Patent Application
20140308469
The present invention relates to a manufacturing method of a glass integrally molded product. Specifically, the invention relates to a method to manufacture a glass integrally molded product with a plate-like glass fixed inwards of a frame body by glass insert molding. The invention further relates to a glass integrally molded product.
In Patent Literature 1 described below, there is disclosed a manufacturing method of a glass insert molded product with an integrally molded window frame with a plate glass for a window pane as an insert member. Specifically, there is disclosed a manufacturing method of a plate glass fitted article such as a sash. In this manufacturing method, a tight material with a U-shaped cross-section is fitted in the edge of the glass, and an elastic member is attached to a back surface of the tight material In this state the glass is disposed inside molds, and resin, that is to become a frame such as the sach, is injected and molded. At this time, to prevent glass from breaking with heat from the resin in the melted state, and to prevent the tight material from deforming, a reactive injection resin is used. The elastic member absorbs stress applied to the glass as the molded frame cools down.
By the way, as an example of a member and a component having a configuration similar to the sash disclosed in Reference 1, there is a front cover of a multifunctional portable telephone, known as a smartphone, configured with such as a touch panel (below, a display panel) that is a display device or that is both a display device and an input device in almost the entire region of the front surface.
The front cover 1 forms a surface in which the upper surface 11 of the frame body 10 and an upper surface 21 of the glass plate 20 are continuous and inmost cases is made to be flush. As shown in
Recent portable electrical appliances having a thin display device such as a smartphone, a portable music player, a portable LED television, and a digital camera, require high waterproof property, under the assumption that the portable electrical device will be used in the kitchen, the bathroom, or when raining. Many of these electrical appliances, similar to the front cover of the smartphone, are arranged with a plate-shaped glass in the inner periphery of the resin frame body, and includes the component (below, referred to as a glass integrally molded product) forming a continuous surface with the front surface of the frame body and the front surface of the glass plate.
A conventional glass integrally molded product was manufactured by fitting in the glass plate in the already molded frame body as described above. Thus, to increase waterproof performance between the frame body and the glass plate, an O ring is interposed between the rim of the lower surface of the glass plate and the upper surface of the edge portion, or a waterproof resin was filled in the part where the glass plate and the frame body comes into contact. Thus, components and material to increase waterproof property and additional steps were necessary. Thus, it was difficult to reduce costs.
The inventors of this invention considered increasing waterproof performance and also simplifying manufacturing steps of the glass integrally molded product such as the above described front cover. In fact, the front cover and the like however, has to be configured as a continuous surface between the glass surface and the frame body. Thus different from the sash, at the time of injection molding the edge of the glass plate that contacts the high temperature and high pressure melted resin, which becomes the frame body, cannot be sandwiched and held with any kind of buffer material. Thus, in the case that the glass plate is molded as is as an insert article, there is a high possibility that the edge of the glass may break with heat and pressure at the time of molding. The glass and the resin forming the frame body do not have adhesiveness in both of the materials themselves, and in fact do not have as much waterproof performance as expected. Further, there is also a problem that the glass plate is prone to fall out of the frame body due to weak adhesiveness which relates to reliability. With the technique disclosed in Reference 1, before injection molding, the tight material is sandwiched and held with the glass plate, and the buffer material is arranged in the rim of the tight material. Reactive resin is used as resin to be injected. Thus, there are many additional members and steps, and the resin itself is also special, and it is practically impossible to apply the technique disclosed in Reference 1 to the glass integrally molded product. Of course, decreasing costs is also difficult.
The present invention aims to provide a method to manufacture with glass insert molding a glass integrally molded product having high reliability and waterproof performance without causing increase in costs. Note that, other features will become clear below.
The present invention to achieve the above objects is a method for manufacturing a glass integrally molded product having a plate glass fixed inwards of a frame body of resin, wherein the frame body has an upper surface to be continuous with an upper surface of the plate glass and an edge portion for supporting a rim of a lower surface of the plate glass,
the method comprising the steps of forming a resin layer to the lower surface of the plate glass in a frame shape to extend around the lower rim of the plate glass, the resin layer having compatibility with the resin of the frame body and functioning as a buffer to alleviate stress applied to the plate glass at the time of molding the frame body,
disposing the plate glass in molds to mold the frame body, and
injecting the melted resin into the molds in a closed state to form the frame body,
whereby the lower rim of the plate glass is integrally fixed to the edge portion of the frame body.
