U.S. patent application number 09/875175 was filed with the patent office on 2001-10-25 for ultraviolet/infrared absorbent glass.
This patent application is currently assigned to NIPPON SHEET GLASS CO., LTD.. Invention is credited to Nakagaki, Shigeki, Sakaguchi, Koichi, Seto, Hiromitsu.
Application Number | 20010034295 09/875175 |
Document ID | / |
Family ID | 26568996 |
Filed Date | 2001-10-25 |
United States Patent
Application |
20010034295 |
Kind Code |
A1 |
Seto, Hiromitsu ; et
al. |
October 25, 2001 |
Ultraviolet/infrared absorbent glass
Abstract
The ultraviolet/infrared transmittance glass consists of base
glass including: 65 to 80 wt. % SiO.sub.2; 0 to 5 wt. %
B.sub.2O.sub.3; 0 to 5 wt. % Al.sub.2O.sub.3; 0 to 10 wt. % MgO; 5
to 15 wt. % CaO; 10 to 18 wt. % Na.sub.2O; 0 to 5 wt. % K.sub.2O; 5
to 15 wt. % total amount of MgO and CaO; and 0 to 20 wt. % total
amount of Na.sub.2O and K.sub.2O, colorants including: equal to or
more than 0.05 wt. % and less than 0.2 wt. % total iron oxide
(T-Fe.sub.2O.sub.3) expressed as Fe.sub.2O.sub.3; 0.63 to 1.4 wt. %
CeO.sub.2; 0.02 to 1.5 wt. % TiO.sub.2; 0.0005 to 0.005 wt. % CoO;
and 0.0003 to 0.002 wt. % Se. FeO expressed as Fe.sub.2O.sub.3 is
between 30 wt. % and 60 wt. % of T-Fe.sub.2O.sub.3.
Inventors: |
Seto, Hiromitsu; (Osaka,
JP) ; Sakaguchi, Koichi; (Osaka, JP) ;
Nakagaki, Shigeki; (Osaka, JP) |
Correspondence
Address: |
KANESAKA AND TAKEUCHI
1423 Powhatan Street
Alexandira
VA
22314
US
|
Assignee: |
NIPPON SHEET GLASS CO.,
LTD.
|
Family ID: |
26568996 |
Appl. No.: |
09/875175 |
Filed: |
June 7, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09875175 |
Jun 7, 2001 |
|
|
|
09409381 |
Sep 30, 1999 |
|
|
|
Current U.S.
Class: |
501/71 |
Current CPC
Class: |
C03C 3/095 20130101;
C03C 4/02 20130101; C03C 4/085 20130101; C03C 4/082 20130101 |
Class at
Publication: |
501/71 |
International
Class: |
C03C 003/087 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 9, 1998 |
JP |
H10-317355 |
Claims
What is claimed is:
1. An ultraviolet/infrared absorbent glass consisting of base glass
comprising: 65 to 80 wt. % SiO.sub.2; 0 to 5 wt. % B.sub.2O.sub.3;
0 to 5 wt. % Al.sub.2O.sub.3; 0 to 10 wt. % MgO; 5 to 15 wt. % CaO;
10 to 18 wt. % Na.sub.2O; 0 to 5 wt. % K.sub.2O; 5 to 15 wt. %
total amount of MgO and CaO; and 10 to 20 wt. % total amount of
Na.sub.2O and K.sub.2O, colorants comprising: equal to or more than
0.05 wt. % and less than 0.2 wt. % total iron oxide
(T-Fe.sub.2O.sub.3) expressed as Fe.sub.2O.sub.3; 0.63 to 1.4 wt. %
CeO.sub.2; 0.02 to 1.5 wt. % TiO.sub.2; 0.0005 to 0.005 wt. % CoO;
and 0.0003 to 0.002 wt. % Se, FeO expressed as Fe.sub.2O.sub.3
being between 30 wt. % and 60 wt. % of T-Fe.sub.2O.sub.3.
