U.S. patent application number 16/734327 was filed with the patent office on 2020-07-09 for polymer plastic front plate and method for manufacturing the same.
This patent application is currently assigned to Enflex Corporation. The applicant listed for this patent is Enflex Corporation. Invention is credited to Hsin Yuan Chen, Yu Ling Chien, Chun Kai Wang.
Application Number | 20200215572 16/734327 |
Document ID | / |
Family ID | 71404143 |
Filed Date | 2020-07-09 |
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United States Patent
Application |
20200215572 |
Kind Code |
A1 |
Chen; Hsin Yuan ; et
al. |
July 9, 2020 |
Polymer Plastic Front Plate And Method For Manufacturing The
Same
Abstract
A polymer plastic front plate comprises: a plastic substrate and
a hard coating layer formed on an adhesion surface of the plastic
substrate. The hard coating layer comprises: organic-inorganic
hybrid UV oligomer, high Tg UV resin additive, a plurality of
dispersed flaky nano inorganic material, and photo initiator, so as
to form a gas barrier hard coating layer with high surface dyne
value (>44 dyne) on the adhesion surface of the plastic
substrate. It not only has good ink printability and OCA
adhesiveness, but also inhibits the diffusion of fugitive gas from
polymer plastic front plates during high-temperature,
high-temperature and high-humidity, high-low temperature thermal
shocks and other harsh automotive industry environmental tests. The
gas can be avoided from entering the OCA layer, thereby solving the
problems of bubbles and delamination after the environmental tests
are performed.
Inventors: |
Chen; Hsin Yuan; (Taoyuan
City, TW) ; Wang; Chun Kai; (Taoyuan City, TW)
; Chien; Yu Ling; (Taoyuan City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Enflex Corporation |
Taoyuan City |
|
TW |
|
|
Assignee: |
Enflex Corporation
Taoyuan City
TW
|
Family ID: |
71404143 |
Appl. No.: |
16/734327 |
Filed: |
January 4, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08J 2475/04 20130101;
C08J 7/042 20130101; C08J 5/18 20130101; C09D 7/61 20180101; C08J
2369/00 20130101; C09D 175/04 20130101; H05K 1/0313 20130101; B05D
7/04 20130101; C08J 2333/12 20130101; H05K 3/28 20130101; C09D 7/70
20180101 |
International
Class: |
B05D 7/04 20060101
B05D007/04; C08J 5/18 20060101 C08J005/18; C08J 7/04 20060101
C08J007/04; C09D 175/04 20060101 C09D175/04; C09D 7/40 20060101
C09D007/40; C09D 7/61 20060101 C09D007/61; H05K 1/03 20060101
H05K001/03; H05K 3/28 20060101 H05K003/28 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 8, 2019 |
TW |
108100686 |
Claims
1. A polymer plastic front plate for bonding on a touch panel,
comprising: a plastic substrate, having an operation surface and a
bonding surface; a protective layer, furnished on the operation
surface; and a hard coating layer, furnished on the bonding
surface; characterized by that: said hard coating layer comprising:
a first weight percentage of organic-inorganic hybrid UV-curable
oligomer, a second weight percentage of UV-curable resin additives
with high glass transition temperature (Tg) value, a plurality of
dispersed nano-scale flaky inorganic substances, and a photo
initiator; wherein, the plurality of dispersed nano-scale flaky
inorganic substances are arranged in a randomly distributed
horizontal direction in the hard coating layer to form a
discontinuously layered dispersed gas barrier layer in the hard
coating layer.
2. The polymer plastic front plate of claim 1, wherein the
organic-inorganic hybrid UV-curable oligomer includes a
polyurethane resin and a sol-gel silica hybrid mixture.
3. The polymer plastic front plate of claim 1, wherein the glass
transition temperature (Tg) value of the UV-curable resin additives
is not less than 120.degree. C. ; in addition, the UV-curable resin
additives contain at least one of the following: UV-curable
oligomer with high glass transition temperature (high Tg UV
oligomer) and UV-curable monomer with high glass transition
temperature (high Tg UV monomer).
4. The polymer plastic front plate of claim 3, wherein the
UV-curable oligomer with high glass transition temperature is
polyurethane acrylate, which has a glass transition temperature
(Tg) value not less than 120.degree. C.; in addition, the
UV-curable monomer with high glass transition temperature is
Tris(2-hydroxy ethyl) isocyanuratetriacrylate (THEICTA), which has
a glass transition temperature (Tg) value not less than 240.degree.
C. .
5. The polymer plastic front plate of claim 1, wherein the
nano-scale flaky inorganic substances are composed of at least one
of the following materials: SiO.sub.2, Al.sub.2O.sub.3,
Si.sub.3N.sub.4, SiO.sub.xN.sub.y, and AlO.sub.xN.sub.y.
6. The polymer plastic front plate of claim 1, wherein each of the
nano-scale flaky inorganic substances has a thickness (t), a
longitudinal width (w1) and a lateral width (w2); wherein, the
measuring directions of the thickness (t), the longitudinal width
(w1) and the lateral width (w2) are perpendicular to each other,
and w1 w2 wherein, the thickness (t) is between 0.1 nm and 50 nm,
the longitudinal width (w1) is between 100 nm and 1000 nm, and the
ratio of the lateral width to the longitudinal width (w2/w1) is
between 0.01 and 1.
7. The polymer plastic front plate of claim 6, wherein 10
nm.ltoreq.t.ltoreq.30 nm, 300 nm.ltoreq.w1.ltoreq.800 nm, and
0.1.ltoreq.(w2/w1).ltoreq.1.
8. The polymer plastic front plate of claim 1, wherein the value of
the first weight percentage is ranged between 50% and 70%, the
value of the second weight percentage is ranged between 30% and
50%, and the value of the weight percentage of the nano-scale flaky
inorganic substances in the hard coating layer is between 5% and
15%.
9. The polymer plastic front plate of claim 1, wherein the plastic
substrate is one of the following: polymethyl methacrylate (PMMA)
plate, polycarbonate (PC) plate, PMMA/PC double-layer composite
plate, and PMMA/PC/PMMA three-layer composite plate; in addition,
the surface of the hard coating layer can be applied with an ink
layer and an optical clear adhesive (OCA) layer for attaching to
the surface of the touch panel.
10. A method for manufacturing a polymer plastic front plate,
comprising: Step (A): providing a plastic substrate and a coating
material; the plastic substrate having a bonding surface; said
coating material including: a first weight percentage of
organic-inorganic hybrid UV-curable oligomer, a second weight
percentage of UV-curable resin additives with high glass transition
temperature (Tg) value, a plurality of dispersed nano-scale flaky
inorganic substances, and a photo initiator; Step (B): applying the
coating material onto the bonding surface of the plastic substrate;
Step (C): curing the coating material to form a hard coating layer
on the bonding surface of the plastic substrate; wherein, during
the curing process, the plurality of dispersed nano-scale flaky
inorganic substances will be affected by the gravity and
hydrodynamics, and randomly dispersed and arranged along a
horizontal direction in a parallel manner within the hard coating
layer, such that the plurality of dispersed nano-scale flaky
inorganic substances can form a discontinuously layered dispersed
gas barrier layer in the hard coating layer.
