U.S. patent application number 14/064921 was filed with the patent office on 2014-09-18 for anti-glare coatings with sacrificial surface roughening agents and methods for forming the same.
This patent application is currently assigned to Intermolecular Inc.. The applicant listed for this patent is Intermolecular Inc.. Invention is credited to Scott Jewhurst, Nikhil Kalyankar.
Application Number | 20140272127 14/064921 |
Document ID | / |
Family ID | 51528221 |
Filed Date | 2014-09-18 |
United States Patent
Application |
20140272127 |
Kind Code |
A1 |
Kalyankar; Nikhil ; et
al. |
September 18, 2014 |
Anti-Glare Coatings with Sacrificial Surface Roughening Agents and
Methods for Forming the Same
Abstract
Embodiments provided herein describe optical coatings, panels
having optical coatings thereon, and methods for forming optical
coatings and panels. A sol-gel matrix is formed above a surface of
a substrate. Organic micro-particles are embedded in a surface of
the sol-gel matrix. A heat treatment is applied to the sol-gel
matrix and the embedded plurality of organic micro-particles.
Substantially all of the organic micro-particles are removed during
the heat treatment, and after the heat treatment, the sol-gel
matrix has a surface roughness suitable to provide anti-glare
properties.
Inventors: |
Kalyankar; Nikhil; (Mountain
View, CA) ; Jewhurst; Scott; (Redwood City,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Intermolecular Inc. |
San Jose |
CA |
US |
|
|
Assignee: |
Intermolecular Inc.
San Jose
CA
|
Family ID: |
51528221 |
Appl. No.: |
14/064921 |
Filed: |
October 28, 2013 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61777995 |
Mar 12, 2013 |
|
|
|
Current U.S.
Class: |
427/162 |
Current CPC
Class: |
G02B 2207/109 20130101;
G02B 2207/107 20130101; G02B 1/113 20130101; G02B 1/12 20130101;
C09D 5/006 20130101; Y10T 428/259 20150115; G02B 5/0294 20130101;
Y10T 428/25 20150115; C09D 7/63 20180101 |
Class at
Publication: |
427/162 |
International
Class: |
G02B 1/11 20060101
G02B001/11 |
Claims
1. A method of forming an anti-glare coating, the method
comprising: forming a sol-gel matrix above a surface of a
substrate; embedding a plurality of organic micro-particles in a
surface of the sol-gel matrix, wherein the plurality of organic
micro-particles have a size distribution between about 0.1
micrometers (.mu.m) and 10 .mu.m; applying a heat treatment to the
sol-gel matrix and the embedded plurality of organic
micro-particles, wherein substantially all of the embedded
plurality of organic micro-particles are removed during the heat
treatment, and after the heat treatment, the sol-gel matrix has an
effective surface roughness between 0.2 .mu.m and 0.8 .mu.m.
2. The method of claim 1 wherein the sol-gel matrix has a thickness
between 1 .mu.m and 100 .mu.m.
3. The method of claim 1 wherein the plurality of organic
micro-particles comprise polystyrene beads, polymethylmethacrylate
(PMMA) beads, or a combination thereof.
4. The method of claim 1 wherein each of the plurality organic
micro-particles have one of a solid, hollow, or core-shell
construction.
5. The method of claim 1 wherein the embedding of the plurality of
organic micro-particles into the surface of the sol-gel matrix is
performed using high velocity spray, application of a mechanical
force, or a combination thereof.
6. The method of claim 1 wherein the heat treatment comprises
heating the sol-gel matrix and the embedded plurality of organic
micro-particles to a temperature in the range of 450.degree. C. to
700.degree. C.
7. A method of forming an anti-glare coating, the method
comprising: forming a sol-gel matrix, wherein the sol-gel matrix
comprises a plurality of organic micro-particles having a size
distribution between about 0.1 .mu.m and 10 .mu.m; applying the
sol-gel matrix to a surface of a substrate, wherein the plurality
of organic micro-particles segregate to a top surface of the
sol-gel matrix after the applying of the sol-gel matrix; applying a
heat treatment to the sol-gel matrix, wherein substantially all of
the plurality organic micro-particles are removed from the sol-gel
matrix during the heat treatment, and after the heat treatment, the
sol-gel has an effective surface roughness between 0.2 .mu.m and
0.8 .mu.m.
