U.S. patent application number 10/021082 was filed with the patent office on 2002-09-05 for antiglare film, process for producting the same, and display device using antiglare film.
This patent application is currently assigned to DAI NIPPON PRINTING CO., LTD.. Invention is credited to Arakawa, Fumihiro, Masaki, Tadahiro, Suga, Taiji.
Application Number | 20020122257 10/021082 |
Document ID | / |
Family ID | 18853333 |
Filed Date | 2002-09-05 |
United States Patent
Application |
20020122257 |
Kind Code |
A1 |
Suga, Taiji ; et
al. |
September 5, 2002 |
Antiglare film, process for producting the same, and display device
using antiglare film
Abstract
Disclosed is an antiglare film having excellent durability. The
antiglare film is disposed on the front of a display device and
comprises a transparent plastic film and, formed on the transparent
plastic film, at least an antiglare layer having fine concaves and
convexes on its surface, wherein the antiglare layer is formed of a
transparent resin and satisfies requirements that: (1) the surface
of the antiglare layer has a three-dimensional ten-point mean
roughness of 0.9 .mu.m to 3 .mu.m; and (2) the mean spacing between
adjacent profile peaks on a three-dimensional roughness reference
plane is 20 .mu.m to 50 .mu.m.
Inventors: |
Suga, Taiji; (Tokyo-To,
JP) ; Masaki, Tadahiro; (Tokyo-To, JP) ;
Arakawa, Fumihiro; (Tokyo-To, JP) |
Correspondence
Address: |
Parkhurst, Wendel, L.L.P.
Suite 210
1421 Prince Street
Alexandria
VA
22314-2805
US
|
Assignee: |
DAI NIPPON PRINTING CO.,
LTD.
|
Family ID: |
18853333 |
Appl. No.: |
10/021082 |
Filed: |
December 19, 2001 |
Current U.S.
Class: |
359/580 ;
349/137; 359/488.01 |
Current CPC
Class: |
G02B 5/0268 20130101;
G02B 1/14 20150115; G02B 5/10 20130101; G02F 1/133504 20130101;
G02F 1/133502 20130101; G02B 5/0294 20130101; G02B 1/111 20130101;
G02B 5/0215 20130101; G02B 5/0278 20130101; G02B 5/02 20130101;
G02B 6/0051 20130101; Y10S 359/90 20130101 |
Class at
Publication: |
359/580 ;
349/137; 359/493 |
International
Class: |
G02F 001/1335 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 20, 2000 |
JP |
2000-386189 |
Claims
1. An antiglare film to be disposed on a front of a display device,
said antiglare film comprising: a transparent plastic film and an
antiglare layer, the antiglare layer being formed on a surface of
the transparent plastic film, the antiglare layer having fine
concaves and convexes on its surface, wherein said antiglare layer
is formed of a transparent resin and satisfies requirements that:
(1) the surface of the antiglare layer has a three-dimensional
ten-point mean roughness of 0.9 .mu.m to 3 .mu.m; and (2) the mean
spacing between adjacent profile peaks on a three-dimensional
roughness reference plane is 20 .mu.m to 50 .mu.m.
2. The antiglare film according to claim 1, which has a total light
transmittance of not less than 87% and a haze of 5 to 40.
3. The antiglare film according to claim 1, wherein the transparent
resin is a cured product of an ionizing radiation-curable
resin.
4. The antiglare film according to claim 1, which further comprises
a primer layer to be formed between the transparent plastic film
and the antiglare layer.
5. The antiglare film according to claim 4, wherein the primer
layer comprises transparent fine particles.
6. A polarizing plate comprising the antiglare film according to
any one of claims 1 to 5.
7. A display device comprising the polarizing plate according to
claim 6 disposed on the front of a display.
8. A liquid crystal panel for a display device, comprising: two
polarizing plates, the liquid crystal display cell being sandwiched
between the two polarizing plates, at least one of the polarizing
plates being the polarizing plate according to claim 6.
9. A display device comprising the liquid crystal panel according
to claim 8 and a surface light source device disposed on the
underside of the liquid crystal panel.
10. A display device comprising the antiglare film according to any
one of claims 1 to 5 disposed on the front of a display.
11. A display device comprising a touch panel and the antiglare
film according to any one of claims 1 to 5 formed in that order on
the front of a display.
12. A process for producing an antiglare film, comprising the steps
of: bringing a transparent plastic film in a molding tool having on
its surface concaves and convexes which have an inverted shape of
fine concaves and convexes of the antiglare layer to be formed;
placing an ionizing radiation-curable resin between the transparent
plastic film and the molding tool; applying an ionizing radiation
to the ionizing radiation-curable resin to cure the ionizing
radiation-curable resin and to adhere the cured product of the
ionizing radiation-curable resin to the transparent plastic film,
thereby forming an antiglare layer having fine concaves and
convexes on its surface; and separating the transparent plastic
film with the antiglare layer formed thereon from the molding tool,
said antiglare layer satisfying requirements that: (1) the surface
of the antiglare layer has a three-dimensional ten-point mean
roughness of 0.9 .mu.m to 3 .mu.m; and (2) the mean spacing between
adjacent profile peaks on a three-dimensional roughness reference
plane is 20 .mu.m to 50 .mu.m.
13. The process according to claim 12, wherein the molding tool is
in a roller form.
14. The process according to claim 12, wherein the primer layer is
formed on a surface on the transparent plastic film and the
ionizing radiation-curable resin is coated on a surface of the
primer layer.
15. The process according to claim 12, wherein the primer layer
comprises transparent fine particles.
16. An antiglare film produced by the process according to any one
of claims 12 to 15.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an antiglare film which, in
use, is disposed on the front of various display devices, such as
liquid crystal display devices, or an antiglare film which is
durable against touch inputting. The present invention also relates
to a production process which can produce said antiglare film with
high efficiency by means of a molding tool having concaves and
convexes on its surface, preferably a molding roller. Further, the
present invention relates to a display device comprising said
antiglare film disposed on the front of a liquid crystal display
device or the like.
[0003] 2. Background Art
[0004] Various display devices (=displays) for displaying static
images or moving images according to electronic information are
known, and CRTs, plasma displays, liquid crystal displays,
electroluminescence displays and the like are currently on the
market.
[0005] FIG. 1 shows an example of a liquid crystal display device
100. The liquid crystal display device 100 comprises: a liquid
crystal panel 101 comprising two polarizing plates 101a, 101 a' and
a liquid crystal display cell 101b sandwiched between the two
polarizing plates 101a, 101a'; and a surface light source device
102 disposed on the underside (as viewed in the drawing) (which, in
use of the liquid crystal display device 100, corresponds to a side
opposite to the viewer side) of the liquid crystal display device
100.
