Patent EP-2740717-A2 (EP)
Inventor: NAHAS NABIL
IPC: C04B35/626
Filed: 2011-12-22
Abstract: Particulate mixture comprises: a chemical composition of >= 10 wt.% of zirconium oxide, greater than 2 wt.% to = 80 wt.% of aluminum oxide, 2-20 wt.% of oxides comprising yttrium oxide, scandium oxide, magnesium oxide, calcium oxide and/or cerium oxide, 0-18 wt.% of oxides comprising zinc oxide and/or lanthanide oxides except cerium oxide, and less than 12 wt.% of other oxides; and 0.5-10 wt.% of a pigment made of a material comprising oxide(s) of perovskite structure, oxides of spinel structure, oxides of hematite, oxides of rutile structure and/or orthosilicates. Particulate mixture comprises: a chemical composition of >= 10 wt.% of zirconium oxide, greater than 2 wt.% to = 80 wt.% of aluminum oxide, 2-20 wt.% of oxides comprising yttrium oxide, scandium oxide, magnesium oxide, calcium oxide and/or cerium oxide, where the sum of magnesium oxide and calcium oxide is less than 5 wt.%, 0-18 wt.% of oxides comprising zinc oxide and/or lanthanide oxides except cerium oxide, and less than 12 wt.% of other oxides, in which oxides from the group one and/or two and/or alumina are optionally wholly or partially replaced by equivalent amount of precursors of these oxides; and 0.5-10 wt.% of a pigment made of a material comprising oxide(s) of perovskite structure (optionally wholly or partially replaced by an equivalent amount of precursors of these oxides), oxides of spinel structure, oxides of hematite structure of formula (E 2O 3), oxides of rutile structure of formula (F1O 2) and/or orthosilicates comprising the group formed by orthosilicates of zirconium and praseodymium ((Zr,Pr)SiO 4), orthosilicates of zirconium and vanadium ((Zr,V)SiO 4), and/or orthosilicates of zirconium in which iron oxide is found as an inclusion. E : group one element formed by the mixtures of aluminum and chromium, and/or the mixtures of aluminum and manganese; and F1 : group one element formed by the mixtures of tin and vanadium, the mixtures of titanium and chromium and niobium, the mixtures of titanium and chromium and tungsten, the mixtures of titanium and niobium and manganese, and/or the mixtures of tin and chromium. Independent claims are included for: (1) preparing colored sintered part comprising mixing raw materials to form a feedstock comprising the particulate mixture, forming a preform, or greenware from the feedstock, sintering the preform at 1200-1500[deg] C to obtain a sintered part, where the feedstock is determined based on a desired color for the sintered part; (2) sintered part comprising the particulate mixture; (3) article such as jewelry, watches, bracelet, necklace, ring, brooch, scarf pin, handbag, telephone, furniture and household object, handle, button, plating, visible part of an equipment of consumer goods, spectacle frame, crockery, frame, comprising the sintered part; (4) manufacturing a decorative article comprising preparing a support, preparing a sintered part to desired color, optionally verifying color of the sintered part, preferably by measuring one, preferably all the parameters of L*, a* and b*, fixing, rigidly or removable part on the sintered part to constitute a decorative article, and optionally packaging the decorative article; and (5) assembly comprising the particulate mixture having a composition for producing a sintered part by sintering, and a note providing one or more of the following information, where the particulate mixture is intended for the fabrication of decorative sintered parts, description of a process to transform the particulate mixture into ceramic part, description of a process for polishing the ceramic part, and description of a process for verifying the color of the ceramic part.