8. The method of claim 7 wherein the sol-gel matrix has a thickness
between 1 .mu.m and 100 .mu.m.
9. The method of claim 7 wherein the plurality of organic
micro-particles comprise polystyrene beads, polymethylmethacrylate
(PMMA) beads, or a combination thereof.
10. The method of claim 7 wherein each of the plurality organic
micro-particles have one of a solid, hollow, or core-shell
construction.
11. The method of claim 7 wherein the heat treatment comprises
heating the sol-gel matrix to a temperature in the range of
450.degree. C. to 700.degree. C.
12. The method of claim 7 wherein the segregation of the plurality
of organic micro-particles to the top surface of the sol-gel matrix
is facilitated by at least one of the use of micro-particles that
are buoyant in the sol-gel matrix, a surface segregating surfactant
within the sol-gel matrix, or by the application of an external
electric field.
13. A method of forming an anti-glare coating, the method
comprising: forming a sol-gel matrix; forming a particle dispersion
formulation, wherein the particle dispersion formulation comprises
a plurality of organic micro-particles having a size distribution
between about 0.1 .mu.m and 10 .mu.m; applying the sol-gel matrix
to a surface of a substrate; applying the particle dispersion
formulation to a top surface of the sol-gel matrix, the sol-gel
matrix and the particle dispersion formulation jointly forming a
coating; applying a heat treatment to the coating, wherein
substantially all of the plurality of organic micro-particles are
removed from the coating during the heat treatment, and after the
heat treatment, the coating maintains a surface roughness between
0.2 .mu.m and 0.8 .mu.m.
14. The method of claim 13 wherein the coating has a thickness
between 1 .mu.m and 100 .mu.m.
15. The method of claim 13 wherein the plurality of organic
micro-particles comprise polystyrene beads, polymethylmethacrylate
(PMMA) beads, or a combination thereof.
16. The method of claim 13 wherein each of the plurality organic
micro-particles have one of a solid, hollow, or core-shell
construction.
17. The method of claim 13 wherein the heat treatment comprises
heating the coating to a temperature in the range of 450.degree. C.
to 700.degree. C.
18. The method of claim 13 wherein the applying of the sol-gel
matrix and the applying of the particle dispersion formulation
occur simultaneously.
19. The method of claim 13 wherein the applying of the sol-gel
matrix and the applying of the particle dispersion formulation are
performed with a coating mechanism having a first slot and a second
slot, wherein the sol-gel matrix is dispensed from the first slot
and the particle dispersion formulation is dispensed from the
second slot.
20. The method of claim 13, wherein the plurality of organic
micro-particles are completely embedded within the coating.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Patent
Application No. 61/777,995, filed Mar. 12, 2013, entitled "Sol-Gel
Coatings," which is incorporated by reference herein in its
entirety.
TECHNICAL FIELD
[0002] The present invention relates to optical coatings. More
particularly, this invention relates to optical coatings that
improve, for example, the anti-glare performance of transparent
substrates and methods for forming such optical coatings.
BACKGROUND OF THE INVENTION
[0003] Anti-glare coatings, and anti-glare panels in general, are
desirable in many applications including, portrait glass, privacy
glass, and display screen manufacturing. Such optical coatings
scatter specular reflections into a wide viewing cone to diffuse
glare and reflection. It is difficult to achieve a substrate that
simultaneously reduces gloss (i.e., specular reflection) and haze
(i.e., diffuse transmittance) while relying on light scattering to
obtain anti-glare properties.
