U.S. patent application number 09/809287 was filed with the patent office on 2001-08-02 for method of partially forming oxide layer on glass substrate.
Invention is credited to Ishii, Osamu, Sakaguchi, Koichi, Shiraishi, Yasunori.
Application Number | 20010010836 09/809287 |
Document ID | / |
Family ID | 27336780 |
Filed Date | 2001-08-02 |
United States Patent
Application |
20010010836 |
Kind Code |
A1 |
Sakaguchi, Koichi ; et
al. |
August 2, 2001 |
Method of partially forming oxide layer on glass substrate
Abstract
A method of partially forming oxide layers on a surface of a
glass substrate by forming an oxide layer on the surface of the
substrate, partially contacting the surface of the oxide layer
formed on the substrate with a paste comprising an inorganic
compound different from the oxide, organic solvents and silicon
powder to partially dissolving the oxide layer with the paste, and
removing the dissolved components of the layer together with the
paste, by which the oxide layers are partially formed on the
surface of the substrate efficiently and surely.
Inventors: |
Sakaguchi, Koichi; (Osaka,
JP) ; Ishii, Osamu; (Ibaraki, JP) ; Shiraishi,
Yasunori; (Osaka, JP) |
Correspondence
Address: |
SUGHRUE, MION, ZINN, MACPEAK & SEAS, PLLC
2100 Pennsylvania Avenue, N.W.
Washington
DC
20037
US
|
Family ID: |
27336780 |
Appl. No.: |
09/809287 |
Filed: |
March 16, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09809287 |
Mar 16, 2001 |
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09308843 |
May 26, 1999 |
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6231924 |
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Current U.S.
Class: |
427/343 ;
427/376.2 |
Current CPC
Class: |
C03C 17/002 20130101;
C03C 2217/21 20130101; C03C 2218/355 20130101; C03C 17/23 20130101;
C03C 2218/328 20130101 |
Class at
Publication: |
427/343 ;
427/376.2 |
International
Class: |
B05D 003/10; B05D
003/02 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 26, 1996 |
JP |
P. HEI 8-314614 |
Oct 14, 1997 |
JP |
P. HEI 9-280818 |
Claims
What is claimed is:
1. A method of partially forming an oxide layer on a surface of a
glass substrate, consisting essentially of: (a) a step of forming a
layer comprising an oxide on the surface of the glass substrate;
(b) a step of contacting a fixed portion of the oxide layer of step
(a) with a paste comprising an inorganic compound, organic
solvents, and silicon powder in order to dissolve the oxide layer
of step (a) with the paste, wherein said inorganic compound is not
the same as the oxide of step (a); and (c) a step of removing the
dissolved portion of the oxide layer from step (b) together with
the paste.
2. The method of partially forming oxide layers as claimed in claim
1, wherein said inorganic compound is phosphoric acid.
Description
CROSS REFERENCE TO THE RELATED APPLICATION
[0001] This application is a continuation-in-part application of
application Ser. No. 09/308,843, filed May 26, 1999, entitled
"METHOD OF PARTIALLY FORMING OXIDE LAYER", now pending.
FIELD OF THE INVENTION
[0002] The present invention belongs to a technical field of a
glass substrate having formed thereon an oxide layer, which is used
for automobiles, buildings, various industrial instruments, etc.
Particularly, the invention belongs to a technical field of a glass
substrate having formed an oxide layer on the necessary portions
only of the surface thereof.
BACKGROUND OF THE INVENTION
[0003] On the surface of a glass plate or a ceramic plate, oxide
layers having various functions according to the use are formed.
For example, as glasses used for automobiles, vehicles, buildings,
etc., a heat-reflective layer containing the oxide of titanium,
cobalt, etc., is generally used for the purpose of reducing the
cooling load, etc. Also, as glass substrates for various displays,
an electrically conductive film comprising tin oxide, etc., is used
from the necessity of element driving. These layers are frequently
formed on only parts of the surface of a substrate for the
necessity of each use described above.
