U.S. patent application number 13/294509 was filed with the patent office on 2012-03-08 for housing case, method for manufacturing housing case, and glass insert molding die used in same.
This patent application is currently assigned to NISSHA PRINTING CO., LTD.. Invention is credited to Takeshi Nishimura.
Application Number | 20120055826 13/294509 |
Document ID | / |
Family ID | 39200560 |
Filed Date | 2012-03-08 |
United States Patent
Application |
20120055826 |
Kind Code |
A1 |
Nishimura; Takeshi |
March 8, 2012 |
Housing Case, Method for Manufacturing Housing Case, and Glass
Insert Molding Die Used in Same
Abstract
A housing case (1) for a small electric device and communication
device includes a flat plate (2) having a dimension substantially
the same as that of the front portion of the housing case and
comprising at least a glass plate, and a resin frame (3) integrated
with the flat plate (2) to support the backside periphery of the
flat plate (2).
Inventors: |
Nishimura; Takeshi;
(Kyoto-shi, JP) |
Assignee: |
NISSHA PRINTING CO., LTD.
Kyoto-shi
JP
|
Family ID: |
39200560 |
Appl. No.: |
13/294509 |
Filed: |
November 11, 2011 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
12441635 |
Mar 17, 2009 |
|
|
|
13294509 |
|
|
|
|
Current U.S.
Class: |
206/320 |
Current CPC
Class: |
B29C 45/14073 20130101;
B29K 2709/08 20130101; B29C 2045/14155 20130101; H04M 1/0283
20130101; B29L 2031/3431 20130101; H05K 5/0017 20130101; B29L
2031/445 20130101; H04M 1/0266 20130101; B29C 45/401 20130101; B29C
45/14688 20130101; B29C 45/14778 20130101 |
Class at
Publication: |
206/320 |
International
Class: |
B65D 85/00 20060101
B65D085/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 22, 2006 |
JP |
2006-258126 |
Oct 30, 2006 |
JP |
2006-294799 |
Claims
1. A housing case for a small electric device and communication
device, the housing case comprising: a flat plate having a
dimension substantially the same as that of a front portion of the
housing case and comprising at least a glass plate; and a resin
frame integrated with the flat plate to support a backside
periphery of the flat plate.
2. The housing case according to claim 1, wherein the flat plate
has decoration on a rear surface of the glass plate.
3. The housing case according to claim 1, wherein the device
includes a display device; and the flat plate has decoration on the
front surface and/or the rear surface of the glass plate except at
least a display window for the display device.
4. The housing case according to claim 1, wherein the rear surface
of the glass plate is not decorated; and the rear surface of the
glass plate is integrated with the resin frame, with an adhesive
layer for glass, a primer layer, and an adhesive layer for resin
interposed between the rear surface of the glass plate and the
resin frame.
5. The housing case according to claim 3, wherein the rear surface
of the glass plate is decorated, the layer having the decoration
also serves as an adhesive layer for glass in the portion where the
rear surface of the flat plate is integrated with the resin frame;
and the rear surface of the flat plate is integrated with the resin
frame with a primer layer and an adhesive layer for resin
interposed between the rear surface of the flat plate and the resin
frame.
6. The housing case according to claim 1, wherein the flat plate
has an opening.
7. The housing case according to claim 6, further comprising an
opening resin frame integrated with the flat plate to support the
surrounding portion of the opening.
8. The housing case according to claim 1, wherein the resin frame
covers a side surface of the flat plate.
9. The housing case according to claim 1, wherein the integrated
flat plate and resin frame has a box shape.
10. The housing case according to claim 1, wherein the resin frame
supports the entire backside periphery of the flat plate.
11. The housing case according to claim 1, wherein the resin frame
supports one, two, or three sides of the backside periphery of the
flat plate.
12. The housing case according to claim 1, wherein a plurality of
divided portions of the resin frame support the backside periphery
of the flat plate.
13. The housing case according to claim 1, wherein the resin frame
is made of a resin material having a molding shrinkage rate of 0.6%
or lower.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a division of U.S. patent application
Ser. No. 12/441,635 filed Sep. 20, 2007 which is incorporated
herein by reference in its entirety.
TECHNICAL FIELD
[0002] The present invention relates to a housing case for a small
electric device and communication device, the front portion of the
housing case; in particular, the portion of the housing case that
covers an LCD or any other display screen having been adequately
hardened, and also relates to a method for manufacturing the
housing case and a glass insert molding die used in the same.
BACKGROUND ART
[0003] Small electric devices and communication devices, such as a
digital audio player and a mobile phone, which can be placed in
clothing or in a bag and carried, are often subject to impact on
their surfaces when they are accidentally dropped or hit with other
articles in the bag.
[0004] To address the problem, the housing case of such a device
needs to have a highly robust hard coat layer coated on the front
portion of the housing case; in particular, the portion that covers
an LCD or any other display screen, in order to enhance scratch
resistance. For example, Patent Document 1 discloses a housing case
100 (see FIG. 38) manufactured from a continuous film having a
peelable layer, a hard coat layer 103, a printed layer, and an
adhesive layer successively stacked on a base film. The hard coat
layer 103 comprises layered hard coats for hardening the front
portion of the housing case 100, and the printed layer includes a
plurality of printed patterns, each of which having a non-printed
portion 102. The housing case 100 is manufactured by continuously
passing the continuous film through a glass insert molding die,
injecting a transparent synthetic resin onto the adhesive layer of
the continuous film in the glass insert molding die, and drawing
the continuous film into the shape of the cavity of the glass
insert molding die so as to form a synthetic resin layer 101. After
the synthetic resin layer has hardened, the hard coat layer 103,
the printed layer, the adhesive layer, and the synthetic resin
layer 101 are removed from the base film and the peelable layer. In
FIG. 38, reference numeral 104 denotes a display window that covers
an LCD display screen, and reference numeral 105 denotes a button
hole.
[0005] The hard coat layer 103 is typically manufactured by forming
a thin coated film, ranging from approximately 3 to 10 .mu.m in
thickness, made of a thermoset resin, a UV curable resin, or any
other suitable active energy radiation polymerizable resin on a
plastic substrate directly or with an interposed primer layer
having a thickness ranging from 0.03 to 0.5 .mu.m.
[0006] The hard coat layer 103 comprising a thin coated film,
however, is not hard enough as the front portion of the housing
case; in particular, the portion that covers an LCD or any other
display screen where high hardness is required.
