Abstract: Alkali silicate glasses are described which, in view of their good chemical stability and their optical properties and processing properties, are particularly suitable as a coating or veneering material for ceramic dental frameworks and hence for the production of all-ceramic dental restorations such as crowns or bridges.

Abstract: The invention relates to a barium-free, X-ray-opaque dental glass, to a dental glass/polymer composite comprising the glass, and to the use thereof as dental filling, where the dental glass has the following composition (in % by weight): SiO2 20-45, Al2O3 5-35, B2O3 1-10, Na2O 1-10, K2O 0-8, Cs2O 0-8, sum all alkali metal oxides 1-15, CaO 0-8, SrO 0-27, ZnO 2-20, ZrO2 2-10, P2O5 0-10, La2O3 0-10, F 2-20, the total content of B2O3, ZnO, ZrO2 and La2O3 is >20% by weight, and the refractive index nd of the dental glass is in the range from 1.47 to 1.70.

Abstract: Zinc-containing optical glass materials with a refractive index nd between 1.52 and 1.66, an Abbe number &ngr;d of between 35 54 and a composition (in % by weight based on oxide) of: SiO2 38-58, ZnO 0.3-42, PbO 0-<30, ZnO+PbO 20-55, Li2O 0-<3, Na2O 0-14, K2O 0-12, Li2O+Na2O+K2O≧2, F 0-3, MgO 0-6, CaO 0-<5, SrO 0-6, BaO 0-<0.9, B2O3 0-<1, Al2O3 0-<1.5 and ZrO2 0-<2 and, if appropriate, refining agents in the customary amounts.

Abstract: The object of the present invention is brown solar glasses, absorbing UV or IR radiation, as well as solar ophthalmic lenses in said glasses. Said glasses have the following composition, expressed in percentages by weight: SiO2: 64-71; B2O3: 2-8; Al2O3: 0-4; ZrO2: 0-2; Li2O: 0-4; Na2O: 6-10; K2O: 7-16; CaO: 0-5.5; ZnO: 0-5.5; TiO2; 0-2; Fe2O3: 3-9; Co3O4: 0-0.030; NiO: 0-0.2; SeO2: 0.0030-0.1; As2O3: 0-0.1; Sb2O3: 0-0.1; SnO2: 0-0.1; Cl: 0-2; Br: 0-2; F: 0-2.

Abstract: A dielectric layer for use in a magneto-optic storage medium contains a compound glass of SiO2—MO2, SiO2—M2O3, or SiO2—M2O5 and combinations thereof where M is selected from Zr, Ti, Al, Nb, Y, Sn, In, Ta and Sb.

Abstract: Porcelain compositions of the present invention comprises particulate of one or more glass or glass-ceramic powder components. Additionally, one or more opacifing agents, pigments, fluorescing agents and the like may be included in the composition. Based on volume percent, the particulate has a d10 of from about 1.1 and about 1.8 microns; a d50 of from about 3 to about 6 microns; a d90 of from about 8 to about 16 microns; and about 1.0 to about 4.0% by volume of the particulate has a particle size greater than or equal to about 20 microns. The mean particle size is preferably in the range of about 3.0 microns to about 7.5 microns.

Abstract: An apatite glass ceramic is described which is characterized by good chemical stability, a low expansion coefficient and high translucence, and is particularly suitable, by itself or together with glasses or other glass ceramics, as a veneering material for ceramic dental restorations.

Abstract: A glass composition comprising, in mole percent of the total composition: glass-forming compounds in a total amount of 75 to 85%, wherein said glass forming compounds comprise 40 to 65% SiO2, 10 to 20% Bi2O3 and 0.1 to 3% Al2O3, and glass modifiers in a total amount of 15 to 25%, wherein said glass modifiers comprise 1 to 23 % ZnO, 0.1 to 5% CuO, 0.1 to 5 CaO and 0.1 to 2% MgO, thick film formulations containing said composition and uses thereof.

Abstract: A dental porcelain composition, comprising a glassy matrix and leucite crystallites embedded therein, and having maturing temperatures in the range from about 600.degree. C. to about 885.degree. C. and CTEs in the range from about 11 to about 19, more preferably in the range from about 11.5 to about 18, and most preferably in the range from about 12 to about 17.5.times.10.sup.-6 /.degree.C. (measured from 25.degree. C. to 500.degree. C.). The tetragonal leucite is preferably both fine-grained (i.e, having average diameters of less than about 7 microns) and uniformly-sized. Preferably, the average diameters are less than about 1 to about 3 microns.