[0006] The surface light source device 102 comprises, for example,
a reflector plate 103, a light guide plate 104 having a dot pattern
104a on its underside, a light diffusive film 105, a lens sheet
106, and a protective film 107 provided in that order from the
lower side.
[0007] In driving a liquid crystal display device to view images,
an image of an object present behind the viewer is reflected from
the screen of the liquid crystal display, and the viewer often
catches the reflected image. In particular, when there is indoor
lighting equipment and outdoor light behind the viewer, an image of
the sun or the like is reflected from the display. This
significantly deteriorates the visibility of images.
[0008] A touch panel is one input means of computers. Among others,
a touch panel operated on the screen of display devices is
convenient because sites to be selected and touched can be freely
prepared and displayed on the screen of the display devices.
[0009] Touch inputting with high frequency is causative of the
deposition of fingerprints or the occurrence of scratches, and, in
this case, in addition, various types of durability are required of
the touch panel.
[0010] In order to prevent a catch of an image of indoor lighting
equipment or the sun on the screen, a matte film prepared by
coating a coating composition with organic or inorganic fine beads
incorporated therein onto a transparent plastic film and then
drying or solidifying the coating to form an antiglare layer has
hitherto been used.
[0011] Organic or inorganic fine beads, which have hitherto been
used in the antiglare film, however, suffer from an unavoidable
problem that the beads come off in service and scratch the
antiglare film. In addition, at the time of the production of the
antiglare film, in coating the coating composition with beads
incorporated thereinto, unfavorable phenomena, such as occurrence
of streaks or uneven coating, occur making it difficult to provide
even antiglare properties.
[0012] Further, in using the antiglare film thus obtained as a
surface material of a touch panel, beads, which have come off,
scratches the antiglare film upon the application of pressure by a
finger or a touch pen. Thus, the beads accelerate the occurrence of
scratches.
SUMMARY OF THE INVENTION
[0013] Accordingly, it is an object of the present invention to
solve the problems involved in the conventional antiglare film
attributable to organic or inorganic fine beads contained in the
antiglare layer, that is, susceptibility to scratching, uneven
properties, and, in the case of the application of the antiglare
film to a touch panel, accelerated occurrence of scratches.
[0014] The above object of the present invention could have been
attained by forming an antiglare layer in an antiglare film while
specifying the three-dimensional ten-point mean roughness and the
mean spacing between adjacent convexes (profile peaks) in convexes
and concaves of the antiglare layer or while specifying haze in
addition to these parameters.
[0015] The antiglare film may be provided with a primer layer,
preferably a primer layer containing transparent fine
particles.
[0016] According to one aspect of the present invention, there is
provided an antiglare film to be disposed on a front of a display
device, said antiglare film comprising:
[0017] a transparent plastic film and an antiglare layer, the
antiglare layer being formed on a surface of the transparent
plastic film, the antiglare layer having fine concaves and convexes
on its surface,
[0018] wherein said antiglare layer is formed of a transparent
resin and satisfies requirements that:
[0019] (1) the surface of the antiglare layer has a
three-dimensional ten-point mean roughness of 0.9 .mu.m to 3 .mu.m;
and
[0020] (2) the mean spacing between adjacent profile peaks on a
three-dimensional roughness reference plane is 20 .mu.m to 50
.mu.m.
[0021] Preferably, the antiglare film according to the first aspect
of the present invention is disposed on the front of a display
device, said antiglare film comprising
[0022] a transparent plastic film; and, formed on the transparent
plastic film, at least an antiglare layer having fine concaves and
convexes on its surface, wherein
[0023] said antiglare layer is formed of a transparent resin and
satisfies requirements that:
[0024] (1) the surface of the antiglare layer has a
three-dimensional ten-point mean roughness of 0.9 .mu.m to 3 .mu.m;
and
[0025] (2) the mean spacing between adjacent profile peaks on a
three-dimensional roughness reference plane is 20 .mu.m to 50
.mu.m.
[0026] Preferably, the antiglare film has a total light
transmittance of not less than 87% and a haze of 5 to 40.
[0027] Preferably, the transparent resin is a cured product of an
ionizing radiation-curable resin.
[0028] Preferably, a primer layer is provided between the
transparent plastic film and the antiglare layer.
[0029] The primer layer may comprise transparent fine
particles.
[0030] According to another aspect of the present invention, there
is provided a process for producing an antiglare film, comprising
the steps of:
[0031] providing a molding tool having on its surface concaves and
convexes, which have an inverted shape of concaves and convexes on
the surface of an antiglare layer to be formed and satisfy the
following requirements (1) and (2), and forming an ionizing
radiation-curable resin between the concave/convex mold face and
the transparent plastic film to form a laminate (step of
forming);
[0032] while maintaining the formed state, applying an ionizing
radiation to the ionizing radiation-curable resin to form a cured
product of the ionizing radiation-curable resin and, at the same
time, adhering the cured product to the transparent plastic film to
form an antiglare layer of the cured product with concaves and
convexes, which have an inverted shape of the concaves and convexes
on the surface of the molding tool, formed thereon (step of
curing), and then
[0033] separating the laminate of the antiglare layer and the
transparent plastic film from the concave/convex face of the
molding tool (step of separation):
[0034] (1) the surface of the inverted concave/convex shape has a
three-dimensional ten-point mean roughness of 0.9 .mu.m to 3 .mu.m;
and
[0035] (2) the mean spacing between adjacent profile peaks on a
three-dimensional roughness reference plane is 20 .mu.m to 50
.mu.m.
[0036] Preferably, the production process according to the second
aspect of the present invention comprises the steps of:
[0037] bringing a transparent plastic film in a molding tool having
on its surface concaves and convexes which have an inverted shape
of fine concaves and convexes of the antiglare layer to be
formed;
[0038] placing, by coating, an ionizing radiation-curable resin
between the transparent plastic film and the molding tool;
[0039] applying an ionizing radiation to the ionizing
radiation-curable resin to cure the ionizing radiation-curable
resin and to adhere the cured product of the ionizing
radiation-curable resin to the transparent plastic film to form an
antiglare layer having fine concaves and convexes on its surface;
and
[0040] separating the transparent plastic film with the antiglare
layer formed thereon from the molding tool,
[0041] said antiglare layer satisfying requirements that:
[0042] (1) the surface of the antiglare layer has a
three-dimensional ten-point mean roughness of 0.9 .mu.m to 3 .mu.m;
and
[0043] (2) the mean spacing between adjacent profile peaks on a
three-dimensional roughness reference plane is 20 .mu.m to 50
.mu.m.