[0007] The invention has therefore been contrived in view of the
above problem. An object of the invention is to provide a housing
case, the front portion of the housing case; in particular, the
portion of the housing case that covers an LCD or any other display
screen, being adequately hardened. Other objects of the invention
are to provide a method for manufacturing the housing case and a
glass insert molding die used in the same. [0008] [Patent Document
1] Japanese Laid-open Patent Application No. 2001-36258
DISCLOSURE OF THE INVENTION
[0009] To achieve the above objects, a housing case according to
the invention is characterized in that the housing case is used for
a small electric device or communication device, and comprises a
flat plate having a dimension substantially the same as that of a
front portion of the housing case and comprising at least a glass
plate; and a resin frame integrated with the flat plate to support
a backside periphery of the flat plate.
[0010] In the housing case, the flat plate preferably has
decoration on a rear surface of the glass plate.
[0011] In the housing case, the device preferably includes a
display device, and the flat plate preferably has decoration on the
front surface and/or the rear surface of the glass plate except at
least a display window for the display device.
[0012] In the housing case, the rear surface of the glass plate is
preferably not decorated, and the rear surface of the glass plate
is preferably integrated with the resin frame with an adhesive
layer for glass, a primer layer, and an adhesive layer for resin
interposed between the rear surface of the glass plate and the
resin frame.
[0013] In the housing case, the rear surface of the glass plate is
preferably decorated, and the layer having the decoration also
preferably serves as an adhesive layer for glass in the portion
where the rear surface of the flat plate is integrated with the
resin frame. The rear surface of the flat plate is preferably
integrated with the resin frame with a primer layer and an adhesive
layer for resin interposed between the rear surface of the flat
plate and the resin frame.
[0014] In the housing case, the flat plate preferably has an
opening.
[0015] The housing case preferably further comprises an opening
resin frame integrated with the flat plate to support the
surrounding portion of the opening.
[0016] In the housing case, the resin frame preferably covers a
side surface of the flat plate.
[0017] In the housing case, the integrated flat plate and resin
frame preferably has a box shape.
[0018] In the housing case, the resin frame preferably supports an
entire backside periphery of the flat plate.
[0019] In the housing case, the resin frame preferably supports
one, two, or three sides of the backside periphery of the flat
plate.
[0020] In the housing case, a plurality of divided portions of the
resin frame preferably support the backside periphery of the flat
plate.
[0021] In the housing case, the resin frame is preferably made of a
resin material having a molding shrinkage rate of 0.6% or
lower.
[0022] To achieve the above objects, a glass insert molding die
used to form a housing case according to the invention is
characterized in that the glass insert molding die comprises a
stationary die and a movable die that sandwich a flat plate
primarily comprised of a glass plate when the dies are closed and
form a cavity that faces periphery of the flat plate facing the
stationary die and also an end surface of the flat plate. The glass
insert molding die is also characterized in that the stationary die
includes a sliding core having a bottom portion that comes into
contact with the periphery of the flat plate facing the stationary
die and a wall portion that is connected to the bottom portion and
positionably comes into contact with the end surface of the flat
plate, the bottom portion and the wall portion provided at the
front end of the sliding core; and a suction hole provided in the
surface where the flat plate is sandwiched. The glass insert
molding die is also characterized in that the sliding core can be
advanced and retracted in the die-closing direction between a flat
plate positioning position and a cavity forming position, the flat
plate positioning position being the position where the front-end
bottom portion does not protrude from the surface of the stationary
die where the flat plate is sandwiched but the front-end wall
portion comes into contact with the flat plate, and the cavity
forming position being the position where the front-end bottom
portion and the front-end wall portion are separated from the flat
plate.
[0023] In the glass insert molding die, it is preferable that the
sliding core is partially provided along the entire perimeter of
the flat plate.
[0024] In the glass insert molding die, it is preferable that the
sliding core is further capable of being advanced to a glass insert
mold pushing position where the front-end bottom portion protrudes
from the surface of the stationary die where the flat plate is
sandwiched.
[0025] To achieve the above objects, a method for manufacturing a
housing case using the glass insert molding die according to the
invention is characterized in that the method comprises the steps
of: using the glass insert molding die, moving the sliding core to
the flat plate positioning position and then placing the flat plate
on the surface of the stationary die where the flat plate is
sandwiched; suctioning and securing the positioned flat plate on
the surface where the flat plate is sandwiched; closing the
stationary die to which the flat plate has adhered and the movable
die; and after the dies are closed, moving the sliding core to the
cavity forming position and then injecting a molten resin into the
cavity to integrate a resin frame with the flat plate.
[0026] To achieve the above objects, a method for manufacturing a
housing case using the glass insert molding die according to the
invention is characterized in that the method comprises the steps
of: using the glass insert molding die including the pushing
mechanism, moving the sliding core to the flat plate positioning
position, and then placing the flat plate on the surface of the
stationary die where the flat plate is sandwiched; suctioning and
securing the positioned flat plate on the surface where the flat
plate is sandwiched; closing the stationary die to which the flat
plate has adhered and the movable die; after the dies are closed,
moving the sliding core to the cavity forming position and then
injecting a molten resin into the cavity to integrate a resin frame
with the flat plate; and opening the dies and then moving the
sliding core to the glass insert mold pushing position.
[0027] In the method for manufacturing a housing case, the flat
plate preferably has decoration on the glass plate.
[0028] In the method for manufacturing a housing case, the flat
plate preferably has an adhesive layer for glass, a primer layer,
and an adhesive layer for resin sequentially formed on the glass
plate.
[0029] In the method for manufacturing a housing case, the portion
where the flat plate is sandwiched between the stationary die and
the movable die preferably has an opening.
[0030] In the method for manufacturing a housing case, the material
of the molten resin preferably has a molding shrinkage rate of 0.6%
or lower.
[0031] The configuration of the invention described above provides
the following advantages:
[0032] Since the housing case of the invention includes a flat
plate comprising a glass plate and a resin frame integrated with
the flat plate to support the backside periphery of the flat plate,
the front portion of the housing case; in particular, the portion
that covers an LCD or any other display screen, can be adequately
hardened.