11. The method for manufacturing a polymer plastic front plate of
claim 10, wherein the process for providing the coating material
described in Step (A) comprises the following steps: Step (A1):
forming an inorganic layer on a carrier plate; Step (A2): detaching
and braking the inorganic layer into a plurality of tiny inorganic
fragments; Step (A3): smoothing and dispersing the plurality of
tiny inorganic fragments in order to transform the plurality of
tiny inorganic fragments into the plurality of dispersed nano-scale
flaky inorganic substances; and Step (A4): adding and mixing the
plurality of dispersed nano-scale flaky inorganic substances into a
solution of the organic-inorganic hybrid UV-curable oligomer, the
UV-curable resin additive and the photo initiator to form the
coating material.
12. The method for manufacturing a polymer plastic front plate of
claim 11, wherein: in Step (A1), the carrier plate is a glass
carrier plate, and a release film is provided on a surface of the
glass carrier plate; an inorganic material is plated on the release
film by a vacuum sputtering process in order to form a whole piece
of the inorganic layer on the surface of the release film; in Step
(A2), the inorganic layer is broken by shaking, vibrating or
striking the carrier plate, such that the broken inorganic layer
can be detached from the release film of the carrier plate and be
broken into the plurality of tiny inorganic fragments; in Step
(A3), the plurality of tiny inorganic fragments are mixed and
stirred by a nano dispersion equipment, so that the plurality of
tiny inorganic fragments can collide with each other to gradually
smooth their sharp edges and also disperse them evenly and
individually, so as to form the plurality of dispersed nano-scale
flaky inorganic substances.
13. The method for manufacturing a polymer plastic front plate of
claim 10, wherein the organic-inorganic hybrid UV-curable oligomer
includes a polyurethane resin and a sol-gel silica hybrid
mixture.
14. The method for manufacturing a polymer plastic front plate of
claim 10, wherein the glass transition temperature (Tg) value of
the UV-curable resin additives is not less than 120.degree. C.; in
addition, the UV-curable resin additives contain at least one of
the following: UV-curable oligomer with high glass transition
temperature (high Tg UV oligomer) and UV-curable monomer with high
glass transition temperature (high Tg UV monomer).
15. The method for manufacturing a polymer plastic front plate of
claim 14, wherein the UV-curable oligomer with high glass
transition temperature is polyurethane acrylate, which has a glass
transition temperature (Tg) value not less than 120.degree. C. ; in
addition, the UV-curable monomer with high glass transition
temperature is Tris(2-hydroxy ethyl) isocyanuratetriacrylate
(THEICTA), which has a glass transition temperature (Tg) value not
less than 240.degree. C.
16. The method for manufacturing a polymer plastic front plate of
claim 10, wherein the nano-scale flaky inorganic substances are
composed of at least one of the following materials: SiO.sub.2,
Al.sub.2O.sub.3, Si.sub.3N.sub.4, SiO.sub.xN.sub.y, and
AlO.sub.xN.sub.y.
17. The method for manufacturing a polymer plastic front plate of
claim 10, wherein each of the nano-scale flaky inorganic substances
has a thickness (t), a longitudinal width (w1) and a lateral width
(w2); wherein, the measuring directions of the thickness (t), the
longitudinal width (w1) and the lateral width (w2) are
perpendicular to each other, and w1.gtoreq.w2.gtoreq.t; wherein,
the thickness (t) is between 0.1 nm and 50 nm, the longitudinal
width (w1) is between 100 nm and 1000 nm, and the ratio of the
lateral width to the longitudinal width (w2/w1) is between 0.01 and
1.
18. The method for manufacturing a polymer plastic front plate of
claim 17, wherein 100 nm.ltoreq.t.ltoreq.30 nm, 300
nm.ltoreq.w1.ltoreq.800 nm, and 0.1.ltoreq.(w2/w1).ltoreq.1.
19. The method for manufacturing a polymer plastic front plate of
claim 10, wherein the value of the first weight percentage is
ranged between 50% and 70%, the value of the second weight
percentage is ranged between 30% and 50%, and the value of the
weight percentage of the nano-scale flaky inorganic substances in
the hard coating layer is between 5% and 15%.
20. The method for manufacturing a polymer plastic front plate of
claim 10, wherein the plastic substrate is one of the following:
polymethyl methacrylate (PMMA) plate, polycarbonate (PC) plate,
PMMA/PC double-layer composite plate, and PMMA/PC/PMMA three-layer
composite plate; in addition, the surface of the hard coating layer
can be applied with an ink layer and an optical clear adhesive
(OCA) layer for attaching to the surface of the touch panel.
Description
BACKGROUND OF INVENTION
1. Field of the Invention
[0001] The invention refers to a polymer plastic front plate and a
method for manufacturing the same, especially refers to a polymer
plastic front plate which is suitable for bonding on the surface of
automotive touch panels.
2. Description of the Prior Art
[0002] Generally speaking, a touch panel on a touch-sensitive
electronic device for a car is usually fitted with a front panel,
not only because the front panel can protect the touch panel from
scratches, but also because the front panel can also be printed
with specific patterns or text for marking a specific touch area on
the touch panel so as to improve the convenience of the user to
operate the touch panel.
[0003] Please refer to FIG. 1, which is a schematic diagram of a
typical example of a conventional technology, in which a front
panel is attached to the front surface of a touch panel. The front
panel 10 currently used for laminating on a touch panel is usually
composed of a polymer plastic material, which comprises a plastic
substrate 11 primary made of polymethyl methacrylate (PMMA) or
polycarbonate (PC), a protective layer 12 disposed on an operation
surface (outer surface) of the plastic substrate 11, and a hard
coating layer 13 disposed on a bonding surface (inner surface) of
the plastic substrate 11. The protective layer 12 and the hard
coating layer 13 are applied to two different surfaces of the
plastic substrate 11 by a hard coating (HC) technology. Currently,
common HC materials include UV-curable multifunctional high surface
tension oligomers (Oligomer) or high surface tension monomer
formulations, which can be formed as a thin film on the surface of
the plastic substrate 11 for increasing the hardness thereof, so as
to provide a scratch-resistant effect. HC technology is mainly used
on the surface of soft substrates, such as PC or PMMA plastic
substrates 11. These kinds of plastic substrate 11 are relatively
soft. After the surface is hardened by hard coating, the hardness
can be as hard as glass, which is easy to be wiped clean and uneasy
to be scratched. In addition, an ink layer 21 of a specific pattern
or text can be printed on the surface of the hard coating layer 13
formed on the bonding surface of the plastic substrate 11 by means
of ink printing; after that, an optical clear adhesive 22 (OCA) is
applied to the hard coating layer 13 formed on the bonding surface
of the plastic substrate 11, and then the front panel 10 is
attached to the touch panel 23, letting the hard coating layer 13
and the ink layer 21 to be sandwiched between the plastic substrate
11 and the touch panel 23 and are adhesively bonded by the optical
clear adhesive 22.
