U.S. patent application number 12/695251 was filed with the patent office on 2010-10-07 for method and apparatus for producing optical multilayer body.
This patent application is currently assigned to Dai Nippon Printing Co., Ltd.. Invention is credited to Yukimitsu IWATA, Takashi Kodama, Koichi Mikami, Yoshihiro Nishimura.
Application Number | 20100252202 12/695251 |
Document ID | / |
Family ID | 36916599 |
Filed Date | 2010-10-07 |
United States Patent
Application |
20100252202 |
Kind Code |
A1 |
IWATA; Yukimitsu ; et
al. |
October 7, 2010 |
METHOD AND APPARATUS FOR PRODUCING OPTICAL MULTILAYER BODY
Abstract
An optical laminate produced by a process for producing an
anti-dazzling laminate comprising a light transparent base material
and an anti-dazzling layer provided on the light transparent base
material. The process includes providing the light transparent base
material and forming the anti-dazzling layer having a concavoconvex
shape on the light transparent base material, wherein the
concavoconvex shape of the anti-dazzling layer satisfies the
following requirements: Sm is not less than 100 .mu.m and not more
than 600 .mu.m, .theta.a is not less than 0.1 degree and not more
than 1.2 degrees, and Rz is more than 0.2 .mu.m and not more than 1
.mu.m, wherein Sm represents the average spacing of concavoconvexes
or profile irregularities in the anti-dazzling layer; .theta.a
represents the average inclination angle of the concavoconvexes or
profile irregularities; and Rz represents the average roughness of
the concavoconvexes or profile irregularities.
Inventors: |
IWATA; Yukimitsu; (Aioi-Shi,
JP) ; Mikami; Koichi; (Okayama-Shi, JP) ;
Nishimura; Yoshihiro; (Okayama-Shi, JP) ; Kodama;
Takashi; (Okayama-Shi, JP) |
Correspondence
Address: |
BURR & BROWN
PO BOX 7068
SYRACUSE
NY
13261-7068
US
|
Assignee: |
Dai Nippon Printing Co.,
Ltd.
Shinjuku-Ku
JP
|
Family ID: |
36916599 |
Appl. No.: |
12/695251 |
Filed: |
January 28, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11884394 |
Mar 27, 2008 |
|
|
|
PCT/JP2006/303058 |
Feb 21, 2006 |
|
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12695251 |
|
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Current U.S.
Class: |
156/500 |
Current CPC
Class: |
G02F 1/133502 20130101;
Y10T 428/26 20150115; G02B 1/111 20130101 |
Class at
Publication: |
156/500 |
International
Class: |
B29C 70/78 20060101
B29C070/78 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 21, 2005 |
JP |
2005-044231 |
Mar 29, 2005 |
JP |
2005-095835 |
Claims
1. An apparatus for producing an optical laminate comprising a
light transparent base material and an anti-dazzling layer provided
on the light transparent base material, the apparatus comprising: a
feed part for feeding the light transparent base material and the
anti-dazzling layer having a concavoconvex shape; and a forming
part for forming the anti-dazzling layer on the light transparent
base material, wherein the concavoconvex shape of the anti-dazzling
layer satisfies the following requirements: Sm is not less than 100
.mu.m and not more than 600 .mu.m, .theta.a is not less than 0.1
degree and not more than 1.2 degrees, and Rz is more than 0.2 .mu.m
and not more than 1.2 .mu.m, wherein Sm represents the average
spacing of concavoconvexes in the anti-dazzling layer; .theta.a
represents the average inclination angle of the concavoconvexes;
and Rz represents the average roughness of the concavoconvexes.
2. An apparatus for producing an optical laminate comprising a
light transparent base material and an anti-dazzling layer provided
on the light transparent base material, the apparatus comprising: a
feed part for feeding the light transparent base material and the
anti-dazzling layer; and a forming part for forming the
anti-dazzling layer on the light transparent base material and
forming a concavoconvex shape in the anti-dazzling layer, wherein
the concavoconvex shape of the anti-dazzling layer satisfies the
following requirements: Sm is not less than 100 .mu.m and not more
than 600 .mu.m, .theta.a is not less than 0.1 degree and not more
than 1.2 degrees, and Rz is more than 0.2 .mu.m and not more than 1
.mu.m, wherein Sm represents the average spacing of concavoconvexes
in the anti-dazzling layer; .theta.a represents the average
inclination angle of the concavoconvexes; and Rz represents the
average roughness of the concavoconvexes.
3. The apparatus according to claim 2, wherein the forming part
comprises a mold having a reversed concavoconvex shape in relation
to the concavoconvex shape in the anti-dazzling layer.
4. An apparatus for producing an optical laminate comprising a
light transparent base material and an anti-dazzling layer provided
on the light transparent base material, the apparatus comprising: a
feed part for feeding the light transparent base material; an
application part for applying a composition for an anti-dazzling
layer on the light transparent base material; and a forming part
for curing the composition for an anti-dazzling layer to form the
anti-dazzling layer having a concavoconvex shape, wherein the
concavoconvex shape of the anti-dazzling layer satisfies the
following requirements: Sm is not less than 100 .mu.m and not more
than 600 .mu.m, .theta.a is not less than 0.1 degree and not more
than 1.2 degrees, and Rz is more than 0.2 .mu.m and not more than 1
.mu.m, wherein Sm represents the average spacing of concavoconvexes
in the anti-dazzling layer; .theta.a represents the average
inclination angle of the concavoconvexes; and Rz represents the
average roughness of the concavoconvexes.
5. The apparatus according to claim 4, wherein the composition for
an anti-dazzling layer is free from fine particles and contains a
resin and/or a polymer.
6. The apparatus according to claim 4, wherein the forming part
comprises an irradiation part for applying an ionizing radiation to
the composition for an anti-dazzling layer.
7. An apparatus for producing an optical laminate comprising a
light transparent base material and an anti-dazzling layer provided
on the light transparent base material, the apparatus comprising: a
feed part for feeding the light transparent base material; a mold
having a reversed concavoconvex shape in relation to the
concavoconvex shape of the surface of the anti-dazzling layer
provided on the light transparent base material; an introduction
part for introducing the composition for an anti-dazzling layer
into the mold; and a forming part for curing the composition for an
anti-dazzling layer to form the anti-dazzling layer having a
concavoconvex shape, wherein the concavoconvex shape of the
anti-dazzling layer satisfies the following requirements: Sm is not
less than 100 .mu.m and not more than 600 .mu.m, .theta.a is not
less than 0.1 degree and not more than 1.2 degrees, and Rz is more
than 0.2 .mu.m and not more than 1 .mu.m, wherein Sm represents the
average spacing of concavoconvexes in the anti-dazzling layer;
.theta.a represents the average inclination angle of the
concavoconvexes; and Rz represents the average roughness of the
concavoconvexes.
8. The apparatus according to claim 7, wherein the composition for
an anti-dazzling layer is free from fine particles and contains a
resin and/or a polymer.
9. The apparatus according to claim 7, wherein the forming part
comprises an irradiation part for applying an ionizing radiation to
the composition for an anti-dazzling layer.
10. The apparatus according to claim 1, which further comprises a
second forming part for forming a surface modifying layer on the
surface of the concavoconvex shape of the anti-dazzling layer after
the anti-dazzling layer formation.
11. The apparatus according to claim 1, wherein Rz is more than 0.2
.mu.m and not more than 1.0 .mu.m.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of U.S. patent
application Ser. No. 11/884,394, filed Mar. 27, 2008 and claims the
benefit of priority from the prior Japanese Patent Applications No.
44231/2005 and No. 95835/2005 under the Paris Convention, and,
thus, the entire contents thereof are incorporated herein by
reference.
FIELD OF THE INVENTION
[0002] The present invention provides a process and apparatus for
producing an optical laminate for use in displays such as CRTs and
liquid crystal panels.
BACKGROUND OF THE INVENTION
[0003] The prevention of lowered contrast and lowered visibility
caused by external light reflection or image reflection is required
of image display devices, for example, cathode-ray tube display
devices (CRTs), plasma displays (PDPs), electroluminescent displays
(ELDs), or liquid crystal displays (LCDs). Accordingly, it is
common practice to provide a reflection preventive laminate on the
outermost surface of an image display device from the viewpoint of
reducing image reflection or reflectance using the principle of
light scattering or the principle of optical interference.
[0004] In image display devices, for example, liquid crystal
displays, the use of an anti-dazzling laminate as one of
antireflection laminates has hitherto been known for realizing
regulating optical properties to realize excellent image displays.
The anti-dazzling laminate is utilized for preventing a lowering in
visibility as a result of external light reflection or image
reflection within image display devices. The anti-dazzling laminate
is generally realized by forming an anti-dazzling layer having a
concavoconvex shape on a base material. In conventional image
display devices, for example, liquid crystal displays, the use of
an anti-dazzling laminate as one antireflection laminate has
hitherto been known for regulating optical properties to realize
excellent image display. The anti-dazzling laminate is utilized for
preventing a lowering in visibility as a result of external light
reflection or image reflection within image display devices. The
anti-dazzling laminate is produced as having a concavoconvex shape
obtained by curing a composition containing various particles, or
having a concavoconvex shape formed by embossing (Japanese Patent
Laid-Open No. 341070/2004).
[0005] In recent years, a demand for a higher level of definition
of panel resolution has led to a higher level of fineness of the
concavoconcex shape of the anti-dazzling layer. Accordingly, a
concavoconvex shape having a broad and large curve has been
regarded as unsuitable for meeting a demand for higher definition
in the anti-dazzling laminate having the above construction and
thus have not been adopted. On the other hand, when increasing the
fineness of the concavoconvex shape involved in higher definition
of panel resolution can meet a demand for higher definition of the
panel resolution. Regarding this technique, however, it has often
been pointed out that, for example, external light is reflected
from the display surface resulting in such a phenomenon that, for
example, the image display surface is seen white (whitening), or
lowered contrast. When the anti-dazzling laminate is used on the
image display surface of notebook computers and the like, a certain
level of satisfactory optical properties can be provided. When the
light transmitted through the backside of backlight within a
display is transmitted through the concavoconvex shape face of the
anti-dazzling laminate formed on the outermost surface of the
panel, however, the concavoconvex shape functions as fine lenses
which disturb the displayed pixels and the like, that is, "glare"
is likely to occur. This unfavorable phenomenon makes it difficult
to attain the effect of the anti-dazzling laminate per se. In
particular, the occurrence of the "glare" increases with increasing
the definition of the panel resolution, and, thus, effectively
preventing this unfavorable phenomenon has been desired.
[0006] In order to eliminate this "glare," for example, a method
has been adopted in which surface concavoconvexes are densely
provided to enhance the sharpness and, at the same time, scattering
particles different from the resin for anti-dazzling layer
formation in refractive index are added to impart internal
scattering effect to the anti-dazzling laminate. All of proposed
methods could satisfactorily solve the problem of the "glare," but
on the other hand, they sometimes lowered the visibility of the
whole image. On the other hand, in the anti-dazzling laminate, the
method for reducing the "glare" in high-definition panels has been
regarded as a main cause of an unfavorable phenomenon, for example,
a deterioration in contrast such as clouding caused by surface
whitening, internal scattering effect or the like. That is, it has
been regarded that "glare prevention" and "contrast improvement"
are in the relationship of tradeoff, and simultaneously meeting
both the requirements is difficult. In the above methods, for
example, black color reproduction including glossy black feeling
(wet glossy black color) in on-screen display, contrast and the
like have sometimes been poor. That is, gradation rendering of
black color in a light room, particularly a black color gradation
difference in low gradation, cannot be regarded without
difficulties resulting in lowered sensitivity. Specifically, black
and gray colors are only recognized as a blurred and identical
color-tone black color. In particular, it can be said that an
anti-dazzling laminate having better anti-glare properties has a
significantly lowered level of visibility.
[0007] Accordingly, at the present time, the development of a
production process (and production apparatus) for an optical
laminate, which can effectively prevent the glare of an image
surface and, at the same time, can realize good black color
reproduction, especially glossy black feeling, has been desired. In
particular, a production process (and production apparatus) for an
optical laminate, which can be used in liquid crystal displays
(LCDs) as well as in other applications such as cathode ray tube
display devices (CRTs), plasma displays (PDPs), fluorescent display
tubes, and field emission-type displays.
SUMMARY OF THE INVENTION
[0008] At the time of the present invention, the present inventors
have found a process and apparatus for producing an optical
laminate which, while imparting anti-dazzling properties, can
realize the so-called glossy black feeling (glossy black color) by
improving the anti-glare property and the contrast, especially by
improving black color reproduction. The present invention has been
made based on such finding.
[0009] Accordingly, the present invention provides a process (and
apparatus) for producing an optical laminate which can realize an
anti-dazzling function and an excellent anti-glare property and, at
the same time, can realize image display having a high level of
visibility.
[0010] Production Process
[0011] According to the present invention, there is provided a
process for producing an optical laminate comprising: a light
transparent base material; and an anti-dazzling layer provided on
the light transparent base material, the process comprising the
steps of:
[0012] providing the light transparent base material; and
[0013] forming the anti-dazzling layer having a concavoconvex shape
on the light transparent base material, wherein
[0014] the concavoconvex shape of the anti-dazzling layer satisfies
the following requirements:
[0015] Sm is not less than 100 .mu.m and not more than 600
.mu.m,
[0016] .theta.a is not less than 0.1 degree and not more than 1.2
degrees, and
[0017] Rz is more than 0.2 .mu.m (preferably not less than 0.35
.mu.m) and not more than 1 .mu.m (preferably not more than 0.9
.mu.m),
[0018] wherein Sm represents the average spacing of concavoconvexes
or profile irregularities in the anti-dazzling layer; .theta.a
represents the average inclination angle of the concavoconvexes (or
profile irregularities); and Rz represents the average roughness of
the concavoconvexes (or profile irregularities).
[0019] Production Apparatus
[0020] According to another aspect of the present invention, there
is provided an apparatus for producing an optical laminate
comprising: a light transparent base material and an anti-dazzling
layer provided on the light transparent base material, the
apparatus comprising:
[0021] a feed part for feeding the light transparent base material
and the anti-dazzling layer having a concavoconvex shape; and
[0022] a forming part for forming the anti-dazzling layer on the
light transparent base material, wherein the concavoconvex shape of
the anti-dazzling layer satisfies the following requirements:
[0023] Sm is not less than 100 .mu.m and not more than 600
.mu.m,
[0024] .theta.a is not less than 0.1 degree and not more than 1.2
degrees, and
[0025] Rz is more than 0.2 .mu.m (preferably not less than 0.35
.mu.m) and not more than 1 .mu.m (preferably not more than 0.9
.mu.m),
[0026] wherein Sm represents the average spacing of concavoconvexes
or profile irregularities in the anti-dazzling layer; .theta.a
represents the average inclination angle of the concavoconvexes (or
profile irregularities); and Rz represents the average roughness of
the concavoconvexes (or profile irregularities).
[0027] The production process and production apparatus according to
the present invention can provide an optical laminate which can
realize excellent anti-dazzling properties and black color
reproduction having glossy black feeling, can realize a high level
of sharpness and excellent anti-glare property, contrast, and
letter blurring preventive property, and can be used in various
displays. In particular, the process for producing an optical
laminate according to the present invention can provide an optical
laminate which is significantly improved in black color gradation
rendering (glossy black color reproduction), which could not have
been realized by the conventional anti-dazzling laminate without
difficulties. More specifically, it is possible to provide an
optical laminate which, in an image in movie display, can render
gradation substantially comparable with a conventional display
provided with a laminate comprising a clear hard coat layer free
from any concavoconvex shape and an antireflection layer provided
on the clear hard coat layer and, at the same time, can realize a
good sharpness of the contour of letters and can prevent
scintillation. In a preferred embodiment of the present invention,
the provision of an optional layer such as a surface modifying,
layer or a low-refractive index layer on the anti-dazzling layer
means that the surface of the concavoconvex shape constituting the
anti-dazzling layer is sealed by the optional layer, and, thus, a
large and smooth desired concavoconvex shape can be realized.
Further, various functions such as antistatic property, refractive
index regulation, and contamination prevention can be imparted to
the optical laminate. When an optional layer such as a surface
modifying layer or a low-refractive index layer is provided on the
anti-dazzling layer, the surface concavoconvex shape of the
optional layer such as the surface modifying layer or the
low-refractive index layer conforms to the optical property values
of the surface concavoconvex shape of the anti-dazzling layer
according to the present invention. That is, in the optical
laminate according to the present invention, the concavoconvex
shape of the outermost surface conforms to the optical property
values of the surface concavoconvex shape of the anti-dazzling
layer specified in the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a graph showing the relationship between the
reflection Y value and the surface haze value for an optical
laminate.
[0029] FIG. 2 is a graph showing the relationship between .theta.a
and Sm for an optical laminate.
[0030] FIG. 3 is a diagram showing a production process of an
optical laminate according to the present invention.
[0031] FIG. 4 is a schematic diagram showing a production apparatus
according to the present invention.
[0032] FIG. 5 is a schematic diagram showing a production apparatus
according to the present invention.
[0033] FIG. 6 is a schematic diagram showing a production apparatus
according to the present invention.
[0034] FIG. 7 is an optical photomicrograph of a surface shape of
each of an optical laminate according to the present invention and
a conventional anti-dazzling optical laminate.
[0035] FIG. 8 is a photograph of an optical laminate according to
the present invention taken by three-dimensional measurement under
AFN.
[0036] FIG. 9 is a photograph of a conventional optical laminate
taken by three-dimensional measurement under AFN.
DETAILED DESCRIPTION OF THE INVENTION
Definition
[0037] Terms used in the present specification (working examples
and the like) will be defined as follows.
[0038] 1) Ten-Point Average Roughness (Rz)
[0039] The average roughness is measured by measuring the surface
shape as a two-dimensional or three-dimensional profile. In fact,
the measurement in this case is carried out under a scanning probe
microscope or an atomic force microscope. It is generally difficult
to objectively compare curves per se, and, hence, various roughness
indexes are calculated based on the profile curve data.
Accordingly, in the present invention, the ten-point average
roughness (Rz) is calculated using the above measurement results
and is expressed in terms of the sum of the average value of
absolute values of the highest five deviation values and the
average value of absolute values of the lowest five deviation
values among deviation values determined from average values.
[0040] 2) Average Spacing of Profile Irregularities
(Concavoconvexes) Sm (.mu.m) and Average Inclination Angle
.theta.a
[0041] The anti-dazzling layer constituting the optical laminate
according to the present invention has a concavoconvex shape. Sm
(.mu.m) represents the average spacing of concavoconvexes (profile
irregularities) of the anti-dazzling layer, and .theta.a (degree)
represents the average inclination angle of the concavoconvex part.
Sm (.mu.m) and .theta.a (degree) may be defined as described in an
instruction manual (revised on Jul. 20, 1995) of a surface
roughness measuring device (model: SE-3400, manufactured by Kosaka
Laboratory Ltd.). .theta.a (degree) represents the angle mode, and,
when the inclination is .DELTA.a in terms of aspect ratio, .theta.a
(degree) is determined by .theta.a (degree)=1/tan .DELTA.a=1/(sum
of values of difference between the lowest part and the highest
part in each concavoconvex (corresponding to the height of each
convex part)/reference length). The "reference length" is the same
as in the following measuring conditions 1.