[0044] In the production process according to the second aspect of
the present invention, a construction may be adopted wherein the
molding tool is a roller, the step of forming is carried out while
winding the transparent plastic film on the molding tool in a
roller form, and the step of curing is carried out on the molding
tool in a roller form.
[0045] The transparent plastic film may have a primer layer formed
on its side on which an ionizing radiation-curable resin is to be
formed.
[0046] The primer layer may contain transparent fine particles.
[0047] According to a further aspect of the present invention,
there is provided an antiglare film produced by any one of the
above production processes.
[0048] According to a still further aspect of the present
invention, there is provided a display device comprising any one of
the above antiglare films disposed on the front of a display
device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] FIG. 1 is a diagram showing a surface light source device
and a liquid crystal display device using an antiglare film;
[0050] FIG. 2 is a cross-sectional view of the antiglare film
according to the present invention;
[0051] FIG. 3 is a diagram showing an embodiment of an apparatus
for producing an antiglare film; and
[0052] FIG. 4 is a diagram showing an embodiment wherein an
antiglare film has been applied to a touch panel.
DETAILED DESCRIPTION OF THE INVENTION
[0053] As shown in FIG. 2A, an antiglare film 1 according to the
present invention comprises a transparent plastic film 2 and,
formed on one side of the transparent plastic film 2 (upper surface
in the drawing), an antiglare layer 3 having concaves and convexes
4 on its upper surface, or alternatively as shown in FIG. 2B,
comprises a transparent plastic film 2 and, formed on the upper
surface of the transparent plastic film 2, a primer layer 5 and an
antiglare layer 3 having concaves and convexes 4 on its upper
surface.
[0054] The concaves and convexes 4 in the antiglare layer 3 satisfy
requirements that:
[0055] (1) the surface of the antiglare layer has a
three-dimensional ten-point mean roughness of 0.9 .mu.m to 3 .mu.m;
and
[0056] (2) the mean spacing between adjacent profile peaks on a
three-dimensional roughness reference plane is 20 .mu.m to 50
.mu.m.
[0057] The three-dimensional ten-point mean roughness in the
requirement (1) is a measured value based on JIS B 0601-1994. More
specifically, a reference length is sampled from a profile curve of
an object, and an average line is determined, followed by the
calculation of a difference between the average value of the
heights of five highest profile peaks and the depths of five
deepest profile valleys. This difference value is regarded as the
ten-point mean roughness.
[0058] Regarding the requirement (1), the three-dimensional
ten-point mean roughness of the concaves and convexes 4 is
preferably in the range of 0.9 .mu.m to 3 .mu.m.
[0059] When the three-dimensional ten-point mean roughness is less
than 0.9 .mu.m, the level of concaves and convexes is too small to
prevent "external light reflection" wherein, for example, an image
of indoor lighting equipment or the sun behind the viewer is
reflected from the display and, consequently, the viewer catches
the reflected image. On the other hand, when the three-dimensional
ten-point mean roughness exceeds 3 .mu.m, the haze is increased.
Therefore, when the viewer views the display through the antiglare
film, the clouding level of the screen is increased and, as a
result, the contrast of images is significantly deteriorated.
[0060] In realizing images having a high contrast, the
three-dimensional ten-point mean roughness is more preferably 0.9
.mu.m to 1.3 .mu.m.
[0061] The mean spacing Sm between adjacent profile peaks on the
three-dimensional roughness reference plane in the requirement (2)
is measured according to JIS B 0601-1994 and, when n profile peaks
with spacings S.sub.m1, S.sub.m2, S.sub.m3, . . . , S.sub.sm exist
in the reference length, is determined as
S.sub.m=(1/n).times.(S.sub.m1+S.sub.m2- +S.sub.m3+. . . +S.sub.mi).
The three-dimensional ten-point mean roughness is preferably 20
.mu.m to 50 .mu.m. When the three-dimensional ten-point mean
roughness is less than 20 .mu.m, the image sharpness is lowered,
while, when the three-dimensional ten-point mean roughness exceeds
50 .mu.m, the "external light reflection" cannot be prevented.
[0062] The antiglare film according to the present invention
satisfies the requirements (1) and (2) and, preferably, at the same
time, has a total light transmittance of not less than 87% and a
haze of 5 to 40.
[0063] When the total light transmittance is less than 87%, the use
of the antiglare film disadvantageously lowers the brightness of
images. So far as the total light transmittance is not less than
87%, the higher the total light transmittance, the better the
results. The construction of the antiglare film according to the
present invention comprising a transparent plastic film 2, an
antiglare layer 3 formed on the transparent plastic film 2, and
optionally a primer layer interposed between the transparent
plastic film 2 and the antiglare layer 3 provides a total light
transmittance up to about 92%.
[0064] When the haze is less than 5, although the image sharpness
is increased, bright points randomly occur and, consequently, glare
of the screen cannot be avoided. On the other hand, when the haze
exceeds 40, the image sharpness is disadvantageously lowered. The
haze is more preferably not more than 30 from the viewpoint of
ensuring the image sharpness.
[0065] In order to overcome the drawbacks of the prior art,
concaves and convexes may be imparted to the resin layer, not
containing organic or inorganic fine beads for the formation of
concaves and convexes, to provide the antiglare film 1 according to
the present invention.
[0066] Imparting the concaves and convexes may be carried out by
the so-called "embossing method" wherein an embossing plate,
preferably an embossing roller in a roller form, is pressed,
optionally with heating, to a resin layer after or during the
formation thereof. Preferably, a more efficient method may be
adopted which comprises the steps of: providing a concave/convex
mold having on its surface concaves and convexes, which have an
inverted shape of desired concaves and convexes of an antiglare
layer to be formed; coating a highly curable resin composition,
such as an ultraviolet-curable resin, onto the mold surface;
covering the coating with a transparent plastic film; applying
ultraviolet light to cure the ultraviolet-curable resin or the like
within the concave/convex mold and, in addition, integrating the
cured coating with the transparent plastic film to form a laminate;
and then separating the laminate from the concave/convex mold.
[0067] In this case, the resin composition may be coated onto the
transparent plastic film followed by the application of the
assembly to the concave/convex mold. Alternatively, a method may be
used wherein the resin composition is supplied to the interface
between the transparent plastic film and the concave/convex mold to
simultaneously perform coating and forming. In any event, what is
required here is to sandwich the resin composition between the
concave/convex mold and the transparent plastic film.