[0033] Since the glass insert molding die and the method for
manufacturing a housing case of the invention can provide a housing
case in which a resin frame is integrated with a flat plate
primarily comprising a glass plate to support the backside
periphery thereof, the front portion of the housing case; in
particular, the portion that covers an LCD or any other display
screen, can be adequately hardened. Further, since the sliding core
provided in the glass insert molding die not only forms a cavity
for molding the resin frame for supporting the backside periphery
but also serves as a mechanism for positioning the flat plate as
well as a mechanism for pushing the glass insert mold as required,
the housing case can be manufactured at a low cost.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] FIG. 1 is a perspective view showing an embodiment of a
housing case according to the invention;
[0035] FIG. 2 is a cross-sectional view of the housing case taken
along the line II-II shown in FIG. 1;
[0036] FIG. 3 is a cross-sectional view showing another embodiment
of the housing case according to the invention;
[0037] FIG. 4 is a cross-sectional view showing another embodiment
of the housing case according to the invention;
[0038] FIG. 5 is a cross-sectional view showing another embodiment
of the housing case according to the invention;
[0039] FIG. 6 is a cross-sectional view showing another embodiment
of the housing case according to the invention;
[0040] FIG. 7 is a rear view showing an embodiment of the housing
case according to the invention;
[0041] FIG. 8 is a rear view showing another embodiment of the
housing case according to the invention;
[0042] FIG. 9 is a rear view showing another embodiment of the
housing case according to the invention;
[0043] FIG. 10 is a rear view showing another embodiment of the
housing case according to the invention;
[0044] FIG. 11 is a rear view showing another embodiment of the
housing case according to the invention;
[0045] FIG. 12 is a rear view showing another embodiment of the
housing case according to the invention;
[0046] FIG. 13 is a perspective view showing another embodiment of
the housing case according to the invention;
[0047] FIG. 14 is an enlarged cross-sectional view showing an
embodiment of the structure of a flat plate of the housing case
according to the invention;
[0048] FIG. 15 is an enlarged cross-sectional view showing another
embodiment of the structure of the flat plate of the housing case
according to the invention;
[0049] FIG. 16 is a perspective view showing another embodiment of
the housing case according to the invention;
[0050] FIG. 17 is a perspective view showing another embodiment of
the housing case according to the invention;
[0051] FIG. 18 shows an embodiment of a stationary die of a glass
insert molding die according to the invention, the stationary die
viewed from a movable die side;
[0052] FIG. 19 is a cross-sectional view of the stationary die
taken along the line XIX-XIX shown in FIG. 18;
[0053] FIG. 20 shows the arrangement in which the flat plate is
placed in the stationary die, the arrangement viewed from the
movable die side;
[0054] FIG. 21 is a cross-sectional view of the stationary die
taken along the line XXI-XXI shown in FIG. 20;
[0055] FIG. 22 is a cross-sectional view showing an embodiment of a
step of manufacturing the housing case according to the
invention;
[0056] FIG. 23 is a cross-sectional view showing an embodiment of a
step of manufacturing the housing case according to the
invention;
[0057] FIG. 24 is a cross-sectional view showing an embodiment of a
step of manufacturing the housing case according to the
invention;
[0058] FIG. 25 is a cross-sectional view showing an embodiment of a
step manufacturing of the housing case according to the
invention;
[0059] FIG. 26 shows an example of the housing case obtained by
using the stationary die shown in FIG. 18;
[0060] FIG. 27 shows another embodiment of the stationary die of
the glass insert molding die according to the invention, the
stationary die viewed from the movable die side;
[0061] FIG. 28 shows another embodiment of the stationary die of
the glass insert molding die according to the invention, the
stationary die viewed from the movable die side;
[0062] FIG. 29 shows an example of the housing case obtained by
using the stationary die shown in FIG. 27;
[0063] FIG. 30 shows an example of the housing case obtained by
using the stationary die shown in FIG. 28;
[0064] FIG. 31 shows another embodiment of the stationary die of
the glass insert molding die according to the invention, the
stationary die viewed from the movable die side;
[0065] FIG. 32 is a cross-sectional view of the stationary die
taken along the line XXXII-XXXII shown in FIG. 31;
[0066] FIG. 33 shows an example of the housing case obtained by
using the stationary die shown in FIG. 31;
[0067] FIG. 34 is a cross-sectional view showing another embodiment
of the stationary die of the glass insert molding die according to
the invention;
[0068] FIG. 35 shows another example of the housing case obtained
by using the stationary die shown in FIG. 18;
[0069] FIG. 36 shows an embodiment of the glass insert molding die
according to the invention in which a transfer film is sandwiched
between the stationary die to which the flat plate has adhered and
the movable die;
[0070] FIG. 37 shows an example of the closed glass insert molding
die shown in FIG. 36 after the transfer film is sandwiched;
[0071] FIG. 38 is a perspective view showing a housing case of
related art; and
[0072] FIG. 39 is a cross-sectional view showing how molding
shrinkage occurs when a glass plate, instead of a film comprising a
hard coat layer, is inserted into a die and the glass plate is
integrated with the whole front portion of a housing case.
BEST MODE FOR CARRYING OUT THE INVENTION
1. Housing Case
[0073] Embodiments of the invention will be described below in
detail with reference to the drawings.
[0074] A housing case 1 shown in FIG. 1 includes a flat plate 2
having a dimension substantially the same as that of the front
portion of the housing case and comprising at least a glass plate,
and a resin frame 3 integrated with the flat plate 2 to support the
backside periphery of the flat plate. The portion (b) in FIG. 1 is
an exploded view of the portion (a). The housing case 1 is
integrated with a back case (not shown), and the resultant
integrated case houses a substrate on which a variety of electronic
components are mounted to form a small electric device or
communication device.
[0075] The flat plate 2 comprises at least a glass plate, which can
provide sufficient hardness (at least 9H) of the front portion of
the housing case 1. The glass plate can be any of a standard plate
glass, a reinforced plate glass, a polished plate glass, and other
suitable plate glass. The thickness of the glass plate, in
consideration of the strength, preferably ranges from 0.3 mm to 2.0
mm, more preferably from 0.5 mm to 2.0 mm, still more preferably
from 0.8 mm to 1.5 mm.
[0076] To solve the problem described above, the inventor first
planned, in the housing case of the related art, to integrate the
synthetic resin layer with the flat plate 2 instead of the hard
coat 103 in the front portion of the case. Specifically, the whole
flat plate 2 is in contact with the synthetic resin layer 101 in
the front portion of the case. The synthetic resin layer 101 that
has been formed in the injection molding die, however, experiences
molding shrinkage during cooling solidification, whereas the
portion in contact with the whole flat plate 2 does not experience
molding shrinkage, as shown in FIG. 39. Since only one side thus
experiences the molding shrinkage (in the direction indicated by
the arrows in FIG. 39, for example), the resultant housing case 106
is warped in some cases. In this case, the flat plate 2 breaks when
it cannot withstand the warping.
