14, even after the touch panel 5 is pasted, the straight line of the window frame from the outside. Can be visually recognized as a straight line. In the case of FIG. 5, when the touch panel 5 crushes the edge portion 16a from above, the edge portion 16a is wrinkled or rattled. However, since such a wrinkle or rattle is hidden by the window frame portion 14a, it is visually recognized from the outside. Never happen.

  That is, according to the manufacturing method of the cover glass 6 of this embodiment, even when decorating the main surface 12a and the inner wall surface 13a of the cover glass 6 made of 3D glass, the distortion of the window frame decorated on the main surface 12a. In addition, it is possible to stably ensure the linearity of the edge of the window frame, to realize a high-quality window frame, and to suppress deterioration in appearance due to ink pieces and bubbles.

  Moreover, the cover glass 6 of this embodiment is the structure provided with the cover main body 11, the decorating film 14 which printed the window frame part 14a, and the coating film 16. FIG. The cover main body 11 includes a substrate 12 having a main surface 12 a and a standing wall 13 extending from an end of the substrate 12. The main surface 12a and the inner wall surface 13a of the standing wall 13 are connected. The decorative film 14 is bonded to the main surface 12 a of the cover main body 11. The coating film 16 is formed by spraying coating ink from the surface of the window frame portion 14a of the decorative film 14 to the main surface 12a and the inner wall surface 13a outside the window frame portion 14a.

  According to the said structure, the decorating film 14 is bonded by the main surface 12a of the cover main body 11, and the coating film 16 is the main of the outer side of the window frame part 14a from the surface of the window frame part 14a of the decorating film 14. It is formed by spray coating over the surface 12a and the inner wall surface 13a. Thus, since the inner surface of the cover glass 6 is decorated, the window frame shape of the cover glass 6 is decided by the shape of the window frame part 14a. Since the shape and quality of the window frame portion 14a are ensured in advance with high quality by high-quality printing, a high-quality window frame shape free from distortion, roughness, and backlash can be stably realized.

  The touch panel 5 can be adhered to the cover glass 6 so as to overlap the edge portion 16a of the coating film 16 or overlap the edge portion 16a. In the former case, since the edge portion 16a is not crushed when the touch panel 5 is bonded, dust due to the ink piece is not visually recognized from the outside. In addition, since the touch panel 5 is bonded to the inner side of the edge portion 16a of the coating film 16, the entrainment of bubbles in the adhesive layer due to the step of the edge portion 16a is suppressed when the touch panel 5 is bonded, and glare caused by bubbles. It is also possible to suppress the visibility from the outside. On the other hand, in the latter case, there is a concern that the edge portion 16a may be crushed when the touch panel 5 is bonded, and an ink piece may be generated or bubbles may be involved in the adhesive layer. However, the edge portion 16a is located on the surface of the window frame portion 14a. Since the cover frame 6 is hidden by the window frame portion 14a from the outer surface side, even if an ink piece or a bubble is generated in the vicinity of the edge portion 16a, the ink piece or the bubble is hardly visible from the outside. Therefore, in any of the above cases, deterioration in appearance quality can be suppressed by the generation of ink pieces or bubbles.

  By the way, in this embodiment, although the thing of the layer structure shown in FIG. 3 is used as the decorating film 14, the decorating film 14 is not necessarily limited to this structure. For example, as shown in FIG. 6, the decorative film 14 has a pressure-sensitive adhesive layer 23 formed on one surface side (cover glass bonding side) of the film substrate 21 and a decorative layer 22 formed on the other surface side. It may be. Moreover, as shown in FIG.7 and FIG.8, in the decorating film 14, the inner side of the decorating layer 22 of a window frame shape may be hollowed, and the opening may be formed, and the adhesive layer 23 and the film base material 21 are formed. Alternatively, openings having the same size as the openings of the decorative layer 22 may be formed. The layer configuration of the decorative film 14 in FIG. 7 corresponds to the layer configuration in FIG. 3, and the layer configuration of the decorative film 14 in FIG. 8 corresponds to the layer configuration in FIG.