[0004] Conventional methods of forming anti-glare panels include,
for example, wet etching the surface of the substrate, using
mechanical rollers with pre-defined textures on substrates to
create a surface roughness, and applying thin, polymeric films with
texture to the substrates using adhesives. Such methods are
expensive, have low throughput (i.e., a low rate of manufacture),
and lack of precise control with respect to surface texture, which
results in a diffuse scattering coating with poor light
transmittance or good light transmittance, but poor reduction of
glare.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] To facilitate understanding, identical reference numerals
have been used, where possible, to designate identical elements
that are common to the figures. The drawings are not to scale and
the relative dimensions of various elements in the drawings are
depicted schematically and not necessarily to scale.
[0006] The techniques of the present invention can readily be
understood by considering the following detailed description in
conjunction with the accompanying drawings, in which:
[0007] FIG. 1 is a cross-sectional view of a substrate;
[0008] FIG. 2 is cross-sectional view of the substrate of FIG. 1
with a matrix layer formed thereon;
[0009] FIG. 3 is a cross-sectional view of the substrate of FIG. 2
with micro-particles deposited onto the matrix layer;
[0010] FIG. 4 is a cross-sectional view of the substrate of FIG. 3
illustrating the micro-particles being pressed into the matrix
layer with a roller;
[0011] FIG. 5 is a cross-sectional view of the substrate of FIG. 4
after the micro-particles have been pressed into the matrix
layer;
[0012] FIG. 6 is a cross-sectional view of the substrate of FIG. 5
after undergoing a heat treatment to remove the
micro-particles;
[0013] FIG. 7 is a cross-sectional view of a substrate;
[0014] FIG. 8 is a cross-sectional view of the substrate of FIG. 7
illustrating a multi-layer coating being deposited thereon with a
coating mechanism;
[0015] FIG. 9 is a cross-sectional view of the substrate of FIG. 8
after the multi-layer coating is formed thereon;
[0016] FIG. 10 is a cross-sectional view of the substrate of FIG. 9
after undergoing a heat treatment; and
[0017] FIG. 11 is a flow chart illustrating a method for forming an
anti-glare coating, or a coated article, according to some
embodiments.
DETAILED DESCRIPTION
[0018] A detailed description of one or more embodiments is
provided below along with accompanying figures. The detailed
description is provided in connection with such embodiments, but is
not limited to any particular example. The scope is limited only by
the claims and numerous alternatives, modifications, and
equivalents are encompassed. Numerous specific details are set
forth in the following description in order to provide a thorough
understanding. These details are provided for the purpose of
example and the described techniques may be practiced according to
the claims without some or all of these specific details. For the
purpose of clarity, technical material that is known in the
technical fields related to the embodiments has not been described
in detail to avoid unnecessarily obscuring the description.
[0019] The term "horizontal" as used herein will be understood to
be defined as a plane parallel to the plane or surface of the
substrate, regardless of the orientation of the substrate. The term
"vertical" will refer to a direction perpendicular to the
horizontal as previously defined. Terms such as "above", "below",
"bottom", "top", "side" (e.g. sidewall), "higher", "lower",
"upper", "over", and "under", are defined with respect to the
horizontal plane. The term "on" means there is direct contact
between the elements. The term "above" will allow for intervening
elements.
[0020] Embodiments described herein provide for optical coatings,
and methods for forming optical coatings, that improve the
anti-glare (and/or the anti-reflective) performance of transparent
substrates. In accordance with some embodiments, this is
accomplished by forming a layer above transparent substrate with
micro-particles (e.g., organic micro-particles) embedded in or near
the upper surface thereof. The layer (and/or the substrate as a
whole) then undergoes a heat treatment which causes the
micro-particles to be "combusted off" (i.e., removed). As a result,
the upper surface of the layer has a series of surface features
thereon which give the layer an effective surface roughness or
texture (e.g., between 0.2 micrometers (.mu.m) and 0.8 .mu.m) that
is suitable for providing the layer with anti-glare properties.
Effective surface roughness may refer to the average surface
roughness that a beam of light encounters upon incidence. Effective
roughness may refer to the same concept as average surface
roughness for normal beam incidence.