[0077] Accordingly, in the invention, the resin frame 3 is employed
so that only the periphery of the backside of the flat plate 2 is
integrated. For example, in FIG. 1, the resin frame 3 supports the
entire backside periphery of the flat plate 2. Since the resin
frame 3 of the invention is not in contact with the whole flat
plate 2, molding shrinkage of the resin frame 3, if any during the
cooling solidification, will likely not affect the whole flat plate
2. The resultant housing case will therefore not be warped.
[0078] The resin frame 3 may be made of a polystyrene resin, a
polyolefin resin, an ABS resin, an AS resin, an AN resin, or any
other suitable general-purpose resin. Other useable materials may
be a polyphenylene oxide/polystyrene resin, a polycarbonate resin,
a polyacetal resin, a polyacrylic resin, a polycarbonate/denatured
polyphenylene ether resin, a polybutylene terephthalate resin, an
ultrahigh-molecular-weight polyethylene resin, and any other
general-purpose engineering resin; and a polysulfone resin, a
polyphenylene sulfide resin, a polyphenylene oxide resin, a
polyallylate resin, a polyether-imide resin, a polyimide resin, a
liquid crystal polyester resin, a polyallyl heat-resistant resin,
and any other suitable super-engineering resin. In particular, a
resin material having a molding shrinkage rate of 0.6% or lower is
more preferably used for the resin frame 3 from the viewpoint of
warping prevention, and an example of such a resin material is a
polyacrylic resin. The resin frame 3 may or may not be colored.
[0079] The flat plate 2 is integrated with the resin frame 3 in the
following manner. First, the flat plate 2 is introduced into a
molding die comprising a movable die and a stationary die, and
secured in a predetermined position on the cavity surface, for
example, through vacuum suction. After the molding die is closed, a
molten resin is injected through a gate into the cavity to fill it.
The resin frame 3 is formed and at the same time bonded to the flat
plate 2. After the resin frame 3 is cooled, the molding die is
opened and the integrated flat plate 2 and resin frame 3 is
removed. When a vertical molding die, which opens vertically, is
used, the flat plate 2 can be secured without using vacuum suction
or other methods.
[0080] The integrated flat plate 2 and resin frame 3 may have a box
shape (see FIGS. 2 to 4) or a lid shape (see FIGS. 5 and 6: The
broken line represents a counterpart back case). FIG. 2 is a
cross-sectional view taken along the line shown in FIG. 1, and
FIGS. 3 to 6 show other embodiments of that shown in FIG. 2. In
either case, the box shape or the lid shape, setting the dimension
of the flat plate 2 to be slightly smaller than that of the front
portion of the housing case 1 as shown in FIGS. 2, 5, and 6
provides more degrees of freedom in designing the exterior
appearance of the housing case 1 than a case where the dimension of
the flat plate 2 is the same as that of the front portion of the
housing case 1 as shown in FIGS. 3 and 4. For example, it is
possible to design the housing case 1 in such a way that the
corners thereof are rounded (see FIGS. 2, 5, and 6). When a box
shape is employed, setting the width of the portion where the flat
plate 2 is integrated with resin frame 3 to be greater than the
thickness of the sidewall of the box as shown in FIGS. 2 and 3
increases the area that supports the flat plate 2 accordingly,
whereby the housing case 1 is more strengthened.
[0081] Roughening the backside periphery of the flat plate 2 allows
the flat plate 2 to more intimately adhere to the resin frame
3.
[0082] The configuration of the housing case 1 of the invention is
not limited to the aspect described above. For example, the resin
frame 3 may support one, two, or three sides of the backside
periphery (see FIGS. 7 to 10), or a plurality of divided portions
of the resin frame 3 may support the backside periphery of the flat
plate 2 (see FIGS. 11 and 12). In these cases, molding shrinkage of
the resin frame 3, if any during the cooling solidification, will
likely not affect the whole flat plate 2. Specifically, the housing
case will less likely warp than the case where the resin frame 3
supports the entire backside periphery of the flat plate 2.
Further, when the resin frame 3 does not support the entire
backside periphery of the flat plate 2, input/output terminals and
other components are readily provided on a side surface of the
housing case 1.
[0083] The flat plate 2 may have decoration on the backside of the
glass plate (not shown). Since the glass plate has a sufficient
hardness (at least 9H), it is unlikely scratched, and the
decoration on the backside viewed through the glass plate will not
be degraded in terms of aesthetics.
[0084] The decoration on the backside of the glass plate is
preferably formed by printing a decoration layer. Preferred
examples of the material of the decoration layer include a
polyvinyl chloride resin, a polyamide resin, a polyester resin, a
polyacrylic resin, a polyurethane resin, a polyvinyl acetal resin,
a polyester urethane resin, a cellulose ester resin, and an alkyd
resin, any of which is used as a binder along with a coloring ink
containing a pigment or a dye having an appropriate color as a
coloring agent. A preferred example of the printing method is
screen printing. For a solid single color, a variety of coating
methods, such as spray coating, can be used.
[0085] The decoration layer may alternatively comprise a metal thin
film layer or a combination of a printed layer and a metal thin
film layer. The metal thin film layer serves to exhibit metallic
luster as the decoration layer and is formed by using vacuum
deposition, sputtering, ion plating, plating, or any other suitable
method. In this case, aluminum, nickel, gold, platinum, chromium,
iron, copper, tin, indium, silver, titanium, lead, zinc, or any
other suitable metal, or any of the alloys or compounds thereof is
used in accordance with the metallic luster color to be exhibited.
To form a partial metal thin film layer, for example, after a
solvent-soluble resin layer is formed on the portion where no metal
thin film layer is required, a metal thin film is formed over the
surface, and the solvent-soluble resin layer and the unnecessary
metal thin film thereon are removed by solvent cleaning. The
solvent used in this process is water or an aqueous solution in
many cases. Alternatively, a metal thin film is formed over the
surface, and a resist layer is formed on the portion where the
metal thin film needs to be left. Acid or alkali is used to etch
away the resist layer.
[0086] When the housing case 1 is used for a device including a
display device, the flat plate 2 may have decoration on the front
surface and/or the rear surface of the glass plate except at least
a display window for the display device (see FIG. 13). In FIG. 13,
the portion (b) is an exploded view of the portion (a), and
reference characters 2A and 2B denote a decorated portion and an
undecorated portion, respectively. When the front surface of the
glass plate is decorated, the display screen of the display device
viewed through the glass plate in the undecorated portion 2B will
not be degraded in terms of clarity, because the glass plate has
such a sufficient hardness (at least 9H) that it is unlikely to be
scratched. When the rear surface of the glass plate is decorated,
not only will the display screen not be degraded in terms of
clarity as in the case where the front surface of the glass plate
is decorated, because the glass plate has such a sufficient
hardness (at least 9H) that it is unlikely to be scratched, but
also the decoration on the rear surface viewed through the glass
plate in the decorated portion 2A will not be degraded in terms of
aesthetics.
