Schott Glaswerke

Schott Ag

Johann Daimer

Hartmut Paschke

Jose Zimmer

Danuta Grabowski

Marc Clement

Joern Besinger

Matthias Rindt

Susanne Kessler

Martin Zöttl

Karine Seneschal-Merz

Richard Haring

An element composed of glass displaying reduced electrostatic charging is provided. The element is suitable as a housing component for electronic elements, an element implantable in the human or animal body including glass tubes for reed switches or transponders and/or implants. The glass includes at least one alkali metal and/or an alkali metal oxide and has a surface. The concentration of at least one alkali metal and/or the alkali metal oxide increases from the surface in a direction of an interior of the element in such a way that a maximum concentration of the alkali metal and/or the alkali metal oxide occurs at a distance of not more than 60 nanometres, measured perpendicularly from the surface.

Element composed of glass displaying reduced electrostatic charging

A glass powder or a glass-ceramic powder is provided that includes multicomponent glasses with at least three elements, where the glass powder or a glass-ceramic powder has a mean particle size of less than 1 &#x3bc;m. In some embodiments, the mean particle size is less than 0.1 &#x3bc;m, while in other embodiments the mean particle size is less than 10 nm.

Nano glass powder and use thereof, in particular multicomponent glass powder with a mean particle size of less than 1 &#x3bc;m

Disclosed is a barium-free glass of good x-ray absorption, which has a composition (in wt.-% on the oxide basis) of SiO.sub.2 50-75; ZrO.sub.2 5-30; Li.sub.2 O 0-5; Na.sub.2 O 0-25; K.sub.2 O 0-25; .SIGMA. alkali oxides 0-25. Preferred is a dental glass of the composition of SiO.sub.2 55-70; ZrO.sub.2 10-25; Li.sub.2 O 0-15; Na.sub.2 O 10-25; K.sub.2 O 0-15; .SIGMA. alkaloids 15-25. The glass can furthermore contain also up to 3 wt.-% of fluorine, up to 5 wt.-% of MgO, up to 5 wt.-% of TiO.sub.2, and in each case up to 10 wt.-% of the oxides Al.sub.2 O.sub.3, GeO.sub.2, P.sub.2 O.sub.5, La.sub.2 O.sub.3, Y.sub.2 O.sub.3, Ta.sub.2 O.sub.3, Gd.sub.2 O.sub.3, ZnO and Nb.sub.2 O.sub.5. The glass finds its use in powder form with an average particle size of .ltoreq.10 .mu.m as filler for dental composites for filling teeth.

Barium-free dental glass having good x-ray absorption

For the preparation of high purity glass powder having a mean particle size of .ltoreq.10 .mu.m, glass powder having a larger particle size up to 300 .mu.m is ground to the desired particle size in a stirred mill with glass grinding elements in the presence of a grinding liquid comprising water or preferably a mixture of at least 50% by weight of water and at least one water-soluble, oxygen-containing organic compound having 1 to 5 carbon atoms in the molecule, e.g., tert.-butyl alcohol; the ground slurry is then frozen, and the solvent is subsequently removed from the frozen slurry by freeze-drying. A resultant glass powder with a mean particle size d.sub.50 of 0.5 to 2 .mu.m is particularly suitable as a filler for synthetic resins in the dental sector.

Preparation of very fine glass powder of high purity

A glass sealant comprises a mixture of about 70-90% of a solder glass powder of a low-melting lead-borate glass with a transformation temperature of 330.degree. C. or lower, 1-20% by weight of cordierite powder, and 1-25% by weight of mullite powder, with the combined content of cordierite and mullite powder being from about 10-30%. The lead-borate glass comprises from about 82-88% by weight of PbO, 12-17% by weight of B.sub.2 O.sub.3, 0-1% by weight of SiO.sub.2, and 0-1% by weight of Al.sub.2 O.sub.3. Both the cordierite and mullite powder are preferably synthetically produced to reduce the .alpha.-radiation. The synthetically produced cordierite powder preferably still contains up to about 9% by weight of a non-crystalline vitreous phase. The grain size of the powders is preferably under 100 microns. This glass sealant has well-balanced properties relative to thermal expansion, melting temperature, dielectric constant, loss angle, mechanical strength, thermal shock resistance, and chemical resistance. It is particularly suitable as ceramic dual-line package solder (CERDIP) for sealing of aluminum oxide housings for integrated circuits.

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Oberahrain, Germany

Johann Daimer