| abstract |
A slip containing a frit and an oxidizing catalyst is sprayed over a substrate and fused at a temperature as low as 550 DEG C. The frit consists of 15-60% by weight of SiO2, 9-35% of B2O3, 10-30% Na2O, 1-25% of Al2O3, 0-20% of Li2O, 0-10% of K2O and 0-10% of CaO but must have at least two of Li2O, K2O and CaO. The oxidizing catalyst is MnOx or CuCO3 Cu(OH)2 or a mixture thereof, the content being preferably between 5 and 50% by weight. The self-cleaning is effected at a temperature as low as at 280 DEG C. |