[0004] In not only the use of display but also other uses of
automobiles, buildings, etc., there is a case of requiring that the
layer is partially formed. For example, in the case of using a
heat-reflective glass for the back window of automobile, it is
required that a layer is not formed on the glass surface adjacent
to a high-mount stop lamp disposed in the inside of the back window
of the automobile but a layer is formed on other portion of the
glass surface for shielding heat rays while ensuring visibility of
the lamp.
[0005] In such a case, a method of foaming the layer after
previously applying masking to the necessary portion of the glass
plate or a method of applying masking after forming a layer on the
whole glass plate and removing the remaining unmasked portion of
layer with a solvent, by releasing, or polishing, etc., is
employed.
[0006] However, according to the conventional methods as described
above, masking is required in any method, which is accompanied by
complicated steps and operations, and thus the effective and ensure
partial formation of layer has been difficult by the conventional
methods.
SUMMARY OF THE INVENTION
[0007] The present invention has been made to overcome the
above-described problems.
[0008] Accordingly, an object of the present invention is to
provide a method of partially forming a layer on a surface of a
glass substrate by a simple and ensure method.
[0009] According to the present invention, the above-described
object can be attained by the method of partially forming an oxide
layer on a surface of a glass substrate, consisting essentially
of:
[0010] (a) a step of forming a layer comprising an oxide on the
surface of the glass substrate;
[0011] (b) a step of contacting a fixed portion of the oxide layer
of step (a) with a paste comprising an inorganic compound, organic
solvents, and silicon powder in order to dissolve the oxide layer
of step (a) with the paste, wherein said inorganic compound is not
the same as the oxide of step (a); and
[0012] (c) a step of removing the dissolved portion of the oxide
layer from step (b) together with the paste.
[0013] The preferred embodiments of the present invention are as
follows.
[0014] (1) The melting point of the inorganic compound is
500.degree. C. or lower or the softening point thereof is
500.degree. C. or lower.
[0015] (2) The dissolving step is a step of carrying out the
dissolution by heating a fixed portion of the oxide layer together
with the paste.
[0016] (3) The inorganic compound used in the paste includes at
least one kind selected from the group consisting of phosphorus
compounds each containing oxygen as a constituent and boron
compounds each containing oxygen as a constituent.
[0017] (4) The phosphorus compound includes at least one kind
selected from the group consisting of phosphoric acid and
phosphates and the boron compound includes boric acid and
borates.
[0018] (5) The inorganic compound is a glass and contains at least
one kind selected from the group consisting of P.sub.2O.sub.5, PbO,
B.sub.2O.sub.3, ZnO, and Bi.sub.2O.sub.3 as the constituent.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is schematic views showing one embodiment of the
present invention from the direction of the cross-section of a
substrate.
[0020] FIG. 2 is a schematic view showing an embodiment in the case
of applying the present invention to a back window of an
automobile.
[0021] The numerals in the drawings are as follows.
[0022] 1: Glass substrate
[0023] 2: Oxide layer
[0024] 3: Paste containing an inorganic compound
[0025] 4: Dissolved layer portion
[0026] 5: Layer-removed portion
[0027] 6: Back window for automobile
DETAILED DESCRIPTION OF THE INVENTION
[0028] The present invention is described in detail below.
[0029] The inorganic compound used in the paste of the present
invention may be an inorganic compound which can dissolve the oxide
of the layer when the compound is contacted with the oxide
constituting the layer and further the contacted layer is heated
and can keep the structure and the physical characteristics of the
glass substrate, and can be properly selected according to the
properties of the layer and the substrate.
[0030] A method of removing the paste containing the inorganic
compound after dissolving the layer includes a physical means and a
chemical means. For example, the physical means includes wiping
off, blowing off, etc., and the chemical means includes dissolving
of the layer with a solvent, etc. A preferred embodiment of a
preferred removing means of a layer is cleaning with an organic
solvent such as alcohols (e.g., methanol and ethanol) followed by
drying and as the case may be, the means can be carried out
together with the above-described physical means.
[0031] In the present invention, it is preferred that about the
layer to be removed, which corresponds to the region of existing
the paste contacted with the layer, all the layer of the
corresponding region is removed, but the residue of the layer to an
extent of not preventing the visibility can be allowed in this
invention.