[0004] The composition of HC materials of the hard coating layer 13
formed on the bonding surface of the conventional plastic substrate
11 is a highly cross-linked ultraviolet light curing typed
(UV-curable) resin formulation, for example, a multifunctional high
surface tension oligomer formulation or a high surface tension
monomer formulation. The highly cross-linked UV-curable resin
formulation is coated on the OCA bonding surface of PC or PMMA
plastic substrate 11, which not only can provide ink-printability
and scratch resistance abilities to the bonding surface of the
plastic substrate 11, but also can avoid surface damage caused by
ink printing process. Although the composition of HC materials of
the hard coating layer 13 of the conventional plastic substrate 11
has a high surface dyne value (>38 dyne), which is capable of
ink printing and suitable for optical clear adhesive 22 (OCA)
bonding, and has good adhesion with the optical clear adhesive 22
(OCA); however, because the ordinary multifunctional high surface
tension oligomer and high surface tension monomer formula are not
effective in blocking gas diffusion, therefore, it is still
impossible to pass the environmental tests of harsh
high-temperature, high-temperature and high-humidity, and high-low
temperature (hot and cold) thermal shocks for the front panel 10 of
the touch panel of vehicle electronic device in the automotive
industry. Thus, the front panel 10 will suffer problems such as
outgassing, delay bubbles caused by moisture intrusion, and
delamination after the environmental tests.
[0005] In the embodiments described below, since most of the
elements are the same or similar to the typical example shown in
FIG. 1, the same or similar elements will be given with the same
name and numeral directly, and will not be described in detail.
[0006] Please refer to FIG. 2, which is a schematic diagram of
another typical example of a conventional front panel. In order to
improve the effect for blocking the diffusion of gas, one approach
is to additionally provide a "single-layer" continuous gas barrier
layer 14 on the hard coating layer 13 formed on the bonding surface
of the front panel 10a. The material of the single-layer continuous
gas barrier layer 14 can be an air-impermeable material such as
alumina, and is completely covering the entire surface of the hard
coating layer 13. The advantage of this approach is that the
continuity of the gas barrier layer 14 and the optical clear
adhesive 22 (OCA) is good, and the initial gas barrier effect is
excellent. However, since the continuous gas barrier layer 14 is
subjected to the environmental tests with high-low temperature (hot
and cold) thermal shocks, many micro or nano cracks will be
generated, and thus, the gas barrier effect becomes poor after the
environmental tests; in addition, the continuous gas barrier layer
14 must be formed by using vacuum coating process, the costs is
high, and the production efficiency is low; furthermore, the
printability of ink of the continuous gas barrier layer 14 is poor
(poor adhesion between the inorganic layer material and the ink);
therefore, such approach is not a good solution.
[0007] Please refer to FIG. 3, which is a schematic diagram of a
further typical example of a conventional front panel. Another
approach of the prior art is to add a plurality of dispersed
spherical nano gas barrier particles 212 into the hard coating
layer 210 formed on the bonding surface of the front panel 20.
These spherical nano gas barrier particles 212 can be made of
air-impermeable material such as alumina, and are discontinuously
dispersed in the highly cross-linked UV-curable resin material 211
included in the entire hard coating layer 210, in order to form a
discontinuous gas barrier structure in the hard layer 210. The
advantages of this approach are that the adhesion between the hard
coating layer 210 and the optical clear adhesive (OCA) is good, and
the printability of ink is also good; in addition, the material of
spherical nano gas barrier particles 212 is also easy to get.
However, because the gas barrier structure included in the hard
coating layer 210 is discontinuous, there are many gaps between
these spherical nano gas barrier particles 212, therefore the
initial gas barrier effect for blocking the gas diffusion is not
good, and the effect for blocking the gas diffusion after the
environmental test is also poor, and thus leaves a room for further
improvements.
SUMMARY OF THE INVENTION
[0008] The primary objective of the invention is to provide a
polymer plastic front plate suitable for bonding on the surface of
automotive touch panels, which can form a gas barrier hard coating
layer with high surface dyne value (>44 dyne) on the adhesion
surface of the plastic substrate. It not only has good ink
printability and OCA adhesiveness, but also inhibits the diffusion
of fugitive gas from polymer plastic front plates during
high-temperature, high-temperature and high-humidity, high-low
temperature (hot and cold) thermal shocks and other harsh
automotive industry environmental tests. The gas can be avoided
from entering the OCA layer, thereby solving the problems of
bubbles and delamination after the environmental tests are
performed.
[0009] Another objective of the invention is to provide a method
for manufacturing a polymer plastic front plate suitable for
bonding on the surface of automotive touch panels, which can apply
a hard coating layer on the bonding surface of the plastic
substrate by using a hard coating (HC) technology. Wherein, the
hard coating layer contains a plurality of dispersed nano-scale
flaky inorganic substances arranged in a randomly distributed
horizontal direction in the hard coating layer, so as to form a
discontinuously layered dispersed gas barrier layer in the hard
coating layer. Not only can provide good gas barrier effect but
also can prevent cracks from happening.
[0010] In order to achieve the aforementioned objectives, the
invention provides a polymer plastic front plate which comprises: a
plastic substrate having an operation surface and a bonding
surface, a protective layer furnished on the operation surface, and
a hard coating layer furnished on the bonding surface; wherein the
hard coating layer comprises: a first weight percentage of
organic-inorganic hybrid UV-curable oligomer, a second weight
percentage of UV-curable resin additives with high glass transition
temperature (Tg) value, a plurality of dispersed nano-scale flaky
inorganic substances, and a photo initiator; wherein, the plurality
of dispersed nano-scale flaky inorganic substances are arranged in
a randomly distributed horizontal direction in the hard coating
layer to form a discontinuously layered dispersed gas barrier layer
in the hard coating layer.
[0011] In a preferred embodiment, the organic-inorganic hybrid
UV-curable oligomer includes a polyurethane resin and a sol-gel
silica hybrid mixture.
[0012] In a preferred embodiment, the glass transition temperature
(Tg) value of the UV-curable resin additives is not less than
120.degree. C. ; in addition, the UV-curable resin additives
contain at least one of the following: UV-curable oligomer with
high glass transition temperature (high Tg UV oligomer) and
UV-curable monomer with high glass transition temperature (high Tg
UV monomer).
[0013] In a preferred embodiment, the UV-curable oligomer with high
glass transition temperature is polyurethane acrylate, which has a
glass transition temperature (Tg) value not less than 120.degree.