  The example in which the coating film 16 is formed by spraying the coating ink has been described above, but the method for forming the coating film 16 is not limited to this. In addition to spray coating (spray coating), the coating film 16 can also be formed by, for example, brush coating or tampo coating.

(Details of components used during manufacturing)
Next, the member which comprises the above-mentioned exterior cover, the member used for manufacture of an exterior cover, and the detail of various processes are demonstrated.

<Decoration object>
The decoration target object may have a shape in which all four standing walls at the end of the substrate stand up with respect to the rectangular substrate in plan view having the main surface, or only one, two, or three. It may be a raised shape. That is, the standing wall may be provided on the entire circumference around the substrate, or may be provided only on a part of the circumference. Further, the inner wall surface of the standing wall may be a shape that rises perpendicularly or obliquely with respect to the main surface, and may be a flat surface or a curved surface (concave surface). The planar shape of the substrate is not limited to the above-mentioned rectangular shape, and may be a polygonal shape other than a quadrangle, a circle or an ellipse, or a shape in which the corners of the rectangle are curved. May be.

  The material to be decorated is not particularly limited as long as it is transparent, and may be made of glass or resin. As the glass material, borosilicate glass, alkali glass, soda lime glass, crown glass, alkali-free glass, or the like can be used. As a glass forming method, a direct press in which molten glass is put into a mold and the glass is directly formed may be used, or reheating (reheat) forming may be used. Further, the glass may be formed into a concave shape by grinding, polishing, cutting, and joining the glass. The glass may be chemically strengthened in order to increase impact resistance.

  When the object to be decorated is made of resin, polymethyl methacrylate (PMMA), polycarbonate (PC), polystyrene (PS), polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), cyclic polyolefin (COP) ) Or the like can be used. Injection molding may be used as a resin molding method. Further, the resin may be formed in a concave shape by grinding, polishing, cutting, and joining the resin.

<Decorative film>
When leaving a film base material after pasting a decoration film to a decoration subject, a decoration film should just be constituted by laminating a decoration layer and an adhesion layer in order on a film base material. Moreover, when not leaving a film base material after bonding of a decorative film, the decorative film should just be comprised by laminating | stacking a peeling layer, a decorative layer, and an adhesion layer in order on a film base material.

  As the film substrate, use is made of transparent resin sheets such as polyacrylic resins, polyethylene resins, polypropylene resins, polyester resins, polyvinyl chloride resins, polyamide resins, or composites of these sheets can do. The thickness of the film substrate is desirably, for example, 30 to 500 μm, and more desirably 30 to 200 μm. If the thickness of the film substrate is less than 30 μm, the film becomes hard and difficult to handle. On the other hand, if the thickness of the film substrate is thicker than 500 μm, the film substrate becomes too hard and the bonding process becomes difficult. In addition, the overall thickness of the final assembled product increases.

  As the release layer, an ultraviolet curable resin may be used. As the ultraviolet curable resin, for example, an acrylic resin, a urethane resin, an epoxy resin, or a silicon resin can be used. By irradiating the release layer with ultraviolet light after pasting the decorative film, the resin of the release layer is cured, and the film substrate is peeled off from the release layer. The release layer remains as a cured transparent resin layer on the surface of the decorative layer. As a method for forming the release layer, a coating method such as a roll coating method or a spray coating method, a printing method such as a gravure printing method, or a screen printing method can be used.

  In addition, you may use a mold release material as a peeling layer. When using a mold release agent, peeling within a layer is caused and a part may remain on the outermost surface of a decorative film. As release agents, melamine resin release agents, silicone resin release agents, fluororesin release agents, cellulose derivative release agents, urea resin release agents, polyolefin resin release agents, paraffin types Release agents and composite release agents thereof can be used.