[0032] Examples of the inorganic compounds which are generally used
in this invention are phosphorus compounds containing oxygen as the
constituent, boron compounds containing oxygen as the constituent,
etc., each having a melting point of 500.degree. C. or lower and
being a liquid at normal temperature. Prefered examples thereof are
phosphoric acids, phosphates, boric acid, and borates satisfying
the above-described conditions as shown below. The phosphoric acid
in this invention means the general names of the acids formed by
the hydration of diphosphorus pentoxide and includes
orthophosphoric acid (H.sub.3PO.sub.4, liquid at room temperature),
pyrophosphoric acid (H.sub.4P.sub.2O.sub.7, liquid at room
temperature), triphosphoric acid (H.sub.5P.sub.3O.sub.10, liquid at
room temperature), etc. Also, practical examples of the phosphate
include sodium dihydrogenphosphate (NaH.sub.2PO.sub.4) (typically,
dihydrate: NaH.sub.2PO.sub.4.2H.sub.2O, melting point 60.degree.
C.) and potassium dihydrogenphosphate (KH.sub.2PO.sub.4, melting
point 96.degree. C.). The borates practically include boric acid
(H.sub.3BO.sub.3, melting point 185.degree. C.), etc.
[0033] The inorganic compound having a melting point of 500.degree.
C. or lower also includes glasses. Examples of the glass preferably
includes glasses having generally a low-melting point composition
(so-called low-melting glasses), and the glasses containing
P.sub.2O.sub.5, B.sub.2O.sub.3, ZnO, PbO, Bi.sub.2O.sub.3, etc.,
are more preferred. Practically, the glass composition series such
as an R.sub.2O--P.sub.2O.sub.5 series, an R.sub.2O--B.sub.2O.sub.3
series, a PbO--B.sub.2O.sub.3--ZnO series, a
PbO--SiO.sub.2--B.sub.2O.sub.3 series, a
Bi.sub.2O.sub.3--ZnO--B.sub.2O.sub.3 series, an
R.sub.2O--ZnO--SiO.sub.- 2--B.sub.2O.sub.3 series, a
ZnO--B.sub.2O.sub.3 series, an R.sub.2O--ZnO--P.sub.2O.sub.5 series
(wherein, R represents an alkali metal such as Na, K, etc.), etc.,
can be suitably used.
[0034] The characteristic of the present invention is that by
contacting the paste containing the inorganic compound with the
oxide constituting the layer, the layer is dissolved. To practice
the dissolution of the layer, it is more preferred that the paste
is contacted with only a portion of the surface of the layer to
proceed dissolution of the layer.
[0035] The layer is preferably dissolved by heating in the state
that the paste is contacted with the oxide constituting the layer.
To conduct the dissolution of the layer, it is more preferred to
contact the paste with only a part of the surface of the layer to
proceed the dissolution of the layer by heating.
[0036] The method of selectively contacting the paste with a part
of the layer is, for example, that the paste obtained by mixing the
inorganic compound, an organic solvent, silicon powder, and the
like is coated on a part of the surface of the layer.
[0037] After contacting the paste with a part of the surface of the
layer by the above method, the glass substrate is generally heated
(as the case may be, only the circumference of the paste thus
applied is heated). When the inorganic compound used in the paste
is a solid, the inorganic compound is melted by a heating step.
Before melting the inorganic compound, the paste is usually
fluidized and deposited on the surface of the layer.
[0038] There is no particular limitation on the organic solvent
used. However, a water-soluble organic solvent is preferably used.
Preferred example of the water-soluble organic solvent is a mixture
of one kind of water-soluble resins (such as a modified ethyl
cellulose resin, a modified polyamide resin, or polymers of
n-vinylpyrrolidone) and one kind of water-soluble solvents (such as
oxyethylene glycol ether, propylene glycol, or propylene glycol
ether). The mixing ratio of the resins in the mixture is
appropriately controlled according to the kinds and the amounts of
the inorganic compound, the silicon powder, etc.