The above method of manufacturing a glass integrally molded product, may be a method further comprising a step of putting a transfer film across the molds, the film being an in-mole use and having a decoration film laminated on a base film, wherein,
the transfer film putting step is carried out such that the base film of the transfer film and an inner surface of one of the molds are opposed,
the plate glass disposing step is carried out such that the transfer film is interposed between the inner surface of the mold and the upper surface of the plate glass, and
the melted resin is injected while the transfer film is sandwiched with the molds in the closed state,
whereby the frame body is molded and the decoration film is transferred to a surface of the frame body.
The method may be a method of manufacturing a glass integrally molded product, wherein the resin layer forming step is carried out by printing a resin on the plate glass, the resin having a function as a decoration at the time when viewed through the upper surface of the plate glass, and the injection molding step is carried out to mold the frame body into a shape in which the printed layer is visible through the upper surface of the plate glass. Further, the resin layer forming step may be carried out by printing a resin having a decorative function on the lower surface of the plate glass to form a decoration layer and then printing another resin having compatibility with the resin configuring the frame body on the lower side of the decoration layer to form an adhesive layer.
The method may be a method of manufacturing the glass integrally molded product wherein an intermediate resin layer is formed in between the decoration layer and the adhesive layer with a resin that is more elastically deformable than the resins that form the decoration layer and the adhesive layer. Further the method may be a method of manufacturing the glass integrally molded product wherein the upper surface region of the plate glass is included in the lower surface region thereof when seen from above, and a side surface of the plate glass has a slanted surface inclined outwardly from the upper surface to the lower surface, and wherein the resin layer printing step is carried out such that the decoration layer and the lower layer laminated below the decoration layer are aligned in outer edges and that a width of the decoration layer is made wider than the lower layer.
In any one of the methods set forth above, the method may further comprise a step of forming a pressure buffer portion in between the resin layer printing step and the plate glass disposing step, wherein the buffer portion extends around the side surface of the plate glass in contact with a portion of the lower surface and the side surface of the resin layer, and the buffer portion is formed with a resin that is more elastically deformable than the resin forming the frame body and the resin layer.
The present invention covers a glass integrally molded product having a plate glass fixed inwards of a frame body of resin. The product comprises the frame body having an upper surface continuous with an upper surface of the plate glass and an edge portion supporting a rim of a lower surface of the plate glass, wherein the rim of the plate glass supported by the edge portion of the frame body is formed with a resin layer, which is fixed to the upper surface of the edge portion of the frame body and functions as a buffer between an upper surface of the edge portion and the rim of the glass lower surface.
The glass integrally molded product may be a such product wherein the upper surface of the resin layer is decorated so as to be visible through the upper surface of the plate glass. Further the product may be a such product wherein an adhesive layer is laminated to a lower side of the decorated layer and fixed to the upper surface of the edge portion.
The glass integrally molded product may be a such product wherein an intermediate layer is interposed in between the decoration layer and the adhesive layer, and the intermediate layer is formed of a resin that is more elastically deformable than resins that forms the decoration layer and the adhesive layer.
The glass integrally molded product may be a such product wherein the upper surface region of the plate glass is included in the lower surface region thereof when seen from above, and a side surface of the plate glass has a slanted surface inclined outwardly from the upper surface to the lower surface, and wherein the resin layers forming the frame shaped decoration layer and the lower layer laminated below the decoration layer are aligned in outer edges, and a width of the decoration layer is made wider than the lower layer.
In any one of the products set forth above, the product may comprise a pressure buffer portion extending around the side surface of the plate glass in contact with a portion of the lower surface and the side surface of the resin layer, wherein the buffer portion is formed with a resin that is more elastically deformable than the resins forming the frame body and the resin layer.
According to the manufacturing method of this invention, a glass integrally molded product having high reliability and waterproof performance can be manufactured by glass insert molding.
A front cover of a smartphone is given as an example of a glass integrally molded product molded with a manufacturing method of the present invention. A specific manufacturing method according to a configuration and the like of the front cover is explained as an embodiment of this invention.