[0068] The method wherein the resin composition is sandwiched
between the concave/convex mold and the transparent plastic film,
is superior particularly in the reproducibility of the mold, to the
embossing method. Therefore, this sandwich method is advantageous
in that contemplated optical characteristics can be easily provided
and, in addition, a fine and hard concave/convex layer can be
formed without posing a problem of a product, obtained by the
so-called "embossing method," such that the concaves and convexes
of the product are returned to an original flat state with the
elapse of time.
[0069] FIG. 3 is a diagram illustrating a production process using
an embossing device 10 wherein the above-described
ultraviolet-curable resin or the like is used.
[0070] At the outset, a transparent plastic film 2 is unwound from
left, and is supplied toward an embossing roller 12. The surface of
the embossing roller 12 is an concave/convex mold face having
concaves and convexes 12a which have an inverted shape of desired
concaves and convexes of an antiglare layer to be formed.
[0071] A coating head 13 is installed at the bottom of the
embossing roller 12, and an ultraviolet-curable resin composition
14 is fed from a liquid reservoir (not shown) through a pipe 16 to
the coating head 13. The fed ultraviolet-curable resin composition
14 is extruded through a slit 15, which is opened toward the upper
part of the coating head 13, and is deposited onto the embossing
roller 12 in its molding face having concaves and convexes 12a. The
deposited ultraviolet-curable resin composition is then moved left
by the rotation of the embossing roller 12 (in the drawing,
rotation in clockwise direction), and the transparent plastic film
2 and an ultraviolet-curable resin composition layer 17 are
laminated onto each other between the embossing roller 12 and the
nip roller 11a on the film feed side.
[0072] Instead of this method wherein the ultraviolet-curable resin
composition 14 is deposited onto the mold face followed by
lamination of the transparent plastic film 2 onto the coating, a
method may be adopted wherein, while winding the transparent
plastic film 2 on the embossing roller 12, the ultraviolet-curable
resin composition 14 is fed into between the transparent plastic
film 2 and the embossing roller 12 to laminate the
ultraviolet-curable resin composition layer 17 onto the transparent
plastic film 2.
[0073] The laminate of the transparent plastic film 2 and the
ultraviolet-curable resin composition layer 17 is moved to the
upper part of the embossing roller 12, and is irradiated with
ultraviolet light from an ultraviolet exposure system 18 installed
above the embossing roller 12 to cure the ultraviolet-curable resin
composition layer 17 and to adhere the cured product to the
transparent plastic film 2.
[0074] The laminate of the transparent plastic film 2 and the cured
ultraviolet-curable resin composition layer 17 is moved to the
right side of the embossing roller 12, and is separated by means of
a separation roller 11b from the embossing roller 12. Thus, an
antiglare film is prepared which comprises a transparent plastic
film 2 and, formed on the transparent plastic film 2, concaves and
convexes 3, of a cured product of the ultraviolet-curable resin,
which have an inverted shape of the concaves and convexes in the
concave/convex mold face of the embossing plate.
[0075] In this case, preferably, the material of the transparent
plastic film 2 is transparent and smooth and, in addition, does not
contain any foreign matter. Further, preferably, the transparent
plastic film 2 is mechanically strong from the viewpoints of
working and use applications.
[0076] Generally preferred examples of the transparent plastic film
2 include films of thermoplastic resins, for example, cellulose
diacetate, cellulose triacetate, cellulose acetate butyrate,
polyamide, polyimide, polyethersulfone, polysulfone, polypropylene,
polymethylpentene, polyvinyl chloride, polyvinyl acetal, polyether
ketone, polymethyl methacrylate, polycarbonate, polyesters, such as
polyethylene terephthalate, and polyurethane.
[0077] Films of polyester resins, such as polyethylene
terephthalate resins, extensively used in photographic films having
an emulsion layer are preferred as the transparent plastic film 2
from the viewpoints of mechanical strength and coatability.
Cellulose triacetate and the like are preferred from the viewpoints
of high transparency, freedom from optical anisotropy, and low
refractive index. Polycarbonate is preferred from the viewpoints of
transparency and heat resistance.
[0078] These thermoplastic resin films are flexible and easy to
handle. When there is no need to bend the material including the
time of handling and, at the same time, when a hard material is
desired, plates of the above resins, glass plates or other plates
may also be used.
[0079] The thickness is preferably about 8 to 1000 .mu.m, more
preferably about 50 to 200 .mu.m. In the case of plates, the
thickness may exceed this thickness range.
[0080] In order to improve the adhesion between the transparent
plastic film 2 and a layer to be formed thereon, any one of or both
the upper surface and the lower surface of the transparent plastic
film 2 may be subjected to conventional various physical and
chemical treatments, such as corona discharge treatment and
oxidation treatment, or may be previously coated with an anchor
agent or a coating material called a primer to form a primer layer
5.
[0081] As described later, optical functions may be imparted to the
primer layer 5.
[0082] In the embodiment shown in FIG. 3, in forming the
concave/convex layer 3, an ultraviolet light-curable resin
composition has been used. In this case, ionizing radiation-curable
resin compositions including electron beam-curable resin
compositions may be used.
[0083] The ionizing radiation-curable resin composition may be a
mixture prepared by properly mixing prepolymer, oligomer, and/or
monomer, having a polymerizable unsaturated bond or an epoxy group
in the molecule thereof, together. Ionizing radiations applicable
for curing include electromagnetic radiations or charged particle
beams which have energy quantum high enough to polymerize or
crosslink the molecule. In general, ultraviolet light or electron
beam is used.
[0084] Examples of prepolymers and oligomers usable in the ionizing
radiation-curable resin composition include: unsaturated
polyesters, such as condensates of unsaturated dicarboxylic acids
with polyhydric alcohols; methacrylates, such as polyester
methacrylate, polyether methacrylate, polyol methacrylate, and
melamine methacrylate; acrylates, such as polyester acrylate, epoxy
acrylate, urethane acrylate, polyether acrylate, polyol acrylate,
and melamine acrylate; and cationically polymerizable epoxy
compounds.
[0085] Examples of monomers usable in the ionizing
radiation-curable resin composition include: styrene monomers, such
as styrene and a-methylstyrene; acrylic esters, such as methyl
acrylate, 2-ethylhexyl acrylate, methoxyethyl acrylate, butoxyethyl
acrylate, butyl acrylate, methoxybutyl acrylate, and phenyl
acrylate; methacrylic esters, such as methyl methacrylate, ethyl
methacrylate, propyl methacrylate, methoxyethyl methacrylate,
ethoxymethyl methacrylate, phenyl methacrylate, and lauryl
methacrylate; unsaturated substituted amino alcohol esters, such as
2-(N,N-diethylamino)ethyl acrylate, 2-(N,N-dimethylamino)ethyl
acrylate, 2-(N,N-dibenzylamino)methyl acrylate, and
2-(N,N-diethylamino)propyl acrylate; unsaturated carboxylic acid
amides, such as acrylamide and methacrylamide; compounds, such as
ethylene glycol diacrylate, propylene glycol diacrylate, neopentyl
glycol diacrylate, 1,6-hexanediol diacrylate, and triethylene
glycol diacrylate; polyfunctional compounds, such as dipropylene
glycol diacrylate, ethylene glycol diacrylate, propylene glycol
dimethacrylate, and diethylene glycol dimethacrylate; and polythiol
compounds having two or more thiol groups in the molecule thereof,
for example, trimethylolpropane trithioglycolate,
trimethylolpropane trithiopropylate, and pentaerythritol
tetrathioglycolate.
