Glass plate and its production process
AssigneeAsahi Glass Company, Limited
InventorsYusuke Arai, Tomoyuki Kobayashi, Yuki Kondo
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Abstract
To provide an inexpensive glass plate on the surface of which elution of Na+ is suppressed, and its production process. A glass plate comprising soda lime silica glass containing at least elements of Si, Al, Ca and Na, wherein when the Na amount at a depth of 2,000 nm from at least one surface of the glass plate is 100%, the Na amount at a depth of 20 nm from the above surface is at most 45%, the Na amount at a depth of 40 nm from the above surface is at most 70%, and the Na amount at a depth of 60 nm from the above surface is at most 80%.
Claims4
A glass plate comprising soda lime silica glass containing at least elements of Si, Al, Ca and Na, wherein when the Na amount at a depth of 2,000 nm from at least one surface of the glass plate is 100%, the Na amount at a depth of 20 nm from the above surface is at most 45%, the Na amount at a depth of 40 nm from the above surface is at most 70%, and the Na amount at a depth of 60 nm from the above surface is at most 80%.
A process for producing a glass plate comprising soda lime silica glass containing at least elements of Si, Al, Ca and Na, which comprises forming molten glass into a glass plate, and when the glass plate is cooled, bringing a SO2 gas or a SO3 gas on at least one surface of the glass plate having a surface temperature of from the glass transition temperature of the glass plate +50° C. to the glass transition temperature of the glass plate −150° C., to obtain a glass plate wherein when the Na amount at a depth of 2,000 nm from the above surface after cooling is 100%, the Na amount at a depth of 20 nm from the above surface is at most 45%, the Na amount at a depth of 40 nm from the above surface is at most 70%, and the Na amount at a depth of 60 nm from the above surface is at most 80%.
Dependencies are inferred from the claim text.