Abstract: Alkali silicate glasses are described which, in view of their good chemical stability and their optical properties and processing properties, are particularly suitable as a coating or veneering material for ceramic dental frameworks and hence for the production of all-ceramic dental restorations such as crowns or bridges.

Abstract: Glass compositions displaying decreased far infrared radiation transmission, high biosolubility, and excellent moisture resistance are capable of fiberization by the rotary process, and may be used to prepare thermal insulation products exhibiting high thermal insulation efficiency as reflected by low thermal index values. The insulation products also exhibit excellent stiffness and recovery properties.

Abstract: A dental porcelain composition, comprising a glassy matrix and rubidium leucite crystallites embedded therein, and having maturing temperatures in the range from about 650.degree. C. to about 800.degree. C. and CTEs in the range from about 13 to about 17, more preferably in the range from about 13.5 to about 16, and most preferably in the range from about 14 to about 16.times.10.sup.-6 /.degree. C. (measured from 25.degree. C. to 400.degree. C.). The tetragonal rubidium leucite is preferably both fine-grained (i.e., having average diameters of less than about 5 microns) and uniformly sized. Preferably, the average diameters are less than about 1 to about 2 microns.

Abstract: Porcelain compositions of the present invention possess non-greening properties and comprise one or more glass or glass-ceramic components. Additionally, an oxygen release agent is included in the compositions. The porcelain compositions may vary depending upon the specific thermal properties desired.The application temperature of the porcelain compositions ranges from about 600.degree. C. to about 930.degree. C. depending upon the method of application of the porcelain. The coefficient of thermal expansion is preferably in the range of about 11.times.10.sup.-6 /.degree. C. to about 16.times.10.sup.-6 /.degree. C. The porcelain is compatible with cores and/or substrates having coefficients of thermal expansion in the range of about 11 to about 20.times.10.sup.-6 /.degree. C.

Abstract: The invention relates to a glass ceramic in which mica and ZrO.sub.2 are present in crystallized form, containing:K.sub.2 O: 0-9% by weightNa.sub.2 O: 0-9% by weight with the condition that Na.sub.2 O and K.sub.2 O together make up at least about 4% by weight,SiO.sub.2 : 35-60% by weightMgO: 10-25% by weightAl.sub.2 O.sub.3 : 7-30% by weightZrO2: 4-12% by weightF.sup.- : 2-10% by weight which is essentially free of lithium, calcium, strontium and barium, to a process for its production and to its use as a tooth replacement.

Abstract: The invention relates to brown glasses which absorb ultraviolet radiation that are used in the production of ophthalmic sun glasses, and that have the following composition, expressed in wt. %:______________________________________ SiO.sub.2 59-78 Al.sub.2 O.sub.3 2-6 B.sub.2 O.sub.3 0-3 Na.sub.2 O 7-16 K.sub.2 O 2-9 CaO 0-7 BaO 0-12 ZnO 0-12 ZrO.sub.2 0-6 TiO.sub.2 0-6 MnO.sub.2 0.25-6 V.sub.2 O.sub.5 1-3 Fe.sub.2 O.sub.3 0-1.5 NiO 0-0.5 CoO 0-0.1 Sb.sub.2 O.sub.3 0-0.7 As.sub.2 O.sub.3 0-0.7 F 0.05-1.0 With MnO.sub.2 + Fe.sub.2 O.sub.3 + V.sub.2 O.sub.5 >1.5 Al.sub.2 O.sub.3 + SiO.sub.2 .gtoreq.65.

Abstract: A photochromic glass lens and method of producing such lens, the lens having a plus power and a composition consisting essentially of:______________________________________ SiO.sub.2 54-58% Ag 0.20-0.33% B.sub.2 O.sub.3 18-22% Cl 0.30-0.50% Al.sub.2 O.sub.3 7-8% Br 0.04-0.14% Li.sub.2 O 3.75-4.5% CuO 0.007-0.012% Na.sub.2 O 0-1% PbO 0-0.08% TiO.sub.2 0-2% Sb.sub.2 O.sub.3 0-0.20% ZrO.sub.2 2-4.5% K.sub.2 O 5.5-7.5% ______________________________________and wherein the mole ratio of Li.sub.2 O:Na.sub.2 O is =>9:1.