As shown in
This invention is a method that makes it possible to manufacture by glass insert molding a glass integrally molded product, such as a front cover, which was difficult to manufacture by glass insert molding conventionally. As the first embodiment of this invention, the manufacturing method of the front cover 1a shown in
Next, the glass plate 20 printed with this resin layer 30 is disposed inside molds (41, 42) (
Next, the molds (41, 42) are closed and clamped. As a result, there is formed a cavity 44 to be filled with the melted resin 110 that becomes the frame body 10 in the end (
According to the manufacturing method of the glass integrally molded product according to the above first embodiment (below, referred to as a molded product manufacturing method), the pressure applied to the part of the glass plate 20 that contacts the melted resin 110 at the time of clamping and at the time of injection molding is reduced by the resin layer 30 formed in the contacting part. In other words, the resin layer 30 functions as a buffer at the time of injection molding. Thus, glass insert molding of a glass integrally molded product such as front cover 1a becomes practically applicable in which the upper surface 21 of the glass plate 20 and the upper surface 11 of the frame body 10a form a continuous surface without breaking the glass plate 20 at the time of injection molding. Since the periphery of the lower surface 22 of the glass plate 20 and the upper surface 14 of the edge portion 13 of the frame body 10a are fixed in an integrated state, the glass plate 20 and the frame body 10a are strongly adhered and extremely high reliability can be realized and also sufficient waterproof performance can be achieved with regards to the peripheral edge of the glass plate 20. Of course, with glass insert molding, the manufacturing cost of the front cover 1a can also be reduced.
By the way, with a glass plate integral component such as a conventional front cover 1, in order to further improve continuity of the peripheral edge of the upper surface 21 of the glass plate 20 and the upper surface 11 of the frame body 10 and also to make it difficult for water drops and the like from above to enter between the glass plate 20 and the frame body 10, the peripheral edge of the upper surface 21 of the glass plate 20 is beveled and a part that overhangs so as to cover the beveled part from above is formed in the inner peripheral edge of the upper surface 11 of the frame body 10.
By the way, in the case of manufacturing the front cover 1b shown in
By applying the molded product manufacturing method of the first embodiment, the melted resin 110 can be filled to smooth the beveled slanted surface 23 at the time of injection molding, and the front cover 1b having the glass plate 20 integrated with the frame body 10b can be taken out in a completed state from the molds (41, 42). Thus, the undercut process to form the canopy portion 16 becomes unnecessary, and there is no increase in cost of the molds (41, 42).
The front cover 1a previously shown in
In the case of the front cover 1b shown in
Note that, the edge to the upper surface 21 side of the glass plate 20b, as with the front cover 1b shown in
In any case, the lower surface 22 of the glass plate (20b, 20c) may be a shape including the region of the upper surface 21, and may be formed with a slanted surface 23 on the side surface of the glass plate (20b, 20c). Note that, in the case the side surface of the glass plate 20c is a line shape formed with a plurality of slanted surfaces 23a, as with the front cover 1c shown in
With a glass integral component to be a part of an outer case of an electric appliance such as a front cover of a smartphone, decoration is made in many cases on such as an upper surface 11 of a frame body or an outer side surface of a side wall 15, on a surface which is exposed to the outside as an outer case (below, referred to as an outer surface). There are cases where the decoration is performed in a limited way on a part of an outer surface of the frame body, with such as a logo of a product, and there are cases where the decoration is performed on an entire region of the outer surface imitating other material (such as metal). Below, as a second embodiment of this invention, with the first embodiment as a precondition, there is described a molded product manufacturing method to perform decoration with high reliability at low cost on a frame body of a front cover.
The Second Embodiment, based on the First Embodiment, has a feature of using an in-mold molding technique to perform decoration to an outer surface of the frame body 111. As is well-known, with in-mold molding technique, a transfer film in which a film to be the base (below, base film) is laminated with a film (a decoration film) formed with a design, characters, or a pattern imitating other material (below, decoration design) to be the decoration is sandwiched inside the molds of the injection molding machine and melted resin is injected, and the decoration film is transferred to the resin with heat from the base film.
In the case where the molds (41, 42) are closed, the melted resin 110 is injected into the molds (41, 42) (
With the conventional glass integrally molded product 1 shown in
With the molded product manufacturing method according to the Second Embodiment, the glass integrally molded product is manufactured by glass insert molding so that a continuous surface is formed with the upper surface 21 of the glass plate 20 and the frame body 10c. In other words, with the molded product manufacturing method according to the First Embodiment as a precondition, the manufacturing method of the Section Embodiment becomes possible. In the Second Embodiment, decoration can be performed at the same time as molding of the frame body 111 by using an in-mold molding technique on a substantially flat surface. Thus, high quality decoration can be performed at a low cost.
The upper surface area of the glass integrally molded product is mostly occupied by a glass plate. Thus, it was difficult to show the design feature. For example, although the front cover of a smartphone is a component that greatly influences the design feature of the product, only a small region on an outer surface of the frame body on the front cover can be used to perform decoration to appeal the features of the product. Thus, the smartphone has no choice but to have a design that are all similar except the outer shape, and it is difficult to differentiate the smartphone in design from products made by other companies. The outer shape also becomes an almost similar shape when considering portability and operability.