C.; in addition, the UV-curable monomer with high glass transition
temperature is Tris(2-hydroxy ethyl) isocyanuratetriacrylate
(THEICTA), which has a glass transition temperature (Tg) value not
less than 240.degree. C.
[0014] In a preferred embodiment, the nano-scale flaky inorganic
substances are composed of at least one of the following materials:
SiO.sub.2, Al.sub.2O.sub.3, Si.sub.3N.sub.4, SiO.sub.xN.sub.y, and
AlO.sub.xN.sub.y.
[0015] In a preferred embodiment, each of the nano-scale flaky
inorganic substances has a thickness (t), a longitudinal width (w1)
and a lateral width (w2); wherein, the measuring directions of the
thickness (t), the longitudinal width (w1) and the lateral width
(w2) are perpendicular to each other, and w1.gtoreq.w2.gtoreq.t;
wherein, the thickness (t) is between 0.1 nm and 50 nm, the
longitudinal width (w1) is between 100 nm and 1000 nm, and the
ratio of the lateral width to the longitudinal width (w2/w1) is
between 0.01 and 1.
[0016] In a preferred embodiment, 10 nm.ltoreq.t.ltoreq.30 nm, 300
nm.ltoreq.w1.ltoreq.800 nm, and 0.1.ltoreq.(w2/w1).ltoreq.1.
[0017] In a preferred embodiment, the value of the first weight
percentage is ranged between 50% and 70%, the value of the second
weight percentage is ranged between 30% and 50%, and the value of
the weight percentage of the nano-scale flaky inorganic substances
in the hard coating layer is between 5% and 15%.
[0018] In a preferred embodiment, the plastic substrate is one of
the following: polymethyl methacrylate (PMMA) plate, polycarbonate
(PC) plate, PMMA/PC double-layer composite plate, and PMMA/PC/PMMA
three-layer composite plate; in addition, the surface of the hard
coating layer can be applied with an ink layer and an optical clear
adhesive (OCA) layer for attaching to the surface of the touch
panel.
[0019] In order to achieve the aforementioned objectives, the
invention provides a method for manufacturing a polymer plastic
front plate, comprising: Step (A): providing a plastic substrate
and a coating material;
[0020] the plastic substrate having a bonding surface; said coating
material including: a first weight percentage of organic-inorganic
hybrid UV-curable oligomer, a second weight percentage of
UV-curable resin additives with high glass transition temperature
(Tg) value, a plurality of dispersed nano-scale flaky inorganic
substances, and a photo initiator; Step (B): applying the coating
material onto the bonding surface of the plastic substrate; and
Step (C): curing the coating material to form a hard coating layer
on the bonding surface of the plastic substrate; wherein, during
the curing process, the plurality of dispersed nano-scale flaky
inorganic substances will be affected by the gravity and
hydrodynamics, and randomly dispersed and arranged along a
horizontal direction in a parallel manner within the hard coating
layer, such that the plurality of dispersed nano-scale flaky
inorganic substances can form a discontinuously layered dispersed
gas barrier layer in the hard coating layer.
[0021] In a preferred embodiment, the process for providing the
coating material described in Step (A) comprises the following
steps: Step (A1): forming an inorganic layer on a carrier plate;
Step (A2): detaching and braking the inorganic layer into a
plurality of tiny inorganic fragments; Step (A3): smoothing and
dispersing the plurality of tiny inorganic fragments in order to
transform the plurality of tiny inorganic fragments into the
plurality of dispersed nano-scale flaky inorganic substances; and
Step (A4): adding and mixing the plurality of dispersed nano-scale
flaky inorganic substances into a solution of the organic-inorganic
hybrid UV-curable oligomer, the UV-curable resin additive and the
photo initiator to form the coating material.
[0022] In a preferred embodiment, in Step (A1), the carrier plate
is a glass carrier plate, and a release film is provided on a
surface of the glass carrier plate; an inorganic material is plated
on the release film by a vacuum sputtering process in order to form
a whole piece of the inorganic layer on the surface of the release
film; in Step (A2), the inorganic layer is broken by shaking,
vibrating or striking the carrier plate, such that the broken
inorganic layer can be detached from the release film of the
carrier plate and be broken into the plurality of tiny inorganic
fragments; in Step (A3), the plurality of tiny inorganic fragments
are mixed and stirred by a nano dispersion equipment, so that the
plurality of tiny inorganic fragments can collide with each other
to gradually smooth their sharp edges and also disperse them evenly
and individually, so as to form the plurality of dispersed
nano-scale flaky inorganic substances.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The present invention will now be specified with reference
to its preferred embodiment illustrated in the drawings, in
which:
[0024] FIG. 1 is a schematic diagram of a typical example of a
conventional front panel;
[0025] FIG. 2 is a schematic diagram of another typical example of
a conventional front panel;
[0026] FIG. 3 is a schematic diagram of a further typical example
of a conventional front panel;
[0027] FIG. 4 is a schematic diagram of a preferred embodiment of a
polymer plastic front panel suitable for a sunroof of vehicle
according to the present invention;
[0028] FIG. 5 is a flow chart showing an embodiment of the method
for manufacturing the polymer plastic front plate in accordance
with the invention;
[0029] FIG. 6 is a flowchart of an embodiment of the process for
providing the coating material of the hard coating layer in
accordance with the method for manufacturing the polymer plastic
front panel of the present invention;
[0030] FIGS. 7A to 7C respectively are some schematic diagrams of
several different steps of the flowchart shown in FIG. 6, in
accordance with the method for manufacturing the polymer plastic
front panel of the present invention;
[0031] FIG. 8A to FIG. 8C respectively are the schematic diagrams
of the hard coating layer at some different stages during the
curing process of coating material in accordance with the
manufacturing method of the polymer plastic front panel of the
present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0032] The polymer plastic front plate of the invention is suitable
for bonding on the surface of automotive touch panels. By means of
the addition of organic-inorganic high Glass Transition Temperature
(Tg) UV oligomers and nano-scale flake-like inorganic oxides, a gas
barrier hard coating layer with high surface dyne value (>44
dyne) can be formed on the adhesion surface of the plastic
substrate. It not only has good ink printability and OCA
adhesiveness, but also inhibits the diffusion of fugitive gas from
polymer plastic front plates during high-temperature,
high-temperature and high-humidity, high-low temperature (hot and
cold) thermal shocks and other harsh automotive industry
environmental tests, which is due to the fact that these nano-scale
flaky inorganic oxides can form a discontinuously layered dispersed
gas barrier layer in the hard coating layer. The gas can be avoided
from entering the OCA layer, thereby solving the problems of
bubbles and delamination after the environmental tests are
performed.
[0033] In order to more clearly describe the structure of the
polymer plastic front plate and method for manufacturing the same,
detailed descriptions will be provided below with reference to the
drawings.