[0087] The flat plate 2 of the housing case 1 of the invention may
include a layer that allows the flat plate 2 to adhere more
intimately to the resin frame 3. For example, an undecorated rear
surface of a glass plate 2E may be integrated with the resin frame
3 with an adhesive layer for glass 2F, a primer layer 2G, and an
adhesive layer for resin 2H interposed between the rear surface of
the glass plate 2E and the resin frame 3 (see FIG. 14). FIG. 14 is
an enlarged cross-sectional view of the flat plate 2, and reference
character 2D in FIG. 14 denotes a front surface decoration
layer.
[0088] The adhesive layer for glass 2F may be made of a known
adhesive for glass, which can be, for example, an adhesive for
glass made of a polyester resin.
[0089] The primer layer 2G may be made of a known primer material,
which can be, for example, a primer material made of a polyester
resin. When the adhesive layer for glass 2F strongly adheres to the
adhesive layer for resin 2H, the primer layer 2G can be
omitted.
[0090] The adhesive layer for resin 2H may be made of a known
adhesive for resin, which can be, for example, an adhesive for
resin made of a vinyl chloride/vinyl acetate/acrylic resin.
[0091] The flat plate 2 of the housing case 1 of the invention may
alternatively include the layer described below that allows the
flat plate 2 to adhere more intimately to the resin frame 3.
Specifically, the rear surface of the glass plate 2E is decorated,
and the layer containing the decoration also serves as an adhesive
layer for glass in the portion where the rear surface of the flat
plate 2 is integrated with the resin frame 3. The rear surface of
the flat plate 2 can be integrated with the resin frame 3 with the
primer layer 2G and the adhesive layer for resin 2H interposed
between the rear surface of the flat plate 2 and the resin frame 3
(see FIG. 15). FIG. 15 is an enlarged cross-sectional view of the
flat plate 2. Reference character 2I in FIG. 15 denotes the
backside decoration layer, which also serves as the adhesive layer
for glass in the integrated portion. The decorative layer/adhesive
layer for glass can be made of the same material as that of the
adhesive layer for glass 2F described above but containing a
pigment or a dye having an appropriate color as a coloring agent.
In this case, the glass plate is unlikely to be scratched because
it has a sufficient hardness (at least 9 H), whereby the decoration
on the rear surface viewed through the glass plate will not be
degraded in terms of aesthetics.
[0092] The adhesive layer for glass 2F, the primer layer 2G, the
adhesive layer for resin 2H, and the decorative layer/adhesive
layer for glass may be formed, for example, by screen printing.
[0093] The flat plate 2 of the housing case 1 of the invention may
have an opening 2C (see FIG. 16). The housing case 1 shown in FIG.
16 is integrated with a back case (not shown), and the resultant
integrated case houses a substrate on which a flash memory or other
electronic elements, a liquid crystal panel or other display
devices, a piezoelectric speaker for outputting an operating sound,
a battery, and an operation panel that fits in the opening 2C are
mounted. A digital audio player is thus formed. The portion (b) in
FIG. 16 is an exploded view of the portion (a).
[0094] When the flat plate 2 of the housing case 1 of the invention
has the opening 2C, it is further preferable to provide an opening
resin frame 4 integrated with the flat plate 2 to support the
surrounding portion of the opening 2C, as shown in FIG. 17. The
thus configured housing case 1 is further strengthened. The opening
resin frame 4 can be implemented in a variety of aspects as in the
case of the resin frame 3. The portion (b) in FIG. 17 is an
exploded view of the portion (a).
[0095] When the housing case 1 of the invention is configured in
such a way that the resin frame 3 covers the side surfaces of the
flat plate 2 not to create any step as shown in FIGS. 2, 5, and 6,
there is no risk that the flat plate 2 is peeled off the resin
frame 3 when any of the side surfaces of the flat plate 2 is caught
by something when the product is in use.
2. Glass Insert Molding Die and Method for Manufacturing Housing
Case
[0096] A glass insert molding die and a method for manufacturing
the housing case will now be described. First, the housing case 1
provided in the present embodiment will be described with reference
to FIGS. 26, 29, 30, 33, and 35. Any of the housing cases 1 shown
in FIGS. 26, 29, 30, 33, and 35 includes the flat plate 2, which
takes up almost all the front area of the housing case and
comprises at least a glass plate, and the resin frame 3, which
supports the backside periphery of the flat plate 2 and is
integrated with the flat plate 2 in such a way that the resin frame
3 covers at least the portion of the end surfaces of the flat plate
2 that is connected to the supported portion. In FIGS. 26, 29, 30,
33, and 35, the portion (a) is a front view; the portion (b) is a
rear view; and the portions (c) and (d) are cross-sectional views.
The housing case 1 is integrated with a back case (not shown), and
the resultant integrated case houses a substrate on which a variety
of electronic components are mounted. A small electric device or
communication device is thus formed.
[0097] In the invention, the resin frame 3, which is integrated
with the periphery of the rear surface of the flat plate 2, is
insert-molded. For example, in FIGS. 26, 33, and 35, the resin
frame 3 supports all the backside periphery of the flat plate 2,
whereas in FIGS. 29 and 30, the resin frame 3 supports a
substantially C-shaped portion obtained by cutting part of the
backside periphery of the flat plate 2. Since the resin frame 3 of
the invention is not in contact with the whole flat plate 2,
molding shrinkage of the resin frame 3, if any during the cooling
solidification, will likely not affect the whole flat plate 2. The
resultant housing case will therefore not suffer from warping.
[0098] Further, in the invention, since the resin frame 3 covers
the end surfaces of the flat plate 2, there is no risk of the flat
plate 2 peeling off the resin frame 3 when any of the end surfaces
of the flat plate 2 is caught by something when the product is in
use.
[0099] The flat plate 2 is integrated with the resin frame 3 by
using a glass insert molding die, which will be described
below.
[0100] The glass insert molding die includes a stationary die 15
and a movable die 10 that sandwich the flat plate 2 primarily
comprising a glass plate when the dies are closed and form a cavity
that faces not only the periphery of the flat plate 2 facing the
stationary die 15 but also the end surfaces of the flat plate 2.
The stationary die 15 includes a sliding core 5 having a bottom
portion that comes into contact with the periphery of the flat
plate 2 facing the stationary die 15 (hereinafter referred to as a
front-end bottom portion 5b) and a wall portion that is connected
to the front-end bottom portion 5b and positionally comes into
contact with the end surfaces of the flat plate 2 (hereinafter
referred to as a front-end wall portion 5a). The front-end wall
portion 5a and the front-end bottom portion 5b are provided at the
front end of the sliding core 5. The stationary die 15 further
includes suction holes 8 provided in the surface where the flat
plate 2 is sandwiched (hereinafter referred to as a flat plate
abutting surface 7) (see FIGS. 18 and 19). FIG. 19 is a
cross-sectional view taken along the line XIX-XIX shown in FIG.
