초록 ▼

A method for producing decorations which are color-stable in a porcelain firing (glost firing), and a pigment composition suitable for this method, is disclosed. Inclusion pigments based on heavy-metal sulfides and selenides in an oxidic or silicate casing, especially ZrSiO4, result in more color-st

A method for producing decorations which are color-stable in a porcelain firing (glost firing), and a pigment composition suitable for this method, is disclosed. Inclusion pigments based on heavy-metal sulfides and selenides in an oxidic or silicate casing, especially ZrSiO4, result in more color-stable decorations in a porcelain firing if color-stabilizing auxiliary agents from the series of Zn compounds, especially ZnO or zinc-containing glass frits, or cerium(III) or cerium(IV) compounds, especially CeO2, are used in the decorative layer and/or glaze layer as color-stabilizing auxiliary agents. The amount used in the decorative layer is generally 5 to 50% by weight in the case of ZnO and CeO2, relative to the inclusion pigment. The pigment composition contains at least one of the color-stabilizing auxiliary agents in addition to an inclusion pigment.

대표청구항 ▼

A method for the production of a decoration on a porcelain surface which decoration is essentially color-stable in a porcelain firing, said method comprising the steps of (a) applying a decorative layer onto said porcelain surface which is unfired or pre-fired in a biscuit firing and (b) applying a

A method for the production of a decoration on a porcelain surface which decoration is essentially color-stable in a porcelain firing, said method comprising the steps of (a) applying a decorative layer onto said porcelain surface which is unfired or pre-fired in a biscuit firing and (b) applying a layer of glaze onto said porcelain and (c) firing said porcelain at a temperature in a range of 1300°to 1500°C., wherein said decorative layer contains a pigment composition containing a inclusion pigment selected from the group consisting of crystals of colored heavy-metal sulfides, selenides and sulfoselenides enclosed in a transparent oxidic or silicate casing and at least one color-stabilizing auxiliary agent being present in said decorative layer or present in said layer of glaze or being present in both of said decorative layer and said layer of glaze, wherein said agent is selected from the group consisting of cerium(III) compounds, cerium (IV) compounds, zinc oxide and zinc compounds forming zinc ions during the porcelain firing, and said agent is present in an amount of at least 2% by weight calculated as ZnO or Ce2O3 or CeO2 and relative to the amount of inorganic solids in the decorative layer or layer of glaze. A pigment composition for the production of a decoration which is essentially color-stable in a porcelain firing, comprising an inclusion pigment based on crystals enclosed in a transparent oxidic or silicate casing and containing a colored heavy-metal sulfide, selenide or sulfoselenide or mixture thereof and at least one color-stabilizing auxiliary agent selected from the group consisting of cerium(III) compounds and cerium (IV) compounds, said agent being present in an amount of at least 2% by weight calculated as Ce2O3 or CeO2 and relative to the amount of said inclusion pigments.