[0034] Please refer to FIG. 4, which is a schematic diagram of a
preferred embodiment of a polymer plastic front panel suitable for
a sunroof of vehicle according to the present invention. The
polymer plastic front panel 30 of the present invention can be
bonded on a touch panel (not shown in the figure) of a
touch-sensitive typed electronic device for a vehicle by using
optical clear adhesive (not shown in the figure), which comprises:
a plastic substrate 11, a protective layer 12 and a hard coating
layer 31. The polymer plastic front panel 30 of the present
invention can be made into a polymer plastic sheet with high
hardness, high wear resistance, high impact resistance, high
flexibility, and extremely low gas transmission rate, or be used to
replace traditional tempered glass as the cover material of touch
panel, which is particularly suitable for cover materials of
automotive touch panels in order to meet the harsh high-temperature
or high-temperature high-humidity environmental testing
specifications.
[0035] In in embodiment, the plastic substrate 11 is one of the
following: polymethyl methacrylate (PMMA) plate, polycarbonate (PC)
plate, PMMA/PC double-layer composite plate, PMMA/PC/PMMA
three-layer composite plate, or other kind of single-layer or
multi-layer co-extruded plate made of polymer materials. When the
plastic substrate is a multilayer plate, polycarbonate (PC) can be
used as the material of the main-layer with a thickness accounting
for 60%-99.99% of the total thickness of the plastic substrate. In
the other hand, each of the sub-layers located on either one side
or two opposite (outer and inner) sides of the main-layer may have
a thickness accounting for 0.01%-40% of the total thickness of the
plastic substrate, and the material of the sub-layer may be chosen
from one of the following: PMMA, Modified PMMA, Modified PC, PMMI,
PET, PEN, PES, PI, and etc. The plastic substrate 11 has a
corresponding operation surface (outer surface) and a bonding
surface (inner surface); in which, the side of the operation
surface is for the user to touch and operate the touch panel, while
the side of the bonding surface is for printing an ink layer and
for applying an optical clear adhesive in order to bond to the
touch panel. The protective layer 12 is furnished on the operation
surface (outer surface) of the plastic substrate 11, while the hard
coating layer 31 is furnished on the bonding surface (inner
surface) of the plastic substrate 11. The protective layer 12 and
the hard coating layer 31 are respectively applied to the operation
surface (outer surface) and the bonding surface (inner surface) of
the plastic substrate 11 by a hard coating (HC) technology. As
shown in FIG. 4, the surface of the hard coating layer 31 of the
invention can also be applied with both an ink layer and an optical
clear adhesive (OCA) layer for attaching to the surface of the
touch panel. In this embodiment, the thickness of the plastic
substrate 11 is between 100 .mu.m and 1000 .mu.m.
[0036] In the present invention, the thickness of the hard coating
layer 31 can be between 0.1 .mu.m and 100 .mu.m, and is better
between 1 .mu.m and 50 .mu.m, and is best between 5 .mu.m and 30
.mu.m. In this embodiment, the hard coating layer 31 is composed of
a mixture of: a coating material 32, a plurality of dispersed
nano-scale flaky inorganic substances 33, and a photo initiator;
wherein, the resin formulation of the coating material 32 includes
a first weight percentage of organic-inorganic hybrid UV-curable
oligomer, and a second weight percentage of UV-curable resin
additives with high glass transition temperature (Tg) value. In
addition, the plurality of dispersed nano-scale flaky inorganic
substances 33 are arranged in a randomly distributed horizontal
direction in the coating material 32 of the hard coating layer 31,
so as to form a discontinuously layered dispersed gas barrier layer
in the hard coating layer 31. These randomly and horizontally
distributed nano-scale flaky inorganic substances 33 not only can
provide good gas barrier effect but also can prevent cracks from
happening in the hard coating layer 31. In this embodiment, the
organic-inorganic hybrid UV-curable oligomer includes a
polyurethane resin and a sol-gel silica hybrid mixture. The glass
transition temperature (Tg) value of the UV-curable resin additives
is not less than 120; in addition, the UV-curable resin additives
contain at least one of the following: UV-curable oligomer with
high glass transition temperature (high Tg UV oligomer) and/or
UV-curable monomer with high glass transition temperature (high Tg
UV monomer). In a preferred embodiment of the invention, the
UV-curable oligomer with high glass transition temperature is
polyurethane acrylate, which has a glass transition temperature
(Tg) value not less than 120.degree. C. The UV-curable monomer with
high glass transition temperature is Tris(2-hydroxy ethyl)
isocyanuratetriacrylate (THEICTA), which has a glass transition
temperature (Tg) value not less than 240.degree. C. The nano-scale
flaky inorganic substances 33 are composed of at least one of the
following materials: SiO.sub.2, Al.sub.2O.sub.3, Si.sub.3N.sub.4,
SiO.sub.xN.sub.y, and/or AlO.sub.xN.sub.y. In this embodiment, the
value of the first weight percentage is ranged between 50% and 70%,
the value of the second weight percentage is ranged between 30% and
50%, and the value of the weight percentage of the nano-scale flaky
inorganic substances 33 in the hard coating layer is between 5% and
15%.
[0037] The organic-inorganic hybrid UV oligomer contained in the
hard coating layer 31 can provide the optical clear adhesive (OCA)
bonding surface of the polymer plastic front panel 30 with high
hardness and high wear resistance. In addition, the high Tg UV
oligomer (.gtoreq.120.degree. C.) and/or high Tg UV monomer
(.gtoreq.240.degree. C.) contained in the hard coating layer 31 can
provide the optical clear adhesive (OCA) bonding surface of the
polymer plastic front panel 30 with high impact resistance, high
flexibility, and stability at high temperatures, which can reduce
the air chamber space during the high-temperature and high-humidity
environmental tests, reduce polymer pores, and thus reduce gas
permeability. The reason why the polymer plastic front panel 30 of
the present invention contains a material with a high Tg (above
120.degree. C.) is that, when the temperature of working
environment of the polymer plastic front panel 30 is close to the
Tg point (glass transition temperature) of the polymer material,
the porosity of the polymer material will increase, which will
cause water vapor to enter. The highest testing temperature of the
environmental tests for vehicles is 90.degree. C. If the Tg of the
material is lower than or close to 90.degree. C., when the working
temperature of 90.degree. C. is reached, the polymer segment will
soften and the porosity will increase, which will cause water vapor
to penetrate more easily and fail to provide the effect of blocking
water vapor. This problem can be avoided as long as the Tg of the
resin formulation material contained in the coating material 32 of
the hard coating layer 31 is 120.degree. C. or above. Moreover, the
randomly and horizontally distributed nano-scale flaky inorganic
substances 33 contained in the coating material 32 of the hard
coating layer 31 can provide the polymer plastic front panel 30
with a very low gas transmission rate, and can also maintain high
transparency and low haze. Because these nano-scale flaky inorganic
substances 33 can form a discontinuously layered dispersed gas
barrier layer in the hard coating layer 31, which inhibits the
diffusion of fugitive gas from the polymer plastic front plate
during the high-temperature, high-temperature and high-humidity,
high-low temperature (hot and cold) thermal shocks and other harsh
automotive industry environmental tests, prevents the gas from
entering the OCA layer, solves the problems of bubbles and
delamination after the environmental tests, and thereby indeed
effectively improves the various shortcomings of the aforementioned
conventional techniques.