[0086] In general, one or a mixture of two or more compounds
described above is used as the monomer in the ionizing
radiation-curable resin composition. Preferably, however, in order
to impart usual coatability to the ionizing radiation-curable resin
composition, the ionizing radiation-curable resin composition
comprises not less than 5% by weight of the prepolymer or the
oligomer and not more than 95% by weight of the monomer and/or the
polythiol compound.
[0087] When flexibility is required of a cured product of the
ionizing radiation-curable resin composition, the amount of the
monomer may be reduced, or alternatively, an acrylate monomer
having one or two functional groups may be used. When a cured
product of the ionizing radiation-curable resin composition is
required to have abrasion resistance, heat resistance, and solvent
resistance, for example, an acrylate monomer having three or more
functional groups may be used. Thus, the degree of freedom in the
design of the ionizing radiation-curable resin composition is high.
Here acrylate monomers having one functional group include
2-hydroxy acrylate, 2-hexyl acrylate, and phenoxyethyl acrylate.
Acrylate monomers having two functional groups include ethylene
glycol diacrylate and 1,6-hexanediol diacrylate. Acrylate monomers
having three or more functional groups include trimethylolpropane
triacrylate, pentaerythritol triacrylate, pentaerythritol
tetraacryalte, and dipentaerythritol hexaacrylate.
[0088] A resin, which is uncurable by the application of an
ionizing radiation, may also be added to the ionizing
radiation-curable resin composition to regulate properties, such as
flexibility or surface hardness, of a cured product of the ionizing
radiation-curable resin composition. Specific examples of resins
include thermoplastic resins, such as polyurethane resin, cellulose
resin, polyvinylbutyral resin, polyester resin, acrylic resin,
polyvinyl chloride resin, and polyvinyl acetate. Among others, the
addition of polyurethane resin, cellulose resin, polyvinylbutyral
resin or the like is preferred from the viewpoint of improving the
flexibility.
[0089] When the ionizing radiation-curable resin composition is
cured by the application of light, particularly ultraviolet light,
photopolymerization initiators or photopolymerization accelerators
are added to the ionizing radiation-curable resin composition. In
the case of a resin system having a radically polymerizable
unsaturated group, for example, acetophenones, benzophenones,
Michler's benzoyl benzoate, .alpha.-amyloxime esters,
thioxanthones, benzoins, and benzoin methyl ether may be used as
the photopolymerization initiator either solely or as a mixture of
two or more. In the case of a resin system having a cationically
polymerizable functional group, for example, aromatic diazonium
salts, aromatic sulfonium salts, aromatic iodonium salts,
metallocene compounds, and benzoinsulfonic esters may be used as
the photopolymerization initiator either solely or as a mixture of
two or more. The amount of the photopolymerization initiator added
is 0.1 to 10 parts by weight based on 100 parts by weight of the
ionizing radiation-curable resin composition.
[0090] In addition, sensitizers, such as n-butylamine,
triethylamine, and tri-n-butylphosphine may be used.
[0091] The following reactive organosilicon compound may be
additionally used in the ionizing radiation-curable resin
composition.
[0092] For example, the first reactive organosilicon compound
usable herein is represented by formula R.sub.mSi(OR').sub.n
wherein R and R' each independently represent an alkyl group having
1 to 10 carbon atoms. The subscript m of R and the subscript n of
R' are each an integer which satisfies a requirement represented by
m+n=4.
[0093] Specific examples thereof include tetramethoxysilane,
tetraethoxysilane, tetra-iso-propoxysilane, tetra-n-propoxysilane,
tetra-n-butoxysilane, tetra-sec-butoxysilane,
tetra-tert-butoxysilane, tetrapentaethoxysilane,
tetrapenta-iso-propoxysilane, tetrapenta-n-propoxysilane,
tetrapenta-n-butoxysilane, tetrapenta-sec-butoxysilane,
tetrapenta-tert-butoxysilane, methyltriethoxysilane,
methyltripropoxysilane, methyltributoxysilane,
dimethyldimethoxysilane, dimethyldiethoxysilane,
dimethylethoxysilane, dimethylmethoxysilane, dimethylpropoxysilane,
dimethylbutoxysilane, methyldimethoxysilane, methyldiethoxysilane,
and hexyltrimethoxysilane.
[0094] Silane coupling agents are usable as the second reactive
organosilicon compound in combination with the ionizing
radiation-curable resin composition.
[0095] Specific examples of silane coupling agents include
.gamma.-(2-aminoethyl)aminopropyltrimethoxysilane,
.gamma.-(2-aminoethyl)aminopropylmethyldimethoxysilane,
.beta.-(3,4-epoxycyclohexyl)ethyltrimethoxysilane,
.gamma.-aminopropyltriethoxysilane,
.gamma.-methacryloxypropylmethoxysila- ne,
N-.beta.-(N-vinylbenzylaminoethyl)-.gamma.-aminopropylmethoxysilane
hydrochloride, .gamma.-glycidoxypropyltrimethoxysilane,
aminosilane, methylmethoxysilane, vinyltriacetoxysilane,
.gamma.-mercaptopropyltrimeth- oxysilane,
.gamma.-chloropropyltrimethoxysilane, hexamethyldisilazane,
vinyltris(.beta.-methoxyethoxy)silane,
octadecyldimethyl[3-(trimethoxysil- yl)propyl]ammonium chloride,
methyltrichlorosilane, and dimethyldichlorosilane.
[0096] Ionizing radiation-curable silicon compounds are usable as
the third reactive organosilicon compound in combination with the
ionizing radiation-curable resin composition.
[0097] Specific examples thereof include organosilicon compounds
having a plurality of functional groups, which are reacted and
crosslinked upon the application of an ionizing radiation, for
example, organosilicon compounds having a polymerizable double bond
group with a molecular weight of not more than 5,000. More specific
examples of the third reactive organosilicon compound include
functional polysilanes having vinyl at one terminal, functional
polysilanes having vinyl at both terminals, functional
polysiloxanes having vinyl at one terminal, functional
polysiloxanes having vinyl at both terminals, and polysilanes
having vinyl as a functional group or polysiloxanes having vinyl as
a functional group produced by reacting these compounds.