Of course, decoration to the glass plate itself can also be considered, but in order to perform decoration to the glass plate, some processes for the decoration will have to be added, causing cost increase. The glass plate will be decorated by printing or sticking on a film, but in the case of using it as a cover glass for a touch panel, the upper surface of the glass plate will be constantly rubbed with fingers operating the device. Even if it is not a cover glass for a touch panel, in the case that it is a display panel that is to be protected by a cover glass, in order to see some display through this glass plate, there are cases of wiping dirt off to ensure visibility at all times. In other words, the glass plate is in an environment where friction is always applied with fingers, cloth, and the like, and there is concern of deterioration over time of the decoration. Thus, as in the second embodiment, when compared to decoration formed on the surface of the resin by in-mold molding, decoration on the glass plate 20 is prone to deteriorate over time. Further, with such as the front cover of the smartphone, a coating to improve various optical characteristics and improve strength is performed on the upper surface side of the glass plate, thus adhesiveness to other material (such as an adhesive) is weak. In other words, by adhering film and the like, decorating per se becomes difficult. As the third embodiment, there is described a molded product manufacturing method in which decoration with high durability can be performed on a glass plate at low cost.
The third embodiment is achieved by developing the molded product manufacturing method in the first embodiment. Specifically, in the first embodiment, the resin layer 30 was formed by printing to the rim of the lower surface 22 of the glass plate 20, so as to protect the glass plate 20 at the time of injection molding of the frame body 10a, and to strongly adhere the resin configuring the frame body 10a and the glass plate 20 so as to increase waterproof performance. In the third embodiment, the resin layer 30 is to also be a decoration.
For the resin layer 30 to function as a decoration, it can be realized by, for example, using resin material that has a predetermined colored appearance in the resin layer 30, or using resin dispersed with pigments. Further, since the resin layer 30 is formed by printing, it is not limited to a shape that surrounds the glass plate 20 and it can be formed as designs or characters. Since the decoration is formed on the lower surface 22 of the glass plate 20, in principle no deterioration over time due to friction occurs. Compared to decoration that is exposed to the outside, deterioration over time due to the surrounding environment and the like (such as humidity, ultraviolet rays) is also greatly reduced. In particular, since the glass absorbs ultraviolet rays, great improvement in light resistance can be expected.
As described above, the third embodiment has a feature of using the resin layer 30 on the lower surface 22 of the glass plate 20 as decoration. The original purpose of this resin layer 30 however, is to make the glass integrally molded product possible without breaking the glass at the time of molding. Thus, it would be preposterous if the original function of the resin layer 30 is lost to improve the function as the decoration. Ideally, it is preferable to balance the original function and the decorative function at a high level. The resin layer 30 can be a two-layer configuration formed of a layer that functions as a decoration (decoration layer) and a layer of resin that functions as a buffer material at the time of injection molding (buffer layer). The decoration layer may also function as the buffer layer, and the layer that is formed at the lower layer of the decoration layer may be a layer of a binder (adhesive layer) that adheres the decoration layer to the frame body. The two layers may both function as the buffer layer. Further, it is not limited to two layers, and there may be equal to or more than two layers of resin laminated to the lower surface of the decoration layer.
The glass plate 20f of the front cover 1f shown in
Note that, in the front covers (1f, 1g) shown in
Hereinbelow, as the third embodiment, the manufacturing method of the front cover 1f shown in
The resin that forms the decoration layer 33 is visualized through the upper surface 21 of the glass plate 20f and functions as a decoration. Further, this decoration layer 33 functions as a buffer material at the time of injection molding and also needs to be considered regarding adhesiveness with the glass plate 20f, thus in this example resin ink dispersed with pigments in acrylic urethane resin is used. The resin that forms the adhesive layer 34 functions as a binder to strongly adhere the decoration layer 33 and the resin configuring the frame body 10f. Thus, the above resin is excellent in adhesiveness with the resin forming the decoration layer 33, and is required to be compatible with the resin forming the frame body 10f. In this example, a transparent acrylic resin is used, in consideration of the function that it does not interfere with the decoration function of the decoration layer 33. Note that, here the thickness of the decoration layer 33 and the adhesive layer 34 are both 4 μm. Of course, as long as the original function of the resin layer 30 is not damaged, the thickness of each layer (33, 34) can be appropriately adjusted. For example, by appropriately increasing and decreasing the thickness of the decoration layer 33 for decoration, various designs can be achieved. The shade of the color of the decoration portion can be controlled with the thickness of the decoration layer 33. By making the thickness of the decoration layer 33 thin, the color of the resin configuring the frame body 10f, or in the case the adhesive layer 34 is not a transparent color, the color of the adhesive layer 34 that can be made transparent to the upper side, can be mixed with color of the resin configuring the frame body 10f and the decoration layer 33.
