Heat-radiation reflective glass

Details Heat-radiation reflective glass Heat-radiation reflective glass

1999-07-15

2001-09-18

Jones, Deborah (Department: 1775)

Stock material or miscellaneous articles

Composite

Of quartz or glass

C428S426000, C428S432000

Reexamination Certificate

active

06291074

ABSTRACT:

TECHNICAL FIELD
This invention relates to a heat-radiation reflective glass for cars and vehicles or buildings.
BACKGROUND ART
In recent years, heat-radiation reflective glass having a small visible light transmittance is used in glass for cars and vehicles or buildings so that they can be air-conditioned at a lower load and the hotness due to direct sunlight can be reduced. Such heat-radiation reflective glass having a small visible light transmittance is worth using also from the viewpoint of the protection of privacy. Heat-radiation reflective glass that can meet such needs is conventionally obtained by a method of forming a film on the glass surface by vacuum deposition or sputtering of a highly conductive material such as titanium nitride or silver. A method is also available in which an oxide film containing cobalt, iron, chromium or nickel is formed on a glass plate by thermal decomposition.
Of the above film forming methods, however, the method of forming a film by vacuum deposition or sputtering of a highly conductive material such as titanium nitride or silver has the problem of a high production cost. As for the method in which an oxide film is formed on a glass plate by thermal decomposition, the method can be simply operated and can enjoy a low production cost, but has the problem that, depending on the composition of oxide film, the glass with a film formed may cause a great change in transmittance, a deterioration of chemical resistance of the film or a clouding of the film, when subjected to tempering.
DISCLOSURE OF INVENTION
The present invention was made in order to solve these problems. Accordingly, an object of the present invention is to provide a heat-radiation reflective glass that may hardly cause a change in film properties such as transmittance even when subjected to tempering, and can be produced at a low cost.
According to a first embodiment of the present invention, the heat-radiation reflective glass comprises a glass plate and a film formed on the glass plate;
the film having composition comprising cobalt, chromium and iron in weight percentages within the ranges shown below, based on the total metal weight per unit area; and having a layer thickness of from 10 nm to 70 nm.
Cobalt, from 65% to 96%;
chromium, from 2% to 25%; and
iron, from 2% to 33%.
Cobalt may preferably be in a content not more than 90% by weight. Iron or chromium may also preferably be contained in weight percentages that fulfill at least one of the following conditions (1) to (3).
(1): Iron, 10% or less;
(2): chromium, 8% or less; and
(3): chromium, 18% or more.
According to a second embodiment of the present invention, the heat-radiation reflective glass comprises a glass plate and a film formed on the glass plate;
the film having composition comprising cobalt, chromium and iron in weight percentages within the ranges shown as condition (4) below, based on the total metal weight per unit area, in its part on the side coming into contact with the glass plate, and in weight percentages within the ranges that fulfill at least one of conditions (5) and (6) shown below, based on the total metal weight per unit area, in its part on the outermost side; and having a layer thickness of from 10 nm to 70 nm.
(4): Cobalt, from 65% to 96%;
chromium, from 2% to 25%; and
iron, from 2% to 33%.
(5): Cobalt, from 2% to 96%;
chromium, from 2% to 8% or from 18% to 96%; and
iron, from 2% to 96%.
(6): Cobalt, from 2% to 96%;
chromium, from 2% to 96%; and
iron, from 2% to 10%.
In the above condition (4), cobalt may preferably be in a content not more than 90% by weight. The film may have a double layer construction comprised of the part that is on the side coming into contact with the glass plate and the part that is on the outermost side, the latter being superimposed formed on the former.
In the heat-radiation reflective glass according to the first or second embodiment of the present invention, the film properties such as transmittance are very little affected even when the glass is subjected to tempering with heating at a temperature not lower than the distortion point of the glass plate used and not higher than the softening point thereof.


REFERENCES:
patent: 4217392 (1980-08-01), Vong
patent: 4294881 (1981-10-01), Meyer et al.
Ruzakowski Athey P et al.: “Determining the optical properties of a mixed-metal oxide file, Co3-x-yCrxFeyO4, with spectroscopic ellipsometry and atomic force microscopy”43rd National Symposium of the American Vacuum Society, Philadelphia, PA, USA, Oct. 14-18, 1996, vol. 15, No. 3, Pt. 1, ISSN 0734-2101, Journal of Vacuum Science & Technology May/Jun. 1997 pp. 998-1006.
Greenberg C.B., “Enabling Thin Films for Solar Control Transparencies: A Review” Journal of the Electrochemical Society, vol. 140, No. 11, Nov. 1993, pp. 3332-3337, XP000424507.
Database WPI, Section Ch, Week 9723, Derwent Publications Ltd., London, GB; Class L01, AN 97-255259 XP002041756 & JP 09 086 966 A, Mar. 31, 1997.
Database WPI, Section Ch, Week 9715, Derwent Publications Ltd., London, GB; Class L01, AN 97-161296 XP002041757 & JP 09 030 837 A, Feb. 4, 1997.

Affiliated with

Also associated with

Rating

Heat-radiation reflective glass does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Heat-radiation reflective glass, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Heat-radiation reflective glass will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2540056