[0021] FIGS. 1-6 illustrate a method for forming a coated article
(or anti-glare panel) 100 according to some embodiments of the
present invention. Referring to FIG. 1, a transparent substrate 102
is shown. In some embodiments, the transparent substrate 102 is
made of glass and has a thickness 104 of, for example, between 0.1
and 2.0 centimeters (cm). Although only a portion of the substrate
102 is shown, it should be understood that the substrate 102 may
have a width of, for example, between 5.0 cm and 2.0 meters (m). In
some embodiments, the substrate 102 is made of a transparent
polymer.
[0022] As shown in FIG. 2, a matrix (or matrix layer) 106 is formed
above the transparent substrate 102. In some embodiments, the
matrix 106 is formed directly on the transparent substrate 102.
However, in some embodiments, other materials and/or layers may be
formed between the substrate 102 and the matrix 106. In some
embodiments, the matrix 106 is formed using a sol-gel formulation.
The sol-gel formulation may include a combination of matrix forming
silanes or siloxanes containing one or more of the following:
tetraalkoxysilane, oligomeric alkoxysiloxanes, bis(alkoxysilanes),
silesquioxanes, dipodal alkoxysilane and/or
(alkyl/aryl)trialkoxysilane. An organic solvent, such as an
alcohol, ketone, ester, tetrahydrofuran (THF), etc. may be added
which serves as a cosolvent for the ingredients. The formulation
may also include an accelerator or a catalyst such as an acid, a
base, a metal carboxylate or any other type of chemical which can
catalyze the sol-gel reaction and water for hydrolysis of the
alkoxide groups of the silanes/siloxanes. Additionally, inorganic
nanoparticles (e.g., 3-200 nanometers (nm)) may be added to provide
structural rigidity to the matrix, along with a stabilizer, such as
a surfactant, and ultraviolet (UV) blocking nanoparticles, such as
ZnO, TiO.sub.2, CeO.sub.2.
[0023] The components of the sol-gel formulation are mixed (as
needed) in a pre-determined manner (i.e., composition, order of
addition, temperature during mixing, etc.) for a pre-determined
time. The presence of alkyltrialkoxysilane in the formulation may
help in providing the ability to prepare a several micron thick
gelled layer while reducing the likelihood that the layer will
crack during thermal treatment to burn off the micro-particles (see
below). In some embodiments, a pre-existing matrix formulation may
be used to form the matrix, such as commercially available
polysiloxane formulations, polysilazane formulations, polyamide
formulations, polyacrylate formulations etc.
[0024] Still referring to FIG. 2, the formulation is deposited onto
the transparent substrate 102 (e.g., via spin coating) to form a
gelled or solidified layer (i.e., the matrix layer 106) that has a
thickness 108 of, for example, between 1 and 100 micrometers
(.mu.m). Most of the solvent is removed during the gelation,
leaving a compliant, deformable solid layer (or film). After the
solvent is removed, the matrix 106 has a substantially smooth, flat
upper surface 110.
[0025] As shown in FIG. 3, in some embodiments, a plurality of
micro-particles (or micro-crystals) 112 are deposited onto the
upper surface 110 of the matrix 106. In some embodiments, the
micro-particles 112 are made of organic materials. Exemplary
micro-particles 112 include polystyrene beads,
polymethylmethacrylate (PMMA) beads, or the like, which may be
solid, hollow, or of a core-shell construction. The micro-particles
112 may have a uniform, multi-modal, or random particle size
distribution. In some embodiments, the size distribution, or
effective particles size, (or widths 114) of micro-particles is
between 0.1 and 10 .mu.m. In some embodiments, the micro-particles
may be non-spherical such as ellipsoidal, or of random shape and
surface features.
[0026] As shown in FIG. 3, the micro-particles 112 substantially
lie on the upper surface 110 of the matrix 106. However, depending
on the method of deposition, the micro-particles 112 may at least
partially penetrate the matrix 106. For example, in some
embodiments, a high velocity spray deposition is used, which
provides sufficient force for the micro-particles to completely
penetrate the top surface 110 (which may have a crust-like barrier)
of the matrix 106.
[0027] However, in some embodiments, an additional process may be
performed to embed, or further embed, the micro-particles 112 into
the matrix 106. For example, in some embodiments, the
micro-particles 112 are deposited using a wet deposition process in
which the micro-particles 112 are suspended in a carrier solvent.