Next, the glass plate 20f having the two-layer configuration resin layers 30 is disposed in the molds (41, 42) (
The glass integrally molded product such as the front cover 1f molded with the molded product manufacturing method according to the third embodiment has a decoration on the lower surface 22 of the glass plate 20f, and has an excellent durability. The decoration to the glass plate 20f is formed only by the process to print and form the resin layer 30 to the glass plate 20f. Further, by using this glass plate 20f, the frame body 10f is formed by glass insert molding, thus the glass integrally molded product is provided. In other words, the glass integrally molded product with the decoration made on the glass plate 20f can be manufactured cheaply.
In the case that the resin layer 30 printed to the lower surface 22 of the glass plate 20f is to be a two-layer configuration of the decoration layer 33 for decoration and an adhesive layer 34 that functions as a binder between the decoration layer 33 and the frame body 10f, then the original function of making the glass insert molding of the glass integrally molded product possible and the decorative function, of the resin layer 30, can be attained with a balance at high level.
Note that, the resin layer 30 does not have to be a two-layer configuration of the decoration layer 33 for the decoration and the adhesive layer 34, and may be a configuration that has equal to or more than three layers. For example, if the resin is printed in one region on the upper surface of the decoration layer 33, it is possible to visualize a logo with the decoration layer 33 as a background, through the upper surface 21 of the glass plate 20, and further improve the design. Of course, in view of the manufacturing cost and the design of the product, the resin layer 30 can be a single layer configuration. In any case, the upper surface side of the resin layer 30 that can be visualized through the upper surface 21 of the glass plate 20 can be used for decoration, and the lower surface side can be used for adhesion with the frame body 10f.
Further, the original function of the resin layer 30 is as a buffer material to the pressure at the time of injection molding, and for example, in the case that the resin layer 30 is made as a configuration with equal to or more than three layers, as the intermediate later other than a first uppermost layer and the lowermost layer, resin excellent in buffer function and that can relatively elastically deform more easily than the resin that sandwiches the intermediate layer may be used.
In the above embodiments, by forming the resin layer 30 around the rim of the lower surface 22 of the glass plate (20, 20b, 20c, 20f), the pressure applied to the glass plate (20, 20b, 20c, 20f) at the time of glass insert molding is alleviated, and damage and the like to the glass plate (20, 20b, 20c, 20f) is prevented. By further developing this technical idea, resin that can more easily elastically deform and that is relatively soft (for example, urethane resin) than resin that forms the resin layer 30 (for example, acrylic resin) can be formed to go around the rim of the glass plate (20, 20b, 20c, 20f).
As a method of forming this pressure buffer portion 80, the ring-shaped pressure buffer portion 80 is formed around the glass plate 20c in advance and then an injection molding of the frame body may be performed. Alternatively, the pressure buffer portion 80 may be formed around the glass plate 20c by a first glass-insert molding, and then a second glass-insert molding can be performed again using different molds in which the glass plate 20c with the pressure buffer portion 80 formed in the first glass insert molding is set and finally the front cover 1i shown in
As embodiments of this invention, methods to manufacture the front cover of the smartphone by glass-insert molding were disclosed. Of course, this invention is not limited to the smartphone and may be applied to various articles, such as portable phones, portable music players, flat panel displays of such as navigation systems for vehicles, finders and displays of digital cameras.
Further, the upper surface shape of the glass plate is not limited to a substantially rectangular shape, and may be an appropriate shape such as a polygonal shape or a circular shape. In a case that an upper surface of the glass plate is a complex shape, by applying the manufacturing method of the glass integrally molded product of this invention, a frame body having an inner peripheral shape along the shape of the glass can be molded without using a complex mold.
This invention is appropriate as a manufacturing method of a front cover that protects a display panel such as a touch panel of a smartphone.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011-269261 | Dec 2011 | JP | national |
| 2012-137993 | Jun 2012 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2012/071984 | 8/30/2012 | WO | 00 | 6/5/2014 |