[0098] More specifically, the following compounds may be mentioned
as the third reactive organosilicon compound.
CH.sub.2.dbd.CH--(R.sup.1R.sup.2Si).sub.n--CH.dbd.CH.sub.2 (a)
[0099] 1
[0100] In formulae (a) to (e), R.sup.1 and R.sup.2 each
independently represent an alkyl group having 1 to 4 carbon atoms,
and a to d and n are values that bring the molecular weight of the
compound to not more than 5,000.
[0101] Other organosilicon compounds additionally usable in the
ionizing radiation-curable resin composition include
(meth)acryloxysilane compounds, such as 3-(meth)
acryloxypropyltrimethoxysilane and
3-(meth)acryloxypropylmethyldimethoxysilane.
[0102] In the production of the antiglare film 1 according to the
present invention, the embossing roller 12 in a roller form has
been used in the embodiment described above with reference to FIG.
3. A flat embossing plate may be used instead of the embossing
roller.
[0103] The surface having concaves and convexes of the molding
tool, such as the embossing roller 12 or the flat embossing plate,
may be formed by various methods, for example, sandblasting or
bead-shot blasting.
[0104] In the antiglare film produced using the embossing plate
formed by the sandblasting, a large number of concaves (that is,
downward projections as viewed in section) are distributed on its
surface. On the other hand, in the antiglare film produced using
the embossing plate formed by the bead-shot blasting, a large
number of convexes (that is, upward projections as viewed in
section) are distributed on its surface. Studies conducted by the
present inventors have revealed that, when the mean roughness (for
example, ten-point mean roughness Rz) is identical, as compared
with the antiglare film having a large number of concaves
distributed on its surface, the antiglare film having a large
number of convexes distributed on its surface has a lower haze
value and is less likely to cause light, for example, from interior
lighting equipment to be reflected, that is, to cause the image of
the interior lighting equipment or the like to be reflected from
the antiglare film.
[0105] Accordingly, in the antiglare film 1 according to the
present invention, more preferably, in addition to the above
requirements, an additional requirement should be satisfied such
that the antiglare film has been produced by means of a molding
tool having concaves and convexes formed by the bead-shot blasting
and, in the concaves and convexes on the surface of the antiglare,
the proportion of upward projections as viewed in section is higher
than the proportion of downward projections as viewed in section.
Further, in the production process of an antiglare film according
to the present invention, more preferably, a molding tool, which
has on its surface concaves and convexes having an inverted shape
of concaves and convexes in the antiglare film 1, that is, a
molding tool satisfying, in addition to the above requirements, an
additional requirement such that the molding tool has been formed
by the bead-shot blasting and, in the concaves and convexes on the
surface of the molding tool, the proportion of downward projections
as viewed in section (that is, concaves) is higher than the
proportion of upward projections as viewed in section (that is,
convexes), is used as the molding tool for forming concaves and
convexes.
[0106] Materials usable for constituting a molding tool having
concaves and convexes include metals, plastics, and wood and
composites of these materials. The metal is preferably chromium
from the viewpoints of strength and low susceptibility to abrasion
in repeated use. A material prepared by plating the surface of an
iron roller with chromium is suitable, for example, for economic
reasons.
[0107] Particles (beads) usable for blasting include metal
particles and inorganic particles, such as silica, alumina, or
glass particles. The particle size (diameter) of these particles is
preferably about 100 .mu.m to 300 .mu.m.
[0108] In blasting these particles against the material for the
molding tool, the particles, together with a high-speed gas, are
blasted. In this case, the particles, except for the glass beads,
may be used in combination with a suitable liquid, such as water.
The use of the liquid can realize the formation of a more stable
surface shape. The combined use of the glass beads and the liquid,
however, causes aggregation of particles which makes it difficult
to perform blasting.
[0109] Before the use of the molding tool on which concaves and
convexes have been formed, the surface of the molding tool is
preferably plated, for example, with chromium from the viewpoint of
improving durability in service. This can advantageously realize
film hardening and prevention of corrosion.
[0110] In the production of the antiglare film according to the
present invention, preferably, the concaves and convexes on the
surface of the molding tool has an inverted shape of concaves and
convexes in the antiglare film to be formed.
[0111] Accordingly, the inverted shape in the concaves and convexes
on the surface of the molding tool for forming concaves and
convexes should be as specified above in connection with the
concaves and convexes of the antiglare layer in the antiglare film,
that is, should satisfy requirements that: (1) the surface of the
antiglare layer has a three-dimensional ten-point mean roughness of
0.9 .mu.m to 3 .mu.m; and (2) the mean spacing between adjacent
profile peaks on a three-dimensional roughness reference plane is
20 .mu.m to 50 .mu.m.
[0112] In use, when the antiglare film 1 according to the present
invention is disposed, for example, by applying the antiglare film
1 to a display device on its viewer side in such a manner that the
concaves and convexes on the surface of the antiglare layer 3 face
the viewer, since the concaves and convexes 4 have a lens effect,
light from a display device, such as a liquid crystal display
device 101, is randomly refracted. As a result, there is a fear
that bright points randomly occur and "glare" occurs on the
screen.
[0113] In order to avoid the occurrence of this "glare," a method
may be adopted wherein a primer layer 5 is provided between the
transparent plastic film 2 and the antiglare layer 3 and, in this
case, fine organic or inorganic transparent fine particles having a
diameter of about 1 .mu.m, such as a polystyrene resin, are
incorporated into the primer layer 5. The formation of the primer
layer containing transparent fine particles can provide internal
light diffusion effect (=internal diffusion) which prevents
"glare."
[0114] Transparent fine particles, which can be incorporated into
the primer layer 5, include, in addition to polystyrene resin
beads, acrylic resin beads and silica beads.
[0115] Beads used have high transparency and small diameter, and,
thus, the incorporation of the transparent fine particles can
provide the effect of diffusing light without sacrificing the
sharpness of transmitted image.
[0116] Preferably, the beads have a particle diameter of 1 to 5
.mu.m and are incorporated in an amount of about 0.8 to 4 (by mass
ratio) based on 10 of the transparent resin constituting the primer
layer.
[0117] In use, the antiglare film 1 according to the present
invention is disposed on the uppermost (in the drawing) of the
liquid crystal display device 100 described above in conjunction
with FIG. 1.
