Procedimiento de fabricación de fritas para azulejos antiguos

N. de publicación: ES2357521 T3

The subject of the present invention is manufacturing alkaline lead frits containing tin dioxide (SnO 2 ), having low lead solubility and representing antique tile glazes. According to the invention, this frit may be produced easily by mixing alkaline components, lead oxide, tin dioxide and a silica source, melting materials together and it is poured directly into cold water to make it easily grinding. The recipe of the produced frit is; 0-5 % dolomite, 20-25 % sodium bicarbonate, 0-3 % potassium carbonate, 5-7 % colourless glass cullet, 25-30 % red lead, 1-5 % tin dioxide and 30-40 % silica source. CoO is added to the mixture to provide a light bluish appearance to transparent, colourless and glassy properties of frit. The homogenous mixture is melted at 1000-1250 DEG C for 3,5 h.; The thermal expansion coefficient of the frits is in the range of 10-15×10 -6 / DEG C at 20-500 DEG C, Tg point (glass transition temperature) and Tm point (melting point) are in the range of 450-465 DEG C and 550-565 DEG C respectively. Lead solubility values of these frits and glazes prepared by using these frits are as 0,2 mg/dm 2 . Vickers micro hardness values of produced frits are between 4,9-5,9 GPa. Tin dioxide (SnO 2 ) containing frit can be used in glazes, which are compatible with antique like tile glazes (Iznik tiles) and compose 90 to 99 % by weight of the glaze mixture. The optimal firing temperature and dwell time for the glaze prepared from this frit is 900-960 DEG C and 0-45 min. Tin dioxide (SnO 2 ) containing lead alkaline frit can be used in manufacturing of antique like tiles and glazes of lead safe solubility values.

Si desea obtener más información sobre este contenido contacte con nuestro Centro de Documentación

Regístrate para leer más