2. An ultraviolet/infrared absorbent glass as claimed in claim 1,
wherein the glass at any thickness in a range of 2.6 to 6.3 mm has
the visible light transmittance of equal to or more than 65% when
measured by using the CIE illuminant A, the solar energy
transmittance of equal to or less than 65%, and the ultraviolet
transmittance specified by ISO of equal to or less than 20%.
3. An ultraviolet/infrared absorbent glass as claimed in claim 1 or
2, wherein the glass at any thickness in a range of 2.6 to 6.3 mm
has a bronze color shade having the excitation purity of equal to
or less than 10% when measured by using the CIE illuminant C, and
the chromaticity expressed as a* and b* by using the L*a*b*
coordinates in ranges of -2.ltoreq.a*.ltoreq.=1 and
4.ltoreq.b*.ltoreq.=10.
4. An ultraviolet/infrared absorbent glass as claimed in claim 1 or
2, wherein the glass at any thickness in a range of 2.6 to 6.3 mm
has a gray color shade having the excitation purity of equal to or
less than 5% when measured by using the CIE illuminant C, and the
chromaticity expressed as a* and b* by using the L*a*b* coordinates
in ranges of -2.ltoreq.a*.ltoreq.1 and -1.ltoreq.b*.ltoreq.4.
5. An ultraviolet/infrared absorbent glass as claimed in any of
claims 1 to 4, wherein the glass further comprises NiO in a range
of 0.001 to 0.01 wt. %.
6. An ultraviolet/infrared absorbent glass as claimed in any of
claims 1 to 5, wherein the glass further comprises La.sub.2O.sub.3
in a range of 0.01 to 1 wt. %.
7. An ultraviolet/infrared absorbent glass as claimed in any of
claims 1 to 6, wherein the glass comprises Al.sub.2O.sub.3 in a
range of 0.1 to 2 wt. %.
8. An ultraviolet/infrared absorbent glass as claimed in any of
claims 1 to 7, wherein the glass further comprises at least one
selected from a group consisting of ZnO, MnO, V.sub.2O.sub.5,
MoO.sub.3 and SnO in a range of 0 to 1 wt. %.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This is a continuation-in-part application of patent
application Ser. No. 09/409,381 filed on Sep. 30, 1999.
FIELD OF THE INVENTION
[0002] The present invention relates to an ultraviolet/infrared
absorbent glass having a bronze or gray color shade.
BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT
[0003] Recently, a variety of glasses with ultraviolet/infrared
absorptivity to be used as a vehicle window glass including a
windshield have been proposed with a view of preventing degradation
of luxurious interior materials and reducing cooling load of the
vehicle.
[0004] For example, glasses having a green color shade and being
improved in the infrared absorptivity and the ultraviolet
absorptivity due to including a relatively large amount of
Fe.sub.2O.sub.3 have been developed as a window glass of a
vehicle.
[0005] A glass having a bronze, brown or gray color shade includes
a smaller amount of Fe.sub.2O.sub.3 than that of the glass having a
green color shade and employs ultraviolet absorbing agents
including CeO.sub.2, TiO.sub.2 and V.sub.2O.sub.5 so as to be
provided with the ultraviolet absorptivity. For example, a heat
rays absorbent glass having a bronze color shade disclosed in the
Japanese Patent H6-40741A consists of a base glass including 68 to
74 wt. % SiO.sub.2, 0.1 to 3.0 wt. % Al.sub.2O.sub.3, 2 to 4.5 wt.
% MgO, 8 to 11 wt. % CaO, 11.5 to 16 wt. % Na.sub.2O, 0.5 to 3.0
wt. % K.sub.2O, 0.1 to 0.4 wt. % SO.sub.3, 68 to 74 wt. % total
amount of SiO.sub.2 and Al.sub.2O.sub.3, 11 to 15 wt. % total
amount of CaO and MgO and 12 to 17 wt. % total amount of Na.sub.2O
and K.sub.2O, and colorants including 0.13 to 0.55 wt. % total iron
oxide (T-Fe.sub.2O.sub.3) expressed as Fe.sub.2O.sub.3, 0.2 to 0.6
wt. % CeO.sub.2, 0.15 to 0.45 wt. % TiO.sub.2, 0.3 to 14 ppm CoO
and 5 to 20 ppm Se, in which the reduction rate of the glass
(Fe.sup.2+/Fe.sup.3+) is between 17% and 55%.