[0118] Regarding the disposition of the antiglare film 1, the
antiglare film 1 may be mechanically fixed. Preferably, however, a
method is adopted wherein either a pressure-sensitive adhesive
layer or an adhesive layer is formed on the underside of the
antiglare film 1 shown in FIG. 2A or 2B (cross-sectional view) and
the assembly is applied onto the upper surface (in the drawing) of
the liquid crystal display device 100, generally the liquid crystal
panel 101.
[0119] A polarizing plate 101a generally has a laminate structure
wherein a polarizer is sandwiched between two cellulose triacetate
films. Therefore, when the cellulose triacetate film on the viewer
side is utilized as a transparent plastic film which is the
substrate of the antiglare film according to the present invention,
unlike the case where an antiglare film is prepared separately from
the polarizing plate and is formed on the polarizing plate, one
layer, i.e., the plastic film, and the pressure-sensitive adhesive
used at the time of forming can be omitted.
[0120] In use, the antiglare film 1 according to the present
invention may be merely disposed on the front of display devices,
such as liquid crystal display devices, or alternatively may be
disposed on the front of a touch panel disposed on the front of
display devices, such as liquid crystal display devices.
[0121] FIG. 4 is a diagram showing an embodiment wherein an
antiglare film 1 has been applied onto the front of a touch panel
21 formed on the front of a liquid crystal display device 100
through an adhesive layer 24.
[0122] The liquid crystal display device 100 comprises a liquid
crystal panel 101 and a surface light source device 102 disposed on
the underside of the liquid crystal panel 101, and the liquid
crystal display device 100 shown in FIG. 4 corresponds to the
liquid crystal display device 100 shown in FIG. 1, except that the
details of the liquid crystal display device 100 in FIG. 1 are not
shown.
[0123] The touch panel 21 is prepared as follows. A first laminate
of a transparent conductive layer 23, such as an indium tin oxide
layer, formed on the underside of a transparent plastic film 22 is
provided. Further, a second laminate of a transparent conductive
layer 23', such as an indium tin oxide layer, formed on the upper
surface of the transparent plastic film 22' is provided. The first
laminate is put and formed on the top of the second laminate so
that the transparent conductive layer 23 faces the transparent
conductive layer 23' while interposing a spacer 25 therebetween. In
this touch panel 21, the application of a pressure onto the upper
side of the touch panel brings the transparent conductive layers 23
and 23' into contact with each other and thus brings about an
electrically conducting state and enables inputting. This touch
panel 21 is only one example, and the touch panel may be any one so
far as input can be done by pressing.
[0124] The antiglare film 1 comprises: a transparent plastic film
2; a primer layer 5 and an antiglare layer 3 having fine concaves
and convexes 4 on its upper surface formed in that order on the
upper surface of the transparent plastic film 2; and a
pressure-sensitive adhesive layer 6 provided on the underside of
the transparent plastic film 2.
[0125] As shown in FIG. 4, in an assembly comprising a liquid
crystal display device 101 and, formed on the liquid crystal
display device 101 in the following order, a touch panel 21 and an
antiglare film 1, pressing the top of the antiglare film 1 in its
predetermined selected site by a finger or a touch pen according to
indication on the screen of the display in the liquid crystal
display device 101 can permit input utilizing the touch panel 21.
The antiglare film 1 does not substantially deteriorate the
visibility of the screen of display devices and, at the same time,
has excellent durability such as excellent surface scratch
resistance and thus can be stably used for a long period of
time.
EXAMPLES
[0126] The present invention will be described in more detail with
reference to the following examples and comparative examples.
Example 1
[0127] An iron roller was provided. Concaves and convexes were
formed on the surface of the roller by bead-shot blasting using
glass beads having a size of 100 mesh (particle diameter
distribution: 106 to 150 .mu.m). The surface of concaves and
convexes was plated with chromium to a plating thickness of 5 .mu.m
to prepare an embossing roller.
[0128] In the bead-shot blasting, the blasting pressure, the space
between the blasting nozzle and the roller and the like were
regulated, and the embossing roller thus obtained had a
three-dimensional ten-point mean roughness of 0.9 to 3 .mu.m and a
spacing between adjacent concaves (profile valleys) of 20 to 50
.mu.m.
[0129] A 75 .mu.m-thick polyethylene terephthalate resin film
(stock number: A 4300, manufactured by Toyobo Co., Ltd.) was
provided as a transparent plastic film. A composition prepared by
mixing a polyurethane resin primer coating material (a medium main
agent for chemical mat varnish, curing agent (XEL curing agent (D),
manufactured by The Inctec Inc.) in a mass ratio of main agent to
curing agent to solvent of 10:1:3.3 was gravure coated on the
transparent plastic film, and the coating was dried to form a 3
.mu.m-thick primer layer. The solvent used was a mixed solvent
composed of toluene and methyl ethyl ketone in a ratio of 1 : 1.
Here the mixing ratio is by mass (the same shall apply
hereinafter).
[0130] The apparatus, which has been described above with reference
to FIG. 3, was provided, and an ultraviolet-curable resin (Unidic
RC 20-058, manufactured by Dainippon Ink and Chemicals, Inc.) was
coated on the embossing roller. The transparent plastic film with
the primer layer formed thereon was laminated onto the coated
embossing roller so that the primer layer faced the coating on the
embossing roller. Subsequently, ultraviolet light was applied from
an ultraviolet light source (D-bulb, manufactured by Fusion) to the
laminate through the transparent plastic film. Thereafter, the
laminate was separated from the embossing roller to prepare an
antiglare film provided with an antiglare layer having concaves and
convexes on its surface according to the present invention.
Example 2
[0131] An antiglare film was prepared in the same manner as in
Example 1, except that, in forming the primer layer, 3 parts of
organic material beads (polystyrene resin beads, stock number:
MX-130 H, manufactured by Soken Chemical Engineering Co., Ltd.)
were added based on 10 parts of the main agent to the composition
to render the primer layer light diffusive.
Comparative Example
[0132] A silica bead-containing ultraviolet-curable resin
composition was coated directly on a transparent plastic film (as
used in Example 1) without the formation of a primer layer by means
of a gravure reverse coater. Thus, an antiglare layer having
concaves and convexes was formed by coating only.
[0133] The antiglare films prepared in Examples 1 and 2 and
Comparative Example were evaluated for the following items: (1)
(1a) total light transmittance and (1b) haze; (2) (2a)
three-dimensional surface roughness and (2b) mean spacing between
adjacent profile peaks; (3) sharpness (distinctness) of transmitted
image; (4) external light reflection preventive property; (5)
antiglare property; and (6) scratch resistance. (1) (1a) The total
light transmittance and (1b) haze were measured with a haze meter
("direct reading haze meter," manufactured by Toyo Seiki Seisaku
Sho, Ltd.).