18.
[0101] The sliding core 5 is capable of being advanced and
retracted using a drive unit (not shown) in the direction in which
the dies are closed between a flat plate positioning position I and
a cavity forming position II. The flat plate positioning position I
is the position where the front-end bottom portion 5b does not
protrude from the surface of the stationary die 15 where the flat
plate 2 is sandwiched but the front-end wall portion 5b comes into
contact with the flat plate 2 (see FIGS. 19, 21 and 22). The cavity
forming position II is the position where the front-end bottom
portion 5b and the front-end wall portion 5a are separated from the
flat plate 2 (see FIGS. 23 and 24). The sliding core 5 is capable
of being advanced to a glass insert mold pushing position III where
the front-end bottom portion 5b protrudes from the flat plate
abutting surface 7 of the stationary die 15 as required (see FIG.
25).
[0102] In FIGS. 19, 21, and 22, the front-end bottom portion 5b of
the sliding core 5 is seamlessly connected with the flat plate
abutting surface 7 of the stationary die 15. A groove 14 may
alternatively be formed between the front-end bottom portion 5b and
the flat plate abutting surface 7 (see FIG. 34). In this case, the
area of the resin frame 3 that is integrated with the backside
periphery of the flat plate 2 increases by the amount of the resin
that fills the groove 14 in the molding process. The flat plate
positioning position I may be set in such a way that the front-end
bottom portion 5b is flush with the flat plate abutting surface 7
of the stationary die 15 as shown in FIGS. 19, 21, and 22. The flat
plate positioning position I may alternatively be set in such a way
that the front-end bottom portion 5b is retracted from the flat
plate abutting surface 7 of the stationary die 15, because the flat
plate 2 can be positioned as long as the front-end wall portion 5a
comes into contact with the end surfaces of the flat plate 2.
[0103] The front-end wall portion 5a to positionally come into
contact with the end surfaces of the flat plate 2 can be formed
into two U-shaped portions facing each other when viewed in the
direction perpendicular to a die parting plane 6, for example, as
shown in FIG. 18. The arrangement of the front-end wall portion 5a
is, of course, not limited to the aspect described above, but the
arrangement may be determined as appropriate not to misalign the
flat plate 2 in accordance with the shape of the flat plate 2. For
example, the front-end wall portion 5a can be disposed at each
corner of the flat plate 2 or at part of each side of the flat
plate 2. The flat plate 2 can have an arbitrary shape, such as a
rectangle with rounded corners as shown in FIG. 18, a rectangle
with square corners, and an ellipse. Further, the number of sliding
cores 5 is not limited to a specific number. Moreover, the sliding
core 5 may be partially provided along the perimeter of the flat
plate 2 as shown in FIG. 18, or the front-end wall portion 5a may
completely surround the flat plate 2.
[0104] A method for manufacturing the housing case 1 using the thus
configured glass insert molding die will now be described.
[0105] First, after the sliding core 5 is moved to the flat plate
positioning position I, the flat plate 2 is placed on the flat
plate abutting surface 7 of the stationary die 15 (see FIGS. 20 and
21). FIG. 21 is a cross-sectional view taken along the line XXI-XXI
shown in FIG. 20.
[0106] In this positioned state, the flat plate 2 is suctioned and
secured on the flat plate abutting surface 7 as a result of air 12
being suctioned through the suction holes 8 provided in the flat
plate abutting surface 7 (see FIG. 22). The process by which the
flat plate is suctioned and secured is not necessarily limited to
the suctioning of air. For example, suction cups may be provided on
the surface where the flat plate 2 is sandwiched.
[0107] The movable die 10 is then advanced toward the stationary
die 15 to which the flat plate 2 has adhered so as to close the
dies, whereby the movable die 10 and the flat plate abutting
surface 7 of the stationary die 15 sandwich the flat plate 2, and
the stationary die 15, the movable die 10, and the flat plate 2
form a cavity 13, which is a die space (see FIG. 23). At this
point, the drive unit (not shown) retracts the sliding core 5 to
the position where the front-end bottom portion 5b is separated by
a predetermined distance from the backside periphery of the flat
plate 2, and a molten resin can now reach the portion that was in
contact with the front-end wall portion 5a and the front-end bottom
portion 5b of the sliding core 5 (cavity forming position II). The
retraction of the sliding core 5 may be carried out at any of the
following points in time immediately before the movable die 10
starts being advanced, during the forward movement, and immediately
after the advancing movement is completed.
[0108] After the sliding core 5 is moved to the cavity forming
position II and the cavity 13 is filled with the molten resin
injected through a gate 11, the resin frame 3 is integrated with
the flat plate 2 in such a way that the resin frame 3 supports the
backside periphery of the flat plate 2 and covers the portion of
the end surfaces of the flat plate 2 that is connected to the
supported portion. The housing case 1, which is the glass insert
mold, is thus obtained (see FIG. 24).
[0109] The molten resin may be a polystyrene resin, a polyolefin
resin, an ABS resin, an AS resin, an AN resin, or any other
suitable general-purpose resin. Other useable materials may be a
polyphenylene oxide/polystyrene resin, a polycarbonate resin, a
polyacetal resin, a polyacrylic resin, a polycarbonate/denatured
polyphenylene ether resin, a polybutylene terephthalate resin, an
ultrahigh-molecular-weight polyethylene resin, and any other
general-purpose engineering resin; and a polysulfone resin, a
polyphenylene sulfide resin, a polyphenylene oxide resin, a
polyallylate resin, a polyether-imide resin, a polyimide resin, a
liquid crystal polyester resin, a polyallyl heat-resistant resin,
and any other suitable super-engineering resin. In particular, a
resin material having a molding shrinkage rate of 0.6% or lower is
more preferably used for the resin frame 3 in terms of preventing
warping, and an example of such a resin material is a polyacrylic
resin. The resin frame 3 may or may not be colored.
[0110] After the movable die 10 is refracted to be separated from
the stationary die 15, specifically, the dies are opened, the drive
unit forwards the sliding core 5 to the glass insert mold pushing
position III (see FIG. 25). In this process, the sliding core 5
serves as an ejector pin, and the housing case 1 is smoothly
separated from the stationary die 15. The housing case 1 can thus
be readily removed from the die device. When a dedicated ejector
pin is separately prepared, the sliding core 5 is not necessarily
used to push the glass insert mold.
[0111] As described above, in the method for manufacturing the
housing case using the glass insert molding die according to the
present embodiment, since the sliding core 5 not only forms the
cavity for molding the resin frame 3 for supporting the backside
periphery but also serves as the mechanism for positioning the flat
plate 2 as well as the mechanism for pushing the glass insert mold
as required, the housing case 1 can be manufactured at a low
cost.