[0042] When the parameters (Sm, .theta.a, and Rz) representing the
surface roughness of the optical laminate according to the present
invention may be measured, for example, with the above surface
roughness measuring device under the following measurement
conditions. This measuring method is favorable in the present
invention.
[0043] Measuring Conditions
[0044] 1) Tracer in surface roughness detector:
[0045] Model/SE2555N (standard 2 .mu.m), manufactured by Kosaka
Laboratory Ltd. (radius of curvature in tip 2 .mu.m/apex angle: 90
degrees/material: diamond)
[0046] 2) Measuring conditions for surface roughness measuring
device:
[0047] Reference length (cut-off value of roughness curve
.lamda.C): 2.5 mm
[0048] Evaluation length (reference length (cut-off value
.lamda.C).times.5): 12.5 mm
[0049] Feed speed of tracer: 0.5 mm/sec
[0050] .psi..ident.Rz/Sm
[0051] The ratio .psi. between the average roughness Rz of
concavoconvexes and the average spacing Sm of concavoconvexes is
defined by .psi..ident.Rz/Sm. The ratio between the average
roughness Rz of concavoconvexes and the average spacing Sm of
concavoconvexes can be used as an index for indicating the gradient
of the inclination of the concavoconvexes. The ratio .psi. between
the average roughness Rz of concavoconvexes and the average spacing
Sm of concavoconvexes is defined by .psi..ident.Rz/Sm. The ratio
between the average roughness Rz of concavoconvexes and the average
spacing Sm of concavoconvexes can be used as an index for
indicating the tilt angle of the inclination of the
concavoconvexes.
[0052] 3) Reflection Y Value
[0053] The reflection Y value is a value indicating a luminous
reflectance determined by measuring 5-degree regular reflectance in
a wavelength range of 380 to 780 nm with a spectrophotometer MPC
3100 manufactured by Shimadzu Seisakusho Ltd. and then converting
the reflectance values to lightness which can be perceived by the
human eye with a software (incorporated in MPC 3100). The 5-degree
regular reflectance is measured in such a state that, in order to
prevent the backside reflection of the film as the optical
laminate, a black tape (manufactured by Teraoka Seisakusho Co.,
Ltd.) is applied to the side remote from the film face to be
measured.
[0054] 4) Haze Value, Total Light Transmittance, 60-Degree Gloss,
and Transmission Sharpness
[0055] The haze value may be measured according to JIS K 7136. A
reflection-transmittance meter HR-100 (Murakami Color Research
Laboratory) may be mentioned as an instrument used for the
measurement. The total light transmittance of the anti-dazzling
laminate may be measured with the same measuring device as in the
haze value according to JIS K 7361. The haze and total light
transmittance are measured in such a state that the coated face is
directed to a light source. The 60-degree gloss can be measured
with a precision gloss meter (GM-26D, manufactured by Murakami
Color Research Laboratory) according to JIS Z 8741. The 60-degree
gloss is measured in such a state that, in order to eliminate the
influence of backside reflection of a sample, a double face
adhesive tape (manufactured by Teraoka Seisakusho Co., Ltd.) is
applied to the backside of a sample and a black lid of the
measuring device. The transmission sharpness is expressed in terms
of the total of numerical values obtained by measurement with four
types of optical combs (0.125 mm, 0.5 mm, 1 mm, and 2 mm) with an
image clarity measuring device (stock number; "ICM-1DP",
manufactured by Suga Test Instruments Co., Ltd.) according to JIS K
7105.
[0056] 5) Definition of Surface Haze
[0057] The term "surface haze" as used herein is determined as
follows. A pentaerythritol triacrylate or other resin (including
resin components such as monomers or oligomers) is diluted with
toluene or the like to a solid content of 60%, and the diluted
solution is coated with a wire bar onto concavoconvexes of the
anti-dazzling layer to a thickness on a dry film basis of 8 .mu.m,
whereby the surface concavoconvexes of the anti-dazzling layer are
rendered flat. In this case, when the recoating agent is likely to
be repelled and less likely to wet the anti-dazzling layer due to
the presence of a leveling agent in the composition for
anti-dazzling layer formation, a method may be adopted in which the
anti-dazzling film is previously rendered hydrophilic by
saponification. The saponification is carried out by immersing the
anti-dazzling film in a 2 mol/liter NaOH (or KOH) solution
(55.degree. C.) for 3 min, washing the film with water, completely
removing water droplets with a Kimwipe, and then drying the film in
an oven (50.degree. C.) for one min. The film having a flattened
surface does not have any haze derived from surface concavoconvexes
but has only an internal haze. This haze can be determined as an
internal haze. The value obtained by subtracting the internal haze
from the original film haze (overall haze) is determined as a haze
(a surface haze) attributable only to surface concavoconvexes.
[0058] 6) Thickness of Anti-Dazzling Layer
[0059] The thickness of the anti-dazzling layer refers to a part
extended from the interface, between the base material on its
display surface side and the outermost surface of the anti-dazzling
concavoconvex in contact with the air. In the part extended from
the base material surface to the outermost surface, the
anti-dazzling layer has either a single layer or a multilayer
structure comprising a surface modifying layer and other optical
function layers stacked onto the anti-dazzling layer.
[0060] Method for Measuring Layer Thickness
[0061] The cross section of the optical laminate was subjected to
transmission observation under a confocal laser microscope
(LeicaTCS-NT, manufactured by Leica: magnification "100 to 300
times) to determine whether or not the interface was present, and
the results were evaluated according to the following criteria.
Specifically, in order to provide a halation-free sharp image, a
wet objective lens was used in a confocal laser microscope, and
about 2 ml of an oil having a refractive index of 1.518 was placed
on an optical laminate, followed by observation to determine the
presence or absence of the interface. The oil was used to allow the
air layer between the objective lens and the optical laminate to
disappear.
[0062] Measurement Procedure
[0063] 1: The average thickness of the layer was measured by
observation under a laser microscope.
[0064] 2: The measurement was carried out under the following
conditions.
[0065] 3: For one image plane, the layer thickness from the base
material to the maximum profile peak (convex) part was measured for
one point, and the layer thickness from the base material to the
minimum valley (concave) part was measured for one point. That is,
the layer thickness was measured for two points in total for one
image plane. This measurement was carried out for five image
planes, that is, 10 points in total, and the average value was
determined.
[0066] Production Process
[0067] The concavoconvex shape of the anti-dazzling layer formed by
the production process according to the present invention is formed
as having optical properties which will be described later in
connection with "optical laminate." In an embodiment of the present
invention, the anti-dazzling layer in the optical laminate produced
by the process according to the present invention satisfies the
following requirements:
[0068] Sm is not less than 100 .mu.m and not more than 600
.mu.m,
[0069] .theta.a is not less than 0.1 degree and not more than 1.2
degrees, and
[0070] Rz is more than 0.2 .mu.m and not more than 1 .mu.m,
[0071] wherein Sm represents the average spacing of concavoconvexes
(or profile irregularities) in the anti-dazzling layer; .theta.a
represents the average inclination angle of the concavoconvexes (or
profile irregularities); and Rz represents the average roughness of
the concavoconvexes (or profile irregularities).
[0072] First Production Process
[0073] According to the present invention, there is provided a
first process for producing an optical laminate comprising: a light
transparent base material; and an anti-dazzling layer provided on
the light transparent base material, the process comprising the
steps of:
[0074] providing the light transparent base material; and
[0075] forming the anti-dazzling layer having a concavoconvex shape
on the light transparent base material.
[0076] The production process of an optical laminate (HG) according
to the present invention will be described with reference to FIG.
3. FIG. 3 is a cross-sectional view of an optical laminate
according to the present invention. In the production process of
present invention, a light transparent base material 2 is first
provided. Next, an anti-dazzling layer 4 is formed on the upper
surface of the light transparent base material 2 to produce the
optical laminate. In the present invention, various methods for
anti-dazzling layer formation can be utilized. Preferred methods
are as follows.
[0077] Second Production Process
[0078] The second production process according to the present
invention is the same as the first production process of the
present invention, except that an anti-dazzling layer on which a
concavoconvex shape has been previously formed is provided on the
light transparent base material. The second production process may
be described in more detail with reference to FIG. 3. Specifically,
an anti-dazzling layer 4 on which a concavoconvex shape has been
previously formed is provided on a light transparent base material
1. Preferably, the anti-dazzling layer 4 is formed with the aid of
an easy-adhesion layer such as an adhesive agent (layer) or a
primer. Alternatively, a method may also be adopted in which a
previously formed anti-dazzling layer is formed onto the upper
surface of the light transparent base material 2 through an
adhesive (agent) layer and the adhesive (agent) layer is then
subjected to curing or the like.
[0079] Third Production Process
[0080] The third production process according to the present
invention is the same as the first production process of the
present invention, except that an anti-dazzling layer is formed on
the light transparent base material and a concavoconvex shape is
formed on the surface of the anti-dazzling layer. In a preferred
embodiment of the present invention, the concavoconvex shape is
formed by embossing treatment using a mold having a reversed
concavoconvex shape in relation to the concavoconvex shape in the
anti-dazzling layer. The concavoconvex shape formation may be
described in detail with reference to FIG. 3. Specifically, an
anti-dazzling layer 4 having a concavoconvex shape can be formed by
forming an anti-dazzling layer on a light transparent base material
1 and then forming a concavoconvex shape on the surface of the
anti-dazzling layer. In a preferred embodiment of the present
invention, the concavoconvex shape may be formed in the
anti-dazzling layer 4 by using a mold having a reversed
concavoconvex shape in relation to the concavoconvex shape in the
anti-dazzling layer 4. The anti-dazzling layer 4 per se may be
formed in the same manner as in the second production process.
[0081] Fourth Production Process
[0082] The fourth production process according to the present
invention is the same as the first production process according to
the present invention, except that a composition for an
anti-dazzling layer is applied onto the light transparent base
material to form the above anti-dazzling layer having a
concavoconvex shape. In a preferred embodiment of the present
invention, for example, a method may be adopted in which the
composition for an anti-dazzling layer is subjected to curing or
the like in the formation of the anti-dazzling layer having a
concavoconvex shape. In FIG. 3, the anti-dazzling layer 4 contains
a resin and fine particles. The fine particles may be those having
an identical shape or average particle diameter or the same or
different shape or average particle diameter, or may be
aggregation-type fine particles. On the other hand, in the present
invention, the anti-dazzling layer may also be formed by using a
polymer or resin only. The details of the method for anti-dazzling
layer 4 formation may be the same as described below in connection
with "anti-dazzling layer."
[0083] Fifth Production Process
[0084] The fifth production process is a process for producing an
optical laminate, comprising: a light transparent base material;
and an anti-dazzling layer provided on the light transparent base
material, the process comprising the steps of:
[0085] providing the light transparent base material;
[0086] introducing the light transparent base material into a mold
having a reversed concavoconvex shape in relation to the
concavoconvex shape of the surface of the anti-dazzling layer;
and
[0087] applying a composition for an anti-dazzling layer to the
mold to form an anti-dazzling layer having a concavoconvex shape on
the light transparent base material.
[0088] Optional Process
[0089] In a preferred embodiment of the present invention, there is
also provided a production process in which a surface modifying
layer 6 is formed on an anti-dazzling layer 4. In a more preferred
embodiment of the present invention, in an optical laminate to be
disposed on the outermost surface of a display device, lowering the
reflection (a reduction in reflectance) of the optical laminate
utilizing the principle of optical interferences is preferred from
the viewpoint of preventing, for example, contrast deterioration or
visibility deterioration by external tight reflection or image
reflection. For example, there is proposed a production process in
which a low-refractive index layer 8 having a lower refractive
index than the refractive index of the anti-dazzling layer 4 or the
surface modifying layer 6 is formed on the surface of the surface
modifying layer 6.
[0090] Production Apparatus
[0091] The concavoconvex shape of the anti-dazzling layer formed by
the production apparatus according to the present invention is
formed as having optical properties which will be described later
in connection with "optical laminate." In a preferred embodiment of
the present invention, the concavoconvex shape of the anti-dazzling
layer in the optical laminate produced by the production apparatus
according to the present invention satisfies the following
requirements:
[0092] Sm is not less than 100 .mu.m and not more than 600
.mu.m,
[0093] .theta.a is not less than 0.1 degree and not more than 1.2
degrees, and
[0094] Rz is more than 0.2 .mu.m and not more than 1 .mu.m,
[0095] wherein Sm represents the average spacing of concavoconvexes
or profile irregularities in the anti-dazzling layer; .theta.a
represents the average inclination angle of the concavoconvexes (or
profile irregularities); and Rz represents the average roughness of
the concavoconvexes (or profile irregularities).
[0096] First Production Apparatus
[0097] The first production apparatus according to the present
invention is an apparatus for producing an optical laminate
comprising a light transparent base material and an anti-dazzling
layer provided on the light transparent base material, the
apparatus comprising:
[0098] a feed part for feeding the light transparent base material
and the anti-dazzling layer having a concavoconvex shape; and
[0099] a forming part for forming the anti-dazzling layer on the
light transparent base material.
[0100] Any schematic diagram of this apparatus is not specifically
shown, and the construction of the first production apparatus may
be the same as that of the second production apparatus, described
below, the first embodiment of which is schematically shown in FIG.
4, except that a roller emboss 27 and a roller 25c are not
provided.
[0101] Second Production Apparatus
[0102] The second production apparatus according to the present
invention is an apparatus for producing an optical laminate
comprising a light transparent base material and an anti-dazzling
layer provided on the light transparent base material, the
apparatus comprising:
[0103] a feed part for feeding the light transparent base material
and the anti-dazzling layer; and
[0104] a forming part for forming the anti-dazzling layer on the
light transparent base material and forming a concavoconvex shape
in the anti-dazzling layer.
[0105] The second production apparatus will be briefly described
with reference to FIG. 4. FIG. 4 is a schematic diagram of the
second production apparatus according to the present invention. A
light transparent base material 21 is fed through a roller 25a as a
feed part, and an anti-dazzling layer (free from a concavoconvex
shape) 23 is fed through a roller 25b as the feed part. The fed
light transparent base material 21 and anti-dazzling layer 23 are
integrated with each other by the roller 25a and the roller 25b. In
a preferred embodiment of the present invention, a feed part for
feeding an adhesive agent (layer) may be provided. In this case,
the light transparent base material 21 and the anti-dazzling layer
23 are integrated with each other through the adhesive agent
(layer) fed from the feed part. The integrated light transparent
base material 21 and anti-dazzling layer 23 are introduced into a
roller emboss 27 having a reversed concavoconvex shape 22 in
relation to the concavoconvex shape to be imparted to the
anti-dazzling layer. The integrated light transparent base material
21 and anti-dazzling layer 23 is held between the roller emboss 27
and the roller 25c to form a desired concavoconvex shape in the
anti-dazzling layer 23 and thus to form an optical laminate 29. The
optical laminate 29 thus formed is supplied as a product through a
roller 25d.
[0106] In a preferred embodiment of the present invention, the
forming part comprises a mold having a reversed concavoconvex shape
in relation to the concavoconvex shape in the anti-dazzling layer.
Besides the roller emboss 27, a flat-type emboss plate may be used.
Emboss treatment methods, roller emboss, flat-type emboss plates
and the like may be the same as described below in connection with
the fourth production apparatus according to the present
invention.
[0107] Third Production Apparatus
[0108] The third production apparatus according to the present
invention is an apparatus for producing an optical laminate
comprising a light transparent base material and an anti-dazzling
layer provided on the light transparent base material, the
apparatus comprising:
[0109] a feed part for feeding the light transparent base
material;
[0110] an application part for applying a composition for an
anti-dazzling layer on the light transparent base material; and
[0111] a forming part for curing the composition for an
anti-dazzling layer to form the anti-dazzling layer having a
concavoconvex shape.
[0112] The third production apparatus according to the present
invention will be briefly described with reference to FIG. 5. FIG.
5 is a schematic diagram of the third production apparatus
according to the present invention. A light transparent base
material 31 is held between rollers 35a and 35b as the feed part
and is fed. A coating head 33 is provided behind the rollers 35a
and 35b as the feed part, and a composition 34 for an anti-dazzling
layer is fed from a liquid reservoir through a pipe 36. The fed
composition 34 for an anti-dazzling layer is fed through a slit 39
open toward the lower part of the coating head 33. The composition
34 for an anti-dazzling layer is applied through the slit 39 onto
the fed light transparent base material 31 to form a layer of the
composition 34 for an anti-dazzling layer. Thereafter, curing
treatment is carried out by a curing device 38 provided behind the
coating head 33, whereby the composition 34 for an anti-dazzling
layer is cured to form a desired concavoconvex shape on the
anti-dazzling layer 37. The optical laminate comprising the cured
anti-dazzling layer 37 provided on the light transparent base
material 41 is moved and passed through a roller 25d to produce an
optical laminate.
[0113] Fourth Production Apparatus
[0114] The fourth production apparatus according to the present
invention is an apparatus for producing an optical laminate
comprising a light transparent base material and an anti-dazzling
layer provided on the light transparent base material, the
apparatus comprising:
[0115] a feed part for feeding the light transparent base
material;
[0116] a mold having a reversed concavoconvex shape in relation to
the concavoconvex shape of the surface of the anti-dazzling layer
provided on the light transparent base material;
[0117] an introduction part for introducing the composition for an
anti-dazzling layer into the mold; and
[0118] a forming part for curing the composition for an
anti-dazzling layer to form the anti-dazzling layer having a
concavoconvex shape.
[0119] One embodiment of the fourth production apparatus will be
briefly described with reference to FIG. 6. FIG. 6 is a schematic
diagram of the fourth production apparatus (embossing apparatus 40)
according to the present invention. A light transparent base
material 41 is fed to an emboss roller 47 through a nip roller 45a
as the feed part. A reversed concavoconvex shape 42 in relation to
the desired concavoconvex shape of the anti-dazzling layer is
provided on the surface of the emboss roller 47. A coating head 43
is provided on the lower part of the emboss roller 47, and an a
composition 44 for an anti-dazzling layer is fed through a pipe 46
from a liquid reservoir (not shown). The fed composition 44 for an
anti-dazzling layer is fed through a slit 49 open toward the upper
part of the coating head 43. The composition 44 for an
anti-dazzling layer is applied to the emboss roller 47 on its
surface having a concavoconvex shape 42. The emboss roller 47 is
then rotated (in a direction indicated by an arrow in the drawing).
Consequently, the light transparent base material 41 and the
composition 44 for an anti-dazzling layer are brought into intimate
contact with each other between the concavoconvex shape 42 in the
emboss roller 47 and the nip roller 45a as the feed part. In a
preferred embodiment of the present invention, instead of the
formation of the light transparent base material 41 after the
application of the composition 44 for an anti-dazzling layer onto
the concavoconvex shape 42, a method may be adopted in which, while
winding the light transparent base material 41 around the emboss
roller 47, the composition 44 for an anti-dazzling layer is fed
into between the light transparent base material 41 and the emboss
roller 47 to bring the light transparent base material 41 and the
layer of the composition 44 for an anti-dazzling layer into contact
with each other. The assembly in which the light transparent base
material 41 and the layer of the composition 44 for an
anti-dazzling layer have been brought into intimate contact with
each other is moved onto the upper part of the emboss roller 47,
and curing treatment is carried out by a curing device 48 provided
above the emboss roller 47, whereby the layer of the composition 44
for an anti-dazzling layer is cured and integrated with the upper
part of the light transparent base material 41. The optical
laminate comprising the cured layer of the composition 44 for an
anti-dazzling layer provided on the light transparent base material
41 is moved upon the rotation of the emboss roller 47 and is
separated from the emboss roller 47 by a peel-off roller 45b to
produce an optical laminate comprising an anti-dazzling layer
having a concavoconvex shape.
