Degussa Aktiengesellschaft

Ferro Corporation

Juergen Hanich

Dietrich Speer

Peter K Kleinschmit

George E Sakoske

Akos Kiss

Enos Ayres Axtell, Iii

Andreas Schulz

Martin Baumann

Lothar Heck

Jenny Horst

Guenter Halbritter

Enos A Iii Axtell

This invention relates to lead free and cadmium free copper-containing glass frits that can be used as pigments to color other glass frits or to impart color to solid substrates such as glass, ceramic or metals, or to impart color to a thermoplastic mass. The compositions comprise silica, alkali metal oxides, alkaline earth metal oxides, tin oxide and copper oxide. The resulting compositions can be used to decorate and protect automotive, beverage, architectural, pharmaceutical and other glass substrates, generally imparting a red color.

Copper red frits and pigments comprising silica and at least one of cupric oxide and cuprous oxide

This invention relates to lead free and cadmium free copper-containing glass fits that can be used as pigments to color other glass fits or to impart color to solid substrates such as glass, ceramic or metals, or to impart color to a thermoplastic mass. The compositions comprise silica, alkali metal oxides, alkaline earth metal oxides, tin oxide and copper oxide. The resulting compositions can be used to decorate and protect automotive, beverage, architectural, pharmaceutical and other glass substrates, generally imparting a red color.

The grayish-black encapsulated pigments contain carbon black particles with specific surface areas of 10 to 1000 m.sup.2 /g (BET) encapsulated in colorless crystals of zirconium silicate. In order to produce the pigments, mixtures of zirconium oxide with a particle size distribution (D50 values) between 7 and 10 .mu.m and a spec. surface between 2 and 4 m.sup.2 /g, silicon oxide, carbon black and mineralizers are heated under reducing conditions to 900.degree. to 1400.degree. C. and calcined for 0.5 to 8 hours and recalcined under oxidizing conditions to remove the non-included carbon black. The encapsulated pigments of the invention are suitable for the pigmented coloration of glazes.

Grayish-black encapsulated pigments and method of their production

Encapsulation pigments comprising chromophoric particles embedded in glaze-stable casings are prepared by means of calcination from the appropriate initial products. High yields and strong color intensities are obtained if the chromophoric substance or its initial compounds are bound in and/or to a zeolite and are calcined in this form with the remaining constituents.

Methods of preparing encapsulated pigments

Growing community of inventors

Königstein, Germany

Juergen Hanich