The micro-particles 112 may then be pressed into the matrix 104 via
a mechanical force, such as by passing a roller 116 over the
micro-particles 112, such as that shown in FIG. 4. In some
embodiments, a spray deposition or inkjet of the micro-particles
112 may be used, followed by embedding via a mechanical force
applied by a roller (e.g., roller 116 in FIG. 4) or a flat plate.
In some embodiments, a wet deposition may be used with simultaneous
embedding by an applied a mechanical force using a roll (roller)
coating, wire rod coating, draw down coating, doctor blade coating,
gravure coating, etc.
[0028] FIG. 5 illustrates the coated article 100 after the
deposition, and the additional embedding process (if used), of the
micro-particles 112. In some embodiments, the micro-particles 112
are nearly completely embedded into the upper surface 110 of the
matrix 106. However, as suggested above, the degree to which the
micro-particles 112 are embedded into the upper surface 110 of the
matrix 104 may vary (i.e., between partially embedded to completely
embedded) and may be controlled using process parameters during
application as well as the material properties of the gelled matrix
and micro-particles.
[0029] Referring now to FIG. 6, the coated article 100 then
undergoes a thermal treatment to combust away (or "burn out" or
"burn off") substantially all of (e.g., at least 90%) the
micro-particles 112. As shown, after the micro-particles 112 have
been removed, the thickness 108 of the matrix 106 may vary between,
for example, approximately 1 and 50 .mu.m. That is, as shown, the
upper surface 110 of the optical coating 104 has a series a surface
features 116 (i.e., texturing or roughness) formed thereon, which
cause the thickness 108 to vary. Due to the surface features 116,
the upper surface 110 of the matrix 104 may have an average
effective surface roughness ranging, for example, from 0.2 to 0.8
.mu.m. The thermal treatment may also cure the matrix 106 by aiding
in the poly-condensation reactions and removing excessive organics,
leaving an inorganic coating with a textured surface. As will be
appreciated by one skilled in the art, such an effective surface
roughness is suitable to provide the matrix 106 with anti-glare
properties. In other words, the matrix 106 now forms an anti-glare
coating.
[0030] In should also be noted that some of the micro-particles 112
may be embedded into the upper surface 110 of the matrix 106 such
that after the heat treatment, some pores are formed near the upper
surface 110 of the matrix 106. As will be appreciated by one
skilled in the art, the presence of the pores may reduce the
overall refractive index of the respective portion(s) of the matrix
106, thus also providing the matrix 106 (or anti-glare coating)
with anti-reflective properties.
[0031] In some embodiments, similar to those described above, a
sol-gel formulation is prepared using a 50:50 molar combination of
tetraethoxysilane (TEOS) and isooctyltrimethoxysilane (as the
alkyltrialkoxysilane referred to as IOTMS) as the matrix (and/or
binder) material, n-butanol as the solvent, nitric acid as the
catalyst, ORGANOSILICASOL IPA-ST-MS (e.g., particle size
.about.10-20 microns) spherical silica particles (available from
Nissan Chemical America Corporation of Houston, Tex.) as filler
material, and water. The total ash content of the solution is 10%
(based on equivalent weight of SiO.sub.2 produced). The ratio of
alkyltrialkoxysilane-based matrix to silica nano-particle fillers
is 90:10 ash content contributions. Pre-mixed silanes and silica
nano-particles are mixed with water (e.g., 5 times the molar mixed
silane amount), nitric acid (e.g., 0.05 times the molar amount of
TEOS combined with IOTMS) and n-butanol. The solution is stirred
for 24 hours at room temperature, or at an elevated temperature
(e.g., 30.degree. C.-60.degree. C.), and cooled to room temperature
before application.
[0032] The formulation is spin coated onto a clean, dry glass
substrate such that a gelled layer with a thickness of
approximately 5 .mu.m is formed thereon. The substrate may then be
subjected to a limited low temperature pre-cure (e.g., 50.degree.