[0120] Embossing
[0121] The fourth production apparatus according to the present
invention is advantageous in that an optical laminate provided with
an anti-dazzling layer having a desired concavoconvex shape formed
without incorporating fine particles can be produced. In the
present invention, the concavoconvex shape may be formed by an
emboss method in which a formed anti-dazzling layer or an
anti-dazzling layer which is in the course of formation thereof is
embossed by an emboss plate (preferably a roller emboss), and, if
necessary, curing treatment is carried out, for example, by
heating. In a preferred embodiment of the present invention, a
method is adopted which comprises providing a concavoconvex mold
having a surface with a reversed concavoconvex shape in relation to
the desired concavoconvex shape, applying a composition, for an
anti-dazzling layer, having a high level of curability onto the
light transparent base material, and then subjecting the assembly
to curing to integrate the light transparent base material with the
anti-dazzling layer having a concavoconvex shape and thus to
produce an optical laminate. In the present invention, a method may
be adopted in which a composition for an anti-dazzling layer is
first applied followed by embossing with a mold having a
concavoconvex mold shape. Alternatively, a method may also be
adopted in which a composition for an anti-dazzling layer is
supplied to the interface of a light transparent base material and
a mold having a concavoconvex shape to allow the composition for an
anti-dazzling layer to be interposed between the mold having a
concavoconvex shape and the light transparent base material and to
the formation of the concavoconvex shape and the formation of the
anti-dazzling layer simultaneously. In a preferred embodiment of
the present invention, in addition to the emboss roller, a flat
emboss plate may also be used.
[0122] The mold surface having a concavoconvex shape formed, for
example, in an emboss roller or a flat emboss plate may be formed
by various methods, specifically by a sandblasting method or a bead
shot method. The anti-dazzling layer formed using an emboss plate
(an emboss roller) formed by the sandblast method has such a shape
that a number of concaves (on the other hand, downward convexed
cross section) are distributed on the upper side. On the other
hand, the anti-dazzling layer formed using an emboss plate (an
emboss roller) formed by the bead shot method has such a shape that
a number of convexes (on the other hand, upward convexed cross
section) are distributed on the upper side.
[0123] When the average roughness of concavoconvexes formed on the
surface of the anti-dazzling layer is identical, the anti-dazzling
layer in which a number of convexes are distributed on its upper
side is regarded as causing a lower level of reflection of a
lighting equipment in a room or the like as compared with the
anti-dazzling layer in which a number of concaves are distributed
on its upper side. Accordingly, in a preferred embodiment of the
present invention, the concavoconvex shape of the anti-dazzling
layer is formed by utilizing a concavoconvex mold having a shape
identical to the concavoconvex shape of the anti-dazzling layer by
a bead shot method. The concavoconvex shape formed by this
concavoconvex mold is such that the proportion of the upward
convexed cross-sectional shape part is larger than that of the
downward convexed cross-sectional shape part. In another preferred
embodiment of the present invention, the concavoconvex shape of the
anti-dazzling layer is formed by utilizing a concavoconvex mold
having a shape, which is reverse to the concavoconvex shape of the
anti-dazzling layer, formed by the bead shot method. The
concavoconvex shape formed by this concavoconvex mold is such that
the proportion of the downward convexed cross-sectional shape (that
is, concave) part is larger than that of the upward convexed
cross-sectional shape (that is, convex) part.
[0124] Mold materials for forming the concavoconvex mold face
usable herein include metals, plastics, woods, or composites
thereof. Example of preferred mold materials in the present
invention are chromium as a metal from the viewpoints of strength
and abrasion resistance upon repeated use, and are iron emboss
plates (emboss rollers) having a surface plated with chromium, for
example, from the viewpoints of cost effectiveness.
[0125] Specific examples of particles (beads) sprayed in the
formation of the concavoconvex mold by the sandblast or bead shot
method include inorganic particles such as metal particles, silica,
alumina, or glass. The particle size (diameter) of these particles
is preferably about 100 .mu.m to 300 .mu.m. In spraying these
particles against the mold material, a method may be adopted in
which these particles, together with a high speed gas, are sprayed.
In this case, a proper liquid, for example, water or the like may
be used in combination with the particles. In the present
invention, preferably, the concavoconvex mold having a
concavoconvex shape is plated with chromium or the like to improve
the durability during use of the mold and is preferred from the
viewpoints of film hardening and corrosion prevention.
[0126] Optical Laminate
[0127] The optical laminate according to the present invention
simultaneously has anti-dazzling properties and excellent black
color reproduction and contrast. In the present invention, the
optical laminate is referred to as a half glare optical laminate
(HG). HG has both properties of a conventional anti-glare optical
laminate (AG) having excellent anti-dazzling properties and
properties of an optical laminate (AR) comprising a clear hard coat
(glare) layer provided with a low-refractive index layer and having
excellent black color reproduction and contrast. Specifically, the
provision of a surface modifying layer considered as one of methods
for half glare optical laminate (HG) formation on the anti-glare
optical laminate (AG) renders the concavoconvex shape of the
anti-dazzling layer smooth, and, further, imparting a surface
roughness parameter similar to the anti-glare (AG) can realize the
production of an anti-dazzling laminate having a very high level of
glossy black feeling while imparting satisfactory anti-dazzling
properties. Accordingly, the details of the optical laminate (HG)
according to the present invention will be described while
comparing the conventional AR and AG.
[0128] FIG. 1 is a diagram showing the relationship between the
surface haze value (%) and the reflection Y value (%) in the
optical laminate. In FIG. 1, the conventional AR belongs to an area
in which the surface haze value is less than about 0.3%,
specifically an area on the left side from the ruled line indicated
by a reference numeral 1. On the other hand, the conventional AG
belongs to an area where the surface haze value is approximately
4.0% to 25.0% (generally not less than 10.0%) and the reflection Y
value is approximately 1.0 to 4.5, specifically an area surrounded
by a reference numeral 5 (generally a right side area in the area
surrounded by the reference numeral 5). On the other hand, the
optical laminate (HG) according to the present invention belongs to
an area where the surface haze value is approximately not less than
0.2% and not more than 3.5% (preferably not more than 3.0) and the
reflection Y value is approximately not less than 0.5 and not more
than 4.5, specifically an area surrounded by a reference numeral
3.
[0129] The optical properties of the optical laminate produced by
the production process according to the present invention will be
described with reference to FIG. 2. FIG. 2 is a diagram showing the
relationship between the average inclination angle .theta.a (in
degree) in the concavoconvexes part of the anti-dazzling layer in
the optical laminate and the average spacing Sm (.mu.m) of the
concavoconvexes. As can be seen from FIG. 2, in the conventional
AG, specifically, AG having a .theta.a value of not less than 1.5
degrees and not more than 2.5 degrees and an Sm value of
approximately more than 30 .mu.m and not more than 200 .mu.m (an
area indicated by a reference numeral 9), that is, one falling
within the area indicated by a reference numeral 11, has been
regarded as a preferred AG. On the other hand, in the optical
laminate (HG) according to the present invention, the .theta.a
value is more than 0.1 degree and not more than 1.2 degrees.
Preferably, the lower limit of the .theta.a value is 0.3 degree,
and the upper limit of the .theta.a value is 0.6 degree. The Sm
value is approximately not less than 100 .mu.m and not more than
600 .mu.m. Preferably, the lower limit of the Sm value is 120
.mu.m, and the upper limit of the Sm value is 400 .mu.m.
Specifically, an optical laminate falling within an area indicated
by a reference numeral 7 is utilized. The Rz value of the optical
laminate according to the present invention is more than 0.2 .mu.m
(preferably not less than 0.35 .mu.m) and not more than 1.2 .mu.m
(preferably not more than 1 .mu.m, more preferably not more than
0.9 .mu.m).
[0130] 1. Anti-Dazzling Layer
[0131] In the production process according to the present
invention, the anti-dazzling layer may be formed, for example, by
stacking a previously formed anti-dazzling layer onto the surface
of the optical laminate. Additional methods for forming the
anti-dazzling layer on the surface of the optical laminate in the
present invention include 1) a method in which an anti-dazzling
layer having a concavoconvex shape is formed using a composition
for an anti-dazzling layer comprising fine particles added to a
resin, 2) a method in which an anti-dazzling layer having a
concavoconvex shape is formed using a composition for an
anti-dazzling layer containing only a resin or the like without the
addition of fine particles, and 3) a method in which an
anti-dazzling layer is formed by using treatment for forming a
concavoconvex shape. In the present invention, when an
anti-dazzling layer is previously formed, the anti-dazzling layer
may be one formed by any one of the above methods 1) to 3).
[0132] The thickness H .mu.m of the anti-dazzling layer formed by
the production process according to the present invention is not
less than 0.5 .mu.m and not more than 27 .mu.m (preferably not more
than 12 .mu.m). Preferably, the lower limit of the thickness of the
anti-dazzling layer is 1 .mu.m, and the upper limit of the
thickness of the anti-dazzling layer is 7 .mu.m.
[0133] Method for Anti-Dazzling Layer Formation Using Composition
for Anti-Dazzling Layer, Comprising Resin Containing Fine
Particles
[0134] Method for Anti-Dazzling Layer Formation
[0135] The anti-dazzling layer may be formed by mixing fine
particles or aggregation-type fine particles (preferably first fine
particles and second fine particles) and the resin with a proper
solvent to give a composition for an anti-dazzling layer and
coating the composition onto a light transparent base material.
Suitable solvents used in this case include alcohols such as
isopropyl alcohol, methanol, and ethanol; ketones such as methyl
ethyl ketone (MEK), methyl isobutyl ketone (MIBK), and
cyclohexanone; esters such as methyl acetate, ethyl acetate, and
butyl acetate; halogenated hydrocarbons; aromatic hydrocarbons such
as toluene and xylene; or their mixtures.
[0136] Methods usable for coating the composition for anti-dazzling
layer onto the light transparent base material include coating
methods such as roll coating, Mayer bar coating, and gravure
coating. After coating of the composition for an anti-dazzling
layer, the coating is dried and cured by ultraviolet irradiation.
Specific examples of ultraviolet sources include light sources, for
example, ultra-high-pressure mercury lamps, high-pressure mercury
lamps, low-pressure mercury lamps, carbon arc lamps, black light
fluorescent lamps, and metal halide lamps. Regarding the wavelength
of the ultraviolet light, a wavelength range of 190 to 380 nm may
be used. Specific examples of electron beam sources include various
electron beam accelerators, for example, Cockcroft-Walton
accelerators, van de Graaff accelerators, resonance transformer
accelerators, insulated core transformer accelerators, linear
accelerators, Dynamitron accelerators, and high-frequency
accelerators. The resin is cured, and the fine particles in the
resin are fixed to form a desired cancavoconvex shape on the
outermost surface of the anti-dazzling layer.
[0137] Fine Particles
[0138] The fine particles may be in a spherical, for example, truly
spherical, elliptical or acicular form, preferably in a truly
spherical form. In the present invention, the average particle
diameter R (.mu.m) of the fine particles is not less than 1.0 .mu.m
and not more than 20 .mu.m. Preferably, the upper limit is 15.0
.mu.m, and the lower limit is 3.5 .mu.m.
[0139] In the present invention, not less than 80% (preferably not
less than 90%) of the whole fine particles is accounted for by fine
particles having an average particle diameter distribution of
R.+-.1.0 (preferably 0.3) .mu.m. When the average particle diameter
distribution of the fine particles falls within the above-defined
range, the evenness of the concavoconvex shape of the anti-dazzling
laminate can be rendered good and, at the same time, scintillation
and the like can be effectively prevented. Further, the
anti-dazzling layer may further comprise, in addition to the fine
particles, second fine particles or third fine particles or a
combination of a plurality of types of fine particles different
from the fine particles in average particle diameter. For example,
for small fine particles of which the average particle diameter R
(.mu.m) is approximately the lower limit value, i.e., about 3.5
.mu.m, a concavoconvex layer can be efficiently formed using fine
particles having a particle size distribution with the average
particle diameter being 3.5 .mu.m rather than monodisperse fine
particles.
[0140] Aggregation-Type Fine Particles
[0141] In a preferred embodiment of the present invention, the use
of aggregation-type fine particles among the fine particles is
preferred. The aggregation-type fine particles may be identical
fine particles, or alternatively may be a plurality of types of
fine particles, the plurality of types being different from each
other in average particle diameter. In a preferred embodiment of
the present invention, the aggregation-type fine particles comprise
first fine particles and second fine particles different from the
first fine particles in average particle diameter. Further, in a
more preferred embodiment of the present invention, the second fine
particle as such or the aggregation part as such does not exhibit
anti-dazzling properties in the anti-dazzling layer.
[0142] In the present invention, preferably, the fine particles
satisfy the following formula (I):
0.25R (preferably 0.50).ltoreq.r.ltoreq.1.0R (preferably 0.70)
(I)
wherein R represents the average particle diameter of the fine
particles, .mu.m; and r represents the average particle diameter of
the second fine particles, .mu.m.
[0143] When the r value is not less than 0.25R, the dispersion of
the coating composition is easy and, consequently, the particles
are not aggregated. In the step of drying after coating, a uniform
concavoconvex shape can be formed without undergoing an influence
of wind during floating. Further, when r is not more than 0.85R,
advantageously, the function of the fine particles can be clearly
distinguished from the function of the first fine particles.
[0144] In another embodiment of the present invention, preferably,
the total weight ratio per unit area among the resin, (first) fine
particles, and second fine particles satisfies requirements
represented by the following formulae (II) and (III):
0.08(M.sub.1+M.sub.2)/M.ltoreq.0.36 (II)
0.ltoreq.M.sub.2.ltoreq.4.0M.sub.1 (III)
[0145] wherein M.sub.1 represents the total weight of the (first)
fine particles per unit area; M.sub.2 represents the total weight
of the second fine particles per unit area; and M represents the
total weight of the resin per unit area.
[0146] In another preferred embodiment of the present invention,
preferably, a requirement represented by the following formula (IV)
is satisfied:
.DELTA.n=|n.sub.1-n.sub.3|<0.15 and/or
.DELTA.n=|n.sub.2-n.sub.3|<0.18 (IV)
[0147] wherein n.sub.1, n.sub.2, and n.sub.3 represent the
refractive indexes of the (first) fine particles, the second fine
particles, and the resin, respectively.
[0148] Fine particles (second fine particles) may be of inorganic
type and organic type and are preferably formed of an organic
material. The fine particles exhibit anti-dazzling properties and
are preferably transparent. Specific examples of such fine
particles include plastic beads, and transparent plastic beads are
more preferred. Specific examples of plastic beads include styrene
beads (refractive index 1.59), melamine beads (refractive index
1.57), acrylic beads (refractive index 1.49), acryl-styrene beads
(refractive index 1.54), polycarbonate beads, and polyethylene
beads. In a preferred embodiment of the present invention, the
plastic bead has a hydrophobic group on its surface, and, for
example, acrylic beads are preferred.
Resin
[0149] The anti-dazzling layer according to the present invention
may be formed from a (curing-type) resin. In the present invention,
the "resin" is a concept including resin components such as
monomers and oligomers. The curing-type resin is preferably
transparent, and specific examples thereof are classified into
ionizing radiation curing resins which are curable upon exposure to
ultraviolet light or electron beams, mixtures of ionizing radiation
curing resins with solvent drying resins, or heat curing resins.
Preferred are ionizing radiation curing resins.
[0150] Specific examples of ionizing radiation curing resins
include those containing an acrylate-type functional group, for
example, oligomers or prepolymers and reactive diluents, for
example, relatively low-molecular weight polyester resins,
polyether resins, acrylic resins, epoxy resins, urethane resins,
alkyd resins, spiroacetal resins, polybutadiene resins, and
polythiol polyene resins and (meth)acrylates of polyfunctional
compounds such as polyhydric alcohols. Specific examples thereof
include monofunctional monomers such as ethyl (meth)acrylate,
ethylhexyl (meth)acrylate, styrene, methyl styrene, and
N-vinylpyrrolidone, and polyfunctional monomers, for example,
polymethylolpropane tri(meth)acrylate, hexanediol (meth)acrylate,
tripropylene glycol di(meth)acrylate, diethylene glycol
di(meth)acrylate, pentaerythritol tri(meth)acrylate,
dipentaerythritol hexa(meth)acrylate, 1,6-hexanediol
di(meth)acrylate, and neopentyl glycol di(meth)acrylate.
[0151] When ionizing radiation curing resins are used as an
ultraviolet curing resin, preferably, a photopolymerization
initiator is used. Specific examples of photopolymerization
initiators include acetophenones, benzophenones, Michler's benzoyl
benzoate, .alpha.-amyloxime ester, tetramethyl thiuram monosulfide,
and thioxanthones. Preferably, photosensitizers are mixed in the
system. Specific examples of photosensitizers include n-butylamine,
triethylamine, and poly-n-butylphosphine.
[0152] The solvent drying-type resin used as a mixture with the
ionizing radiation curing resin is mainly a thermoplastic resin.
Coating defects of the coated face can be effectively prevented by
adding the solvent drying-type resin. Commonly exemplified
thermoplastic resins are usable. Specific examples of preferred
thermoplastic resins include styrenic resins, (meth)acrylic resins,
vinyl acetate resins, vinyl ether resins, halogen-containing
resins, alicyclic olefinic resins, polycarbonate resins, polyester
resins, polyamide resins, cellulose derivatives, silicone resins,
and rubbers or elastomers. The resin is generally noncrystalline
and, at the same time, is soluble in an organic solvent
(particularly a common solvent which can dissolve a plurality of
polymers and curable compounds). Particularly preferred are resins
having good moldability or film forming properties, transparency,
and weathering resistance, for example, styrenic resins,
(meth)acrylic resins, alicyclic olefinic resins, polyester resins,
and cellulose derivatives (for example, cellulose esters).
[0153] In a preferred embodiment of the present invention, when the
light transparent base material is formed of a cellulosic resin
such as triacetylcellulose "TAC," specific examples of preferred
thermoplastic resins include cellulosic resins, for example,
nitrocellulose, acetylcellulose, cellulose acetate propionate, and
ethylhydroxyethylcellulose. When the cellulosic resin is used, the
adhesion between the light transparent base material and the
antistatic layer (if any) and transparency can be improved. In
addition to the above-described cellulose derivatives such as
acetylcellulose, nitrocellulose, acetylbutylcellulose,
ethylcellulose, and methylcellulose, vinyl resins such as vinyl
acetate and its copolymers, vinyl chloride and its copolymers, and
vinylidene chloride and its copolymers, acetal resins such as
polyvinylformal and polyvinylbutyral, acrylic resins such as
acrylic resin and its copolymers and methacrylic resin and its
copolymers, polystyrene resins, polyamide resins, and polycarbonate
resins.