Abstract: Porcelain compositions of the present invention comprise one or more glass or glass-ceramic powder components. Additionally, one or more opacifying agents, pigments, fluorescing agents and the like may be included in the composition. Based on volume percent, 10% of the particulate in the porcelain has a particle size of less than between about 1.1 microns and about 1.5 microns, 50% of the particulate in the porcelain has a particle size of less than between about 3 and about 6 microns, 90% of the particulate in the porcelain has a particle size of less than between about 8 and about 13.5 microns, and the maximum particle size of the particulate is greater than about 20 microns and less than about 60 microns. The mean particle size is preferably in the range of about 3.0 microns to about 6.5 microns.

Abstract: The present invention provides a porcelain enamel coating composition for use in forming a coating composition upon a metal substrate having an infrared reflectivity of at least 50% at 2.5 .mu.-microns measured with a Perkin Elmer Lambda 19 UV/VIS/NIR spectrometer with a labsphere RSA-PE 19 reflectance spectroscopy accessory. The coating composition comprises a glass component and a separate and distinct addition of cerium oxide. Preferably, the coating composition comprises from about 0.20% to about 3.0% by weight of the cerium oxide.

Abstract: A transparent class ceramic composition includes an oxide component, a rare earth component, a halide component, and a substantially pure rare earth-halide (e.g., REF.sub.3) crystal component. A method for making a transparent oxyfluoride glass includes preparing an oxyfluoride glass containing rare earth ions by a conventional melting method and subjecting the glass to a heat treatment thereby precipitating fluoride fine crystals containing a large amount of rare earth ions.

Abstract: The invention relates to glasses which absorb UV radiation and which have the following composition, in wt. %: SiO.sub.2 30-52; ZnO 0-8; B.sub.2 O.sub.3 12-22; PbO 0-2; ZrO.sub.2 5-14; Y.sub.2 O.sub.3 0-15; Al.sub.2 O.sub.3 0-12; La.sub.2 O.sub.3 5-25; Li.sub.2 O 1.5-3.5; TiO.sub.2 0-2; Na.sub.2 O 0-6; HfO.sub.2 0-2; K.sub.2 O 2-9; Nb.sub.2 O.sub.5 0-2; MgO 0-5; Ta.sub.2 O.sub.5 0-2; CaO 0-5; MoO.sub.3 0-2; SrO 0-9; WO.sub.3 0-2; BaO 0-14; SnO 0-4; Sb.sub.2 O.sub.3 0-4; SnO.sub.2 0-4; AS.sub.2 O.sub.3 0-4; CdO 0-1; CuO 0.15-1; F 0-2; Cl 0-3; Br 0-3; I 0-2 with the following conditions: Li.sub.2 O+Na.sub.2 O+K.sub.2 O (X.sub.2 O) 7-14; MgO+CaO+SrO+BaO (XO) 12-20; ZrO.sub.2 +Al.sub.2 O.sub.3 <15; F+Cl+Br+I 0.2-4.0; TiO.sub.2 +PbO+Nb.sub.2 O.sub.5 .ltoreq.2; AS.sub.2 O.sub.3 +Sb.sub.2 O.sub.3 +SnO.sub.2 +SnO 0.05-4.0 and a ratio R=(M.sub.2 O+2MO-Al.sub.2 O.sub.3 -ZrO.sub.2)/B.sub.2 O.sub.3 where M.sub.

Abstract: An alkali-free glass consisting essentially of from 60 to 74 mol % of SiO.sub.2, from 10 to 16 mol % of Al.sub.2 O.sub.3, from 10 to 12 mol % of B.sub.2 O.sub.3, the molar ratio of Al.sub.2 O.sub.3 /B.sub.2 O.sub.3 being from 1.0 to 1.5, from 0 to 5 mol % of MgO, from 0 to 5 mol % of CaO, from 0 to 12 mol % of SrO, from 0 to 12 mol % of BaO, and from 6 to 12 mol % of SrO+BaO, which contains substantially no alkali metal oxide and has a strain point exceeding 650.degree. C. and an average thermal expansion coefficient of at most 40.times.10.sup.-7 /.degree.C. within a range of from 50.degree. to 300.degree. C., and of which the weight loss per unit area after immersion at 25.degree. C. for 20 minutes in a liquid prepared by mixing a 40 wt % ammonium fluoride aqueous solution and a 50 wt % hydrofluoric acid aqueous solution in a volume ratio of 9:1, is less than 0.60 mg/cm.sup.2, the weight loss per unit area after immersion at 95.degree. C. for 20 hours in 0.1N HCl, is less than 0.20 mg/cm.sup.