  As a decorative layer, a resin such as polyvinyl resin, polyamide resin, polyester resin, acrylic resin, polyurethane resin, polyvinyl acetal resin, polyester urethane resin, cellulose ester resin, alkyd resin, etc. as a binder, Colored inks containing appropriate color pigments or dyes as colorants may be used.

  The decorative layer can be composed of a printed layer, a thin film layer of metal or dielectric, or a combination of a printed layer and a thin film layer. When the decorative layer is formed of a printing layer, a normal printing method such as a gravure printing method, a screen printing method, or an offset printing method can be used as the printing method. In particular, the offset printing method and the gravure printing method are suitable for performing multicolor printing and gradation expression. In the case of monochromatic printing, a coating method such as a gravure coating method, a roll coating method, or a comma coating method can also be employed. The decoration layer can be provided entirely or partially depending on the design to be expressed.

  When the decorative layer is formed of a thin film layer, the thin film layer may be a metal thin film layer, a dielectric thin film layer using a dielectric thin film, or a composite layer thereof. The dielectric thin film layer may be a single layer or a multilayer using a plurality of dielectrics having different refractive indexes. When a metal thin film layer is used, the metallic luster of the color tone according to the kind of metal can be expressed. When the dielectric thin film layer is used, it is possible to express a reflection color or a transmission color having an arbitrary color tone according to the optical thin film design.

  The metal thin film layer as the thin film layer can be formed by a vacuum deposition method, a sputtering method, an ion plating method, a plating method, or the like. At this time, depending on the metallic luster color to be expressed, a metal such as aluminum, nickel, gold, platinum, chromium, iron, copper, tin, indium, silver, titanium, lead, zinc, or an alloy or compound thereof may be used. Good.

Further, the dielectric thin film as the thin film layer can be formed by a vacuum deposition method, a sputtering method, an ion plating method or the like. Various reflection colors and transmission colors can be realized by the optical thin film design from the refractive index and the film thickness of each type of dielectric. Dielectric materials used include titanium oxide (TiO ₂ , Ti ₂ O ₅ ), silicon oxide (SiO, SiO ₂ ), niobium oxide (Nb ₂ O ₅ ), tantalum oxide (Ta ₂ O ₅ ), and lanthanum oxide. (La ₂ O ₃ ), aluminum oxide (Al ₂ O ₃ ), hafnium oxide (HfO ₂ ), zinc oxide (ZnO), zirconium oxide (ZrO ₂ ), magnesium fluoride (MgF ₂ ), cerium oxide (CeO ₂ ) Etc., and a mixture of them.

  The thin film layer can be provided entirely or partially depending on the design desired to be expressed. As an example of forming a partial thin film layer, a solvent-soluble resin layer is formed on a portion that does not require a thin film layer, and then a thin film is formed on the entire surface, followed by solvent cleaning to obtain a solvent-soluble resin. There is a method of removing unnecessary thin films together with layers. The solvent often used in this case is water or an aqueous solution. As another example, there is a method in which a thin film layer is formed on the entire surface, a resist layer is then formed on a portion where the thin film layer is to be left, and etching is performed with acid or alkali.

  In addition, when providing a thin film layer, in order to improve the adhesiveness of another layer and a metal thin film layer, you may provide a front anchor layer and a rear anchor layer. The front anchor layer is a layer formed on another layer before forming the metal thin film layer, and the rear anchor layer is a layer after forming the metal thin film layer and before stacking other layers. It is a layer formed in. As the material of such a front anchor layer and a rear anchor layer, a two-component cured urethane resin, a thermosetting urethane resin, a melamine resin, a cellulose ester resin, a chlorine-containing rubber resin, a chlorine-containing vinyl resin, an acrylic resin Resins, epoxy resins, vinyl copolymer resins, and the like may be used. Examples of methods for forming the front anchor layer and the rear anchor layer include coating methods such as gravure coating, roll coating, and comma coating, printing methods such as gravure printing, and screen printing.