[0154] Specific examples of heat curing resin include phenolic
resins, urea resins, diallyl phthalate resins, melanin resins,
guanamine resins, unsaturated polyester resins, polyurethane
resins, epoxy resins, aminoalkyd resins, melamine-urea cocondensed
resins, silicone resins, and polysiloxane resins. When the heat
curing resin is used, if necessary, for example, curing agents such
as crosslinking agents and polymerization initiators,
polymerization accelerators, solvents, and viscosity modifiers may
be further added.
[0155] Leveling Agent
[0156] In a preferred embodiment of the present invention,
preferably, a fluoro- or silicone-type or other leveling agent is
added to the composition for an anti-dazzling layer. The
composition for an anti-dazzling layer to which the leveling agent
has been added, can effectively prevent the inhibition of curing by
oxygen to the surface of the coating film during coating or drying
and, at the same time, impart scratch resistant effect. Preferably,
the leveling agent is utilized in film-shaped light transparent
base materials (for example, triacetylcellulose) which should be
resistant to heat.
[0157] 2) Method for Forming Anti-Dazzling Layer Using Composition
for Anti-Dazzling Layer, Containing Resin and the Like but not
Containing Fine Particles
[0158] Method for Anti-Dazzling Layer Formation
[0159] The anti-dazzling layer may be formed using a composition
for an anti-dazzling layer, comprising at least one polymer and at
least one curable resin precursor. The use of a composition for an
anti-dazzling layer prepared by mixing at least one polymer and at
least one curable resin precursor with a suitable solvent is
advantageous in that at least an anti-dazzling layer can be formed
by forming a phase separated structure by spinodal decomposition
from a liquid phase and curing the curable resin precursor.
[0160] The spinodal decomposition from the liquid phase can be
carried out by evaporating the solvent. The combination of
materials which can form a phase separated structure may be, for
example, a combination of a plurality of polymers, a combination of
a polymer and a curable resin precursor, or a combination of a
plurality of curable resin precursors. In this method, an
anti-dazzling layer may also be formed by subjecting a composition
comprising a thermoplastic resin, a photocuring compound (for
example, a photopolymerizable monomer or oligomer), a
photopolymerization initiator, and a solvent capable of dissolving
the thermoplastic resin and photocurable compound (a common
solvent) to spinodal decomposition to form a phase separated
structure and exposing the product to light. Alternatively, the
anti-dazzling layer may be formed by subjecting a composition
comprising a thermoplastic resin, a resin incompatible with the
thermoplastic resin and containing a photocurable group, a
photocuring compound, a photopolymerization initiator, and a
solvent capable of dissolving the resin and the photocuring
compound to spinodal decomposition to form a phase separated
structure, and applying light to the assembly. In these methods, at
least one anti-dazzling layer may be formed on a light transparent
base material.
[0161] Specific Formation Method
[0162] The anti-dazzling layer may be formed by a process
comprising the steps of: mixing at least one polymer and at least
one curable resin precursor using a proper solvent to prepare a
composition for an anti-dazzling layer, applying the composition
for an anti-dazzling layer onto a light transparent base material
and then subjecting the coating to spinodal decomposition involving
the evaporation of the solvent to form a phase separated structure;
and curing the curable resin precursor to form at least an
anti-dazzling layer. The phase separation step generally comprises
the step of coating or casting a mixed liquid containing a polymer
and a curable resin precursor and a solvent (particularly a liquid
composition such as a homogeneous solution) onto the surface of a
light transparent base material and the step of evaporating the
solvent from the coating layer or casting layer to form a phase
separated structure having a regular or periodical average
phase-to-phase distance. The anti-dazzling layer can be formed by
curing the curable resin precursor.
[0163] In a preferred embodiment of the present invention, the
mixed liquid may be a composition for an anti-dazzling layer,
comprising a thermoplastic resin, a photocuring compound, a
photopolymerization initiator, and a solvent capable of dissolving
the thermoplastic resin and photocuring compound. The anti-dazzling
layer is formed by applying light to photocurable components in the
phase separated structure formed by the spinodal decomposition to
cure the photocurable components. In another preferred embodiment
of the present invention, the mixed liquid may be a composition for
an anti-dazzling layer, comprising a plurality of mutually
incompatible polymers, a photocuring compound, a
photopolymerization initiator, and a solvent. In this case, the
anti-dazzling layer is formed by applying light to photocurable
components in the phase separated structure formed by the spinodal
decomposition to cure the photocurable components.
[0164] The spinodal decomposition involving the evaporation of the
solvent can impart regularity or periodicity to the average
distance between domains in the phase separated structure. The
phase separated structure formed by the spinodal decomposition can
be immediately fixed by curing the curable resin precursor. The
curable resin precursor can be cured, for example, by heating or
light irradiation or a combination of these methods according to
the type of the curable resin precursor. The heating temperature
can be selected, for example, from a suitable temperature range,
for example, from a range of approximately 50 to 150.degree. C., so
far as the phase separated structure is present, and may be
selected from the same temperature range as in the phase separation
step.
[0165] The anti-dazzling layer constituting a part of the optical
laminate is formed by forming a phase separated structure in the
anti-dazzling layer by spinodal decomposition (wet spinodal
decomposition) from a liquid phase. Specifically, a composition for
an anti-dazzling layer according to the present invention,
comprising a polymer, a curable resin precursor, and a solvent is
provided. The solvent is evaporated or removed from the composition
for an anti-dazzling layer in its liquid phase (or a homogeneous
solution or coating layer thereof) by drying or the like. In the
course of drying or the like, an increase in concentration causes
phase separation by spinodal decomposition to form a phase
separated structure having a relatively regular phase-to-phase
distance. More specifically, the wet spinodal decomposition is
generally carried out by coating a composition for an anti-dazzling
layer (preferably a homogeneous solution) comprising at least one
polymer, at least one curable resin precursor, and a solvent onto a
support and evaporating the solvent from the coating layer.
[0166] In the present invention, in the spinodal decomposition, as
the phase separation proceeds, a co-continuous phase structure is
formed. As the phase separation further proceeds, the continuous
phase is rendered discontinuous by the surface tension of the phase
per se to form a liquid droplet phase structure (a sea-island
structure of spherical, truly spherical, disk-like, elliptical or
other independent phases). Accordingly, depending upon the degree
of the phase separation, a structure intermediate between a
co-continuous structure and a liquid droplet phase structure (a
phase structure in the course of transfer from the co-continuous
phase to the liquid droplet phase) can also be formed. The phase
separated structure of the anti-dazzling layer according to the
present invention may be a sea-island structure (a liquid droplet
phase structure or a phase structure in which one of the phases is
independent or isolated), a co-continuous phase structure (or a
network structure), or an intermediate structure in which a
co-continuous phase structure and a liquid droplet phase structure
exist together. By virtue of the phase separated structure, after
the removal of the solvent by drying, fine concavoconvexes can be
formed on the surface of the anti-dazzling layer.
[0167] In the phase separated structure, concavoconvexes are formed
on the surface of the anti-dazzling layer, and, from the viewpoint
of enhancing the surface hardness, a liquid droplet phase structure
having at least island domains is advantageous. When the phase
separated structure composed of the polymer and the precursor (or
curable resin) is a sea-island structure, the polymer component may
constitutes a sea phase. From the viewpoint of the surface
hardness, however, the polymer component preferably constitutes
island domains. The formation of island domains leads to the
formation of a concavoconvex shape having desired optical
characteristics on the surface of the anti-dazzling layer after
drying.
[0168] The average distance between domains in the phase separated
structure is generally substantially regular or periodical. For
example, the average phase-to-phase distance of domains may be, for
example, approximately 1 to 70 .mu.m (for example, 1 to 40 .mu.m),
preferably 2 to 50 .mu.m (for example, 3 to 30 .mu.m), more
preferably 5 to 20 .mu.m (for example, 10 to 20 .mu.m).
[0169] Polymer
[0170] The polymer may be a plurality of polymers which can be
phase separated by a spinodal decomposition, for example, a
cellulose derivative and a styrenic resin, an (meth)acrylic resin,
an alicyclic olefinic resin, a polycarbonate resin, a polyester
resin or the like, or a combination thereof. The curable resin
precursor may be compatible with at least one polymer in the
plurality of polymers. At least one of the plurality of polymers
may have a functional group involved in a curing reaction of the
curable resin precursor, for example, a polymerizable group such as
an (meth)acryloyl group. In general, a thermoplastic resin is used
as the polymer component.
[0171] Specific examples of thermoplastic resins include styrenic
resins, (meth)acrylic resins, organic acid vinyl ester resins,
vinyl ether resins, halogen-containing resins, olefinic resins
(including alicyclic olefinic resins), polycarbonate resins,
polyester resins, polyamide resins, thermoplastic polyurethane
resins, polysulfone resins (for example, polyethersulfone and
polysulfone), polyphenylene ether resins (for example, polymers of
2,6-xylenol), cellulose derivatives (for example, cellulose esters,
cellulose carbamates, and cellulose ethers), silicone resins (for
example, polydimethylsiloxane and polymethylphenylsiloxane), and
rubbers or elastomers (for example, diene rubbers such as
polybutadiene and polyisoprene, styrene-butadiene copolymers,
acrylonitrile-butadiene copolymers, acrylic rubbers, urethane
rubbers, and silicone rubbers). They may be used either solely or
in a combination of two or more.
[0172] Specific examples of styrenic resins include homopolymers or
copolymers of styrenic monomers (for example, polystyrenes,
styrene-.alpha.-methylstyrene copolymers, and styrene-vinyltoluene
copolymers) and copolymers of styrenic monomers with other
polymerizable monomers (for example, (meth)acrylic monomers, maleic
anhydride, maleimide monomers, or dienes). Styrenic copolymers
include, for example, styrene-acrylonitrile copolymers (AS resins),
copolymers of styrene with (meth)acrylic monomers (for example,
styrene-methyl methacrylate copolymers, styrene-methyl
methacrylate-(meth)acrylic ester copolymers, or styrene-methyl
methacrylate-(meth)acrylic acid copolymers), and styrene-maleic
anhydride copolymers. Preferred styrenic resins include copolymers
of polystyrene or styrene with (meth)acrylic monomers (for example,
copolymers composed mainly of styrene and methyl methacrylate, for
example, styrene-methyl methacrylate copolymers), AS resins, and
styrene-butadiene copolymers.
[0173] For example, homopolymers or copolymers of (meth)acrylic
monomers and copolymers of (meth)acrylic monomers with
copolymerizable monomers may be mentioned as the (meth)acrylic
resin. Specific examples of (meth)acrylic monomers include
(meth)acrylic acid; C.sub.1-10 alkyl (meth)acrylates such as methyl
(meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, t-butyl
(meth)acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate,
octyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate; aryl
(meth)acrylates such as phenyl (meth)acrylate; hydroxyalkyl
(meth)acrylate such as hydroxyethyl (meth)acrylate and
hydroxypropyl (meth)acrylate; glycidyl (meth)acrylate;
N,N-dialkylaminoalkyl (meth)acrylate; (meth)acrylonitrile; and
(meth)acrylates containing an alicyclic hydrocarbon group, such as
tricyclodecane. Specific examples of copolymerizable monomers
include the above styrenic monomers, vinyl ester monomers, maleic
anhydride, maleic acid, and fumaric acid. These monomers may be
used either solely or in a combination of two or more.
[0174] Specific examples of (meth)acrylic resins include
poly(meth)acrylic esters such as polymethyl methacrylate, methyl
methacrylate-(meth)acrylic acid copolymers, methyl
methacrylate-(meth)acrylic ester copolymers, methyl
methacrylate-acrylic ester-(meth)acrylic acid copolymers, and
(meth)acrylic ester-styrene copolymers (for example, MS resins).
Specific examples of preferred (meth)acrylic resins include
poly-C.sub.1-6 alkyl (meth)acrylates such as polymethyl
(meth)acrylate. In particular, methyl methacrylate resins composed
mainly of methyl methacrylate (approximately 50 to 100% by weight,
preferably 70 to 100% by weight) may be mentioned.
[0175] Specific examples of organic acid vinyl ester resins include
homopolymers or copolymers of vinyl ester monomers (for example,
polyvinyl acetate and polyvinyl propionate), copolymers of vinyl
ester monomers with copolymerizable monomers (for example,
ethylene-vinyl acetate copolymers, vinyl acetate-vinyl chloride
copolymers, and vinyl acetate-(meth)acrylic ester copolymers), or
their derivatives. Specific examples of vinyl ester resin
derivatives include polyvinyl alcohol, ethylene-vinyl alcohol
copolymers, and polyvinylacetal resins.
[0176] Specific examples of vinyl ether resins include homopolymers
or copolymers of vinyl C.sub.1-10 alkyl ethers such as vinyl methyl
ether, vinyl ethyl ether, vinyl propyl ether, or vinyl t-butyl
ether, copolymers of vinyl C.sub.1-10 alkyl ethers with
copolymerizable monomers (for example, vinyl alkyl ether-maleic
anhydride copolymers). Specific examples of halogen-containing
resins include polyvinyl chloride, polyfluorinated vinylidenes,
vinyl chloride-vinyl acetate copolymers, vinyl
chloride-(meth)acrylic ester copolymers, and vinylidene
chloride-(meth)acrylic ester copolymers.
[0177] Specific examples of olefinic resins include homopolymers of
olefins such as polyethylene and polypropylene, and copolymers such
as ethylene-vinyl acetate copolymers, ethylene-vinyl alcohol
copolymers, ethylene-(meth)acrylic acid copolymers, and
ethylene-(meth)acrylic ester copolymers. Specific examples of
alicyclic olefinic resins include homopolymers or copolymers of
cyclic olefins (for example, norbornene, dicyclopentadiene) (for
example, polymers containing an alicyclic hydrocarbon group such as
tricyclodecane which is sterically rigid), and copolymers of the
above cyclic olefins with copolymerizable monomers (for example,
ethylene-norbornene copolymers and propylene-norbornene
copolymers). Specific examples of alicyclic olefinic resins include
those which are available, for example, under the tradenames
"ARTON" and "ZEONEX."
[0178] Specific examples of polycarbonate resins include aromatic
polycarbonates based on bisphenols (for example, bisphenol A), and
aliphatic polycarbonates such as diethylene glycol bisallyl
carbonates.
[0179] Specific examples of polyester resins include aromatic
polyesters using aromatic dicarboxylic acids such as terephthalic
acid, for example, homopolyesters, for example,
poly-C.sub.2-4-alkylene terephthalates and poly-C.sub.2-4-alkylene
naphthalates including polyethylene terephthalate and polybutylene
terephthalate, and copolyesters comprising as a main component (for
example, not less than 50% by weight) C.sub.2-4 alkylene arylate
units (C.sub.2-4 alkylene terephthalate and/or C.sub.2-4 alkylene
naphthalate units). Specific examples of copolyesters include
copolyesters in which, in the constituent units of
poly-C.sub.2-4-alkylene arylate, a part of C.sub.2-4 alkylene
glycol has been replaced, for example, with a
polyoxy-C.sub.2-4-alkylene glycol, a C.sub.6-10 alkylene glycol, an
alicyclic diol (for example, cyclohexanedimethanol or hydrogenated
bisphenol A), an aromatic ring-containing diol (for example,
9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene having a fluorenone side
chain, bisphenol A, or a bisphenol A-alkylene oxide adduct), and
copolyesters in which a part of aromatic dicarboxylic acid has been
replaced, for example, with an aliphatic C.sub.6-12 dicarboxylic
acid, for example, an asymmetric aromatic dicarboxylic acid such as
phthalic acid or isophthalic acid, or adipic acid. Specific
examples of polyester resins include polyarylate resins, aliphatic
polyesters using aliphatic dicarboxylic acids such as adipic acid,
and homopolymers and copolymers of lactones such as 6-caprolactone.
Preferred polyester resins are generally noncrystalline polyester
resins such as noncrystalline copolyesters (for example, C.sub.2-4
alkylene arylate copolyesters).
[0180] Specific examples of polyamide resins include aliphatic
polyamides such as nylon 46, nylon 6, nylon 66, nylon 610, nylon
612, nylon 11, and nylon 12, and polyamides produced from
dicarboxylic acids (for example, terephthalic acid, isophthalic
acid, or adipic acid) and diamines (for example, hexa
methylenediamine or metaxylylenediamine). Specific examples of
polyamide resins include homopolymers or copolymers of lactams such
as .di-elect cons.-caprolactam. The polyamide resins may be either
homopolyamides or copolyamides.
[0181] Specific examples of cellulose esters among the cellulose
derivatives include, for example, aliphatic organic acid esters,
for example, cellulose acetates such as cellulose diacetate and
cellulose triacetate; and C.sub.1-6 organic acid esters such as
cellulose propionate, cellulose butyrate, cellulose acetate
propionate, and cellulose acetate butyrate. Further examples
thereof include aromatic organic acid esters (C.sub.7-12 aromatic
carboxylic esters such as cellulose phthalate and cellulose
benzoate) and inorganic acid esters, for example, cellulose
phosphate and cellulose sulphate. Mixed acid esters such as acetic
acid-nitric acid cellulose ester may also be used. Specific
examples of cellulose derivatives include cellulose carbamates (for
example, cellulose phenylcarbamate) and further include cellulose
ethers, for example, cyanoethylcellulose;
hydroxy-C.sub.2-4-alkylcelluloses such as hydroxyethylcellulose and
hydroxypropylcellulose; C.sub.1-6 alkylcelluloses such as
methylcellulose and ethylcellulose; and carboxymethylcellulose or
its salt, benzylcellulose, and acetylalkylcellulose.
[0182] Specific examples of preferred thermoplastic resins include
styrenic resins, (meth)acrylic resins, vinyl acetate resins, vinyl
ether resins, halogen-containing resins, alicyclic olefinic resins,
polycarbonate resins, polyester resins, polyamide resins, cellulose
derivatives, silicone resins, rubbers or elastomers. Resins, which
are usually noncrystalline and soluble in organic solvents
(particularly common solvents which can dissolve a plurality of
polymers or curable compounds). Particularly preferred are, for
example, resins having a high level of moldability or film
formability, transparency and weathering resistance, for example,
styrenic resins, (meth)acrylic resins, alicyclic olefinic resins,
polyester resins, and cellulose derivatives (for example, cellulose
esters).
[0183] Polymers containing a functional group involved in a curing
reaction (or a functional group reactive with a curable compound)
are also usable as the polymer component. The polymers may contain
a functional group in the main chain or side chain. The functional
group may be introduced into the main chain, for example, by
copolymerization or co-condensation. In general, however, the
functional group is introduced into the side chain. Specific
examples of such functional groups include condensable groups and
reactive groups (for example, hydroxyl group, acid anhydride group,
carboxyl group, amino group or imino group, epoxy group, glycidyl
group, and isocyanate group), polymerizable groups (for example,
C.sub.2-6 alkenyl groups such as vinyl, propenyl, isopropenyl,
butenyl and allyl groups, C.sub.2-6 alkynyl groups such as ethynyl,
propynyl, and butynyl groups, and C.sub.2-6 alkenylidene groups
such as vinylidene), or groups containing these polymerizable
groups (for example, (meth)acryloyl group). Among these functional
groups, polymerizable groups are preferred.