Abstract: Glasses for use as substrates for flat panel displays, having a composition consisting essentially of, as calculated in weight percent on an oxide basis, of 42-62 SiO.sub.2, 15-28 Al.sub.2 O.sub.3, 0-4 B.sub.2 O.sub.3, 3-10 Na.sub.2 O, 2-12 K.sub.2 O, 0-6 MgO, 9.5-24 CaO, 0-8 SrO, 0-16 BaO, 0-4 ZrO.sub.2 and 4-16 Li.sub.2 O+Na.sub.2 O+K.sub.2 O.

Abstract: Glasses for use as substrates for flat panel displays, having a composition consisting essentially of, as calculated in weight percent on an oxide basis, 38-56 SiO.sub.2, 10-28 Al.sub.2 O.sub.3, 0-4 Li.sub.2 O, 0-6 Na.sub.2 O, 0-15 K.sub.2 O, 4-18 CaO, 0-5 MgO, more than 8 and less than or equal to about 24 SrO, 0-2 ZrO.sub.2, said glass further consisting essentially of Na.sub.2 O+K.sub.2 O in total between about 6 and 18 weight percent.

Abstract: The invention pertains to a new lead-free glass composition with improved properties, a glass frit of this composition and its use for the production of glass-enamel, particularly for architectural glass. The glass composition contains in mole %:______________________________________ Na.sub.2 O 10-15 K.sub.2 O 0.1-2 SiO.sub.2 40-50 B.sub.2 O.sub.3 8-12 TiO.sub.2 4-7 Al.sub.2 O.sub.3 0.1-3 ZnO 13-17 F 1-5 ______________________________________and less than 0.5 weight % each of the oxides of the series PbO, CdO, P.sub.2 O.sub.5, and alkaline earth metal oxides. Use of a dye preparation containing the glass frit at 600.degree. to 650.degree. C. results in bakeable glazed, crack-free, acid and base resistant enamel layers.

Abstract: The invention pertains to a new lead-free glass composition with improved properties, a glass frit of this composition and its use for the production of glass-enamel, particularly for architectural glass.The glass composition contains in mole %:______________________________________ Na.sub.2 O 10-15 K.sub.2 O 0.1-2 SiO.sub.2 40-50 B.sub.2 O.sub.3 8-12 TiO.sub.2 4-7 Al.sub.2 O.sub.3 0.1-3 ZnO 13-17 F 1-5 ______________________________________and less than 0.5 weight % each of the oxides of the series PbO, CdO, P.sub.2 O.sub.5, and alkaline earth metal oxides. Use of a dye preparation containing the glass frit at 600.degree. to 650.degree. C. results in bakeable glazed, crack-free, acid and base resistant enamel layers.

Abstract: In order to provide an enamel frit composition for a low-expansion crystallized glass, capable of producing an enamel coating excellent in abrasion resistance and acid resistance without occurrence of cracks by using glass powder which does not contain any harmful component such as PbO, and to provide an enamel-coated low-expansion crystallized glass plate using the enamel frit composition, the enamel frit composition for a low-expansion crystallized glass essentially consists 40-98 wt % glass powder, 1-55 wt % coloring pigment, and 0-54 wt % filler. The glass powder consists, by weight, of 55-72% SiO.sub.2, 4-8% Al.sub.2 O.sub.3, 14-22% B.sub.2 O.sub.3, 2-4% BaO, 5.1-15% Na.sub.2 O, 0-2% Li.sub.2 O, 0-2.8% K.sub.2 O, and 0-2% F.sub.2.

Abstract: 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.

