Degussa Aktiengesellschaft

Glaswerk Schuller Gmbh

Werner Voelker

Bernd Dorbath

Kai Dorer

Karl A Starz

Wilan Jerke

Norbert Giesecke

Josef Hammer

Paul F Hahmann

New electromagnetic interference (EMI) shielding pigments based on silver coated carrier pigments are disclosed which have a wider activity spectrum and are more economically available than previously known shielding pigments. The carrier pigments used are platelet shaped, ferro- or ferrimagnetic, Fe-containing, naturally occurring or synthetically produced laminar minerals. The Ag coating amounts to 5 to 25% by weight, based on the carrier pigment. Shielding pigments, which may be prepared by conventional chemical deposition of Ag or by sputtering, may be used for the production of EMI protective coatings and EMI protective films.

EMI shielding pigments, a process for their preparation and their use

Purple pigments based on glass frits having an average particle diameter (D.sub.50 value) of 0.5 to 50 .mu.m, of which the surface has a coating of essentially 0.05 to 5% by weight, based on the pigment, of colloidal gold and, if desired, color-modifying metals from the group consisting of Ag, Cu, Co, Ni, Sn, Ru, Rh, Pd, Os, Ir and Pt in a total quantity below that of the gold. The purple pigments do not require the hitherto necessary calcination step and can be used for pigmenting glazes, enamels, glass colors, decorative colors, plastics, printing inks and lacquers.

Purple pigments, a process for their production and use thereof

The process involves coating on both sides of an endless track of a base material consisting of inorganic fibers, preferably a glass fiber fleece, with aqueous ceramic slips, and drying of the coating. The base material with a weight per unit area of 30-200 g/m.sup.2 is coated with a slip, at least 500 g/m.sup.2, preferably 1000-2000 g/m.sup.2, without the use of an additional support, preferably on one side with a paste and on the other side with a glaze slip. The slips contain 3-20% by weight organic binders that decompose uniformly and without residue between 250.degree. and 600.degree. C. The dried, unfired veneers in free suspension may be coiled and uncoiled and subjected to continual decoration and firing processes.

Method of producing a coilable ceramic veneer in unfired condition

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Bad Vilbel, Germany

Werner Voelker