[0039] When the inorganic compound is a liquid substance, the
compound can selectively be contacted with the desired portion(s)
of the surface of the layer without need of a heating step.
Further, when the inorganic compound is a liquid substance, it is
possible to previously heat the paste containing the liquid
inorganic compound, directly spray the heated paste, and dissolve
the desired portions of the layer by dropping, etc. In this case,
it is preferred to heat the glass substrate to the same temperature
as the temperature of heating the paste, from the point of
preventing the glass substrate from being broken by heating.
[0040] Considering the heat efficiency in the heating step as
described above, when the inorganic compound is a solid, the
melting point thereof is generally preferably low. For example,
when the glass substrate is a glass plate, it is required that the
melting point of the inorganic compound is lower (when a soda-lime
glass is used as the substrate, 735.degree. C. or lower) than at
least the softening point (the temperature at which the viscosity
is 4.5.times.10.sup.7 poise) of the glass. In addition, when a
glass is used as the inorganic compound, it is required that the
softening point of the glass is lower than the softening point of
the glass constituting the substrate. The softening point of the
inorganic compound or the softening point of a glass is preferably
500.degree. C. or lower, more preferably 350.degree. C. or lower,
and most preferably 200.degree. C. or lower, from the points of
energy saving and the ease of handling.
[0041] There is no particular limitation on the glass substrate
used in this invention, but a glass plate is suitable. There is
also no particular limitation on the glass plate and the plates of
a borosilicate glass, an aluminosilicate glass, and various kinds
of crystallized glasses can be used. Typically the plate of a soda
silicate glass (soda-lime silica glass) is used.
[0042] The oxide layer that can be used is a film which functions
as a heat-reflective film, a heat-absorbing film, a colored film,
an electrically conductive film, etc. The oxide layer may contain,
in addition to the oxide, a nitride, a carbide, a metal, etc., in
the range of not reducing the objects of this invention.
[0043] For example, the heat-reflective film includes a film
comprising the oxide of at least one element of cobalt, nickel,
chromium, iron, titanium, tin, and antimony. More practically,
there are a film comprising titanium oxide as the main constituent,
a film comprising the oxide of a metal including cobalt as the main
constituent, a film comprising the oxides of tin and antimony as
the main constituents, etc. The heat-reflective film may further
appropriately contain silicon, aluminum, zinc, copper, indium,
bismuth, vanadium, manganese, zirconium, etc., in addition of the
above-described element, in order to decrease the reflectance and
finely control the color tone.
[0044] The electrically conductive film includes a film comprising
tin oxide having trace components (one or two or more of chlorine,
fluorine, antimony, etc.) added thereto, and a film consisting
essentially of indium oxide or comprising indium oxide containing
tin, a film comprising zinc oxide having trace components (e.g.,
aluminum).
[0045] The method of forming a layer from an oxide, that can be
used includes a sputtering method, a vacuum vapor deposition
method, a liquid-phase film-forming method, etc., and also includes
a so-called thermal decomposition method, that is, a method of
forming an oxide film on the surface of a substrate by thermally
decomposing a raw material compound on the surface of a
high-temperature glass plate and oxidizing. The thermally
decomposing method that can be used includes a method of coating a
metal compound on the surface of a substrate followed by burning, a
method of sending the vapor of a metal compound onto a substrate
heated to a high temperature (CVD method), and a method of blowing
a solution or a dispersion obtained by dissolving or dispersing a
metal compound in an organic solvent as fine liquid droplets
(splaying method).
[0046] The step of forming the oxide layer is preferably a step of
forming a layer on the surface of a glass ribbon in a floating
production method. A method of continuously forming an oxide layer
on the surface of a glass ribbon by a thermal decomposition method
in a float process is a preferred film-forming method in the
production efficiency because the remaining heat of the glass melt
can be utilized for the formation of the layer. However, a simple
method of patterning by partially removing a layer has not yet been
found. The present invention can be particularly suitably performed
for such film-formation.