Abstract: This invention is directed to the production of spontaneous essentially non-crystalline opal glasses exhibiting a very dense, milky-white appearance and excellent resistance to weathering and attack by alkaline detergents consisting essentially, expressed in weight percent on the on the basis, of 1.9-3.6% K.sub.2 O, 4.2-7.3% Na.sub.2 O, 0.2-3% Li.sub.2 O, 0-1.2% MgO, 0-4.9% CaO, 0-12.5% BaO, 0-0.1% NiO, 0.4-4% ZnO, 5.3-9.6% B.sub.2 O.sub.3, 8.8-13.5% Al.sub.2 O.sub.3, 57.2-64.4% SiO.sub.2, and 1.0-2.2% F., where the sum of (MgO+CaO+BaO) is preferably in the range of 4.5-12.5%.

Abstract: Glass-ceramic for information recording disks have a crystalline structure suitably used for substrate materials and the like for magnetic disks and magneto-optic disks as well as have improved surface characteristics obtained by polishing the glass, and besides the base glass thereof is excellent in melting properties and moldability thereof. The base glass composition consists essentially of ingredients of SiO.sub.2 -Al.sub.2 O.sub.3 -ZnO-MgO-CaO-SrO-BaO-TiO.sub.2 system. The main crystalline phase of the glass-ceramic produced by heat-treating the base glass having a viscosity of log .eta.=3.0 poise or less at 1250.degree. C. is gahnite, a size of the crystal grain is within a range of from 50 to 1000 Angstrom, and a degree of surface roughness (Ra) of the polished glass-ceramic is within a range of from 0.5 to 9.0 Angstrom.

Abstract: This invention is directed to the production of glasses useful for ophthalmic applications which exhibit excellent resistance to the development of coloration upon being exposed to x-radiation and excellent resistance to the development of solarization. The glass compositions are essentially free of lead and consist essentially, in weight percent, of______________________________________ SiO.sub.2 60-70 ZrO.sub.2 0.5-2 TiO.sub.2 0-1.5 B.sub.2 O.sub.3 0.5-5 CeO.sub.2 0.1-0.3 Sb.sub.2 O.sub.3 0-0.5 Al.sub.2 O.sub.3 2-6 Li.sub.2 O 0-2 SO.sub.3 0-0.3 Na.sub.2 O 9-14 MgO 0-5 Br 0-0.5 K.sub.2 O 3-10 SrO 0-5 Cl 0-0.5 CaO 0.5-4 BaO 0-5 F 0-0.5.

Abstract: This invention is directed to the production of a silver halide-containing glass article essentially free from silver halide crystals exhibiting a bright yellow coloration which strongly attenuates the transmission of ultraviolet radiation and radiation having a wavelength up to about 450 nm, said article having an integral reduced surface layer thereon, the depth of that layer being sufficient to effectively prevent the transmission therethrough of ultraviolet radiation and radiation having a wavelength up to about 450 nm.

Abstract: The present invention provides a method of adherently depositing a thick film composition on an aluminum nitride substrate comprising the steps of providing an aluminum nitride substrate, providing a thick film composition, and applying the thick film composition on the aluminum nitride substrate. The thick film composition includes a glass frit binder, a conductive metallic material and a lithium-containing adhesion promoting compound.

Abstract: This invention relates to glass compositions intended for forming a substrate used in the production of electronic equipment. The glasses according to this invention comprise the following constituents within the limits expressed below in cation percentages:______________________________________ SiO.sub.2 + B.sub.2 O.sub.3 57 to 67% with B.sub.2 O.sub.3 5 to 20% Al.sub.2 O.sub.3 14 to 18% RO (CaO + MgO + BaO + SrO) 18 to 25% where Cao/Ro .gtoreq. 0.7 and CaO .gtoreq. 18% Na.sub.2 O + K.sub.2 O 0 to 0.5% TiO.sub.2 0 to 2.5% Fe.sub.2 O.sub.3 .ltoreq.0.5% F.sub.2 0 to 3% ______________________________________F.sub.2 being regarded as a cation.

Abstract: The present invention relates to a rare earth-containing, alkali silicate frit which may be applied to a metal substrate to provide a porcelain enamel coating which has good thermal stability, an acid resistance of A on the PEI scale and improved cleanability, wherein the frit contains, based on the total weight of the frit:______________________________________ Oxide Wt. % ______________________________________ R.sub.2 O 10-30 MgO 0-5 B.sub.2 O.sub.3 0-5 SiO.sub.2 45-60 TiO.sub.2 0-10 F 0.5-5 CoO 0-3 NiO 0-5 X 12-30 ______________________________________whereinR represents an alkali metal andX represents a rare earth oxide having an atomic number of 57-60, preferably cerium oxide.The present invention is also directed to porcelain enamel coatings, especially for appliances, prepared from this rare earth-containing, alkali silicate frit.