[0038] Please refer to FIG. 5, which is a flow chart showing an
embodiment of the method for manufacturing the polymer plastic
front plate in accordance with the invention. The method for
manufacturing the polymer plastic front plate of the invention
comprises the following steps.
[0039] Step 51: providing a plastic substrate and a coating
material of hard coating layer. Like the embodiment shown in FIG.
4, the plastic substrate of the polymer plastic front plate of the
invention has a bonding surface and an operation surface. The
coating material of the hard coating layer is a paint-like liquid
mixture including: a first weight percentage of organic-inorganic
hybrid UV-curable oligomer, a second weight percentage of
UV-curable resin additives with high glass transition temperature
(Tg) value, a plurality of dispersed nano-scale flaky inorganic
substances, a photo initiator, and volatile solvents. In one
embodiment, a protective layer has been formed on the operation
surface of the plastic substrate in advance before performing the
following Step 52. However, in another embodiment, there is no
protective layer being formed on the plastic substrate when
performing the Step 52; in contrary, such protective layer is
formed on the operation surface of the plastic substrate after the
Step 52 has been completed.
[0040] Step 52: applying the paint-like liquid coating material of
the hard coating layer onto the entire bonding surface of the
plastic substrate by using a hard coating technology.
[0041] Step 53: curing the coating material to form the hard
coating layer on the bonding surface of the plastic substrate. In
the curing process, the volatile solvent contained in the coating
material is volatilized by a baking or far-infrared (IR)
irradiating process, and the organic-inorganic hybrid UV-curable
oligomer and the UV-curable resin additive contained in the coating
material is hardened by an irradiating process of ultraviolet (UV)
light with a specific wavelength. Wherein, during the curing
process, as the solvent slowly evaporates, the plurality of
dispersed nano-scale flaky inorganic substances will be affected by
the gravity and hydrodynamics, and thus randomly dispersed and
arranged along a horizontal direction in a parallel manner within
the hard coating layer, such that the plurality of dispersed
nano-scale flaky inorganic substances can form a discontinuously
layered dispersed gas barrier layer in the hard coating layer after
the curing process is completed. Thereby, a hard coating layer
including a discontinuously layered dispersed gas barrier layer
composed of the plurality of dispersed nano-scale flaky inorganic
substances can be formed on the bonding surface of the plastic
substrate.
[0042] Please refer to FIG. 6 and FIGS. 7A to 7C, which
respectively are the flowchart of an embodiment of the process for
providing the coating material of the hard coating layer, and some
schematic diagrams of several different steps thereof, in
accordance with the method for manufacturing the polymer plastic
front panel of the present invention. In the embodiment shown in
FIG. 6, the process for providing the coating material of the hard
coating layer comprises the following steps.
[0043] Step 511: forming an inorganic layer 62 on a carrier plate
61. As shown in FIG. 7A, in a preferred embodiment of the
invention, the carrier plate 61 is a glass carrier plate 61, and a
release film 611 is provided on a surface of the glass carrier
plate 61. An inorganic material is plated on the release film 611
by a vacuum sputtering process in order to form a whole piece of
the inorganic layer 62 on the surface of the release film 611.
Wherein, the material of the inorganic material comprises one of
the following: silicon dioxide (SiO.sub.2), aluminum oxide
(Al.sub.2O.sub.3), silicon nitride (Si.sub.3N.sub.4), silicon
oxynitride (SiO.sub.xN.sub.y), and aluminum oxynitride
(AlO.sub.xN.sub.y). In this embodiment, the inorganic material is
preferably made of aluminum oxide (Al.sub.2O.sub.3).
[0044] Step 512: detaching and braking the inorganic layer 62 into
a plurality of tiny inorganic fragments 621. As shown in FIG. 7B,
the entire inorganic layer 62 is broken by shaking, vibrating or
striking the carrier plate 61, such that the broken inorganic layer
62 can be detached from the release film 611 of the carrier plate
61, and the released inorganic layer 62 can be broken into the
plurality of tiny inorganic fragments 621. In this step, the
plurality of the tiny inorganic fragments 621 obtained are
irregular in shape and have sharp edges, but the size of each tiny
inorganic fragment 621 does not differ much.
[0045] Step 513: smoothing and dispersing the plurality of tiny
inorganic fragments 621 in order to transform the plurality of tiny
inorganic fragments 621 into the plurality of dispersed nano-scale
flaky inorganic substances 622. As shown in FIG. 7B, in this step,
the plurality of tiny inorganic fragments 621 are mixed and stirred
by a nano dispersion equipment 63, so that the plurality of tiny
inorganic fragments 621 will collide with each other to gradually
smooth their sharp edges and also disperse them evenly and
individually, so as to form the plurality of dispersed nano-scale
flaky inorganic substances 622. As shown in FIG. 7C, after the
smoothing and dispersing process of the tiny inorganic fragments
621 described in Step 513 is completed, each of the nano-scale
flaky inorganic substances 622 will have a thickness (t), a
longitudinal width (w1) and a lateral width (w2); wherein, the
measuring directions of the thickness (t), the longitudinal width
(w1) and the lateral width (w2) are perpendicular to each other,
and w1.gtoreq.w2.gtoreq.t. In which, the thickness (t) is between
0.1 nm and 50 nm, the longitudinal width (w1) is between 100 nm and
1000 nm, and the ratio of the lateral width to the longitudinal
width (w2/w1) is between 0.01 and 1. In the present invention, a
best effect can be achieved when 10 nm.ltoreq.t.ltoreq.30 nm, 300
nm.ltoreq.w1.ltoreq.800 nm, and 0.1.ltoreq.(w2/w1).ltoreq.1.
[0046] Step 514: adding and mixing the plurality of dispersed
nano-scale flaky inorganic substances 622 into the solution of
organic-inorganic hybrid UV-curable oligomer, the UV-curable resin
additive, the photo initiator, and the volatile solvent to form the
coating material of the hard coating layer. In this embodiment, the
organic-inorganic hybrid UV-curable oligomer comprises polyurethane
resin and sal-gel silica hybrid mixture. The glass transition
temperature (Tg) value of the UV-curable resin additive is not less
than 120.degree. C., in addition, the UV-curable resin additive
comprises at least one of the following: high Tg UV-curable
oligomer or high Tg UV-curable monomer. In a preferred embodiment
of the invention, the high Tg UV-curable oligomer is polyurethane
acrylate, which has a Tg value not less than 120.degree. C. The
high Tg UV-curable monomer is Tris(2-hydroxy ethyl)
isocyanuratetriacrylate (THEICTA), which has a Tg value not less
than 240.degree. C. The weight percentage of the organic-inorganic
hybrid UV oligomer in the coating material is ranged between 50%
and 70%, the weight percentage of the high Tg UV-curable resin
additive is ranged between 30% and 50%, the weight percentage of
the nano-scale flaky inorganic substances in the coating material
of the hard coating layer is between 5% and 15%, and the weight
percentage of the photo initiator is about 5% or so.
