Flat float glass
AssigneeSchott Glas
InventorsFriedrich Siebers, Peter Nass, Gerhard Lautenschläger, Otmar Becker
Life of this patent
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Abstract
This invention relates to a flat float glass that can be prestressed or transformed into a glass ceramic with high quartz mixed crystals or keatite mixed crystals. To eliminate undesirable surface defects during floating and to achieve superior characteristics of the glass or of he glass ceramic, in particular with regard to a low coefficient of thermal expansion and high light transmittance, the glass has a concentration of less than 300 ppb Pt, less than 30 ppb Rh, less than 1.5 wt. % ZnO and less than 1 wt. % SnO2, and is refined during melting without the use of the conventional fining agents arsenic oxide and/or antimony oxide.
Claims20
A flat float glass comprising:
- platinum, rhodium, zinc oxide, and tin dioxide, wherein:
- the concentration of said platinum is contained in a non-zero amount less than 300 parts per billion;
- the concentration of said rhodium is contained in a non-zero amount less than 30 parts per billion;
- the concentration of said zinc oxide is contained in a non-zero amount less than 1.5 weight percent;
- the concentration of said tin dioxide is contained in a non-zero amount less than 1 weight percent;
- said concentrations of said platinum, said rhodium, said zinc oxide, and said tin dioxide configuring said flat float glass to have minimized surface defects;
- and
- said flat float glass being configured to be one of:
- prestressable into a glass-ceramic comprising one of:
- high quartz mixed crystals;
- and
- keatite mixed crystals;
- and
- transformable into a glass-ceramic comprising one of:
- high quartz mixed crystals;
- and
- keatite mixed crystals.
A glass ceramic comprising:
- platinum, rhodium, zinc oxide, and tin dioxide, wherein:
- the concentration of said platinum is contained in a non-zero amount less than 300 parts per billion;
- the concentration of said rhodium is contained in a non-zero amount less than 30 parts per billion;
- the concentration of said zinc oxide is contained in a non-zero amount less than 1.5 weight percent;
- the concentration of said tin dioxide is contained in a non-zero amount less than 1 weight percent;
- and
- said glass ceramic comprising one of:
- high quartz mixed crystals;
- and
- keatite mixed crystals.
A float glass comprising:
- platinum, wherein the concentration of said platinum is contained in a non-zero amount less than 300 parts per billion;
- a concentration of rhodium in a non-zero amount less than 30 parts per billion;
- a concentration of zinc oxide in a non-zero amount less than 1.5 weight percent;
- a concentration of tin dioxide in a non-zero amount less than 1 weight percent;
- said concentrations of said platinum, rhodium, zinc oxide, and tin dioxide configuring said float glass to have minimized surface defects;
- and
- said float glass being configured to be one of:
- prestressable into a glass-ceramic comprising one of:
- high quartz mixed crystals;
- and
- keatite mixed crystals;
- and
- transformable into a glass-ceramic comprising one of:
- high quartz mixed crystals;
- and
- keatite mixed crystals.
A flat glass ceramic comprising:
- platinum, wherein the concentration of said platinum is contained in a non-zero amount less than 300 parts per billion;
- a concentration of rhodium in a non-zero amount less than 30 parts per billion;
- a concentration of zinc oxide in a non-zero amount less than 1.5 weight percent;
- a concentration of tin dioxide in a non-zero amount less than 1 weight percent;
- and
- said flat glass ceramic comprising one
- high quartz mixed crystals;
- and
- keatite mixed crystals.
Dependencies are inferred from the claim text.