| 摘要 |
<p>1,217,660. Treating glass; ion exchange. GLAVERBEL. 22 Dec., 1967 [24 April, 1967], No. 39583/70. Divided out of 1,215,722. Heading C1M. Glass or vitrocrystalline articles have compressive surface stresses set up by contacting the articles with a medium containing atoms of cadmium or zinc in addition to ions of cadmium or zinc to cause cadmium or zinc ions to diffuse into the surface layers of the article. The article may be a soda-line glass of composition by weight 77% SiO 2 , 5% Na 2 O, 7À7% K 2 O, 10À3% CaO. In one example, an article of such glass is immersed in a bath of molten cadmium chloride at a temperature of 610‹ C. This is below but near to the annealing temperature of the glass. Metallic cadmium is added to the bath. Some colouring of the glass results. In an alternative example zinc is used in place of cadmium.</p> |