  The pressure-sensitive adhesive layer (adhesive layer) is for adhering the decoration layer to the surface to be decorated of the object to be decorated. The pressure-sensitive adhesive layer is formed on a portion to be bonded. That is, when the part to be bonded is entirely, the adhesive layer is entirely formed on the decorative layer. Moreover, if the part to adhere | attach is partial, an adhesion layer will be partially formed on a decorating layer.

  As the adhesive layer, a heat-sensitive or pressure-sensitive resin suitable for the material of the object to be decorated can be used as appropriate. For example, when the material of the decoration object is glass, an acrylic resin may be used as the adhesive layer. Moreover, when the material of the decoration target is an acrylic resin, an acrylic resin may be used as the adhesive layer. In addition, when the material of the decoration object is a polyphenylene oxide / polystyrene resin, a polycarbonate resin, a styrene copolymer resin, or a polystyrene blend resin, an acrylic resin having an affinity for these resins as an adhesive layer, A polystyrene resin, a polyamide resin, or the like may be used. Furthermore, when the material of the decoration object is a polypropylene resin, a chlorinated polyolefin resin, a chlorinated ethylene-vinyl acetate copolymer resin, a cyclized rubber, or a coumarone indene resin can be used as the adhesive layer. As a method for forming the adhesive layer, a coating method such as a gravure coating method, a roll coating method or a comma coating method, a printing method such as a gravure printing method or a screen printing method can be used.

  In pasting a decorative film, high-precision pasting is necessary. For that purpose, it is necessary to precisely align and prevent air bubbles from being involved. As high-precision bonding machines, high-precision bonding devices HR-85, HR-1510, HR-E30, HR-E60, APS-5D, APS-80E, etc. manufactured by JP Tech Co., Ltd. The vacuum bonding precision single wafer bonding machine V-SE110 or the like can be used. In particular, if it is a bonding machine manufactured by JP Tech Co., Ltd., the film bonding to the bottom of the concave surface can be realized with a fast tact time by the unique bonding head shape.

  As a process after bonding of a decorative film, there exist the following, for example. When air bubbles are involved at the time of pasting the decorative film, the foam can be removed by pressure defoaming (autoclave) after the pasting. Moreover, when the adhesion layer of a decoration film is a heat sensitive resin, it heat-processes according to resin after bonding, and adheres. When peeling the film base material of the decorative film, when the release layer is an ultraviolet curable resin, the film base material is peeled off by being put into an ultraviolet irradiation device.

<Masking film>
The masking film has a pressure-sensitive adhesive layer on the film substrate. As the film substrate, a transparent resin sheet such as a polyacrylic resin, a polyethylene resin, a polypropylene resin, a polyester resin, a polyvinyl chloride resin, a polyamide resin, or a composite of each of these sheets is used. Can be used.

  The thickness of the film base material is desirably 30 to 500 μm, and more desirably 30 to 200 μm or less. If the thickness of the film base material is less than 30 μm, the film base material is not hard, and handling becomes difficult. If the thickness of the said film base material is thicker than 500 micrometers, on the contrary, a film base material will become hard too much and the bonding process will become difficult. Further, when the masking film is peeled off, the height of the coating ink formed on the edge portion becomes too large.

  Since the masking film needs to be peeled off after spray coating, the adhesive used for the adhesive layer is weakly adhesive, or the adhesive becomes weakened or disappears by UV irradiation or heat treatment. Is preferred. In the case of a pressure-sensitive adhesive that is peeled off by heat treatment, it is necessary to balance the heat peeling temperature with the drying temperature at the time of heat-drying spray coating. That is, in order to avoid peeling of the masking film during spray drying by heating, it is preferable to set the heat peeling temperature higher than the temporary drying temperature during spray coating.