[0184] The polymerizable group may be introduced into the side
chain, for example, by reacting a thermoplastic resin containing a
functional group such as a reactive group or a condensable group
with a polymerizable compound containing a group reactive with the
functional group.
[0185] Examples of such functional group-containing thermoplastic
resins include thermoplastic resins containing a carboxyl group or
its acid anhydride group (for example, (meth)acrylic resins,
polyester resins, and polyamide resins), hydroxyl group-containing
thermoplastic resins (for example, (meth)acrylic resins,
polyurethane resins, cellulose derivatives, and polyamide resins),
amino group-containing thermoplastic resins (for example, polyamide
resins), epoxy group-containing thermoplastic resins (for example,
epoxy group-containing (meth)acrylic resins and polyester resins).
Resins comprising the above functional group introduced into
thermoplastic resins such as styrenic resins, olefinic resins, or
alicyclic olefinic resins by copolymerization or graft
polymerization are also possible.
[0186] Regarding the polymerizable compound, thermoplastic resins
containing a carboxyl or its acid anhydride group include
polymerizable compounds containing epoxy, hydroxyl, amino, or
isocyanate groups. Hydroxyl group-containing thermoplastic resins
include polymerizable compounds containing carboxyl groups or acid
anhydride groups thereof or isocyanate groups. Amino
group-containing thermoplastic resins include polymerizable
compounds containing carboxyl groups or acid anhydride groups
thereof, epoxy groups, and isocyanate groups. Epoxy
group-containing thermoplastic resins, include polymerizable
compounds containing carboxyl groups or acid anhydride groups
thereof or amino groups.
[0187] Among the above polymerizable compounds, epoxy
group-containing polymerizable compounds include, for example,
epoxycyclo-C.sub.5-8-alkenyl (meth)acrylates such as
epoxycyclohexenyl (meth)acrylate, glycidyl (meth)acrylate, and
allyl glycidyl ether. Hydroxyl group-containing compounds include,
for example, hydroxy-C.sub.1-4-alkyl (meth)acrylates such as
hydroxypropyl (meth)acrylate, and C.sub.2-6 alkylene glycol
(meth)acrylates such as ethylene glycol mono(meth)acrylate. Amino
group-containing polymerizable compounds include, for example,
amino-C.sub.1-4-alkyl (meth)acrylates such as aminoethyl
(meth)acrylate, C.sub.3-6 alkenylamines such as allylamine, and
aminostyrenes such as 4-aminostyrene and diaminostyrene. Isocyanate
group-containing polymerizable compounds include, for example,
(poly)urethane (meth)acrylate and vinyl isocyanate. Polymerizable
compounds containing carboxyl groups or acid anhydride groups
thereof include, for example, unsaturated carboxylic acids or
anhydrides thereof such as (meth)acrylic acid and maleic
anhydride.
[0188] A combination of a thermoplastic resin containing a carboxyl
group or its acid anhydride group with an epoxy group-containing
compound, particularly a combination of an (meth)acrylic resin (for
example, an (meth)acrylic acid-(meth)acrylic ester copolymer) with
an epoxy group-containing (meth)acrylate (for example,
epoxycycloalkenyl (meth)acrylate or glycidyl (meth)acrylate) may be
mentioned as a representative example of the polymerizable
compound. Specific examples thereof include polymers comprising a
polymerizable unsaturated group introduced into a part of carboxyl
groups in an (meth)acrylic resin, for example, an (meth)acrylic
polymer produced by reacting a part of carboxyl groups in an
(meth)acrylic acid-(meth)acrylic ester copolymer with an epoxy
group in 3,4-epoxycyclohexenylmethyl acrylate to introduce a
photopolymerizable unsaturated group into the side chain (CYCLOMER
P, manufactured by Daicel Chemical Industries, Ltd)
[0189] The amount of the functional group (particularly
polymerizable group) involved in a curing reaction with the
thermoplastic resin introduced is approximately 0.001 to 10 moles,
preferably 0.01 to 5 moles, more preferably 0.02 to 3 moles based
on 1 kg of the thermoplastic resin.
[0190] These polymers may be used in a suitable combination.
Specifically, the polymer may comprise a plurality of polymers. The
plurality of polymers may be phase separated by liquid phase
spinodal decomposition. The plurality of polymers may be
incompatible with each other. When the plurality of polymers are
used in combination, the combination of a first resin with a second
resin is not particularly limited. For example, a plurality of
suitable polymers incompatible with each other at a temperature
around a processing temperature, for example, two suitable polymers
incompatible with each other may be used. For example, when the
first resin is a styrenic resin (for example, polystyrene or a
styrene-acrylonitrile copolymer), examples of second resins usable
herein include cellulose derivatives (for example, cellulose esters
such as cellulose acetate propionate), (meth)acrylic resins (for
example, polymethyl methacrylate), alicyclic olefinic resins (for
example, polymers using norbornene as a monomer), polycarbonate
resins, and polyester resins (for example, the above
poly-C.sub.2-4-alkylene arylate copolyesters). On the other hand,
for example, when the first polymer is a cellulose derivative (for
example, a cellulose ester such as cellulose acetate propionate),
examples of second polymers usable herein include styrenic resins
(for example, polystyrene or styrene-acrylonitrile copolymer),
(meth)acrylic resins, alicyclic olefinic resins (for example,
polymers using norbornene as a monomer), polycarbonate resins, and
polyester resins (for example, the above poly-C.sub.2-4-alkylene
arylate copolyester). In the combination of the plurality of
resins, at least cellulose esters (for example, cellulose C.sub.2-4
alkyl carboxylic esters such as cellulose diacetate, cellulose
triacetate, cellulose acetate propionate, or cellulose acetate
butyrate) may be used.
[0191] The phase separated structure produced by the spinodal
decomposition is finally cured by the application of an actinic
radiation (for example, ultraviolet light or electron beam), heat
or the like to form a cured resin. By virtue of this, the scratch
resistance can be imparted to the anti-dazzling layer, and the
durability can be improved.
[0192] From the viewpoint of scratch resistance after curing,
preferably, at least one polymer in the plurality of polymers, for
example, one of mutually incompatible polymers (when the first and
second resins are used in combination, particularly both the
polymers) is a polymer having on its side chain a functional group
reactive with a curable resin precursor.
[0193] The weight ratio between the first polymer and the second
polymer may be selected, for example, from a range of first
polymer/second polymer=approximately 1/99 to 99/1, preferably 5/95
to 95/5, more preferably 10/90 to 90/10 and is generally
approximately 20/80 to 80/20, particularly 30/70 to 70/30.
[0194] Regarding the polymer for phase separated structure
formation, in addition to the above two incompatible polymers, the
above thermoplastic resins or other polymers may be
incorporated.
[0195] The glass transition temperature of the polymer may be
selected, for example, from a range of approximately -100.degree.
C. to 250.degree. C., preferably -50.degree. C. to 230.degree. C.,
more preferably 0 to 200.degree. C. (for example, approximately 50
to 180.degree. C.). A glass transition temperature of 50.degree. C.
or above (for example, approximately 70 to 200.degree. C.),
preferably 100.degree. C. or above (for example, approximately 100
to 170.degree. C.), is advantageous from the viewpoint of the
surface hardness. The weight average molecular weight of the
polymer may be selected, for example, from a range of approximately
not more than 1,000,000, preferably 1,000 to 500,000.
[0196] Curable Resin Precursor
[0197] The curable resin precursor is a compound containing a
functional group which can be reacted upon exposure, for example,
to heat or an actinic radiation (for example, ultraviolet light or
electron beams), and various curable compounds, which can be cured
or crosslinked upon exposure to heat, an actinic radiation or the
like to form a resin (particularly a cured or crosslinked resin),
can be used. Examples of such resin precursors include heat curing
compounds or resins [low-molecular weight compounds containing
epoxy groups, polymerizable groups, isocyanate groups, alkoxysilyl
groups, or silanol groups (for example, epoxy resins, unsaturated
polyester resins, urethane resins, or silicone resins)], and
photocuring compounds curable upon exposure to an actinic radiation
(for example, ultraviolet light) (for example, ultraviolet light
curing compounds such as photocuring monomers and oligomers). The
photocuring compound may be, for example, an EB (electron beam)
curing compound. Photocuring compounds such as photocuring
monomers, oligomers, photocuring resins which may have a
low-molecular weight, are sometimes referred to simply as
"photocuring resin."
[0198] Photocuring compounds include, for example, monomers and
oligomers (or resins, particularly low-molecular weight resins).
Monomers include, for example, monofunctional monomers
[(meth)acrylic monomers such as (meth)acrylic esters, vinyl
monomers such as vinylpyrrolidone, crosslinked ring-type
hydrocarbon group-containing (meth)acrylates such as isobornyl
(meth)acrylate or adamantyl (meth)acrylate)], polyfunctional
monomers containing at least two polymerizable unsaturated bonds
[for example, alkylene glycol di(meth)acrylates such as ethylene
glycol di(meth)acrylate, propylene glycol di(meth)acrylate,
butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, and
hexanediol di(meth)acrylate; (poly)oxyalkylene glycol
di(meth)acrylates such as diethylene glycol di(meth)acrylate,
dipropylene glycol di(meth)acrylate, and polyoxytetramethylene
glycol di(meth)acrylate; crosslinked ring-type hydrocarbon
group-containing di(meth)acrylates such as tricyclodecane
dimethanol di(meth)acrylate and adamantane di(meth)acrylate; and
polyfunctional monomers containing about three to six polymerizable
unsaturated bonds such as trimethylolpropane tri(meth)acrylate,
trimethylolethane tri(meth)acrylate, pentaerythritol
tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and
dipentaerythritol penta(meth)acrylate].
[0199] Oligomers or resins include (meth)acrylate or epoxy
(meth)acrylate of bisphenol A-alkylene oxide adducts (for example,
bisphenol A-type epoxy (meth)acrylate and novolak-type epoxy
(meth)acrylate), polyester (meth)acrylates (for example, aliphatic
polyester-type (meth)acrylate and aromatic polyester-type
(meth)acrylate), (poly)urethane (meth)acrylate (for example,
polyester-type urethane (meth)acrylate, polyether-type urethane
(meth)acrylate), and silicone (meth)acrylate. These photocuring
compounds are usable either solely or in a combination of two or
more.
[0200] Preferred curable resin precursors include photocuring
compounds curable in a short time, for example, ultraviolet light
curing compounds (for example, monomers, oligomers and resins which
may have a low-molecular weight), and EB curing compounds. Resin
precursors which are particularly advantageous from the practical
viewpoint are ultraviolet curing resins. From the viewpoint of
improving resistance such as scratch resistance, preferably, the
photocuring resin is a compound having in its molecule two or more
(preferably approximately 2 to 6, more preferably 2 to 4)
polymerizable unsaturated bonds. The molecular weight of the
curable resin precursor is approximately not more than 5000,
preferably not more than 2000, more preferably not more than 1000,
from the viewpoint of compatibility with the polymer.
[0201] The curable resin precursor may contain a curing agent
depending upon the type of the curable resin precursor. For
example, in the case of heat curing resins, curing agents such as
amines or polycarboxylic acids may be contained, and, in the case
of photocuring resins, photopolymerization initiators may be
contained. Examples of photopolymerization initiators include
commonly used components, for example, acetophenones or
propiophenones, benzyls, benzoins, benzophenones, thioxanthones,
and acylphosphine oxides. The content of the curing agent such as a
photocuring agent is approximately 0.1 to 20 parts by weight,
preferably 0.5 to 10 parts by weight, more preferably 1 to 8 parts
by weight (particularly 1 to 5 parts by weight), based on 100 parts
by weight of the curable resin precursor and may be approximately 3
to 8 parts by weight.
[0202] The curable resin precursor may contain a curing
accelerator. For example, the photocuring resin may contain
photocuring accelerators, for example, tertiary amines (for
example, dialkylaminobenzoic esters) and phosphine
photopolymerization accelerators.
[0203] Specific Combination of Polymer with Curable Resin
Precursor
[0204] At least two components in at least one polymer and at least
one curable resin precursor may be used in a combination of
materials which are mutually phase separated at a temperature
around the processing temperature. Examples of such combinations
include (a) a combination of a plurality of polymers which are
mutually incompatible and phase separated, (b) a combination of a
polymer and a curable resin precursor which are mutually
incompatible and phase separated, and (c) a combination of a
plurality of curable resin precursors which are mutually
incompatible and phase separated. Among these combinations, (a) a
combination of a plurality of polymers and (b) a combination of a
polymer with a curable resin precursor are generally preferred, and
particularly (a) a combination of a plurality of polymers is
preferred. When the compatibility of both the materials to be phase
separated is low, both the materials are effectively phase
separated in the course of drying for evaporating the solvent and
the function as an anti-dazzling layer can be improved.
[0205] The thermoplastic resin and the curable resin precursor (or
curing-type resin) are generally incompatible with each other. When
the polymer and the curable resin precursor are incompatible with
each other and phase separated, a plurality of polymers may be used
as the polymer. When a plurality of polymers are used, meeting the
requirement that at least one polymer is incompatible with the
resin precursor (or curing-type resin) suffices for contemplated
results, and the other polymer(s) may be compatible with the resin
precursor.
[0206] A combination of two mutually incompatible thermoplastic
resins with a curing compound (particularly a monomer or oligomer
containing a plurality of curable functional groups) may be
adopted. From the viewpoint of scratch resistance after curing, one
polymer (particularly both polymers) in the incompatible
thermoplastic resins may be a thermoplastic resin containing a
functional group involved in the curing reaction (a functional
group involved in curing of the curable resin precursor).
[0207] When a combination of a plurality of mutually incompatible
polymers is adopted for phase separation, the curable resin
precursor to be used in combination with the plurality of mutually
incompatible polymers is compatible with at least one polymer in
the plurality of incompatible polymers at a temperature around the
processing temperature. Specifically, for example, when the
plurality of mutually incompatible polymers are constituted by the
first resin and the second resin, the curable resin precursor may
be one which is compatible with at least one of the first resin and
the second resin, preferably is compatible with both the polymer
components. When the curable resin precursor is compatible with
both the polymer components, phase separation occurs into at least
two phases, i.e., a mixture composed mainly of a first resin and a
curable resin precursor and a mixture composed mainly of a second
resin and a curable resin precursor.
[0208] When the compatibility of a plurality of selected polymers
is low, the polymers are effectively phase separated from each
other in the course of drying for evaporating the solvent and the
function as an anti-dazzling layer is improved. The phase
separability of the plurality of polymers can be simply determined
by a method in which a homogeneous solution is prepared using a
good solvent for both the components and the solvent is gradually
evaporated to visually inspect whether or not the residual solid
matter is opaque in the course of drying.
[0209] In general, the polymer and the cured or crosslinked resin
produced by curing of the resin precursor are different from each
other in refractive index. Further, the plurality of polymers
(first and second resins) are also different from each other in
refractive index. The difference in refractive index between the
polymer and the cured or crosslinked resin, and the difference in
refractive index between the plurality of polymers (first and
second resins) may be, for example, approximately 0.001 to 0.2,
preferably 0.05 to 0.15.
[0210] The weight ratio between the polymer and the curable resin
precursor is not particularly limited and may be selected, for
example, from a range of polymer/curable resin
precursor=approximately 5/95 to 95/5, and, from the viewpoint of
surface hardness, is preferably polymer/curable resin
precursor=approximately 5/95 to 60/40, more preferably 10/90 to
50/50, particularly preferably 10/90 to 40/60.
[0211] Solvent
[0212] The solvent may be selected and used according to the type
and solubility of the polymer and curable resin precursor. A
solvent capable of homogeneously dissolving at least the solid
matter (a plurality of polymers and curable resin precursor, a
reaction initiator, and other additives) suffices for contemplated
results and may be used in wet spinodal decomposition. Examples of
such solvents include ketones (for example, acetone, methyl ethyl
ketone, methyl isobutyl ketone, and cyclohexanone), ethers (for
example, dioxane and tetrahydrofuran), aliphatic hydrocarbons (for
example, hexane), alicyclic hydrocarbons (for example,
cyclohexane), aromatic hydrocarbons (for example, toluene and
xylene), halogenated hydrocarbons (for example, dichloromethane and
dichloroethane), esters (for example, methyl acetate, ethyl acetate
and butyl acetate), water, alcohols (for example, ethanol,
isopropanol, butanol, and cyclohexanol), cellosolves (for example,
methylcellosolve and ethylcellosolve), cellosolve acetates,
sulfoxides (for example, dimethylsulfoxide), and amides (for
example, dimethylformamide and dimethylacetamide). A mixture
solvents composed of two or more of these solvents may be used.
[0213] The concentration of the solute (polymer and curable resin
precursor, reaction initiator, and other additives) in the
composition for an anti-dazzling layer may be selected from such a
range that causes phase separation and such a range that
castability, coatability and the like are not deteriorated. The
solute concentration is, for example, approximately 1 to 80% by
weight, preferably 5 to 60% by weight, more preferably 15 to 40% by
weight (particularly 20 to 40% by weight).
[0214] 3) Method for Forming Anti-Dazzling Layer Using Treatment
for Imparting a Concavoconvex Shape
[0215] The anti-dazzling layer according to the present invention
may be formed by subjecting the surface of an anti-dazzling layer,
formed using a fine particle-free composition for an anti-dazzling
layer comprising a polymer, a resin and the like or an
anti-dazzling layer, which is not yet in a completed state, that
is, during a stage of formation, to treatment for imparting a
concavoconvex shape. This method may be the same as described above
in connection with the production process and production apparatus
according to the present invention.
[0216] 2. Surface Modifying Layer
[0217] In the present invention, a surface modifying layer may be
formed to regulate the concavoconvex surface of the anti-dazzling
layer. In this case, the surface modifying layer is integrated with
the anti-dazzling layer to exhibit an anti-dazzling function.
Accordingly, in the formation of the surface modifying layer,
optical property values such as Sm, .theta.a, and Rz as surface
concavoconvex shape values fall within the scope of the present
invention. Further, when the surface modifying layer is applied
onto the anti-dazzling layer, the surface concavoconvex shape of
the surface modifying layer is of course identical to the optical
property values of the surface concavoconvex shape of the
anti-dazzling layer in the present invention. The above matter can
be understood from the following detailed description on the
surface modifying layer and working examples.
[0218] In the surface modifying layer, fine concavoconvexes present
along the concavoconvex shape on the scale of one-tenth or less of
the concavo-convex scale (profile peak height of concavoconvexes
and spacing between profile peaks) in the surface roughness
constituting the concavoconvex shape of the anti-dazzling layer can
be sealed for smoothing to form smooth concavoconvexes, or the
spacing between profile peaks of the concavoconvexes and peak
profile height, and the frequency (number) of the profile peaks can
be regulated. The surface modifying layer can be formed, for
example, for imparting antistatic properties, refractive index
regulation, hardness enhancement, contamination preventive
properties and the like. The thickness (on a cured state bases) of
the surface modifying layer is not less than 0.5 .mu.m and not more
than 27 .mu.m (preferably not more than 12 .mu.m). Preferably, the
lower limit of the thickness of the surface modifying layer is 3
.mu.m, and the upper limit of the thickness of the surface
modifying layer is 8 .mu.m.