[0006] A colored ultraviolet absorbent glass disclosed in the
Japanese Patent H6-345482A is a glass having a brown color shade
consisting of 65 to 75 wt. % SiO.sub.2, 0.1 to 5 wt. %
Al.sub.2O.sub.3, 1 to 6 wt. % MgO, 5 to 15 wt. % CaO, 10 to 18 wt.
% Na.sub.2O, 0 to 5 wt. % K.sub.2O, 0.05 to 1.0 wt. % SO.sub.3, 0.2
to 1.5 wt. % CeO.sub.2, 0 to 1.0 wt. % TiO.sub.2, 0 to 0.0015 wt. %
CoO, 0.0002 to 0.0012 wt. % Se and 0.2 to 0.4 wt. %
Fe.sub.2O.sub.3, in which Fe.sup.2+ is in a range of 3 to 15 wt. %
among the total amount of Fe.
[0007] A colored ultraviolet absorbent glass disclosed in the
Japanese Patent H6-345483A consists of 65 to 75 wt. % SiO.sub.2,
0.1 to 5 wt. % Al.sub.2O.sub.3, 1 to 6 wt. % MgO, 5 to 15 wt. %
CaO, 10 to 18 wt. % Na.sub.2O, 0 to 5 wt. % K.sub.2O, 0.05 to 1.0
wt. % SO.sub.3, 0.4 to 1.0 wt. % CeO.sub.2, 0 to 1.0 wt. %
TiO.sub.2, 0.0018 to 0.0030 wt. % CoO, 0.0001 to 0.0010 wt. % Se
and 0.1 to 0.3 wt. % Fe.sub.2O.sub.3, in which Fe.sup.2+ is in a
range of 3 to 20 wt. % among the total amount of Fe.
[0008] A gray glass composition disclosed in the Japanese Patent
H8-48540A consists of 66 to 75 wt. % SiO.sub.2, 0 to 5 wt. %
Al.sub.2O.sub.3, 0 to 5 wt. % MgO, 5 to 15 wt. % CaO, 10 to 20 wt.
% Na.sub.2O, 0 to 5 wt. % K.sub.2O, 0.0003 to 0.0050 wt. % CoO,
0.0001 to 0.0015 wt. % Se, 0.30 to 0.70 wt. % Fe.sub.2O.sub.3
(total iron), not more than 0.21 wt. % FeO and less than 2.0 wt. %
of CeO.sub.2, V.sub.2O.sub.5, TiO.sub.2 and MoO.sub.3 to be
provided with a dull gray color shade.
[0009] An ultraviolet/infrared absorbent glass disclosed in the
Japanese Patent H6-92678A consists of 65 to 80 wt. % SiO.sub.2, 0
to 5 wt. % Al.sub.2O.sub.3, 0 to 5 wt. % B.sub.2O.sub.3, 0 to 10
wt. % MgO, 5 to 15 wt. % CaO, 10 to 18 wt. % Na.sub.2O, 0 to 5 wt.
% K.sub.2O, 5 to 15 wt. % total amount of MgO and CaO, 10 to 20 wt.
% total amount of Na.sub.2O and K.sub.2O, 0.3 to 2 wt. % cerium
oxide expressed as CeO.sub.2, 0 to 1 wt. % TiO.sub.2, 0.1 to 0.8
wt. % T-Fe.sub.2O.sub.3, 0 to 0.006 wt. % CoO, 0 to 0.01 wt. % NiO
and 0 to 0.0015 wt. % Se.
[0010] The conventional ultraviolet/infrared absorbent glasses as
referred above are provided with the ultraviolet absorptivity due
to a sole action and/or an interaction of one or more than two from
among Fe.sub.2O.sub.3, CeO.sub.2, TiO.sub.2 and the like, and with
the heat rays absorptivity due to FeO added in the form of
Fe.sub.2O.sub.3 and reduced therefrom. However, it is difficult to
provide a bronze or gray color shade developed due to Se and a high
ultraviolet and infrared absorptivity for the same glass
simultaneously.