[0112] The integrated flat plate 2 and resin frame 3 may have a lid
shape (see FIGS. 26, 29, and 30) or a box shape (see FIGS. 33 and
35). FIGS. 26(c) and 26(d) are cross-sectional views taken along
the lines XXVIc-XXVIc and XXVId-XXVId in FIG. 26(b), respectively.
FIGS. 29(c) and 29(d) are cross-sectional views taken along the
lines XXIXc-XXIXc and XXIXd-XXIXd in FIG. 29(b), respectively.
FIGS. 30(c) and 30(d) are cross-sectional views taken along the
lines XXXc-XXXc and XXXd-XXXd in FIG. 30(b), respectively. Even
when the box shape is employed, it is conceivable that a box
sidewall cavity is formed outside the sliding core 5 as shown in
FIG. 33, or a sidewall cavity is formed by refracting the sliding
core 5 as shown in FIG. 35. The same notation as that used in the
above cases applies to FIGS. 33 and 35. FIGS. 33(c) and 33(d) are
cross-sectional views taken along the lines XXXIIIc-XXXIIIc and
XXXIIId-XXXIIId in FIG. 33(b), respectively. FIGS. 35(c) and 35(d)
are cross-sectional views taken along the lines XXXVc-XXXVc and
XXXVd-XXXVd in FIG. 35(b), respectively.
[0113] Among the backside periphery and end surfaces of the flat
plate 2, the portions that do not correspond to the sliding core 5
are not necessarily integrated with the resin frame 3 as shown in
FIGS. 26, 33, and 35. For example, only the end surface that does
not correspond to the sliding core 5 may be integrated with the
resin frame 3 as shown in FIG. 29, or the backside periphery or end
surface that does not correspond to the sliding core 5 may not
integrated with the resin frame 3 as shown in FIG. 30. To obtain
the housing case 1 shown in FIG. 29, the flat plate abutting
surface 7 in FIG. 18 is extended to the lower inner wall of a
cavity forming portion 9 as shown in FIG. 27 so that the
corresponding portion of the backside periphery of the glass plate
2 is not filled with the molten resin. To obtain the housing case 1
shown in FIG. 30, the flat plate abutting surface 7 in FIG. 18 is
not changed but the lower inner wall of the cavity forming portion
9 is shifted to the lower end of the flat plate abutting surface 7
as shown in FIG. 28 so that the corresponding portions of the
backside periphery and the end surface of the glass plate 2 are not
filled with the molten resin.
[0114] The flat plate 2 may be a decorated glass plate as shown in
FIGS. 26, 29, 30, 33, and 35, or may be an undecorated, skeleton
glass plate. In FIGS. 26, 29, 30, 33, and 35, reference character
2A denotes the decorated portion, and reference character 2B
denotes the undecorated portion, which becomes a transparent
window.
[0115] The decoration on the rear surface of the glass plate is
formed by printing a decoration layer. Examples of the material of
the decoration layer may include a polyvinyl chloride resin, a
polyamide resin, a polyester resin, a polyacrylic resin, a
polyurethane resin, a polyvinyl acetal resin, a polyester urethane
resin, a cellulose ester resin, and an alkyd resin, any of which is
used as a binder along with a coloring ink containing a pigment or
a dye having an appropriate color as a coloring agent. An example
of the printing method may be screen printing. For a solid single
color, a variety of coating methods, such as spray coating, can be
used.
[0116] The decoration layer may alternatively comprise a metal thin
film layer or a combination of a printed layer and a metal thin
film layer. The metal thin film layer serves to exhibit metallic
luster as the decoration layer and is formed by using vacuum
deposition, sputtering, ion plating, plating, or any other suitable
method. In this case, aluminum, nickel, gold, platinum, chromium,
iron, copper, tin, indium, silver, titanium, lead, zinc, or any
other suitable metal, or any of the alloys or compounds thereof is
used in accordance with the metallic luster color to be exhibited.
To form a partial metal thin film layer, for example, after a
solvent-soluble resin layer is formed on the portion where no metal
thin film layer is required, a metal thin film is formed over the
surface, and the solvent-soluble resin layer and the unnecessary
metal thin film thereon are removed by solvent cleaning. The
solvent used in this process is water or an aqueous solution in
many cases. Alternatively, a metal thin film is formed over the
surface, and a resist layer is formed on the portion where the
metal thin film needs to be left. Acid or alkali is used to etch
away the resist layer.
[0117] Roughening the surface of the flat plate 2 that is
integrated with the resin frame 3 allows the flat plate 2 to more
intimately adhere to the resin frame 3.
[0118] The glass insert molding die of the invention may include
simultaneous molding/painting means 16 for allowing a transfer film
17 to be sandwiched between the stationary die 15 to which the flat
plate 2 has adhered and the movable die 10 (see FIG. 36). After the
transfer film 17 is sandwiched between the stationary die 15 to
which the flat plate 2 has adhered and the movable die 10, and the
dies are closed (see FIG. 37), the painting portion of the transfer
film 17 can be transferred to the resin frame 3 integrated with the
flat plate 2 simultaneously with the injection of the molten resin.
Specifically, the glass insert molding die of the invention also
serves as a simultaneous molding/transferring die.
[0119] The transfer film 17 includes a transfer layer on an
elongated base sheet. The transfer layer has a peelable layer, a
pattern layer, an adhesive layer, and other layers sequentially
stacked. The peelable layer allows the transfer layer to be peeled
off the base sheet. The pattern layer provides the surface of an
injection-molded piece with decorative appearance and
functionality. Examples of the pattern layer include a typical
printed pattern and a conductive pattern made of a conductive
material. The adhesive layer bonds the transfer layer to the resin
frame 3, which is the molded piece.
[0120] The transfer film 17 may be adapted in such a way that a
film feeding device shown in FIG. 36 feeds the painting portion of
the transfer film 17 between the dies by a predetermined length at
a time. Alternatively, a plurality of transfer film sheets may be
fed sheet by sheet.
[0121] Any of the variety of embodiments can be combined as
appropriate to provide the respective advantageous effects. While
the invention has been adequately described with reference to the
accompanying drawings in relation to preferred embodiments, a
variety of variations and modifications shall be apparent to those
skilled in the art. Such variations and modifications should be
taken as encompassed within the scope of the invention to the
extent that they do not depart from the scope of the invention set
forth by the claims.
[0122] Examples, of the values in the above embodiments will be
described below, but the scope of the invention is not limited
thereto.
