| 摘要 |
1. Glass frit required for producing a transparent ceramic surface layer, characterized in that it is obtained from a mixture containing at least two separate glass frits, namely : - approximately 90 % by weight of a first glass frit which is fusible and does not devitrify, and - approximately 10 % by weight of a second glass frit which is more refractory and devitrifies partially to leucite, the said mixture having a maximum particle size of less than 65 mu m and corresponding to the following overall composition : SiO2 59 to 59,5 % by weight Al2 O3 15 to 16 % by weight CaO 0,5 to 1, 5 % by weight MgO 0 to 0,2 % by weight K2 O 11 to 13 % by weight Na2 O 7 to 8 % by weight B2 O3 2,5 to 3,5 % by weight BaO 0 to 3 % by weight CaF2 0,5 to 3 % by weight TiO2 0,2 to 0,5 % by weight the said mixture forming part of the composition of a ready-for-use paste containing an appropriate quantity of a plasticizing agent and capable of being packaged in a tube or a paste dispenser of the aerosol type. |