[0011] For example, the glass having a bronze color shade disclosed
in the Japanese Patent H6-40741A requires relatively large contents
of Fe.sub.2O.sub.3 and TiO.sub.2 in order to provide the
ultraviolet absorptivity because of its relatively small content of
CeO.sub.2. In this case, the glass is reduced in the visible light
transmittance and the shade is tinged with yellow to become tar
tint. It is also difficult to maintain the pink color developed by
Se and to provide the bronze or gray color shade in the sights of
the present invention for the glass because Se is easy to develop
dark brown when the glass includes a large amount of
T-Fe.sub.2O.sub.3.
[0012] Each of the glasses having a bronze or gray color shade
disclosed in the Japanese Patent H6-345482A, H6-345483A and
H8-48540A has a disadvantage that indeed the glass has the
ultraviolet absorptivity, but is reduced in the infrared
absorptivity because the glasses include a small content of FeO in
contrast with its large content of T-Fe.sub.2O.sub.3.
[0013] Examples 1 through 18 of the ultraviolet/infrared glass
disclosed in the Japanese Patent H6-92678 include a small content
of T-Fe.sub.2O.sub.3. These examples except for the example 13 are
disadvantageously reduced in the infrared absorptivity and
increased in the solar energy transmittance (TG). The example 13 is
provided with TG of equal to or less than 65%, while the glass
includes 1.46 wt. % CeO.sub.2 in order to be balanced against the
visible light transmittance and the ultraviolet transmittance
thereof. CeO.sub.2 is not preferable to be used in large amounts
because of its expensive cost.
OBJECT AND SUMMARY OF THE INVENTION
[0014] It is an object of the present invention to solve
conventional problems described above and provide an
ultraviolet/infrared absorbent glass having a bronze or gray color
shade which is provided with a high ultraviolet and infrared
absorptivity.
[0015] The ultraviolet/infrared absorbent glass of the present
invention consists of a base glass comprising:
[0016] 65 to 80 wt. % SiO.sub.2;
[0017] 0 to 5 wt. % B.sub.2O.sub.3;
[0018] 0 to 5 wt. % Al.sub.2O.sub.3;
[0019] 0 to 1 wt. %MgO;
[0020] 0 to 5 wt. % K.sub.2O;
[0021] 5 to 15 wt. % total amount of MgO and CaO; and
[0022] 10 to 20 wt. % total amount of Na.sub.2O and K.sub.2O,
colorants including:
[0023] equal to or more than 0.05 wt. % and less than 0.2 wt. %
total iron oxide (T-Fe.sub.2O.sub.3) expressed as
Fe.sub.2O.sub.3;
[0024] 0.63 to 1.4 wt. % CeO.sub.2;
[0025] 0.02 to 1.5 wt. % TiO.sub.2;
[0026] 0.0005 to 0.005 wt. % CoO; and
[0027] 0.0003 to 0.002 wt. % Se.
[0028] In the glass of the present invention FeO expressed as
Fe.sub.2O.sub.3 is between 30 wt. % and 60 wt. % of
T-Fe.sub.2O.sub.3.
[0029] The ultraviolet/infrared absorbent glass may further
comprise 0.001 to 0.01 wt. % NiO so as to adjust its color of the
shade.
[0030] The ultraviolet/infrared absorbent glass is preferable to
include 0.01 to 1 wt. % La.sub.2O.sub.3.
[0031] The ultraviolet/infrared absorbent glass at any thickness
between 2.6 mm and 6.3 mm is preferable to be provided with the
visible light transmittance of equal to or more than 65% when
measured by using the CIE illuminant A, the solar energy
transmittance of equal to or less than 65% when measured over a
wavelength between 300 nm and 2100 nm and the ultraviolet
transmittance specified by ISO of equal to or less than 20%.