  Specific examples of the masking film include, for example, E-MASK R / HR / RP series manufactured by Nitto Denko Corporation, an elep holder, and a heat release sheet (Riva Alpha (registered trademark)). The shape of the masking film needs to be at least one size smaller than the decorative film and larger than the opening (LCD display portion) of the decorative layer of the decorative film. In addition, it is necessary to have a shape that covers a portion where spray coating is not desired. Note that the masking film may have a shape (size) in which the fog of the coating ink overlaps the touch panel, or a shape (size) that does not overlap.

  In the bonding of the masking film, it is not necessary to align as precisely as the bonding of the decorative film, but because it is bonded to the bottom (main surface) of the concave surface, it is the same as the decorative film. It is sufficient to use a machine.

<Spray painting>
When spray coating (spraying coating) is performed on the surface to be decorated, the object to be decorated is masked on the outer side (viewing side from the outside, convex side) as necessary, Fixed to a spray coating jig as required. Then, spray painting is performed on the object to be decorated by, for example, spindle coating.

  FIG. 9 is a perspective view schematically showing one method of spray coating. First, the decorative object 31 is fixed to the spindle 33 via the jig 32. At this time, the decoration object 31 is fixed with the concave surface, which is the surface to be decorated, facing outward. The spindle 33 is rotated, and the coating ink is sprayed onto the decoration target 31 from various angles by the coating spray 34. Thereby, the main surface and inner wall surface other than the masking portion on the surface to be decorated of the object to be decorated, and the end surface are uniformly coated as necessary.

  Inks used for spray coating include binder resins such as polyvinyl resins, polyamide resins, polyester resins, acrylic resins, polyurethane resins, polyvinyl acetal resins, polyester urethane resins, cellulose ester resins, alkyd resins, and the like. It is preferable to use a colored ink containing a pigment or dye of an appropriate color as a colorant. If the color tone of the ink for spray coating is matched with the color tone of the decorative layer of the decorative film, the boundary can be made inconspicuous.

<Removal of masking film>
After the spray coating is completed, the object to be decorated is sent to a drying furnace, and the coating ink is temporarily dried. The drying temperature condition is, for example, 90 ° C. for 15 minutes. Then, the masking film on the inner surface side of the decoration object is peeled off in a state where the coating ink is temporarily dried. This is because if the masking film is peeled off without drying the coating ink, the coating ink may be undried and the coating ink may be scattered. Also, if the masking film is peeled off after the coating ink has been completely dried, the masking film may be altered due to the strong influence of drying, and the coating ink may become too hard and hard to peel off. This is because there is a possibility that it may be crushed and become dirty.

In addition, if the adhesive of a masking film is an ultraviolet peeling type, a masking film is irradiated with a required amount of ultraviolet rays before peeling of the masking film. The amount of ultraviolet irradiation at this time is, for example, 1000 mJ / cm ² . Moreover, if the adhesive of a masking film is a heat peeling type, the temperature of a furnace will be heated to required temperature and a masking film will be heated. The heating condition of the masking film at this time is, for example, 120 ° C. for 10 minutes. Thus, the masking film can be peeled off by irradiating the masking film with ultraviolet rays or heating.

<Complete drying of paint ink>
After peeling the masking film on the inner surface side, the temperature of the heating furnace is set to completely dry conditions, and the coating ink is completely dried. The drying temperature condition is, for example, 150 ° C. for 30 minutes. After complete drying, the masking film on the outer surface side is removed as necessary, and the decoration object is removed from the jig.

(Other)
In the present embodiment, an example in which the exterior cover is applied to a mobile terminal has been described. However, the present invention can also be applied to a display such as a liquid crystal panel or an organic EL display element.

  It can be said that the exterior cover, the manufacturing method thereof, and the electronic device of the present embodiment described above may be expressed as follows.

  The manufacturing method of the exterior cover of the present embodiment includes a substrate having a main surface and a standing wall extending from an end portion of the substrate, and the main body and the inner wall surface of the standing wall are connected to each other. A step of bonding a decorative film on which a window frame part is printed on the main surface, and a mask so as to cover the window part inside the window frame part of the decorative film inside the outer shape of the decorative film Forming a coating film on the decorative film, on the main surface outside the decorative film and on the inner wall surface of the standing wall, and peeling the mask. You may do it.