[0219] Surface Modifying Agent
[0220] One material or a mixture of two or more materials selected
from the group consisting of antistatic agents, refractive index
regulating agents, contamination preventive agents, water
repellants, oil repellents, fingerprint adhesion preventive agents,
curability enhancing agents, and hardness regulating agents
(cushioning property imparting agents) may be mentioned as the
surface modifying agent.
[0221] Antistatic Agent (Electroconductive Agent)
[0222] When an antistatic agent is contained in the surface
modifying layer, dust adhesion to the surface of the optical
laminate can be effectively prevented. Specific examples of
antistatic agents include cationic group-containing various
cationic compounds such as quaternary ammonium salts, pyridinium
salts, primary, secondary and tertiary amino groups, anionic
group-containing anionic compounds such as sulfonic acid bases,
sulfuric ester bases, phosphoric ester bases, and phosphonic acid
bases, amphoteric compounds such as amino acid and aminosulfuric
ester compounds, nonionic compounds such as amino alcohol, glycerin
and polyethylene glycol compounds, organometallic compounds such as
alkoxides of tin and titanium, and metal chelate compounds such as
their acetylacetonate salts. Further, compounds produced by
increasing the molecular weight of the above compounds may also be
mentioned. Further, poloymerizable compounds, for example, monomers
or oligomers, which contain a tertiary amino group, a quaternary
ammonium group, or a metallic chelate moiety and are polymerizable
upon exposure to ionizing radiations, or organometallic compounds
such as functional group-containing coupling agents may also be
used as the antistatic agent.
[0223] Further, electroconductive ultrafine particles may be
mentioned as the antistatic agent. Specific examples of
electroconductive ultrafine particles include ultrafine particles
of metal oxides. Such metal oxides include ZnO (refractive index
1.90; the numerical values within the parentheses being refractive
index; the same shall apply hereinafter), CeO.sub.2 (1.95),
Sb.sub.2O.sub.2 (1.71), SnO.sub.2 (1.997), indium tin oxide often
abbreviated to "ITO" (1.95), In.sub.2O.sub.3 (2.00),
Al.sub.2O.sub.3 (1.63), antimony-doped tin oxide (abbreviated to
"ATO," 2.0), and aluminum-doped zinc oxide (abbreviated to "AZO,"
2.0). The term "fine particles" refers to fine particles having a
size of not more than 1 micrometer, that is, fine particles of
submicron size, preferably fine particles having an average
particle diameter of 0.1 nm to 0.1 .mu.m.
[0224] In a preferred embodiment of the present invention, the
addition amount ratio of the resin to the antistatic agent
contained in the surface modifying layer is not less than 5 and not
more than 25. Preferably, the upper limit of the addition amount
ratio is 20, and the lower limit of the addition amount ratio is
5.
[0225] Electroconductive polymers may be mentioned as the
antistatic agent, and specific examples thereof include aliphatic
conjugated polyacetylenes, aromatic conjugated
poly(paraphenylenes), heterocyclic conjugated polypyrroles,
polythiophenes, heteroatom-containing conjugated polyanilines, and
mixture-type conjugated poly(phenylenevinylenes). Additional
examples of electroconductive polymers include double-chain
conjugated systems which are conjugated systems having a plurality
of conjugated chains in the molecule thereof, and electroconductive
composites which are polymers prepared by grafting or
block-copolymerizing the above conjugated polymer chain onto a
saturated polymer.
[0226] Refractive Index Regulating Agent
[0227] The refractive index regulating agent may be added to the
surface modifying layer to regulate the optical properties of the
optical laminate. Examples of such refractive index regulating
agents include low-refractive index agents, medium-refractive index
agents, and high-refractive index agents.
[0228] 1) Low-Refractive Index Agent
[0229] The low-refractive index agent has a lower refractive index
than the anti-dazzling layer. In a preferred embodiment of the
present invention, the anti-dazzling layer has a refractive index
of not less than 1.5, and the low-refractive index agent has a
refractive index of less than 1.5, preferably not more than
1.45.
[0230] Specific examples of low-refractive index agents include
silicone-containing vinylidene fluoride copolymers, and an example
thereof is a composition comprising 100 parts by weight of a
fluorine-containing copolymer and 80 to 150 parts by weight of an
ethylenically unsaturated group-containing polymerizable compound.
The fluorine-containing copolymer has a fluorine content of 60 to
70% by weight and is produced by copolymerizing a monomer
composition comprising 30 to 90% by weight of vinylidene fluoride
and 5 to 50% by weight of hexafluoropropylene.
[0231] A copolymer produced by copolymerizing a monomer composition
containing vinylidene fluoride and hexafluoropropylene may be
mentioned as the fluorine-containing copolymer. Regarding the
proportion of each component in the monomer composition, the
content of vinylidene fluoride is 30 to 90% by weight, preferably
40 to 80% by weight, particularly preferably 40 to 70% by weight,
or the content of hexafluoropropylene is 5 to 50% by weight,
preferably 10 to 50% by weight, particularly preferably 15 to 45%
by weight. The monomer composition may further comprise 0 to 40% by
weight, preferably 0 to 35% by weight, particularly preferably 10
to 30% by weight, of tetrafluoroethylene.
[0232] The monomer composition for producing the
fluorine-containing copolymer may if necessary contain other
comonomer component(s), for example, in an amount of not more than
20% by weight, preferably not more than 10% by weight. Specific
examples of such comonomer components include fluorine
atom-containing polymerizable monomers such as fluoroethylene,
trifluoroethylene, chlorotrifluoroethylene,
1,2-dichloro-1,2-difluoroethylene, 2-bromo-3,3,3-trifluoroethylene,
3-bromo-3,3-difluoropropylene, 3,3,3-trifluoropropylene,
1,1,2-trichloro-3,3,3-trifluoropropylene, and
.alpha.-trifluoromethacrylic acid.
[0233] The content of fluorine in the fluorine-containing copolymer
produced from the monomer composition is preferably 60 to 70% by
weight, more preferably 62 to 70% by weight, particularly
preferably 64 to 68% by weight. When the fluorine content is in the
above-defined range, the fluorine-containing copolymer has good
solubility in solvents which will be described later. The
incorporation of the fluorine-containing copolymer as a component
can realize the formation of an optical laminate having excellent
adhesion, a high level of transparency, a low refractive index, and
excellent mechanical strength.
[0234] The molecular weight of the fluorine-containing copolymer is
preferably 5,000 to 200,000, particularly preferably 10,000 to
100,000, in terms of number average molecular weight as determined
using polystyrene as a standard. When the fluorine-containing
copolymer having this molecular weight is used, the fluororesin
composition has suitable viscosity and thus reliably has suitable
coatability.
[0235] The refractive index of the fluorine-containing copolymer
per se is preferably not more than 1.45, more preferably not more
than 1.42, still more preferably not more than 1.40. When the
refractive index is in the above defined range, the formed optical
laminate has good antireflection effect.
[0236] The addition amount of the resin is 30 to 150 parts by
weight, preferably 35 to 100 parts by weight, more preferably 40 to
70 parts by weight, based on 100 parts by weight of the
fluorine-containing copolymer. The content of fluorine based on the
total amount of the polymer forming component comprising the
fluorine-containing copolymer and the resin is 30 to 55% by weight,
preferably 35 to 50% by weight.
[0237] When the addition amount or the fluorine content is in the
above-defined range, the surface modifying layer has good adhesion
to the base material and has a low refractive index, whereby good
antireflection effect can be attained.
[0238] In a preferred embodiment of the present invention, the
utilization of "void-containing fine particles" as a low-refractive
index agent is preferred. "Void-containing fine particles" can
lower the refractive index while maintaining the layer strength of
the surface modifying layer. In the present invention, the term
"void-containing fine particle" refers to a fine particle which has
a structure comprising air filled into the inside of the fine
particle and/or an air-containing porous structure and has such a
property that the refractive index is lowered in reverse proportion
to the proportion of air which occupies the fine particle as
compared with the refractive index of the original fine particle.
Further, such a fine particle which can form a nanoporous structure
in at least a part of the inside and/or surface of the coating film
by utilizing the form, structure, aggregated state, and dispersed
state of the fine particle within the coating film, is also
embraced in the present invention.
[0239] Specific examples of preferred void-containing inorganic
fine particles are silica fine particles prepared by a technique
disclosed in Japanese Patent Laid-Open No. 233611/2001. The
void-containing silica fine particles can easily produced. Further,
the hardness of the void-containing fine particles is high.
Therefore, when a surface modifying layer is formed by using a
mixture of the void-containing silica fine particles with a binder,
the layer has improved strength and, at the same time, the
refractive index can be regulated to a range of approximately 1.20
to 1.45. Hollow polymer fine particles produced by using a
technique disclosed in Japanese Patent Laid-Open No. 80503/2002 are
a specific example of preferred void-containing organic fine
particles.
[0240] Fine particles which can form a nanoporous structure in at
least a part of the inside and/or surface of the coating film
include, in addition to the above silica fine particles, sustained
release materials, which have been produced for increasing the
specific surface area and adsorb various chemical substances on a
packing column and the porous part of the surface, porous fine
particles used for catalyst fixation purposes, or dispersions or
aggregates of hollow fine particles to be incorporated in heat
insulating materials or low-dielectric materials. Specific examples
of such fine particles include commercially available products, for
example, aggregates of porous silica fine particles selected from
tradename Nipsil and tradename Nipgel manufactured by Nippon Silica
Industrial Co., Ltd. and colloidal silica UP series (tradename),
manufactured by Nissan Chemical Industries Ltd., having such a
structure that silica fine particles have been connected to one
another in a chain form, and fine particles in a preferred particle
diameter range specified in the present invention may be selected
from the above fine particles.
[0241] The average particle diameter of the "void-containing fine
particles" is not less than 5 nm and not more than 300 nm.
Preferably, the lower limit of the average particle diameter is 8
nm, and the upper limit of the average particle diameter is 100 nm.
More preferably, the lower limit of the average particle diameter
is 10 nm, and the upper limit of the average particle diameter is
80 nm. When the average diameter of the fine particles is in the
above-defined range, excellent transparency can be imparted to the
surface modifying layer.
[0242] 2) High-Refractive Index Agent/Medium-Refractive Index
Agent
[0243] The high-refractive index agent and the medium-refractive
index agent may be added to the surface modifying layer to further
improve antireflective properties. The refractive index of the
high-refractive index agent and medium-refractive index agent may
be set in a range of 1.46 to 2.00. The medium-refractive index
agent has a refractive index in the range of 1.46 to 1.80, and the
refractive index of the high-refractive index agent is in the range
of 1.65 to 2.00.
[0244] These refractive index agents include fine particles, and
specific examples thereof (the numerical value within the
parentheses being a refractive index) include zinc oxide (1.90),
titania (2.3 to 2.7), ceria (1.95), tin-doped indium oxide (1.95),
antimony-doped tin oxide (1.80), yttria (1.87), and zirconia
(2.0).
[0245] Leveling Agent
[0246] A leveling agent may be added to the surface modifying
layer. Preferred leveling agents include fluorine-type or
silicone-type leveling agents. The surface modifying layer to which
the leveling agent has been added can realize a good coated face,
can effectively prevent the inhibition of curing of the coating
film surface by oxygen in coating or drying, and can impart a
scratch resistance.
[0247] Contamination Preventive Agent
[0248] A contamination preventive agent may be added to the surface
modifying layer. The contamination preventive agent is mainly used
to prevent the contamination of the outermost surface of the
optical laminate and can impart scratch resistance to the optical
laminate. Specific examples of effective contamination preventive
agents include additives which can develop water repellency, oil
repellency, and fingerprint wiping-off properties. More specific
examples of contamination preventive agents include fluorocompounds
and silicon compounds or mixtures of these compounds. More specific
examples thereof include fluoroalkyl group-containing silane
coupling agents such as 2-perfluorooctylethyltriaminosilane. Among
them, amino group-containing compounds are particularly
preferred.
[0249] Resin
[0250] The surface modifying layer may comprises at least a surface
modifying agent and a resin (including a resin component such as a
monomer and an oligomer). When the surface modifying layer does not
contain a surface modifying agent, the resin functions as a
curability enhancing agent or functions to render the
concavoconvexes of the anti-dazzling layer smooth.
[0251] The resin is preferably transparent, and specific examples
thereof are classified into ionizing radiation curing resins which
are curable upon exposure to ultraviolet light or electron beams,
mixtures of ionizing radiation curing resins with solvent
drying-type resins, or heat curing resins. Preferred are ionizing
radiation curing resins.
[0252] Specific examples of ionizing radiation curing resins
include those containing an acrylate-type functional group, for
example, oligomers or prepolymers and reactive diluents, for
example, relatively low-molecular weight polyester resins,
polyether resins, acrylic resins, epoxy resins, urethane resins,
alkyd resins, spiroacetal resins, polybutadiene resins, and
polythiol polyene resins and (meth)acrylates of polyfunctional
compounds such as polyhydric alcohols. Specific examples thereof
include monofunctional monomers such as ethyl (meth)acrylate,
ethylhexyl (meth)acrylate, styrene, methyl styrene, and
N-vinylpyrrolidone, and polyfunctional monomers, for example,
polymethylolpropane tri(meth)acrylate, hexanediol (meth)acrylate,
tripropylene glycol di(meth)acrylate, diethylene glycol
di(meth)acrylate, pentaerythritol tri(meth)acrylate,
dipentaerythritol hexa(meth)acrylate, 1,6-hexanediol
di(meth)acrylate, and neopentyl glycol di(meth)acrylate.
[0253] When the ionizing radiation curing resin is an ultraviolet
curing resin, a photopolymerization initiator is preferably used.
Specific examples of photopolymerization initiators include
acetophenones, benzophenones, Michler's benzoyl benzoate,
.alpha.-amyloxime ester, and thioxanthones. Preferably,
photosensitizers are mixed in the system. Specific examples of
photosensitizers include n-butylamine, triethylamine, and
poly-n-butylphosphine.
[0254] When ionizing radiation curing resins are used as an
ultraviolet curing resin, a photopolymerization initiator or a
photopolymerization accelerator may be added. In the case of a
radical polymerizable unsaturated group-containing resin system,
acetophenones, benzophenones, thioxanthones, benzoins, benzoin
methyl ether and the like are used as a photopolymerization
initiator either solely or as a mixture of two or more. On the
other hand, in the case of a cation polymerizable functional
group-containing resin system, aromatic diazonium salts, aromatic
sulfonium salts, aromatic idonium salts, metallocene compounds,
benzoinsulfonic esters and the like may be used as a
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 curing composition.
[0255] The solvent drying-type resin used as a mixture with the
ionizing radiation curing resin is mainly a thermoplastic resin.
Commonly exemplified thermoplastic resins are usable. Specific
examples of preferred thermoplastic resins include styrenic resins,
(meth)acrylic resins, vinyl acetate resins, vinyl ether resins,
halogen-containing resins, alicyclic olefinic resins, polycarbonate
resins, polyester resins, polyamide resins, cellulose derivatives,
silicone resins, and rubbers or elastomers. The resin is generally
noncrystalline and, at the same time, is soluble in an organic
solvent (particularly a common solvent which can dissolve a
plurality of polymers and curable compounds). Particularly
preferred are resins having good moldability or film forming
properties, transparency, and weathering resistance, for example,
styrenic resins, (meth)acrylic resins, alicyclic olefinic resins,
polyester resins, cellulose derivatives (for example, cellulose
esters).
[0256] The coating film defect of the coated face can be
effectively prevented by adding a solvent drying-type resin. In a
preferred embodiment of the present invention, when the light
transparent base material is formed of a cellulosic resin such as
triacetylcellulose "TAC," examples of preferred thermoplastic
resins include cellulosic resins, for example, nitrocellulose,
acetylcellulose, cellulose acetate propionate, and ethyl
hydroxyethylcellulose.
[0257] Specific examples of heat curing resin include phenolic
resins, urea resins, diallyl phthalate resins, melanin resins,
guanamine resins, unsaturated polyester resins, polyurethane
resins, epoxy resins, aminoalkyd resins, melamine-urea cocondensed
resins, silicone resins, and polysiloxane resins. When the heat
curing resin is used, if necessary, for example, curing agents such
as crosslinking agents and polymerization initiators,
polymerization accelerators, solvents, and viscosity modifiers may
be further added.
[0258] Polymerization Initiator
[0259] In the formation of a surface modifying layer,
photopolymerization initiators may be used. Specific examples
thereof include 1-hydroxy-cyclohexyl-phenyl-ketone. This compound
is commercially available, and examples of commercially available
products include Irgacure 184 (tradename, manufactured by Ciba
Specialty Chemicals, K.K.).
[0260] Solvent
[0261] A composition for a surface modifying layer comprising the
above components mixed with the solvent is utilized for surface
modifying layer formation. Specific examples of solvents usable
herein include alcohols such as isopropyl alcohol, methanol, and
ethanol; ketones such as methyl ethyl ketone, methyl isobutyl
ketone, and cyclohexanone; esters such as methyl acetate, ethyl
acetate, and butyl acetate; halogenated hydrocarbons; aromatic
hydrocarbons such as toluene and xylene; or mixture thereof.
Preferred are ketones and esters.
[0262] Method for Surface Modifying Layer Formation
[0263] The surface modifying layer may be formed by applying a
composition for a surface modifying layer onto the anti-dazzling
layer. The composition for a surface modifying layer may be formed
by coating methods such as roll coating, Mayor bar coating, or
gravure coating. After coating of the composition for a surface
modifying layer, the coating is dried and cured by ultraviolet
light irradiation. Specific examples of ultraviolet light sources
include ultra-high-pressure mercury lamps, high-pressure mercury
lamps, low-pressure mercury lamps, carbon arc lamps, black light
fluorescent lamps, and metal halide lamps. Regarding the wavelength
of the ultraviolet light, a wavelength range of 190 to 380 nm may
be used. Specific examples of electron beam sources include various
electron beam accelerators, for example, Cockcroft-Walton
accelerators, van de Graaff accelerators, resonance transformer
accelerators, insulated core transformer accelerators, linear
accelerators, Dynamitron accelerators, and high-frequency
accelerators.
[0264] Optional Layers
[0265] The optical laminate according to the present invention
comprises a light transparent base material, an anti-dazzling
layer, and an optional surface modifying layer. Optional layers
such as an antistatic layer, a low-refractive index layer, and a
contamination preventive layer may be further provided. The
low-refractive index layer preferably has a lower refractive index
than the refractive index of the anti-dazzling layer or surface
modifying layer. The antistatic layer, low-refractive index layer,
and contamination preventive layer may be formed by using a
composition prepared by mixing a resin and the like with an
antistatic agent, a low-refractive index agent, a contamination
preventive agent or the like as described above in connection with
the surface modifying layer. Accordingly, the antistatic agent,
low-refractive index agent, contamination preventive agent, resin
and the like may be the same as those used in the formation of the
surface modifying layer.
[0266] 4. Light Transparent Base Material
[0267] The light transparent base material is preferably smooth and
possesses excellent heat resistance and mechanical strength.