[0032] The ultraviolet/infrared absorbent glass at any thickness
between 2.6 mm and 6.3 mm is preferable to be provided with the
excitation purity of equal to or less than 10% when measured by
using the CIE illuminant C and a bronze color shade having the
chromaticity expressed as a* and b* defined by the L*a*b*
coordinates in ranges of -2>a*.ltoreq.1 and
4.ltoreq.b*.ltoreq.10.
[0033] The ultraviolet/infrared absorbent glass at any thickness
between 2.6 mm and 6.3 mm is preferable to be provided with the
excitation purity of equal to or less than 5% when measured by
using the CIE illuminant C and a gray color shade having the
chromaticity expressed as a* and b* defined by the L*a*b*
coordinates in ranges of -2.ltoreq.a*.ltoreq.1 and
-1.ltoreq.b*.ltoreq.4.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0034] The description will be made as regard to the
ultraviolet/infrared absorbent glass composition of the present
invention. It should be noted that components will be represented
with percentage by weight. The composition is based on that of a
glass which is suitable for being molded in the floating
process.
[0035] SiO.sub.2 (silica) is a principal component for forming
skeleton of glass. Less than 65% SiO.sub.2 lowers the durability of
the glass and more than 80% SiO.sub.2 raises the melting
temperature of the glass so high.
[0036] B.sub.2O.sub.3 is a component for improving the durability
of the glass, prompting to melt, and yet enhancing the ultraviolet
absorption. B.sub.2O.sub.3 should be less than 5%, since reduction
of the transmittance in the ultraviolet range extends even to the
visible range to tinge the glass with yellow and difficulties
during forming are caused due to the vaporization of B.sub.2O.sub.3
when B.sub.2O.sub.3 exceeds 5%.
[0037] Al.sub.2O.sub.3 is a component for improving the durability
of the glass. More than 5% Al.sub.2O.sub.3 raises the melting
temperature of the glass so high. Al.sub.2O.sub.3 is preferable to
be included equal to or less than 5%, particularly in a range of
0.1 to 2%.
[0038] MgO and CaO improve the durability of the glass and adjust a
liquidus temperature and viscosity of the glass during molding.
More than 10% MgO raises the liquidus temperature. Less than 5% or
more than 15% CaO raises the liquidus temperature of the glass. The
durability of the glass is lowered when the total amount of MgO and
CaO is less than 5%, while the liquidus temperature is increased
when the total exceeds 15%.
[0039] Na.sub.2O and K.sub.2O prompt the glass to melt. The
efficiency of promotion of melting becomes poor when Na.sub.2O is
less than 10% or the total of Na.sub.2O and K.sub.2O is less than
10%, while the durability of the glass is lowered when Na.sub.2O
exceeds 18% or the total of Na.sub.2O and K.sub.2O exceeds 20%.
K.sub.2O also prompts Se to develop its pink color and improve the
ultraviolet absorptivity at the same time. K.sub.2O is preferable
not to exceed 5% because K.sub.2O is expensive as compared to
Na.sub.2O.
[0040] Iron oxide is present in the form of Fe.sub.2O.sub.3
(Fe.sup.3+) and the form of FeO (Fe.sup.2+) in the glass.
Fe.sub.2O.sub.3 is a component for improving the ultraviolet
absorptivity and FeO is a component for improving the heat rays
absorptivity just as CeO.sub.2 and TiO.sub.2.
[0041] When the amount of T-Fe.sub.2O.sub.3 is too small, the glass
is reduced in the infrared absorptivity and ultraviolet
absorptivity, while, when the content of T-Fe.sub.2O.sub.3 is too
large, the glass is reduced in the visible light transmittance and
it is difficult to obtain the desired shade because the color
development of Se becomes to be tinged with dark brown. Therefore,
T-Fe.sub.2O.sub.3 is preferable to be contained in an amount of
equal to or more than 0.05% and less than 0.2%.
[0042] When the amount of FeO is too small, the glass is reduced in
the infrared absorptivity, while, when the content of FeO is too
large, the glass is reduced in the visible light transmittance.
Therefore, a ratio of FeO expressed as Fe.sub.2O.sub.3 to
T-Fe.sub.2O.sub.3 is preferable to be in a range of 30 to 60%.