  In the above manufacturing method, the coating film may be formed by spraying coating ink.

  The manufacturing method of the exterior cover of the present embodiment includes a substrate having a main surface and a standing wall extending from an end portion of the substrate, and the main body and the inner wall surface of the standing wall are connected to each other. A step of bonding a decorative film on which a window frame portion is printed on the main surface, a step of forming a mask inside the outer shape of the decorative film, and a coating ink from above the mask toward the main surface Spraying the coating ink onto the inner wall surface, and peeling the mask.

  In said manufacturing method, it is desirable for the said mask to be a magnitude | size which overlaps with the said window frame part of the said decorating film.

  In the above manufacturing method, the mask is preferably larger than an outer shape of a touch panel or a display panel to be covered by the outer cover.

  In the above manufacturing method, the cover body may be transparent.

  The exterior cover of the present embodiment includes a substrate having a main surface and a standing wall extending from an end of the substrate, the cover main body in which the main surface and the inner wall surface of the standing wall are connected, and the cover main body The decorative film on which the window frame portion is printed, which is bonded to the main surface, and the surface of the window frame portion of the decorative film, the main surface and the inner wall surface outside the window frame portion are formed. It may be provided with a paint film.

  The exterior cover of the present embodiment includes a substrate having a main surface and a standing wall extending from an end of the substrate, the cover main body in which the main surface and the inner wall surface of the standing wall are connected, and the cover main body From the surface of the window frame portion of the decorative film, which is bonded to the main surface of the window frame portion, from the surface of the window frame portion to the main surface and the inner wall surface of the window frame portion, You may provide the coating film formed by the spray injection of coating ink.

  In the above configuration, the cover main body may be transparent.

  The electronic device of this embodiment may include the above-described exterior cover and a touch panel or a display panel covered with the exterior cover.

  The present invention can be used for manufacturing an exterior cover of an electronic device such as a mobile terminal or a display.

1 Mobile terminal (electronic equipment)
4 Display panel 5 Touch panel 6 Cover glass (exterior cover)
DESCRIPTION OF SYMBOLS 11 Cover main body 12 Board | substrate 12a Main surface 13 Standing wall 13a Inner wall surface 14 Decorating film 14a Window frame part 14R Window part 15 Mask 16 Coating film

Claims (8)

A window frame portion is printed on the main surface of the cover body including a substrate having a main surface and a standing wall extending from an end portion of the substrate, and the main surface and the inner wall surface of the standing wall are connected to each other. A process of pasting a decorative film;
A step of forming a mask so as to cover an inner window portion of the window frame portion of the decorative film inside the outer shape of the decorative film;
Forming a coating film on the decorative film, on the main surface outside the decorative film and on the inner wall surface of the standing wall;
And a step of peeling off the mask.   The manufacturing method of the exterior cover according to claim 1, wherein the coating film is formed by spraying coating ink.   The method for manufacturing an exterior cover according to claim 1, wherein the mask has a size overlapping with the window frame portion of the decorative film.   The method for manufacturing an exterior cover according to any one of claims 1 to 3, wherein the mask is larger than an outer shape of a touch panel or a display panel to be covered by the exterior cover.   The said cover main body is transparent, The manufacturing method of the exterior cover in any one of Claim 1 to 4 characterized by the above-mentioned. A cover body including a substrate having a main surface and a standing wall extending from an end of the substrate, wherein the main surface and the inner wall surface of the standing wall are coupled;
A decorative film printed on a window frame, which is bonded to the main surface of the cover body;
An exterior cover comprising: a coating film formed from the surface of the window frame portion of the decorative film to the main surface and the inner wall surface outside the window frame portion.   The exterior cover according to claim 6, wherein the cover body is transparent. The exterior cover according to claim 6 or 7,
An electronic apparatus comprising a touch panel or a display panel covered with the exterior cover.

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