C.-150.degree. C. for 2 min to 10 min) to remove excess solvent and
promote gelation. The substrate is then sprayed with polystyrene
particles (e.g., having a mean particle size of 1 .mu.m) dispersed
in an organic solvent (e.g., 5% by mass) and allowed to air dry,
dry under forced air, and/or dry under forced inert gas, with an
application of heat (e.g., 50.degree. C.-150.degree. C. for 2 min),
or a combination of these methods to remove excessive solvent.
[0033] A roller is used immediately afterwards to embed the
polystyrene particles into the top layer of the gelled matrix using
a fixed and pre-determined normal force without affecting the
structural integrity of the gelled, matrix layer. The glass
substrate is then heat treated at 500.degree. C. to 700.degree. C.
for 3 min to 20 min to combust off the micro-particles, leaving
behind a micro-textured surface (with a rough inorganic coating)
with a mean surface roughness of 0.2 to 0.8 .mu.m. The heat
treatment also helps in curing the matrix material to a more dense,
robust and highly interlinked network leading to additional
cohesive and adhesive durability.
[0034] In some embodiments, the micro-particles are suspended
within the matrix-forming solution before the matrix material is
deposited. After deposition onto the substrate, the micro-particles
segregate preferentially to the coating-air interface (i.e., the
top surface of the matrix layer) to concentrate only in the top
layer as discreet particles before gelation occurs. Upon
application of a thermal treatment, the micro-particles are
combusted off, causing the surface features to be formed on the
matrix layer/anti-glare coating.
[0035] In some embodiments, the segregation of the micro-particles
may be achieved by using micro-particles which are buoyant in the
wet coating, by use of micro-particles which are treated with a
surface segregating surfactant, or by application of an external
electric field which attracts particles with a charged surface to
the top of the coating before it gels.
[0036] FIGS. 7-10 illustrate a method for forming a coated article
200 according to other embodiments of the present invention.
Referring to FIG. 7, a transparent substrate 202, which may be
similar to the substrate 102 described above, is provided.
[0037] Referring to FIG. 8, a coating mechanism 204 is used to
simultaneously deposit a base (or matrix) layer and a coating
layer, with micro-particles suspended therein. Specifically, the
coating mechanism includes a first slot 206 and a second slot 208
which operate simultaneously to deposit a multi-layer coating 210
that includes a base layer 212 and a coating layer 214. In
particular, the base layer 212 is dispensed from the first slot 206
of the coating mechanism 206, and the coating layer 214 is
dispensed from the second slot 208.
[0038] In the embodiment shown, during the deposition process, the
coating mechanism 204 is moved across the transparent substrate 202
(e.g., from right to left in FIG. 8) such that the base layer 212
is deposited above (e.g., on) an upper surface 216 of the
transparent substrate 202 and the coating layer 214 is deposited
above the base layer 212. Although not shown, it should be
understood that the coating mechanism 204 and/or the slots 206 and
208 may extend the width of the transparent substrate 202 so that
the entire transparent substrate 202 may be covered by the
multi-layer coating 210 with only one pass of the coating mechanism
204. In some embodiments, the base layer 212 is made using the same
materials and methods as the matrix 106 described above, and the
coating layer 214 includes a carrier solvent with micro-particles
218 (similar to embodiments described above) suspended therein.
[0039] FIG. 9 illustrates the coated article 200 after the
deposition of the multi-layer coating 210. As shown, the
micro-particles 218 are completely embedded into an upper surface
220 of the multi-layer coating 210 (and/or the coating layer 214)
(because the micro-particles 218 are suspended within the carrier
solvent prior to deposition). Although not shown, the multi-layer
coating 210 may have a thickness similar to the matrix 104
described above (e.g., between 1 and 100 .mu.m before heat
treatment).
[0040] Referring to FIG. 10, the coated article 200 then undergoes
a heat treatment similar to that described above. The heat
treatment combusts off the micro-particles 218 such that a series a
surface features 222 (i.e., texturing or roughness) are formed on
the upper surface 220 of the coating 210, which cause the thickness
thereof to vary. Due to the features 222, the upper surface 220 of
the coating 210 may have an average surface roughness ranging from
0.2 to 0.8 .mu.m, thus providing the coating 210 with anti-glare
properties (i.e., the coating 210 forms an anti-glare coating).