[0134] (2) (2a) Three-dimensional surface roughness and (2b) mean
spacing between adjacent profile peaks were measured with a surface
roughness meter ("SURFCORDER SE-30 K," manufactured by Kosaka
Laboratory Ltd.). Both the three-dimensional surface roughness and
the mean spacing between adjacent profile peaks were expressed in
.mu.m.
[0135] (3) A measurement was carried out using four optical combs
(four slit widths of 0.25 mm, 0.5 mm, 1 mm, and 2 mm) according to
the measuring method for image sharpness for transparent samples
according to JIS K 7105 6.6, and the total of the measured values
was regarded as the sharpness (distinctness) of transmitted image.
The larger the numeric value, the higher the sharpness of
transmitted image. The measuring apparatus used was an image
clarity measuring apparatus "ICP-1PD" manufactured by Suga Test
Instruments Co., Ltd.
[0136] (4) In the measurement of the external light reflection
preventive property, light was applied to the sample through a
square mask. In this case, an image clarity evaluation apparatus
"MJ-RTS" manufactured by MIZOJIRI OPTICAL CO., LTD. was provided,
the luminance of the reflected image was caught in the regular
reflection direction, and the light application angle was varied to
determine the distribution of luminance relative to the application
angle and to prepare a graph based on the results, followed by the
determination of the maximum inclination angle in the graph. In the
case of a film not subjected to antiglare treatment, since the
luminance rapidly increases at the light application boundary
portion, the angle value is substantially equal to 90 degrees. The
smaller the numeric value, the lower the level of the external
light reflection and the higher the antiglare property.
[0137] (5) In the measurement of the antiglare property, the sample
was applied to the front of a color filter in a liquid crystal
display device, and the surface of the sample was photographed with
an image clarity evaluation apparatus "MJ-RTS" manufactured by
MIZOJIRI OPTICAL CO., LTD. to determine the standard deviation of
the luminance, within the screen, as the level of the antiglare
property. The smaller the numeric value indicating the level of the
antiglare property, the lower the glare level.
[0138] (6) In the measurement of the scratch resistance, steel wool
#0000 was provided and reciprocated on the sample while applying a
load of 2000 g to the steel wool to determine, as a numeric value
indicating the scratch resistance, the number of times of
reciprocation necessary for causing a noticeable scratch.
[0139] The results of evaluation for the above items (1) to (6) are
summarized in Table 1. In Table 1, the numbers in parentheses are
the same as those in the above evaluation items.
1 TABLE 1 Evaluation items Ex. 1 Ex. 2 Comp. Ex. (1a) Total light
89.2 88.3 87.4 transmittance (1b) Haze 12.4 25.3 8.1 (2a)
Three-dimensional 0.935 0.935 1.01 surface roughness (2b) Mean
spacing between 25.33 25.33 21.99 adjacent profile peaks (3)
Sharpness of 203.9 200.2 150.2 transmitted image (4) External light
72 72 30 reflection preventive property (5) Antiglare property 17 8
28 (6) Scratch resistance 90 90 20
[0140] The antiglare films prepared in Examples 1 and 2 are
superior to the antiglare film prepared in the comparative example
in sharpness of transmitted image and scratch resistance.
[0141] Further, in the antiglare film prepared in Example 2, the
incorporation of organic material beads into the primer layer
provided internal diffusion effect and, by virtue of this, imparted
an improved antiglare property to the antiglare film as compared
with the antiglare property of the antiglare film prepared in
Example 1.
[0142] The antiglare film according to the first aspect of the
present invention, when disposed on the front of a display device,
such as a liquid crystal display device, can exhibit excellent
external light reflection preventive property and scratch
resistance.
[0143] In an embodiment of the antiglare film according to the
present invention wherein the total light transmittance of the
antiglare film is not less than 87% and the haze of the antiglare
film is 5 to 40, in addition to the above effect, an additional
effect can be attained such that the disposition of the antiglare
film on the front of a display device causes substantially no
deterioration in luminance of images and, at the same time, glare
is less likely to occur while maintaining the sharpness of
images.
[0144] In another embodiment of the antiglare film according to the
present invention wherein the antiglare layer is formed of a cured
product of an ionizing radiation-curable resin, in addition to the
above effects, an additional effect can be attained such that the
antiglare film has excellent physical resistance, such as excellent
scratch resistance, and excellent chemical resistance and, further,
imparting concaves and convexes by means of an embossing plate and
curing the resin can be reliably carried out at a high speed.
[0145] In a further embodiment of the antiglare film according to
the present invention wherein a primer layer is additionally
provided between the transparent plastic film and the antiglare
layer, the antiglare film has improved adhesion strength between
the transparent plastic film and the antiglare layer.
[0146] In a still further embodiment of the antiglare film
according to the present invention wherein the primer layer
contains transparent fine particles, in addition to the above
effect described just above in connection with the provision of the
primer layer, an additional effect can be attained such that glare
can be suppressed by virtue of internal diffusion.
[0147] In the production process of an antiglare film according to
the present invention wherein a tool having predetermined concaves
and convexes is used as a molding tool and an ultraviolet-curable
resin is used as a material, the shape of the concaves and convexes
in the molding tool are faithfully reproduced on the antiglare
layer and, in addition, imparting concaves and convexes by means of
an embossing plate and curing the resin can be carried out at a
high speed.
[0148] In an embodiment of the production process according to the
present invention wherein the molding tool is in a roller form, in
addition to the above effect, a further effect can be attained such
that the processing can be continuously carried out while rotating
the molting tool and, thus, this constitution is suitable for the
production of an antiglare film in a continuous sheet form using a
continuous transparent plastic film.
[0149] In another embodiment of the production process according to
the present invention wherein a transparent plastic film with a
primer layer being formed on its side where the ionizing
radiation-curable resin is to be formed, in addition to the above
effect, a further effect can be attained such that the produced
antiglare film has improved adhesion strength between the
transparent plastic film and the antiglare layer.
[0150] In a further embodiment of the production process according
to the present invention wherein the primer layer contains
transparent fine particles, in addition to the above effect, a
further effect can be attained such that the produced antiglare
film is improved in antiglare properties by virtue of internal
diffusion.
[0151] According to a further aspect of the present invention,
there is provided an antiglare film produced by any one of the
above production processes.
[0152] According to a still further aspect of the present
invention, there is provided a display device comprising any one of
the above antiglare films having the above various effects disposed
on the front of a display. Therefore, this display device can have
an additional effect attained by the antiglare film.
* * * * *