Jenaer Glaswerk Gmbh

Jenaer Glaswerck Gmbh

Gerhard Kemmler

Thomas Kloss

Eckhart Watzke

Andrea Kampfer

The invention relates to brownish, brown to black colored borosilicate glasses which have stepped grades of transmission in the NIR range or are fully non-transmitting. The borosilicate glass, primarily the borosilicate glass 3.3, is melted with defined additives of titanium carbide and/or metallic silicon. The glasses produced in accordance with the invention are to be used as filters, glass vessels and/or decorative colored glass in construction and for decorating because of their absorption/transmission characteristics. On the other hand, the glasses produced in accordance with the invention can also be used as absorbers in solar technology when the light transmissibility in the NIR/IR range is sufficiently low.

Colored borosilicate glass

Borosilicate glass weak in boric acid having a high chemical stability with an alkali resistance according to DIN 52 322 of LBK-Class 1, a thermal expansion .alpha..sub.20/300 between 4.0 to 5.3.times.10.sup.-6 K.sup.-1, a ratio .alpha.'/.alpha. of thermal expansion coefficients above T.sub.g (.alpha.') to below T.sub.g (.alpha.) of 4 to 8, a glass transformation temperature between 500.degree. C. and 600.degree. C., high radiation transmittance and a UV transmission .tau..sub.250 nm/1 mm of 0 to 70% or .tau..sub.300 nm/1 mm of 0 to 91% of the composition in percent by weight on oxide basis of: SiO.sub.2 &gt;75; B.sub.2 O.sub.3 1 to &lt;9; Al.sub.2 O.sub.3 3 to 6; Li.sub.2 O 0 to 4; Na.sub.2 O 0 to 8; K.sub.2 O 0 to 6; MgO 0 to 3; CaO 0 to 3; BaO 0 to 2; SrO 0 to 2; ZnO 0 to 3; ZrO.sub.2 0 to 3; SnO.sub.2 0 to 3; SnO 0 to 3; TiO.sub.2 0 to 2; CeO.sub.2 0 to 2; Fe.sub.2 O.sub.3 0 to 1; with SiO.sub.2 +B.sub.2 O.sub.3 &gt;83; SiO.sub.2 :B.sub.2 O.sub.3 &gt;8; SiO.sub.2 +Al.sub.2 O.sub.3 +ZrO.sub.2 &gt;83; Li.sub.2 O+Na.sub.2 O+K.sub.2 O 5 to 10; MgO+CaO+BaO+SrO+ZnO&gt;3.

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Jena, Germany

Gerhard Kemmler