[0047] One embodiment of the present invention is explained by
referring to FIG. 1. An oxide layer is formed on the surface of a
glass plate 1 (FIG. 1(a)). A paste 3 obtained by adding an organic
solvent to an inorganic compound is placed on definite portions of
the surface of the layer 12 (FIG. 2(b)). If desired and necessary,
the paste may further be diluted with an organic solvent. Propylene
glycol is preferably used as such organic solvent for dilution. The
glass plate 1 is then heated to fluidize the paste 3 and the
inorganic compound contained therein is contacted to the surface of
the layer in a molten state. The inorganic compound dissolves the
layer, whereby the dissolved portions become the state that the
dissolved components of the layer are intermixed in the inorganic
compound (FIG. 1(c)). Together with the heating step described
above, a bending work is applied to the heated glass plate 1 to
make a definite form. The heated glass plate 1 is quenched to cause
a compression stress on the surface to provide a so-called tempered
glass. Finally, when the substrate is immersed in a liquid or
washed with a liquid, the inorganic compound having intermixed
therein the dissolved components of the layer is dissolved in the
liquid. By this, the layer of the portions is removed, and as a
result, the layers are partially formed on the surface of the
molded and tempered glass 1.
[0048] In the above embodiment, the case that the inorganic
compound is solid at room temperature is described, but when the
inorganic compound is a liquid substance at room temperature, such
as phosphoric acid, etc., the embodiment of this case is also the
same as above except that the inorganic compound is in a liquid
state before the heating step.
[0049] When a glass plate is used as the glass substrate as in the
embodiment of the present invention shown in FIG. 1, tempering
and/or a bending work of the glass plate can be conducted by
utilizing the heating step when dissolving the inorganic compound
and the layer. If melting of the layer and the secondary work of a
glass plate as described above are conducted by the same heating
step, the production method is very advantageous in the production
efficiency. The tempered and bending worked glass plate is useful
as a glass for automobile and, in particular, when only the portion
of the layer necessary for the visibility of a high-mount stop lamp
is removed, the glass becomes useful as a glass for a back window
of automobile (see, FIG. 2). The oxide layer in this case can be a
heat-reflective film.
[0050] The present invention is described in more detail below by
reference to the following example, but it should be understood
that the invention is not construed as being limited thereto.
EXAMPLE
[0051] 12.5 g of dipropionylmethane of trivalent cobalt, 0.62 g of
acetyl acetonate of trivalent iron and 1.83 g of acetyl acetonate
of chromium were dissolved in 100 ml of toluene to prepare a raw
material solution.
[0052] One surface of a glass substrate having a size of
150.times.150.times.3.4 mm was spray coated with the raw material
solution to form an oxide layer. This oxide layer functions as a
heat-reflective layer.
[0053] Phosphoric acid (orthophosphoric acid), an organic solvent
and silicon powder were mixed in a weight ratio of 3:2:5,
respectively, to prepare paste for dissolving an oxide layer. The
oraganic solvent used was composed of propylene glycol as a main
component, 1,2-propanediol, an amide resin and a cellulosic
resin.
[0054] This paste was applied to apart of the surface of the oxide
layer formed on the glass substrate by a screen printing. The glass
substrate was placed in an oven and then heat treated at
260.degree. C.
[0055] After cooling the glass substrate, the paste applied was
removed by jet water washing. As a result, the oxide layer was
completely removed on the portion of the glass substrate to which
the paste was applied. Thus, the heat refractive layer could
partially be formed on the glass substrate.
[0056] The glass substrate thus obtained had a visible light
transmittance (by light source A) of 81% at the oxide layer-removed
portion and 31% at the oxide layer-remaining portion.
[0057] Thus, when a paste is prepared using silicon powder as a
solid powder as in the above Example, applying the paste can well
conducted by screen printing, which is preferable.
[0058] According to the present invention, after forming an oxide
layer on a glass substrate, partial formation of the oxide layer
can efficiently and surely be performed without need of masking
accompanied by a complicated step and a troublesome operation. By
such a partial formation of the oxide layer, functions such as an
electrically conductive property, a heat-reflective property, etc.,
can be simply imparted to the surface of a glass substrate.
* * * * *