[0041] The methods described herein allow for controlling the
surface roughness of the formed anti-glare coating by, for example,
adjusting the size(s) and/or distribution of the micro-particles
that are deposited onto and/or embedded in the upper surface of the
matrix (or base) layer. This parameter may be easily adjusted
and/or consistently reproduced.
[0042] FIG. 11 illustrates a method 1100 for forming an anti-glare
coating (or a coated article) according to some embodiments. At
step 1102, a layer is formed above a substrate, such as the
transparent substrates described above. The layer is formed with a
plurality of organic micro-particles embedded therein. The
micro-particles have a size distribution of, for example, between
about 0.1 micrometers (.mu.m) and 10 .mu.m.
[0043] In some embodiments, the layer is formed above the substrate
and the micro-particles are then deposited onto and then embedded
into the layer by, for example, application of a mechanical force.
In some embodiments, the micro-particles are dispersed within the
material used to form the layer before the layer is deposited. In
some embodiments, the layer is a multi-layer coating, and the
micro-particles are included in a separate layer, such as a
particle dispersion, which is deposited above a sol-gel matrix.
[0044] At step 1104, the layer (and/or the substrate) undergoes a
heat treatment. The heat treatment causes the micro-particles to be
removed (e.g., "combusted off") from the layer. As a result of the
removal of the micro-particles, an upper surface of the layer is
provided with an effective surface roughness between 0.2 .mu.m and
0.8 .mu.m. At step 1106, the method 1100 ends with an anti-glare
coating having been formed above the substrate.
[0045] Thus, in some embodiments, a method of forming an anti-glare
coating is provided. A sol-gel matrix is formed above a surface of
a substrate. A plurality of organic micro-particles are embedded in
a surface of the sol-gel matrix. The plurality of organic
micro-particles have a size distribution between about 0.1
micrometers (.mu.m) and 10 .mu.m. A heat treatment is applied to
the sol-gel matrix and the embedded plurality of organic
micro-particles. Substantially all of the embedded plurality of
organic micro-particles are removed during the heat treatment, and
after the heat treatment, the sol-gel matrix has an effective
surface roughness between 0.2 .mu.m and 0.8 .mu.m.
[0046] In some embodiments, a method of forming an anti-glare
coating is provided. A sol-gel matrix is formed. The sol-gel matrix
comprises a plurality of organic micro-particles having a size
distribution between about 0.1 .mu.m and 10 .mu.m. The sol-gel
matrix is applied to a surface of a substrate. The plurality of
organic micro-particles segregate to a top surface of the sol-gel
matrix after the applying of the sol-gel matrix. A heat treatment
is applied to the sol-gel matrix. Substantially all of the
plurality organic micro-particles are removed from the sol-gel
matrix during the heat treatment, and after the heat treatment, the
sol-gel matrix formed has an effective surface roughness between
0.2 .mu.m and 0.8 .mu.m.
[0047] In some embodiments, a method of forming an anti-glare
coating is provided.
[0048] A sol-gel matrix if formed. A particle dispersion
formulation is formed. The particle dispersion formulation includes
a plurality of organic micro-particles having a size distribution
between about 0.1 .mu.m and 10 .mu.m. The sol-gel matrix is applied
to a surface of a substrate. The particle dispersion formulation is
applied to a top surface of the sol-gel matrix. The sol-gel matrix
and the particle dispersion formulation jointly form a coating. A
heat treatment is applied to the coating. Substantially all of the
plurality of organic micro-particles are removed from the coating
during the heat treatment, and after the heat treatment, the
coating maintains an effective surface roughness between 0.2 .mu.m
and 0.8 .mu.m.
[0049] Although the foregoing examples have been described in some
detail for purposes of clarity of understanding, the invention is
not limited to the details provided. There are many alternative
ways of implementing the invention. The disclosed examples are
illustrative and not restrictive.
* * * * *