[0047] Please refer to FIG. 8A to FIG. 8C, which respectively are
the schematic diagrams of the hard coating layer at some different
stages during the curing process of coating material in accordance
with the manufacturing method of the polymer plastic front panel of
the present invention. After completing the Step 52 (shown in FIG.
6) of applying the liquid coating material 32 onto the entire
bonding surface of the plastic substrate 11, the initial status of
the plastic substrate 11 will be similar to the one shown in FIG.
8A that, the coating material 32 applied on the bonding surface of
the plastic substrate 11 is still in a liquid state, and the
thickness of the coating material 32 is relatively thick because
the amount of the solvent contained in the coating material 32 is
still large. At this stage, most of the dispersed nano-scale flaky
inorganic substances 33 contained in the coating material 32 arc in
a non-directional randomly distributed status. Then, as shown in
FIG. 8B, when the solvent contained in the coating material 32 is
gradually evaporated by baking or far-infrared (IR) irradiating
process, the coating material will gradually harden and the
thickness will gradually decrease; therefore, the dispersed
nano-scale flaky inorganic substances 33 contained in the coating
material 32 will be affected by the gravity and hydrodynamics, and
thus randomly dispersed and arranged along a horizontal direction
in a parallel manner within the hard coating layer 31. At last,
when the curing process is completed, as shown in FIG. 8C, the
plurality of dispersed nano-scale flaky inorganic substances 33
will form a discontinuously layered dispersed gas barrier layer in
the cured hard coating layer 31. Such kind of structure of the
discontinuously layered dispersed gas barrier layer not only can
provide a good gas barrier effect similar to the continuous gas
barrier layer shown in FIG. 2 in a crack-free state because of its
"layered" and "horizontally and parallel dispersed" nano-scale
flaky inorganic substances 33; moreover, because these horizontally
and parallel dispersed nano-scale flaky inorganic substances 33 are
"discontinuously" layered and stacked, therefore, no cracks will
occur in the hard coating layer 31 even after the high-temperature,
high-temperature and high-humidity, high-low temperature (hot and
cold) thermal shocks and other harsh automotive industry
environmental tests are performed. As a result, the polymer plastic
front plate 30 made by the manufacturing method of the invention
described above can effectively reduce the diffusion of gas from
polymer plastic plates, avoid spilled gas from entering the optical
clear adhesive (OCA) layer, solve the problems of bubbles and
delamination after the environmental tests are performed, and
thereby indeed effectively improve the various shortcomings of the
aforementioned conventional techniques.
[0048] The applicant has produced several samples of front panels
based on the structures of either the conventional front panels or
the invention shown in FIG. 1 to FIG. 4. Each sample of the front
panel is composed of different resin formulations and solid
ingredient ratios and is tested by using the same harsh regulations
as the aforementioned automotive industry environmental tests. The
results of tests are shown in the Table 1 and Table 2 below. Table
1 lists the information of the resin formulations and solid
ingredient ratios of a total of twelve samples including sample
numbers "Sample1" to "Sample11" and a "Comparative Sample". Table 2
lists a comparison table of the testing results and performances of
these samples shown in Table 1 after conducting the environmental
tests.
[0049] In the Table 1 below:
[0050] the value in the composition column A indicates the weight
percentage of the organic-inorganic hybrid UV-curable oligomer
(including polyurethane resin and sol-gel silica hybrid mixture)
contained in the coating material of the hard coating layer;
[0051] the value in the composition column B indicates the weight
percentage of the High Tg UV-curable oligomer (e.g., Polyurethane
acrylate or High Tg UV-curable monomer such as THEICTA) contained
in the coating material of the hard coating layer;
[0052] the value in the composition column C indicates the weight
percentage of the conventional Spherical Inorganic Nano Gas Barrier
Particles (e.g., Spherical Nano Al.sub.2O.sub.3) contained in the
coating material of the hard coating layer;
[0053] the value in the composition column D indicates the weight
percentage of the Dispersed Nano-scale Flaky Inorganic Substances
(e.g., Laminar Nano Al.sub.2O.sub.3) of the invention contained in
the coating material of the hard coating layer;
[0054] the value in the composition column E indicates the weight
percentage of the Photo Initiator contained in the coating material
of the hard coating layer;
[0055] the "Comparative Sample" is a sample of front panel formed
with a single continuous gas barrier layer on the bonding surface
of plastic substrate by a vacuum sputtering process as which shown
in FIG. 2.
[0056] It can be understood from Table 1 that, because the
composition A and composition B are the primary materials for the
hard coating layer, while the compositions C, D, and E are merely
additives; therefore, in practice, when calculating the solid
ingredient ratios contained in the resin formulation of the hard
coating layer, the sum of the weight percentages of the composition
A and the composition B (primary materials) should be equal to
100%, while the weight percentages of the compositions C, D, E are
considered to be an additional amount of additives which is not
calculated within the aforementioned 100%.
[0057] It can be understood from Table 1 that, except for the
"Comparative Sample" which is formed with a single continuous gas
barrier layer on the bonding surface of plastic substrate by a
vacuum sputtering process as which shown in FIG. 2; samples of
"Sample 1" to "Sample 5" are without any gas blocking structure
like the conventional technology shown in FIG. 1; samples of
"Sample 6" to "Sample 8" are added with spherical inorganic nano
gas barrier particles within the hard coating layer like the
conventional technology shown in FIG. 3; and, samples of "Sample 9"
to "Sample 11" are added with dispersed nano-scale flaky inorganic
substances within the hard coating layer like the embodiment of the
invention shown in FIG. 4.