[0043] The present invention aims to improve the infrared
absorption of the glass while maintaining the visible light
transmittance thereof at a high degree depending on a large content
of FeO in contrast with a small content of T-Fe.sub.2O.sub.3.
Therefore, the glass of the present invention includes
T-Fe.sub.2O.sub.3 and FeO in ranges applying to this aim.
[0044] CeO.sub.2 is an essential component of the present invention
for improving the ultraviolet absorptivity and is present in the
form of Ce.sup.3+ or in the form of Ce.sup.4+ in the glass.
Particularly, Ce.sup.3+ is effective in absorbing ultraviolet with
less absorptivity in the visible range. When CeO.sub.2 is contained
too much, the visible rays having a short wavelength are
excessively absorbed to ting the glass with yellow. Since the
cerium oxide which is the raw material of CeO.sub.2 is expensive
and acts as an oxidizing agent, it is difficult to maintain the
ratio of FeO to T-Fe.sub.2O.sub.3 at a high rate when the glass
including a large amount of CeO.sub.2. Therefore, the content of
CeO.sub.2 is between 0.63% and 1.4%.
[0045] TiO.sub.2 is a component for improving the ultraviolet
absorptivity particularly by interaction with FeO. Too much
TiO.sub.2 tinges the glass with yellow. TiO.sub.2 is preferable to
be included in a range of 0.02 to 1.5%.
[0046] CoO is a component for forming a bronze or gray color shade
by cooperating with Se. Less than 0.0005% CoO can not form a
desired color shade, while more than 0.005% CoO reduces the visible
light transmittance.
[0047] Se contributes a pink color, so that it forms the bronze or
gray color shade with the aid of a complementary color of CoO. Less
than 0.0003% Se can not form a desired color shade, while more than
0.002% Se reduces the visible light transmittance.
[0048] SO.sub.3 is supplied into the glass from the sulfate or the
like which prompts the glass to be refined. The bronze or gray
color shade can not be obtained because the color development of Se
is weakened when SO.sub.3 is more than 0.30%.
[0049] Although NiO brings the bronze or gray color shade, the
content of NiO is not more than 0.01% because the glass is reduced
in the visible light transmittance when NiO is contained too
much.
[0050] La.sub.2O.sub.3 decreases viscosity of the molten glass,
prompts the glass to be melted and improves the chemical durability
including water- resistance of the glass. When La.sub.2O.sub.3 is
added into a glass including Fe.sub.2O.sub.3 and CeO.sub.2,
La.sub.2O.sub.3 also reduces the ultraviolet transmittance. The
content of La.sub.2O.sub.3 is preferable to be not more than 1%
because of its expensive cost. Although La.sub.2O.sub.3 may added
in the form of a raw material including La.sub.2O.sub.3 at a high
rate, such a raw material requires to be refined and increases the
cost. In order to save costs of raw materials, La.sub.2O.sub.3 is
preferable to be added in the form of a mixture with CeO.sub.2
yielded together with La.sub.2O.sub.3. La.sub.2O.sub.3 may be added
also in the form of an impurity left in CeO.sub.2 refined at a low
degree. In this case, traces of oxidized rare earth elements
including Pr.sub.2O.sub.3, Nd.sub.2O.sub.3 and the like may be
added into the glass, but the glass may comprise them in such a
range as not to lose effects of the present invention.
[0051] One or more than two among ZnO, MnO, V.sub.2O.sub.5,
MoO.sub.3, SnO may be added within a rang from 0 to 1% in total or
within such a range as not to lose effects of the present
invention.
[0052] ZnO can prevent from forming the nickel sulfide which is
easy to appear during melting the glass in a reducing atmosphere
and contributes explosion of the glass itself.
[0053] Each of MnO, V.sub.2O.sub.5 and MoO.sub.3 acts as a
component for absorbing the ultraviolet and for fine adjustment of
the bronze or gray color shade depending on its degree of
ultraviolet absorptivity in the glass. While, SnO acts as a
reducing agent or a refining agent.
