| 摘要 |
To colour a sheet of glass obtained by flowing on a bath of molten tin or tin alloy, that surface with which the glass has been in contact is coated with a reducible salt of a monovalent metal and the coated glass heated to a temperature of 600 DEG to 700 DEG C. Preferably an aqueous solution of the salt is used and the water evaporated before the heat treatment which lasts for several minutes. The solution may be sprayed on to the surface of the glass either when it is cold or already at the required temperature. After cooling the sheet may be washed. The colour extends into the surface to give a definite thickness of colour and the intensity of colour may be varied either by varying the concentration of the solution or by repeated applications. The salts used are copper sulphate, 2 to 10% by weight for cold application, 10 to 20% to hot glass to give colours ranging from pink to ruby red and silver nitrate, 0.05 to 0.15% by weight for cold application, 2 to 3% to hot glass to give colours ranging from pale yellow to brownish yellow.
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