TABLE-US-00001 TABLE 1 the information of the resin formulations
and solid ingredient ratios of samples Composition Wt % Sample No A
B C D E Remark Sample1 100% -- -- 5% Sample2 70% 30% -- 5% Sample3
60% 40% -- 5% Sample4 50% 50% -- 5% Sample5 40% 60% -- 5% Sample6
60% 40% 5% -- 5% Sample7 60% 40% 10% -- 5% Sample8 60% 40% 15% --
5% Sample9 60% 40% 5% 5% Sample10 60% 40% 10% 5% Sample11 60% 40%
15% 5% Comparative 100% 5% vacuum sputtering Sample continuous gas
barrier
TABLE-US-00002 TABLE 2 comparison of testing results and
performances Item Tested Free Impact Substrate volume resistance
Adhesion porosity Pencil with falling Water Flexibility Average
hardness/ ball (cm)/ boiling/ Ink Wear-resistance test (R = radius
Sample No. 750 g 375 g Initial 12 hrs adhesion of surface 10 mm) R
@95 dC Sample 1 5H 30 5B 5B 5B .circleincircle. X 1.5 nm Sample 2
6H 60 5B 5B 5B .circleincircle. .largecircle. 1.2 nm Sample 3 5H
100 5B 5B 5B .circleincircle. .circleincircle. 1.0 nm Sample 4 4H
120 5B 5B 5B .largecircle. .circleincircle. 1.0 nm Sample 5 4H 130
5B 5B 5B .DELTA. .circleincircle. 0.9 nm Sample 6 5H 100 5B 5B 5B
.circleincircle. .circleincircle. 0.9 nm Sample 7 5H 100 5B 5B 5B
.circleincircle. .circleincircle. 0.9 nm Sample 8 5H 60 5B 5B 5B
.circleincircle. .largecircle. 0.8 nm Sample 9 5H 100 5B 5B 5B
.circleincircle. .circleincircle. 0.4 nm Sample 10 5H 100 5B 5B 5B
.circleincircle. .circleincircle. 0.3 nm Sample 11 5H 60 5B 5B 5B
.circleincircle. .largecircle. 0.3 nm Comparative 6H <30 5B 5B
5B .circleincircle. X -- Sample Item Tested OCA bonding OCA bonding
85 dC -5% RH OCA bonding -40 dC 95 dC 1000 hrs 1000 hrs OCA bonding
-40 100 hrs environmental environmental dC.rarw. .fwdarw.85 dC 1000
cycles Sample No. environmental test test test environmental test
Sample 1 .DELTA. X X X Sample 2 .circleincircle. .DELTA. .DELTA.
.DELTA. Sample 3 .circleincircle. .DELTA. .DELTA. .DELTA. Sample 4
.circleincircle. .DELTA. .DELTA. .DELTA. Sample 5 .circleincircle.
.DELTA. .DELTA. .DELTA. Sample 6 .circleincircle. .DELTA. .DELTA.
.DELTA. Sample 7 .circleincircle. .DELTA. .DELTA. .DELTA. Sample 8
.circleincircle. .DELTA. .DELTA. .DELTA. Sample 9 .circleincircle.
.largecircle. .largecircle. .largecircle. Sample 10
.circleincircle. .circleincircle. .circleincircle. .circleincircle.
Sample 11 .circleincircle. .circleincircle. .circleincircle.
.circleincircle. Comparative .DELTA. .DELTA. .DELTA. .DELTA. Sample
The meaning of symbols shown in Table 2 are described below:
.circleincircle.: Excellent, .largecircle.: Good, .DELTA.: Normal,
X: Fail NG: Not good or .circleincircle.: no bubbles observed,
.largecircle.: a few bubbles observed .DELTA.: some big bubbles, X:
lamination failure.
[0058] The testing methods performed in Table 2 are described
below:
[0059] 1. Pencil hardness test: using Mitsubishi special pencils
for hardness test, with 750 g loading, performing sliding tests of
pencils with different pencil hardness on the surface of the
material; if there is no scratch, it is defined as the hardness of
the surface (specification: HS K5600).
[0060] 2. Impact resistance with falling ball: using a 375 g
stainless steel iron ball for free falling test to evaluate the
height of impact resistance of the material surface (specification:
defined by Applicant).
[0061] 3. Initial adhesion/adhesion after water boiling: removing
the 3M tape after performing the Cross Cut Test, and then judging
the quality of adhesion according to the surface peeling condition
of the material; in addition, boiling the material with boiling
water and then performing the aforesaid tests to test the adhesion
quality after water boiling (specification: ASTM D3002).
[0062] 4. Wear-resistance of surface: nail scratch resistance under
simulated use of touch panels (specification: defined by
Applicant). The meanings of symbols shown in this column are:
.circleincircle.: Excellent (no scratch), .smallcircle.: Good (very
minor scratches, less than 3 scratches), .DELTA.: Normal (minor
scratches, with 3 to 5 scratches), X: Fail (serious scratches, more
than 5 scratches).
[0063] 5. Flexibility test: winding the material around a cylinder
with a radius of 10 mm and then observing the change of appearance
after flexure (Specification: ASTM D522). The meanings of symbols
shown in this column are: .circleincircle.: Excellent (no scratch),
.smallcircle.: Good (very minor scratches, less than 3 scratches),
.DELTA.: Normal (minor scratches, with 3 to 5 scratches),
[0064] X: Fail (serious scratches, more than 5 scratches).
[0065] 6. OCA bonding environmental test: after the material is
bonded to the hard coating layer with OCA, performing various
environmental tests on it, and then observing whether there are
bubbles or delamination occurred in the bonding surface after the
environmental tests (specification: defined by Applicant). The
meanings of symbols shown in this column are: .circleincircle.: No
Bubble Observed, .smallcircle.: Few Small Bubbles, .DELTA.: Some
Big Bubbles, X: Lamination Failure.
[0066] It can be seen from the above Table 1 and Table 2 that, the
samples "Sample9", "Sample10" and "Sample11" produced according to
the technology of the present invention have obtained the best test
results. It is proved that, the polymer plastic front plate of the
invention is suitable for bonding on the surface of automotive
touch panels. By means of the addition of organic-inorganic high
Glass Transition Temperature (Tg) UV oligomers and nano-scale
flake-like inorganic oxides, a gas barrier hard coating layer with
high surface dyne value (>44 dyne) can be formed on the adhesion
surface of the plastic substrate. It not only has good ink
printability and OCA adhesiveness, but also inhibits the diffusion
of fugitive gas from polymer plastic front plates during
high-temperature, high-temperature and high-humidity, high-low
temperature (hot and cold) thermal shocks and other harsh
automotive industry environmental tests, which is due to the fact
that these nano-scale flaky inorganic oxides can form a
discontinuously layered dispersed gas barrier layer in the hard
coating layer. The gas can be avoided from entering the OCA layer,
thereby solving the problems of bubbles and delamination after the
environmental tests are performed. Wherein, the weight percentage
of the organic-inorganic hybrid UV oligomer contained in the
coating material of the hard coating layer is ranged between 50%
and 70%, the weight percentage of the high Tg UV-curable resin
additive is ranged between 30% and 50%, the weight percentage of
the nano-scale flaky inorganic substances in the coating material
of the hard coating layer is between 5% and 15%, and the weight
percentage of the photo initiator is about 5% or so. By using the
Applicant's above described polymer material formula, coating
material formula and precision coating technology, the polymer
plastic front plates in accordance with the samples "Sample9",
"Sample10" and "Sample11" can be manufactured for passing the harsh
automotive industry environmental tests.
[0067] While the present invention has been shown and described
with reference to the preferred embodiments thereof and the
illustrative drawings, it should not be considered as limited
thereby. Various possible modifications and alterations can be
conceived by persons skilled without departing from the scope and
the spirit of the present invention.
* * * * *