[0054] Hereinafter, the present invention will be described
referring to examples.
[0055] Glass raw material comprising silica sand, dolomite,
limestone, soda ash, potassium carbonate, boron oxide, ferric
oxide, titanium oxide, cerium oxide, cobalt oxide, metallic
selenium, nickel oxide, lanthanum oxide and the carbonaceous
reducing agent (graphite etc.) are mixed in such a manner to obtain
a desired composition. Then, the raw material is heated and melted
in an electric furnace at 1500.degree. C. After 4 hours' melting,
the molten glass is flowed onto a stainless plate and annealed to
the room temperature to obtain glass plates having a thickness of
about 7 mm. Each of the glass plates is polished in order to reduce
the thickness thereof to 3.5 mm, 4 mm or 5 mm to become a sample.
After that, the sample is measured in the optical properties
including the visible light transmittance (YA) measured by using
the CIE illuminant A, the solar energy transmittance (TG), the
ultraviolet transmittance (Tuv) specified by ISO, L*, a* and b*
specified by CIE and measured by using the CIE illuminant C, the
dominant wavelength (.lambda. d), and the excitation purity
(Pe).
[0056] Compositions and optical properties of each Example are
shown in Table 1. The compositions are represented with percent or
ppm by weight and the ratio of FeO expressed as Fe.sub.2O.sub.3 to
T-Fe.sub.2O.sub.3 is also represented with weight percent.
1TABLE 1 Example 1 2 3 4 5 glass SiO.sub.2 70.6 70.6 70.6 71.1 71.1
composition Al.sub.2O.sub.3 1.6 1.6 1.6 1.6 1.6 [wt. %] MgO 3.3 3.3
3.3 3.3 3.3 CaO 8.5 8.5 8.6 8.6 8.6 Na.sub.2O 13.5 13.5 13.7 13.7
13.7 K.sub.2O 0.8 0.8 0.8 0.8 0.8 T-Fe.sub.2O.sub.3 0.19 0.15 0.19
0.18 0.18 FeO 0.079 0.071 0.081 0.080 0.056
FeO/T-Fe.sub.2O.sub.3(%) 41.6 47.3 42.6 44.4 31.1 CeO.sub.2 0.65
0.65 0.65 0.65 0.65 TiO.sub.2 0.90 0.90 0.55 0.10 0.03 Se(ppm) 10
12 14 12 10 CoO(ppm) 25 30 50 31 25 NiO(ppm) 50 optical thickness
of 3.5 3.5 3.5 3.5 4.9 property the glass(mm) YA(%) 71.8 71.7 66.7
72.7 68.7 TG(%) 61.1 62.0 60.9 61.1 61.9 Tuv(%) 14.8 17.5 17.6 20.0
15.4 L* 87.24 87.24 84.82 88.06 85.39 a* -1.19 -1.00 -0.51 0.07
0.14 b* 4.52 3.28 1.16 3.45 6.86 .lambda.d(nm) 573.0 572.5 570.3
577.6 577.7 Pe(%) 4.55 3.27 1.15 3.64 7.45
[0057] Table 1 shows that Examples 1 through 5 are within the
scopeof claim 1. Every glass of the Examples consists of:
[0058] equal to or more than 0.05 wt. % and less than 0.2 wt. %
total iron oxide (T-Fe.sub.2O.sub.3) expressed as
Fe.sub.2O.sub.3;
[0059] 0.63 to 1.4 wt. % CeO.sub.2;
[0060] 0.02 to 1.5 wt. % TiO.sub.2;
[0061] 0.0005 to 0.005 wt. % CoO; and
[0062] 0.0003 to 0.002 wt. % Se,
[0063] wherein FeO expressed as Fe.sub.2O.sub.3 is between 30% and
60% of T-Fe.sub.2O.sub.3.
[0064] Every glass of the Examples is also in the scope of claim 2
and has the high visible light transmittance and the superior
ultraviolet and infrared absorptivity.