Specific examples of materials usable for the light transparent
base material formation include thermoplastic resins, for example,
polyesters (polyethylene terephthalate and polyethylene
naphthalate), cellulose triacetate, cellulose diacetate, cellulose
acetatebutyrate, polyamide, polyimide, polyethersulfone,
polysulfone, polypropylene, polymethylpentene, polyvinyl chloride,
polyvinylacetal, polyether ketone, polymethyl methacrylate,
polycarbonate, and polyurethane. Preferred are polyesters
(polyethylene terephthalate and polyethylene naphthalate) and
cellulose triacetate. Films of amorphous olefin polymers
(cycloolefin polymers: COPs) having an alicyclic structure may also
be mentioned as other examples of the light transparent base
material. These films are base materials using nobornene polymers,
monocyclic olefinic polymers, cyclic conjugated diene polymers,
vinyl alicyclic hydrocarbon polymer resins and the like, and
examples thereof include Zeonex and ZEONOR, manufactured by Zeon
Corporation (norbornene resins), Sumilight FS-1700 manufactured by
Sumitomo Bakelite Co., Ltd., ARTON (modified norbornene resin)
manufactured by JSR Corporation, APL (cyclic olefin copolymer)
manufactured by Mitsui Chemicals Inc., Topas (cyclic olefin
copolymer) manufactured by Ticona, and Optlet OZ-1000 series
(alicyclic acrylic resins) manufactured by Hitachi Chemical Co.,
Ltd. Further, FV series (low birefringent index and low
photoelastic films) manufactured by Asahi Kasei Chemicals
Corporation are also preferred as base materials alternative to
triacetylcellulose.
[0268] In the present invention, preferably, these thermoplastic
resins are used as a highly flexible thin film. Depending upon the
form of use where curability are required, plate-like materials
such as plates of these thermoplastic resins or glass plates are
also usable.
[0269] The thickness of the light transparent base material is not
less than 20 .mu.m and not more than 300 .mu.m. Preferably, the
upper limit of the thickness is 200 .mu.m, and the lower limit of
the thickness is 30 .mu.m. When the light transparent base material
is a plate-like material, the thickness may be above the upper
limit of the above-defined thickness range. In forming an
anti-dazzling layer on the light transparent base material, the
base material may be previously subjected to physical treatment
such as corona discharge treatment or oxidation treatment or may be
previously coated with an anchoring agent or a coating material
known as a primer from the viewpoint of improving the adhesion.
[0270] Utilization of Optical Laminate
[0271] The optical laminate produced by the process according to
the present invention may be used in the following
applications.
[0272] Polarizing Plate
[0273] In another embodiment of the present invention, there is
provided a polarizing plate comprising a polarizing element and the
optical laminate according to the present invention. More
specifically, there is provided a polarizing plate comprising a
polarizing element and the optical laminate according to the
present invention provided on the surface of the polarizing
element, the optical laminate being provided so that the surface of
the optical laminate remote from the anti-dazzling layer faces the
surface of the polarizing element.
[0274] The polarizing element may comprise, for example, polyvinyl
alcohol films, polyvinylformal films, polyvinylacetal films, and
ethylene-vinyl acetate copolymer-type saponified films, which have
been dyed with iodine or a dye and stretched. In the lamination
treatment, preferably, the light transparent base material
(preferably a triacetylcellulose film) is saponified from the
viewpoint of increasing the adhesion or antistatic purposes.
[0275] Image Display Device
[0276] In a further embodiment of the present invention, there is
provided an image display device. The image display device
comprises a transmission display and a light source device for
applying light to the transmission display from its back side. The
optical laminate according to the present invention or the
polarizing plate according to the present invention is provided on
the surface of the transmission display. The image display device
according to the present invention may basically comprise a light
source device (backlight), a display element, and the optical
laminate according to the present invention. The image display
device is utilized in transmission display devices, particularly in
displays of televisions, computers, word processors and the like.
Among others, the image display device is used on the surface of
displays for high-definition images such as CRTs and liquid crystal
panels.
[0277] When the image display device according to the present
invention is a liquid crystal display device, light emitted from
the light source device is applied through the lower side of the
optical laminate according to the present invention. In STN-type
liquid crystal display devices, a phase difference plate may be
inserted into between the liquid crystal display element and the
polarizing plate. If necessary, an adhesive layer may be provided
between individual layers in the liquid crystal display device.
EXAMPLES
[0278] The following embodiments further illustrate the present
invention. However, it should be noted that the contents of the
present invention are not limited by these embodiments. The "parts"
and "%" are by mass unless otherwise specified.
[0279] Compositions for respective layers constituting an optical
laminate were prepared according to the following formulations. The
formulations are summarized in Table 1.
[0280] Preparation of Composition for Anti-Dazzling Layer
[0281] Composition 1 for Anti-Dazzling Layer
[0282] Pentaerythritol triacrylate (PETA) (manufactured by Nippon
Kayaku Co., Ltd., refractive index 1.51) (20.28 parts by mass) as
an ultraviolet curing resin, 8.62 parts by mass of DPHA
(manufactured by Nippon Kayaku Co., Ltd., refractive index 1.51) as
an ultraviolet curing resin, 3.03 parts by mass of an acrylic
polymer (manufactured by Mitsubishi Rayon Co., Ltd., molecular
weight 75,000) as an ultraviolet curing resin, 1.86 parts by mass
of Irgacure 184 (manufactured by Ciba-Geigy Limited) as a
photocuring initiator, 0.31 part by mass of Irgacure 907
(manufactured by Ciba-Geigy Limited) as a photocuring initiator,
6.39 parts by mass of monodisperse acrylic beads (manufactured by
Nippon Shokubai Kagaku Kogyo, Co., Ltd., particle diameter 5.0
.mu.m, refractive index 1.53) as light transparent fine particles,
0.013 part by mass of a silicone leveling agent 10-28 (manufactured
by The Inctec Inc.), 47.60 parts by mass of toluene, and 11.90
parts by mass of cyclohexanone were thoroughly mixed together to
prepare a composition. This composition was filtered through a
polypropylene filter having a pore diameter of 30 .mu.m to prepare
composition 1 for an anti-dazzling layer.
[0283] Composition 2 for Anti-Dazzling Layer
[0284] Composition 2 for an anti-dazzling layer was prepared in the
same manner as in the composition 1 for an anti-dazzling layer,
except that the light transparent fine particles were changed to
monodisperse acrylic beads having a particle diameter of 9.5 .mu.m
(manufactured by Nippon Shokubai Kagaku Kogyo Co., Ltd., refractive
index 1.53).
[0285] Composition 3 for Anti-Dazzling Layer
[0286] Composition 3 for an anti-dazzling layer was prepared in the
same manner as in the composition 1 for an anti-dazzling layer,
except that the light transparent fine particles were changed to
monodisperse acrylic beads having a particle diameter of 13.5 .mu.m
(manufactured by Nippon Shokubai Kagaku Kogyo Co., Ltd., refractive
index 1.53).
[0287] Composition 4 for Anti-Dazzling Layer
[0288] Pentaerythritol triacrylate (PETA) (manufactured by Nippon
Kayaku Co., Ltd., refractive index 1.51) (21.08 parts by mass) as
an ultraviolet curing resin, 10.33 parts by mass of DPHA
(manufactured by Nippon Kayaku Co., Ltd., refractive index 1.51) as
an ultraviolet curing resin, 3.24 parts by mass of an acrylic
polymer (manufactured by Mitsubishi Rayon Co., Ltd., molecular
weight 75,000) as an ultraviolet curing resin, 2.02 parts by mass
of Irgacure 184 (manufactured by Ciba-Geigy Limited) as a
photocuring initiator, 0.34 part by mass of Irgacure 907
(manufactured by Ciba-Geigy Limited) as a photocuring initiator,
3.47 parts by mass of monodisperse acrylic beads (manufactured by
Nippon Shokubai Kagaku Kogyo Co., Ltd., particle diameter 13.5
.mu.m, refractive index 1.53) as light transparent fine particles,
0.014 part by mass of a silicone leveling agent 10-28 (manufactured
by The Inctec Inc.), 47.60 parts by mass of toluene, and 11.90
parts by mass of cyclohexanone were thoroughly mixed together to
prepare a composition. This composition was filtered through a
polypropylene filter having a pore diameter of 30 .mu.m to prepare
composition 4 for an anti-dazzling layer.
[0289] Composition 5 for Anti-Dazzling Layer
[0290] Pentaerythritol triacrylate (PETA) (manufactured by Nippon
Kayaku Co., Ltd., refractive index 1.51) (21.88 parts by mass) as
an ultraviolet curing resin, 12.03 parts by mass of DPHA
(manufactured by Nippon Kayaku Co., Ltd., refractive index 1.51) as
an ultraviolet curing resin, 3.46 parts by mass of an acrylic
polymer (manufactured by Mitsubishi Rayon Co., Ltd., molecular
weight 75,000) as an ultraviolet curing resin, 2.19 parts by mass
of Irgacure 184 (manufactured by Ciba-Geigy Limited) as a
photocuring initiator, 0.37 part by mass of Irgacure 907
(manufactured by Ciba-Geigy Limited) as a photocuring initiator,
6.39 parts by mass of monodisperse acrylic beads (manufactured by
Nippon Shokubai Kagaku Kogyo Co., Ltd., particle diameter 9.5
.mu.m, refractive index 1.53) as light transparent fine particles,
0.015 part by mass of a silicone leveling agent 10-28 (manufactured
by The Inctec Inc.), 47.60 parts by mass of toluene, and 11.90
parts by mass of cyclohexanone were thoroughly mixed together to
prepare a composition. This composition was filtered through a
polypropylene filter having a pore diameter of 30 .mu.m to prepare
composition 5 for an anti-dazzling layer.
[0291] Composition 6 for Anti-Dazzling Layer
[0292] Composition 6 for an anti-dazzling layer was prepared in the
same manner as in the composition 1 for an anti-dazzling layer,
except that the light transparent fine particles were changed to
acrylic beads having a particle size distribution of 5.0 .mu.m in
terms of particle diameter (manufactured by Nippon Shokubai Kagaku
Kogyo Co., Ltd., refractive index 1.53).
[0293] Composition 7 for Anti-Dazzling Layer
[0294] Pentaerythritol triacrylate (PETA) (manufactured by Nippon
Kayaku Co., Ltd., refractive index 1.51) (20.28 parts by mass) as
an ultraviolet curing resin, 8.62 parts by mass of DPHA
(manufactured by Nippon Kayaku Co., Ltd., refractive index 1.51) as
an ultraviolet curing resin, 3.03 parts by mass of an acrylic
polymer (manufactured by Mitsubishi Rayon Co., Ltd., molecular
weight 75,000) as an ultraviolet curing resin, 1.86 parts by mass
of Irgacure 184 (manufactured by Ciba-Geigy Limited) as a
photocuring initiator, 0.31 part by mass of Irgacure 907
(manufactured by Ciba-Geigy Limited) as a photocuring initiator,
4.80 parts by mass of monodisperse acrylic beads (manufactured by
Nippon Shokubai Kagaku Kogyo Co., Ltd., particle diameter 9.5
.mu.m, refractive index 1.53) as first light transparent fine
particles, 1.59 parts by mass of monodisperse acrylic beads
(manufactured by Nippon Shokubai Kagaku Kogyo Co., Ltd., particle
diameter 9.5 .mu.m, refractive index 1.53) as second light
transparent fine particles, 0.013 part by mass of a silicone
leveling agent 10-28 (manufactured by The Inctec Inc.), 47.60 parts
by mass of toluene, and 11.90 parts by mass of cyclohexanone were
thoroughly mixed together to prepare a composition. This
composition was filtered through a polypropylene filter having a
pore diameter of 30 .mu.m to prepare composition 7 for an
anti-dazzling layer.
[0295] Composition 8 for Anti-Dazzling Layer
[0296] Pentaerythritol triacrylate (PETA) (manufactured by Nippon
Kayaku Co., Ltd., refractive index 1.51) (21.28 parts by mass) as
an ultraviolet curing resin, 8.63 parts by mass of DPHA
(manufactured by Nippon Kayaku Co., Ltd., refractive index 1.51) as
an ultraviolet curing resin, 3.18 parts by mass of an acrylic
polymer (manufactured by Mitsubishi Rayon Co., Ltd., molecular
weight 75,000) as an ultraviolet curing resin, 1.96 parts by mass
of Irgacure 184 (manufactured by Ciba-Geigy Limited) as a
photocuring initiator, 0.33 part by mass of Irgacure 907
(manufactured by Ciba-Geigy Limited) as a photocuring initiator,
4.96 parts by mass of acrylic beads (manufactured by Nippon
Shokubai Kagaku Kogyo Co., Ltd., particle diameter 4.6 .mu.m,
refractive index 1.53) as first light transparent fine particles,
1.65 parts by mass of acrylic beads (manufactured by Nippon
Shokubai Kagaku Kogyo Co., Ltd., particle diameter 3.5 .mu.m,
refractive index 1.53) as second light transparent fine particles,
0.013 part by mass of a silicone leveling agent 10-28 (manufactured
by The Inctec Inc.), 46.40 parts by mass of toluene, and 11.60
parts by mass of cyclohexanone were thoroughly mixed together to
prepare a composition. This composition was filtered through a
polypropylene filter having a pore diameter of 30 .mu.m to prepare
composition 8 for an anti-dazzling layer.
[0297] Composition 9 for Anti-Dazzling Layer
[0298] EXG40-77 (V-15M) (amorphous silica ink, average particle
diameter of silica 2.5 .mu.m, solid content 60%, manufactured by
Dainichiseika Color & Chemicals Manufacturing Co., Ltd.) (1.77
g) as an amorphous silica matting agent ink for an anti-dazzling
layer, pentaerythritol triacrylate (PETA) (manufactured by Nippon
Kayaku Co., Ltd., refractive index 1.51) (2.93 g) as an ultraviolet
curing resin, 0.37 g of an acrylic polymer (manufactured by
Mitsubishi Rayon Co., Ltd., molecular weight 40,000) as an
ultraviolet curing resin, 0.17 g of Irgacure 184 (manufactured by
Ciba-Geigy Limited) as a photocuring initiator, 0.6 g of Irgacure
907 (manufactured by Ciba-Geigy Limited) as a photocuring
initiator, 0.043 g of a silicone leveling agent 10-28 (manufactured
by The Inctec Inc.), 7.8 g of toluene, and 1.0 g of MIBK (methyl
isobutyl ketone) were thoroughly mixed together to prepare a
composition. This composition was filtered through a polypropylene
filter having a pore diameter of 80 .mu.m to prepare composition 9
for an anti-dazzling layer.
[0299] Preparation of Composition for Surface Modifying Layer
[0300] Composition 1 for Surface Modifying Layer
[0301] DPHA (manufactured by Nippon Kayaku Co., Ltd., refractive
index 1.51) (39.30 parts by mass) as an ultraviolet curing resin,
3.13 parts by mass of an acrylic polymer (manufactured by
Mitsubishi Rayon Co., Ltd., molecular weight 40,000) as an
ultraviolet curing resin, 2.12 parts by mass of Irgacure 184
(manufactured by Ciba-Geigy Limited) as a photocuring initiator,
0.43 part by mass of Irgacure 907 (manufactured by Ciba-Geigy
Limited) as a photocuring initiator, 0.19 part by mass of a
silicone leveling agent 10-28 (manufactured by The Inctec Inc.),
49.35 parts by mass of toluene, and 5.48 parts by mass of
cyclohexanone were thoroughly mixed together to prepare a
composition. This composition was filtered through a polypropylene
filter having a pore diameter of 10 .mu.m to prepare composition 1
for a surface modifying layer.
[0302] Composition 2 for Surface Modifying Layer
[0303] C-4456 S-7 (an ATO-containing electroconductive ink, average
particle diameter of ATO 300 to 400 nm, solid content 45%,
manufactured by NIPPON PELNOX CORP.) (21.6 g) as a material for an
antistatic layer, 28.69 g of DPHA (manufactured by Nippon Kayaku
Co., Ltd., refractive index 1.51) as an ultraviolet curing resin,
1.56 g of Irgacure 184 (manufactured by Ciba-Geigy Limited) as a
photocuring initiator, 33.7 g of MIBK (methyl isobutyl ketone), and
14.4 g of cyclohexanone were thoroughly mixed together to prepare a
composition. This composition was filtered through a polypropylene
filter having a pore diameter of 30 .mu.m to prepare composition 2
for a surface modifying layer.
[0304] Composition 3 for Surface Modifying Layer
[0305] Composition 3 for a surface modifying layer having the
following formulation was prepared using a zirconia-containing
coating composition (tradename; "KZ 7973", a resin matrix having a
refractive index of 1.69, solid content 50%, manufactured by JSR)
so that the resin matrix had a refractive index of 1.60.
[0306] Pentaerythritol triacrylate (PETA) (manufactured by Nippon
Kayaku Co., Ltd., refractive index 1.51) (18.59 parts by mass) as
an ultraviolet curing resin, 17.18 parts by mass of zirconia
(zirconia contained in "KZ 7973" (tradename), average particle
diameter 40 to 60 nm, refractive index 2.0, manufactured by JSR)
for incorporation in an ultraviolet curing resin to develop a resin
matrix, 1.22 parts by mass of a zirconia dispersant (a zirconia
dispersion stabilizer contained in "KZ 7973" (tradename),
manufactured by JSR), 0.94 part by mass of an acrylic polymer
(manufactured by Mitsubishi Rayon Co., Ltd., molecular weight
40,000) as an ultraviolet curing resin, 1.56 parts by mass of
Irgacure 184 (manufactured by Ciba-Geigy Limited) as a photocuring
initiator, 0.26 part by mass of Irgacure 907 (manufactured by
Ciba-Geigy Limited) as a photocuring initiator, 0.039 part by mass
of a silicone leveling agent 10-28 (manufactured by The Inctec
Inc.), 14.34 parts by mass of toluene, 15.76 parts by mass of
cyclohexanone, and 2.80 parts by mass of MEK were thoroughly mixed
together to prepare a composition. This composition was filtered
through a polypropylene filter having a pore diameter of 30 .mu.m
to prepare composition 3 for a surface modifying layer.
[0307] Preparation of Composition for Low-Refractive Index
Layer
[0308] Composition 1 for Low-Refractive Index Layer
[0309] A photopolymerization initiator (tradename; "JUA701,"
manufactured by JSR) (0.85 g) and 65 g of MIBK were added to 34.14
g of a fluororesin composition (tradename; "TM086", manufactured by
JSR), and the mixture was stirred and was filtered through a
polypropylene filter having a pore diameter of 10 .mu.m to prepare
composition for a low-refractive index layer.
[0310] Composition 2 for Low-Refractive Index Layer
[0311] The following components were stirred according to the
following formulation, and the mixture was filtered through a
polypropylene filter having a pore diameter of 10 .mu.m to prepare
composition 2 for a low-refractive index layer.
TABLE-US-00001 Surface treated silica sol (void-containing 14.3
pts. wt. fine particles) (as 20% methyl isobutyl ketone solution)
Pentaerythritol triacrylate 1.95 pts. wt. (PETA, refractive index
1.51, manufactured by Nippon Kayaku Co., Ltd.) Irgacure 907
(manufactured by Ciba 0.1 pt. wt. Specialty Chemicals, K.K.)
