Patent ID: 6132672
Filing Date: 2000-10-17
Classification: C04B

Abstract:
Process for obtaining ceramic articles coloured, on the surface and below the surface for at least 1.6 mm, in colours ranging, after firing, from yellow to orange, said process comprising adding to a ceramic mass before moulding from 0.5% to 10% by weight of TiO.sub.2 based on the dry material and treating the moulded articles in a process according to the following operative steps:a) drying at 100.degree. C. the molded article to be coloured to a maximum water residue of 0.5% by weight;b) treating the article coming from the preceding step with an aqueous solution of an organic or inorganic Cr compound and an organic or inorganic compound of an element selected from Sb or Zn or Zr or Mn or their mixtures, said solution containing compounds of the above elements in such concentrations that when applied to the ceramic surface in an amount of 30 to 600 g/m.sup.2 secures the application of metal elements based on the total weight of elements present as follows:a) 0.1 to 30 g/m.sup.2 of Cr and 1 to 90 g/m.sup.2 of Sb, orb) 0.05 to 20 g/m.sup.2 of Cr and 1 to 60 g/m.sup.2 of Zn, orc) 0.05 to 20 g/m.sup.2 of Cr and 1 to 60 g/m.sup.2 of Zr, ord) 0.05 to 20 g/m.sup.2 of Cr and 1 to 40 g/m.sup.2 of Mnc) equalization of the article coming from the preceding step, at room temperature for a period of 8 hours;d) subsequent firing according to a ceramic cycle.