[0065] Among the Examples, the glasses of Examples 1, 5 are
provided with the bronze color shade having the excitation purity
of 10% or less when measured by using the CIE illuminant C and the
chromaticity expressed as a* and b* by using the CIE color
coordinates in ranges of -2.ltoreq.a*.ltoreq.1 and
4.ltoreq.b*.ltoreq.10.
[0066] The glasses of Examples 2, 3, 4 are provided with the gray
color shade having the excitation purity of 5% or less when
measured by using the CIE illuminant C and the chromaticity
expressed as a* and b* by using the CIE color coordinates in ranges
of -2.ltoreq.a*.ltoreq.1 and -1.ltoreq.b*.ltoreq.4.
[0067] Example 5 employs NiO as a component for controlling the
color of the shade.
[0068] In Table 2, characteristics of Comparative Examples of the
present invention are shown.
2TABLE 2 Comparative Example 1 2 3 glass SiO.sub.2 72.00 71.0 71.0
composition B.sub.2O.sub.3 0.00 0.0 0.0 [wt. %] Al.sub.2O.sub.3
1.72 1.6 1.6 MgO 3.88 3.3 3.3 CaO 7.60 8.6 8.6 Na.sub.2O 12.80 13.7
13.7 K.sub.2O 0.68 0.8 0.8 T-Fe.sub.2O.sub.3 0.25 0.45 0.29 FeO
0.019 0.038 0.160 FeO/T-Fe.sub.2O.sub.3(%) 7.5 9.4 61.3 Se(ppm) 5
11 12 CoO(ppm) 15 20 12 CeO.sub.2 0.80 1.70 0.65 TiO.sub.2 0.40
0.12 0.03 optical thickness of 5.0 3.5 5.0 property the glass(mm)
YA(%) 74.5 73.5 61.8 TG(%) 70.9 69.2 45.2 L* 84.30 88.26 80.72 a*
-0.93 0.12 -1.55 b* 4.01 6.77 4.96 .lambda.d 578.3 577.6 573.1
Pe(%) 5.01 7.10 6.81 Tuv(ISO)(%) 11.1 9.7 17.7
[0069] Comparative Example 1 consists of the same composition as
the Japanese Patent H6-345482A as referred above. Comparative
Example 1 has the low ratio of FeO to T-Fe.sub.2O.sub.3, the value
of which is out of the scope of the present invention and the solar
energy transmittance of more than 65%. Comparative Example 2 has
T-Fe.sub.2O.sub.3, CeO.sub.2 and the ratio of FeO to
T-Fe.sub.2O.sub.3, every value of which is out of the scope of the
present invention and also the solar energy transmittance of more
than 65%. Comparative Example 3 has the high ratio of FeO to
T-Fe.sub.2O.sub.3, the value of which is out of the scope of the
present invention and the visible light transmittance of less than
65%. Any glasses of the Comparative Examples can not combine the
bronze or gray color shade, the high visible light transmittance,
the low solar energy transmittance and the low ultraviolet
transmittance simultaneously.
[0070] Aforementioned Examples and Comparative Examples show that
the glass of the present invention is obviously a superior
ultraviolet and infrared absorbent glass combining the bronze or
gray color shade, the low ultraviolet transmittance and the low
solar energy transmittance simultaneously.
[0071] As detailed above, according to the present invention, an
ultraviolet/infrared absorbent glass combining the bronze or gray
color shade, the low ultraviolet transmittance and the low solar
energy transmittance can be provided due to color development of Se
and CoO in parallel and also due to containing T-Fe.sub.2O.sub.3 in
the content of more than 0.05 wt. % and less than 0.2 wt. % and FeO
of 30 to 60 wt. % of T-Fe.sub.2O.sub.3 so as to improve the
infrared absorptivity while maintaining the visible light
transmittance at a high rate, CeO.sub.2 of 0.63 to 1.4 wt. % to
perform the melting process in a reducing atmosphere, TiO.sub.2 of
0.02 to 1.5 wt. % to compensate for the ultraviolet
absorptivity.
[0072] The ultraviolet/infrared absorbent glass of the present
invention is excellent in preventing degradation and discoloration
of interior materials when the glass is used for a window glass of
a vehicle, a building or the like.
* * * * *