Abstract: A dental ceramic material is disclosed for the preparation and repair of metal ceramic and fully ceramic dentures, which has a processing temperature of 660.degree..+-.30.degree. C., and has the following composition: 60 to 65% by weight of SiO.sub.2, 8.5 to 11% by weight of Al.sub.2 O.sub.3, 8 to 12% by weight of K.sub.2 O, 10.5 to 12% by weight of Na.sub.2 O, 0.7 to 2% by weight of CaO, 0.5 to 2.5% by weight of B.sub.2 O.sub.3, 0.1 to 0.6% by weight of Sb.sub.2 O.sub.3, 0 to 0.5% by weight of CeO.sub.2, 1.0 to 3.8% by weight of TiO.sub.2, 0.8 to 1.4% by weight of Li.sub.2 O, and 0.6 to 2.4% by weight of F.sub.2.

Abstract: The invention provides a process which makes it possible to regulate the degree of oxidation-reduction of a glass during its production.According to the invention, which relates to glasses intended to be transformed into continuous or staple fibers containing at most about 1% by weight of Fe.sub.2 O.sub.3, the degree of oxidation of the glass is obtained by incorporating in the mixture of vitrifiable products at least two oxidizing agents, one of them being an inorganic nitrate, the other being, according to preference, an oxidized compound of manganese in which the oxidation state of the manganese is greater than 2, potassium dichromate and/or ceric oxide.The invention particularly favors the recycling of waste from products with a glass fiber base in the vitrifiable mixture.

Abstract: Zinc-containing, lead- and cadmium-free glass frits with a softening point of less than 510.degree. C. are disclosed. Obligatory components of the glass-frit composition are 31-50 mole % ZnO, 10-44 mole % SiO.sub.2, 11-35 mole % B.sub.2 O.sub.3 and 11-25 mole % Na.sub.2 O. The glass frits can be used as base frit for the production of decorative coating masses which can be stoved below 630.degree. C., preferably masses for the decorating of glass.

Abstract: The invention provides: a glass composition comprising about 20 to about 85% of SiO.sub.2, about 2 to about 75% of B.sub.2 O.sub.3, about 15% or less of Al.sub.2 O.sub.3, about 30% or less of at least one of Li.sub.2 O, Na.sub.2 O, K.sub.2 O, Rb.sub.2 O and Cs.sub.2 O, about 0.1 to about 10% of ZnO, about 10% or less, calculated as total amount in combination with ZnO, of at least one of MgO, CaO, BaO, SrO and PbO, about 10% or less of at least one of ZrO.sub.2, La.sub.2 O.sub.3, Y.sub.2 O.sub.3, Ta.sub.2 O.sub.3 and Gd.sub.2 O.sub.3, and about 0.05 to about 15% of at least one copper halide.

Abstract: Ceramic masses with processing temperatures of approximately 770.degree. C. and coefficients of thermal expansion of 8-9.multidot.10.sup.-6 K.sup.-1 and 16-17.5.multidot.10.sup.-6 K.sup.-1 are required for dental prostheses consisting of low-melting gold alloys and titanium alloys for their veneering. Such ceramic masses are composed of 60 to 75% by weight SiO.sub.2, 4 to 15% by weight Al.sub.2 O.sub.3, 0.7 to 2.5% by weight B.sub.2 O.sub.3, 0 to 0.9% by weight Sb.sub.2 O.sub.3, 0 to 0.5% by weight CeO.sub.2, 0 to 2.5% by weight BaO, 0 to 0.5% by weight CaO, 7 to 12% by weight K.sub.2 O, 6 to 11% by weight Na.sub.2 O, 0.55 to 1.4% by weight Li.sub.2 O and 0.2 to 1.0% by weight F.sub.2.

Abstract: One component, visible light-cured dental restorative compositions having fluoride release properties for the purpose of reducing the chances of secondary caries are provided. The compositions include inorganic particulate fluoride leachable glass.

Abstract: A CeO.sub.2 -containing enamel frit is disclosed which, upon enamelling, produces an opaque enamel coating with excellent adhesion and acid resistance. The frit can be used to enamel an unpickled or lightly pickled steel plate or article.