Polyether-modified silicone oil TSF4460 0.15 pt. wt. (tradename,
manufactured by GE Toshiba Silicone Co., Ltd.) Methyl isobutyl
ketone 83.5 pts. wt.
[0312] Preparation of Composition for Antistatic Layer
[0313] C-4456 S-7 (an ATO-containing electroconductive ink, average
particle diameter of ATO 300 to 400 nm, solid content 45%,
manufactured by NIPPON PELNOX CORP.) (2.0 g) was provided as a
material for an antistatic layer. Methyl isobutyl ketone (2.84 g)
and 1.22 g of cyclohexanone were added to the material, and the
mixture was stirred and was filtered through a polypropylene filter
having a pore diameter of 30 .mu.m to prepare composition for an
antistatic layer.
Production of Optical Laminate
Example 1
[0314] An optical laminate according to the present invention was
produced as follows to produce an optical laminate (HG1).
[0315] Formation of Anti-Dazzling Layer
[0316] An 80 .mu.m-thick triacetylcellulose film (TD80U,
manufactured by Fuji Photo Film Co., Ltd.) was provided as a
transparent base material. Composition 1 for an anti-dazzling layer
was coated onto the transparent base material with a wire-wound rod
for coating (Mayer's bar), and the coated transparent base material
was heat dried in an oven of 70.degree. C. for one min to evaporate
the solvent component. Thereafter, under nitrogen purge (oxygen
concentration: not more than 200 ppm), ultraviolet light was
applied at an exposure of 30 mJ for half curing to cure the coating
film. Thus, a 5 .mu.m-thick anti-dazzling hardcoat layer was
formed. The light transparent fine particles were monodisperse
acrylic beads having a particle diameter of 5.0 .mu.m.
[0317] Formation of Surface Modifying Layer
[0318] Composition 1 for a surface modifying layer was coated onto
the anti-dazzling layer with a wire-wound rod for coating (Mayer's
bar), and the coating was heat dried in an oven of 70.degree. C.
for one min to evaporate the solvent component. Thereafter, under
nitrogen purge (oxygen concentration: not more than 200 ppm),
ultraviolet light was applied at an exposure of 100 mJ to cure the
coating film. Thus, a 3 .mu.m-thick surface modifying layer was
formed.
Example 2
[0319] An optical laminate (HG2) was produced in the same manner as
in Example 1, except that composition 2 for an anti-dazzling layer
was used. The light transparent fine particles in composition 2 for
an anti-dazzling layer were monodisperse acrylic beads having a
particle diameter of 9.5 and the surface modifying layer had a
thickness of 4.0 .mu.m.
Example 3
[0320] An optical laminate (HG3) was produced in the same manner as
in Example 1, except that composition 3 for an anti-dazzling layer
was used. The light transparent fine particles in composition 3 for
an anti-dazzling layer were monodisperse acrylic beads having a
particle diameter of 13.5 .mu.m
Example 4
[0321] An optical laminate was produced in the same manner as in
Example 1, except that composition 4 for an anti-dazzling layer was
used. The light transparent fine particles in composition 4 for an
anti-dazzling layer were monodisperse acrylic beads having a
particle diameter of 13.5 .mu.m, and the proportion of the light
transparent fine particles to the total weight of the solid content
was 1/2 in the case of Example 3.
Example 5
[0322] An optical laminate was produced in the same manner as in
Example 1, except that composition 5 for an anti-dazzling layer was
used. The light transparent fine particles in composition 5 for an
anti-dazzling layer were monodisperse acrylic beads having a
particle diameter of 9.5 .mu.m, and the proportion of the light
transparent fine particles to the total weight of the solid content
was 75/1000 in the case of Example 2.
Example 6
[0323] An optical laminate was produced in the same manner as in
Example 1, except that composition 6 for an anti-dazzling layer was
used. The light transparent fine particles in composition 6 for an
anti-dazzling layer were acrylic beads having a particle size
distribution of 5.0 .mu.m.
Example 7
[0324] An optical laminate was produced in the same manner as in
Example 1, except that composition 7 for an anti-dazzling layer was
used. The first light transparent fine particles in composition 7
for an anti-dazzling layer were monodisperse acrylic beads having a
particle diameter of 9.5 .mu.m, and the second light transparent
fine particle were monodisperse acrylic beads having a particle
diameter of 5.0 .mu.m.
Example 8
[0325] An optical laminate was produced in the same manner as in
Example 1, except that composition 4 for an anti-dazzling layer and
composition 2 for a surface modifying layer were used. In order to
form an electroconductive surface modifying layer, an
ATO-containing composition was used in composition 2 for a surface
modifying layer. The optical laminate had an electrical surface
resistance value of 2.0.times.10.sup.12.OMEGA./.quadrature..
Example 9
[0326] An optical laminate according to the present invention was
produced as follows to produce an optical laminate.
[0327] Formation of Antistatic Layer
[0328] An 80 .mu.m-thick triacetylcellulose film (TD80U,
manufactured by Fuji Photo Film Co., Ltd.) was provided as a light
transparent base material. The composition for an antistatic layer
was coated onto the light transparent base material with a
wire-wound rod for coating (Mayer's bar), and the coated light
transparent base material was heat dried in an oven of 50.degree.
C. for one min to evaporate the solvent component. Thereafter,
under nitrogen purge (oxygen concentration: not more than 200 ppm),
ultraviolet light was applied at an exposure of 30 mJ for half
curing to cure the coating film. Thus, a 1 .mu.m-thick antistatic
layer was formed.
[0329] Formation of Anti-Dazzling Layer
[0330] Composition 4 for an anti-dazzling layer was coated onto the
antistatic layer with a wire-wound rod for coating (Mayer's bar),
and the coating was heat dried in an oven of 70.degree. C. for one
min to evaporate the solvent component. Thereafter, under nitrogen
purge (oxygen concentration: not more than 200 ppm), ultraviolet
light was applied at an exposure of 30 mJ for half curing to cure
the coating film. Thus, a 3 .mu.m-thick anti-dazzling layer was
formed.
[0331] Formation of Surface Modifying Layer
[0332] Composition 1 for a surface modifying layer was coated onto
the anti-dazzling layer with a wire-wound rod for coating (Mayer's
bar), and the coating was heat dried in an oven of 70.degree. C.
for one min to evaporate the solvent component. Thereafter, under
nitrogen purge (oxygen concentration: not more than 200 ppm),
ultraviolet light was applied at an exposure of 100 mJ to cure the
coating film. Thus, a 3 .mu.m-thick surface modifying layer was
formed to produce an optical laminate. The electrical surface
resistance value of the optical laminate was
3.2.times.10.sup.12.OMEGA./.quadrature..
Example 10
[0333] An optical laminate according to the present invention was
produced as follows. An anti-dazzling layer was formed in the same
manner as in Example 1, except that, in forming an anti-dazzling
layer, composition 4 for an anti-dazzling layer was used. Further,
a surface modifying layer was formed in the same manner as in
Example 1, except that ultraviolet light was applied at an exposure
of 30 mJ for half curing to cure the coating film.
[0334] Formation of Low-Refractive Index Layer
[0335] Composition 2 for a low-refractive index layer was coated
onto the anti-dazzling layer with a wire-wound rod for coating
(Mayer's bar), and the coating was heat dried in an oven of
50.degree. C. for one min to evaporate the solvent component.
Thereafter, under nitrogen purge (oxygen concentration: not more
than 200 ppm), ultraviolet light was applied at an exposure of 150
mJ to cure the coating film. Thus, a 98 .mu.m-thick surface
modifying layer was formed to produce an optical laminate.
Example 11
[0336] An optical laminate according to the present invention
produced as follows. An optical laminate was produced in the same
manner as in Example 10, except that, in forming a surface
modifying layer, composition 3 for a surface modifying layer and
composition 1 for a low-refractive index layer were used. A
zirconia-containing resin matrix was used in composition 3 for a
surface modifying layer, and the refractive index of the surface
modifying layer was regulated to 1.60.
Example 12
Embossing Method
Preparation of Emboss Roller
[0337] An iron roller was provided. 100-mesh (particle size
distribution; 106 .mu.m to 150 .mu.m) glass beads were shot against
the surface of the roller to form concavoconcaves. The
concavoconvex face was plated with chromium to a thickness of 5
.mu.m to prepare an emboss roller. In bead shot blasting, blasting
pressure, the spacing between the blasting nozzle and the roller
and the like were regulated to prepare an emboss roller which
corresponds to optical characteristics of the concavoconvex shape
in the anti-dazzling layer provided in the optical laminate
according to the present invention.
[0338] Preparation of Composition for Anti-Dazzling Layer
[0339] 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, 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.
[0340] Production of Optical Laminate
[0341] A fourth production apparatus (an embossing apparatus 40)
according to the present invention is shown in FIG. 6. The emboss
roller prepared above was mounted on the embossing apparatus, and
the composition for an anti-dazzling layer was supplied into a
liquid reservoir in a coating head. An 80 .mu.m-thick polyethylene
terephthalate resin film (the stock number; A4300, manufactured by
Toyobo Co., Ltd.) was provided and supplied to the emboss roller.
The composition for an anti-dazzling layer was coated onto the
emboss roller and was then applied onto the polyethylene
terephthalate film. Subsequently, ultraviolet light from an
ultraviolet light source (D-bulb, manufactured by Fusion) was
applied to the coating from the film side, and the assembly was
then separated to produce an optical laminate according to the
present invention.
Comparative Example 1
[0342] A conventional anti-dazzling optical laminate was prepared
as follows to produce an optical laminate (AG1). Specifically, an
80 .mu.m-thick triacetylcellulose film (TD80U, manufactured by Fuji
Photo Film Co., Ltd.) was provided as a transparent base material.
Composition 8 for an anti-dazzling layer was coated onto the
transparent base material with a wire-wound rod for coating
(Mayer's bar), and the coated transparent base material was heat
dried in an oven of 70.degree. C. for one min to evaporate the
solvent component. Thereafter, under nitrogen purge (oxygen
concentration: not more than 200 ppm), ultraviolet light was
applied at an exposure of 100 mJ to cure the coating film. Thus, a
6 .mu.m-thick anti-dazzling hardcoat layer was formed. AG1 is an
anti-dazzling optical laminate (AG1) of a mixed particle system
using 4.96 parts by mass of acrylic beads (manufactured by Nippon
Shokubai Kagaku Kogyo Co., Ltd., particle diameter 4.6 .mu.m,
refractive index 1.53) as first light transparent fine particles
and 1.65 parts by mass of acrylic beads (manufactured by Nippon
Shokubai Kagaku Kogyo Co., Ltd., particle diameter 3.5 .mu.m,
refractive index 1.53) as second light transparent fine
particles.
Comparative Example 2
[0343] A conventional anti-dazzling optical laminate was produced
as follows to produce an optical laminate. Specifically, the
procedure of Comparative Example 1 was repeated, except that
composition 9 for an anti-dazzling layer was used and the thickness
of the anti-dazzling layer was 3 .mu.m. The optical laminate of
Comparative Example 2 is an anti-dazzling optical laminate (AG)
using amorphous silica.
[0344] Evaluation Test
[0345] The following evaluation tests were carried out. The results
are shown in FIGS. 7 to 9 and Table 1 (results of evaluations 3 to
6).
[0346] Evaluation 1: Planar Shape Evaluation Test
[0347] Each of the optical laminates of Example and Comparative
Example was mounted on a panel of an image display device, and the
surface shape was photographed with an optical microscope
(tradename; BX60-F3, manufactured by OLYMPUS; 200 times). The
results were as shown in FIG. 7.
[0348] As can be seen from FIG. 7, for HG1 to HG3 which are optical
laminates according to the present invention, the waviness of the
concavoconvex shape was smooth, the concavoconvex shape is not
sharp, and the whole surface is in the form of a plurality of very
gently sloping hills. On the other hand, for AG1 which is a
conventional anti-dazzling optical laminate, the surface is rough
like an enlarged photograph of the human skin, and the
concavoconvex shape is sharp.
[0349] Evaluation 2: Three-Dimensionality Evaluation Test for
Concavoconvex Shape
[0350] Each of the optical laminates of Example and Comparative
Example was mounted on a panel of an image display device, and the
surface shape was photographed with AFM (tradename: a scanning
probe microscope). The results were as shown in FIGS. 8 and 9. As
can be seen from FIG. 8, for HG1 to HG3 which are optical laminates
according to the present invention, the waviness of the
concavoconvex shape was very smooth, the concavoconvex shape is not
sharp, and the whole surface is in the form of a plurality of very
gently sloping hills. On the other hand, as can be seen from FIG.
9, for AG1 which is a conventional anti-dazzling optical laminate,
the surface is in the form of a number of sharp concavoconvex
shapes.
[0351] Evaluation 3: Optical Characteristics Test
[0352] For the optical laminates of Example and Comparative
Example, the haze value (%), 60-degree gloss, Sm, .theta.a, Rz,
reflection Y value (5-degree reflection), and electrical surface
resistance were measured according to the definition described in
the present specification. The results were as shown in Table
1.
[0353] Evaluation 4: Glossy Black Feeling Test
[0354] A crossed Nicol polarizing plate was applied onto each of
the optical laminates of Example and Comparative Example on its
side remote from the film. Sensory evaluation was carried out under
three-wavelength fluorescence, and glossy black feeling
(reproduction of glossy black) was evaluated in detail according to
the following criteria.
[0355] Evaluation Criteria
[0356] .largecircle.: Glossy black could be reproduced.
[0357] .DELTA.: Glossy black could be somewhat reproduced but was
unsatisfactory as a product.
[0358] x: Glossy back could not be reproduced.
[0359] Evaluation 5: Glare Test
[0360] A black matrix pattern plate (105 ppi) formed on a 0.7
mm-thick glass was placed on a viewer manufactured by HAKUBA (light
viewer 7000PRO) so that the pattern surface faced downward. The
optical laminate film prepared above was placed thereon so that the
concavoconvex face was on the air side. Glare was visually observed
in a dark room while lightly pressing with a finger the edge of the
film to prevent the lift of the film, and the results were
evaluated.
[0361] Evaluation Criteria
[0362] .largecircle.: No glare was observed at 105 ppi, and the
antiglareness was good.
[0363] x: Glare was observed at 105 ppi, and the antiglareness was
poor.
[0364] Evaluation 6: Anti-Dazzling Evaluation Test
[0365] A black acrylic plate was applied onto the backside of the
optical laminate with the aid of an optical pressure-sensitive
adhesive. The sample was placed on a horizontal desk. White
fluorescent lamps (32 W.times.2 lamps) were disposed 2.5 m above
the desk. Reflection of the edge part of the white fluorescent
lamps was visually observed and was evaluated.
[0366] Evaluation Criteria
[0367] .largecircle.: The edge was not reflected, and the
anti-dazzling property was good.
[0368] x: The edge was reflected, and the anti-dazzling property
was poor.
TABLE-US-00002 TABLE 1 Composition for anti-dazzling layer Light
transparent fine particles Binder Weight ratio Addition Solvent per
unit area amount of composition between polymer (Ratio of toluene
Particle resin and (based on Monomer to coating compo- diameter
Material particle binder) ratio sition component) Ex. 1 5.0 .mu.m
PMMA 0.20 PMMA PETA: Toluene: polymer DPHA = cyclohexanone = 10 wt
% 65:35 80:20 wt % (mw 75000) wt % (40.5 wet %) Ex. 2 9.5 .mu.m
.dwnarw. .dwnarw. .dwnarw. .dwnarw. .dwnarw. Ex. 3 13.5 .mu.m
.dwnarw. .dwnarw. .dwnarw. .dwnarw. .dwnarw. Ex. 4 13.5 .mu.m
.dwnarw. 0.10 .dwnarw. .dwnarw. .dwnarw. Ex. 5 9.5 .mu.m .dwnarw.
0.015 .dwnarw. .dwnarw. .dwnarw. Ex. 6 5.0 .+-. 2.0 .dwnarw. 0.20
.dwnarw. .dwnarw. .dwnarw. (particle size distribution) Ex. 7 9.5
.mu.m .dwnarw. 0.20 .dwnarw. .dwnarw. .dwnarw. 5.0 .mu.m (9.5 .mu.m
. . . 0.15 Mixed 5.0 .mu.m . . . 0.05) particle system Ex. 8 13.5
.mu.m .dwnarw. 0.10 .dwnarw. .dwnarw. .dwnarw. Ex. 9 .dwnarw.
.dwnarw. .dwnarw. .dwnarw. .dwnarw. .dwnarw. Ex. 10 .dwnarw.
.dwnarw. .dwnarw. .dwnarw. .dwnarw. .dwnarw. Ex. 11 .dwnarw.
.dwnarw. .dwnarw. .dwnarw. .dwnarw. .dwnarw. Ex. 12 Concavo-convex
formation by embossing (embossing treatment) Comp. 4.6 .mu.m
.dwnarw. 0.18 .dwnarw. .dwnarw. .dwnarw. Ex. 1 3.5 .mu.m Mixed
particle system Comp. Average Silica 0.00 PMMA PETA = Toluene: Ex.
2 particle polymer 100 MIBK = diameter 1.25 wt % 90:10 wt % 2.5
.mu.m (mw 45000) (40.5 wet %) Amorphous silica Evaluation 3
Reflection 60- Y value Haze degree (5-degree Evalua- Evalua-
Evalua- (%) gloss Sm .theta.a Rz reflection) tion 4 tion 5 tion 6
Ex. 1 0.3 98.7 233.1 0.384 0.606 -- .smallcircle. .smallcircle.
.smallcircle. (* No low- refractive index layer: 4%) Ex. 2 0.4 94.6
170.2 0.504 0.663 -- .smallcircle. .smallcircle. .smallcircle. Ex.
3 0.6 90.3 362.5 0.539 1.040 -- .smallcircle. .smallcircle.
.smallcircle. Ex. 4 0.5 92.3 354.1 0.478 0.833 -- .smallcircle.
.smallcircle. .smallcircle. Ex. 5 0.4 94.8 375.1 0.422 0.482 --
.smallcircle. .smallcircle. .smallcircle. Ex. 6 0.4 93.2 192.3
0.621 0.834 -- .smallcircle. .smallcircle. .smallcircle. Ex. 7 0.5
94.9 201.3 0.532 0.743 -- .smallcircle. .smallcircle. .smallcircle.
Ex. 8 1.4 93.2 323.1 0.912 0.893 -- .smallcircle. .smallcircle.
.smallcircle. Ex. 9 1.8 93.1 367.3 0.623 0.982 -- .smallcircle.
.smallcircle. .smallcircle. Ex. 10 0.5 65.3 392.3 0.432 0.732 1.8%
.smallcircle. .smallcircle. .smallcircle. Ex. 11 1.3 56.2 245.3
0.392 0.652 1.4% .smallcircle. .smallcircle. .smallcircle. Ex. 12
1.9 70.3 102.2 0.493 0.832 .smallcircle. .smallcircle.
.smallcircle. Comp. 4.7 48.2 93.2 1.892 1.439 -- x x .smallcircle.
Ex. 1 Comp. 3.8 65.0 267.2 1.857 1.932 -- x .smallcircle. x Ex.
2
* * * * *