Example 1
[0123] A glass plate of 88 mm in length, 38 mm in width, and 1 mm
in thickness was prepared, and a circular opening for an operation
panel was provided in the glass plate. A decorative layer was then
formed on one side of the glass plate except a display window for a
liquid crystal screen by using screen printing along with an ink
containing a coloring agent and a polyester resin as a binder. An
adhesive layer for glass made of a polyester resin, a primer layer
made of a polyester resin, and an adhesive layer for resin made of
a vinyl chloride/vinyl acetate/acrylic resin were then sequentially
formed on the entire periphery of the undecorated side of the glass
plate by using screen printing. A flat plate was thus obtained.
[0124] The flat plate was introduced into a molding die comprising
a movable die and a stationary die, and secured in a predetermined
position on the cavity surface through vacuum suction. After the
molding die was closed, a molten polyacrylic resin was injected
through the gate to fill the cavity. A rectangular resin frame was
formed, and at the same time the resin frame was bonded to the
undecorated surface of the flat plate with the adhesive layer for
resin, the primer layer, and the adhesive layer for glass
interposed between the resin frame and the undecorated surface of
the flat plate. After the resin frame was cooled, the molding die
was opened to remove the resin frame integrated with the entire
backside periphery of the flat plate. A digital audio player
housing case of 90 mm in length, 40 mm in width, and 4 mm in height
with the corners rounded at a radius R of 1 mm was thus
obtained.
Example 2
[0125] A glass plate of 88 mm in length, 38 mm in width, and 1 mm
in thickness was prepared, and a circular opening for an operation
panel was provided in the glass plate. A decorative layer/adhesive
layer for glass was then formed on one side of the glass plate
except a display window for a liquid crystal screen by using screen
printing along with an ink containing a coloring agent and a
polyester resin as a binder. A primer layer made of a polyester
resin and an adhesive layer for resin made of a vinyl
chloride/vinyl acetate/acrylic resin were then sequentially formed
on the entire periphery of the decorated side of the glass plate by
using screen printing. A flat plate was thus obtained.
[0126] The flat plate was introduced into the molding die
comprising the movable die and the stationary die, and secured in a
predetermined position on the cavity surface through vacuum
suction. After the molding die was closed, a molten polyacrylic
resin was injected through the gate to fill the cavity. A
rectangular resin frame was formed, and at the same time the resin
frame was bonded to the decorated surface of the flat plate with
the adhesive layer for resin and the primer layer interposed
between the resin frame and the decorated surface of the flat
plate. After the resin frame was cooled, the molding die was opened
to remove the resin frame integrated with the entire backside
periphery of the flat plate. A digital audio player housing case of
90 mm in length, 40 mm in width, and 4 mm in height with the
corners rounded at a radius of 1 mm was thus obtained.
Example 3
[0127] Example 3 only differs from Example 1 in that the adhesive
layer for glass, the primer layer, and the adhesive layer for resin
were sequentially formed on not only the periphery of the glass
plate but also the entire surrounding portion of the opening in the
undecorated surface of the flat plate to form a flat plate; a
rectangular resin frame and a circular opening resin frame were
formed by using injection molding; and at the same time, the resin
frame and the opening resin frame were bonded to the undecorated
surface of the flat plate with the adhesive layer for resin, the
primer layer, the adhesive layer for glass interposed between the
resin frames and the undecorated surface of the flat plate.
Example 4
[0128] Example 4 only differs from Example 2 in that the primer
layer and the adhesive layer for resin were sequentially formed on
not only the periphery of the glass plate but also the entire
surrounding portion of the opening in the decorated surface of the
flat plate to form a flat plate; a rectangular resin frame and a
circular opening resin frame were formed by using injection
molding; and at the same time, the resin frame and the opening
resin frame were bonded to the decorated surface of the flat plate
with the adhesive layer for resin and the primer layer interposed
between the resin frames and the decorated surface of the flat
plate.
Example 5
[0129] Example 5 only differs from Example 3 in that the resin
frame is divided into two.
Example 6
[0130] Example 6 only differs from Example 4 in that each of the
resin frame and the opening resin frame is divided into two.
Example 7
[0131] A glass plate of 88 mm in length, 38 mm in width, and 1 mm
in thickness was prepared, and a circular opening for an operation
panel was provided in the glass plate. A decoration layer was then
formed on one side of the glass plate except a display window for a
liquid crystal screen by using screen printing along with an ink
containing a coloring agent and a polyester resin as a binder. An
adhesive layer for glass made of a polyester resin, a primer layer
made of a polyester resin, and an adhesive layer for resin made of
a vinyl chloride/vinyl acetate/acrylic resin were then sequentially
formed on the entire periphery of the undecorated side of the glass
plate by using screen printing. A flat plate was thus obtained.
[0132] In this case, the glass insert molding die of the invention
described above was used. After the sliding core was moved to the
flat plate positioning position, the flat plate was placed on the
surface of the stationary die where the flat plate was sandwiched,
and the positioned flat plate was suctioned by suctioning air
through the suction holes and secured on the surface where the flat
plate to be sandwiched. After the stationary die to which the flat
plate had adhered and the movable die were closed, and the sliding
core was moved to the cavity forming position, a molten resin was
injected into the cavity to integrate the flat plate with a resin
frame. After the die was opened, the sliding core was moved to the
glass insert mold pushing position and the glass insert mold was
removed. A digital audio player housing case of 90 mm in length, 40
mm in width, and 4 mm in height with the corners rounded at a
radius of 1 mm was thus obtained.
Example 8
[0133] A glass plate of 88 mm in length, 38 mm in width, and 1 mm
in thickness was prepared, and a circular opening for an operation
panel was provided in the glass plate. A decorative layer/adhesive
layer for glass was then formed on one side of the glass plate
except a display window for a liquid crystal screen by using screen
printing along with an ink containing a coloring agent and a
polyester resin as a binder. A primer layer made of a polyester
resin and an adhesive layer for resin made of a vinyl
chloride/vinyl acetate/acrylic resin were then sequentially formed
on the entire periphery of the decorated side of the glass plate by
using screen printing. A flat plate was thus obtained.
[0134] The glass insert molding was performed in the same manner as
Example 7, and a digital audio player housing case of 90 mm in
length, 40 mm in width, and 4 mm in height with the corners rounded
at a radius of 1 mm was obtained.
[0135] For all the housing cases of Examples 1 to 8, the front
portion of the case, in particular, the portion that covers the
display screen, such as an LCD, was adequately hardened.
INDUSTRIAL APPLICABILITY
[0136] The invention is preferably applicable to a housing case,
for example, for a small electric device and communication device,
a method for manufacturing the housing case, and a glass insert
molding die used in the same.
* * * * *