Jenaer Glaswerk Gmbh

Schott Glaswerke

Schott-rohrglas Gmbh

Jenaer Glaswerck Gmbh

Eckhart Watzke

Thomas Kloss

Andrea Kampfer

Peter Brix

Franz Ott

Gerhard Kemmler

The invention relates to a borosilicate glass of high chemical resistance and low viscosity which contains zirconium oxide and lithium oxide. The borosilicate glass has hydrolytic resistance (in accordance with DIN ISO 719), class 1 acid resistance (in accordance with DIN 12116), and class 1 alkali resistance (in accordance with DIN ISO 659), and with a low operating temperature V.sub.A of between 1180.degree. C. to 1230.degree. C. and a coefficient of thermal expansion .alpha..sub.20/300 of 4.9.times.10.sup.-6 K.sup.-1. The borosilicate glass has the composition (in % by weight, based on oxide): SiO.sub.2 73-75; B.sub.2 0.sub.3 7-10; Al.sub.2 0.sub.3 5-7; ZrO.sub.2 1-3; Li.sub.2 0 0.5-1.5; Na.sub.2 0 0-10; K.sub.2 0 0-10; MgO 0-3; CaO 0-3; BaO 0-3; SrO 0-3; ZnO 0-3; ratio of SiO.sub.2 /B.sub.2 0.sub.3 .gtoreq.7.5; .SIGMA. SiO.sub.2 +Al.sub.2 0.sub.3 +ZrO.sub.2 80-83 and .SIGMA. MgO+CaO+BaO+SrO+ZnO.ltoreq.3, and fluorides 0-3. The glass is particularly suitable for use as a versatile primary packaging material for pharmaceuticals, for example as ampule glass.

Borosilicate glass of high chemical resistance and low viscosity which

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

The invention relates to gray, bluish, blue to black colored borosilicate glasses which have a stepped transmission grade in the near infrared range or are fully non-transmitting. The borosilicate glass with defined additions of titanium dioxide is melted together with a reduction agent such as Si(metallic). The glasses produced in accordance with the invention are used as filters because of their absorption/transmission characteristic or, if the light transmissibility in the near infrared/infrared ranges is sufficiently low, the glasses can also be used as absorbers in solar technology, as a glass used in areas of the home and/or as decorative colored glass in construction and for decorating.

Reducing melt borosilicate glass having a UV transmittance of at least 85% for ultraviolet radiation having a wavelength of 254 nm for a sample thickness of 1 mm and a water-resistance of less than 100 micrograms, advantageously less than 62 micrograms, Na.sub.2 O per gram of glass powder according to ISO 719 and a thermal expansion coefficient .alpha..sub.20/300 of from 5 to 6.times.10.sup.-6 K.sup.-1 and comprising from 58 to 65% by weight SiO.sub.2, from 18 to 20.5% by weight B.sub.2 O.sub.3, from 8.1 to 10.4% by weight Al.sub.2O.sub.3, from 0 to 1% by weight CaO, from 0 to 2% by weight BaO, from 0 to 2% by weight SrO, from 0 to 1.5% by weight Li.sub.2 O, from 5.5 to 8.5% by weight Na.sub.2 O, from 0 to 3% by weight K.sub.2 O and from 0 to 2% by weight fluorine. The sum total content of all of the alkali metal oxides present in the glass is not greater than 10% and the sum total content of the CaO, BaO and SrO is not greater than 3% and the molar ratio of Al.sub.2 O.sub.3 : Na.sub.2 O is from 0.6 to 1. The glass is particularly suitable for EPROM windows, UV lamps, photomultipliers, spectrophotometers under difficult climatic conditions and protective tubes for UV lamps immersed in water in waste water treatment operations.

Reducing melt borosilicate glass having improved UV transmission

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.

Borosilicate glass weak in boric acid

The borosilicate glass has a UV transmission of at least 80% at a UV wavelength of about 254 nm for a borosilicate glass sheet thickness of 2 mm, a linear coefficient of thermal expansion, .alpha..sub.20/300, of 3.2 to 3.4.times.10.sup.-6 K.sup.-1, a hydrolytic resistance of class 1 and a composition in % by weight based on oxide of

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Jena, Germany

Eckhart Watzke