Abstract: A dental ceramic material is disclosed for the preparation and repair of metal ceramic and fully ceramic dentures, which has a processing temperature of 660.+-.30.degree. C., and has the following composition: 60 to 65% by weight of SiO.sub.2, 8.5 to 11% by weight of Al.sub.2 O.sub.3, 8 to 12% by weight of K.sub.2 O, 10.5 to 12% by weight of Na.sub.2 O, 0.7 to 2% by weight of CaO, 0.6 to 2% by weight of BaO, 0.5 to 2.5% by weight of B.sub.2 O.sub.3, 0.1 to 0.6% by weight of Sb.sub.2 O.sub.3, 0 to 0.5% by weight of CeO.sub.2, 1.2 to 3.8% by weight of TiO.sub.2, 0.8 to 1.4% by weight of Li.sub.2 O, and 1.2 to 3.8% by weight of F.sub.2.

Abstract: A glass powder crystallizable to yield a sintered glass ceramic containing hexagonal cordierite as the principal crystal phase is of the composition, in mol % on an oxide basis, of 48-61 SiO.sub.2 ; 10-16 Al.sub.2 O.sub.3 ; 23-35 MgO; 0-4 B.sub.2 O.sub.3 ; 0-2.5 P.sub.2 O.sub.5 ; 0.5-5 .SIGMA. B.sub.2 O.sub.3 +P.sub.2 O.sub.5 ; 0-3 ZnO; 0-3 CaO; 0-1.5 BaO and as an essential component 0.5-12 F as a substitute for O. The glass powder may also contain a total of up to 3 mol % of one or more of the oxides PbO, SrO and SnO.sub.2. The glass powder can be crystallized at sintering temperatures below 970.degree. C. in a relatively broad sintering temperature range to yield a sintered glass ceramic having excellent and constant properties. It is particularly suitable for the production of electrotechnical and electronic components since it has very good electrical, dielectrical and mechanical properties.

Abstract: Hollow glass spheres having average densities of approximately 0.10 grams/cc to approximately 2.0 grams/cc are prepared by heating solid glass particles. The glass spheres consist essentially of the following ingredients in the following amounts stated as weight percentages: SiO.sub.2 (50 to 57%); R.sub.2 0(2 to 15%); B.sub.2 O.sub.3 (0 to 20%); S(0.05 to 1.5%); RO(2 to 25%); RO.sub.2 (other than SiO.sub.2) (0 to 5%); R.sub.2 O.sub.3 (other than B.sub.2 O.sub.3) (0 to 10%); R.sub.2 O.sub.5 (0 to 5%); and F(0 to 5%). R represents a metal or an element like phosphorous which combines with oxygen in glass. The sizes of the hollow glass spheres are selected to produce a maximum average strength for a desired average density.

Abstract: Glaze composition for use on bone china and fine china which is essentially free from lead and cadium comprises, by weight, SiO.sub.2 :35 to 60%, Bi.sub.2 O.sub.3 :5 to 45%, Al.sub.2 O.sub.3 :5 to 20%, B.sub.2 O.sub.3 :1 to 15%, at least one of CaO, MgO, SrO or BaO:2 to 20%, at least one of Li.sub.2 O, Na.sub.2 O, K.sub.2 O:1 to 10%, and certain other optional ingredients, with the proviso that BaO is not contained in an amount of more than 2% by weight.

Abstract: Low sodium hollow glass microspheres containing less than about 3 wt. % Na.sub.2 O are produced from aqueous precursors. The method comprisesa) forming an aqueous glass precursor solution or slurry by combining sources of cations contained in the glass, the solution or slurry comprising all of the glass cations in proportions substantially identical to those in the glass,b) forming the solution or slurry into droplets, andc) heating the droplets to form the microspheres.The precursor may also contain surfactants, blowing agents or other known expedients. Nonionic fluorocarbon surfactants are preferred.The droplets may be formed by spraying or any other known technique. The droplets may be spray dried prior to heating step c).

Abstract: Glass compositions useful for forming fibers which are readily able to be degraded in a physiological medium such as that found in a human body. Advantageous compositions formed according to the present invention comprise the following components, set forth in percent by weight:SiO.sub.2 : 57 to 70%Al.sub.2 O.sub.3 : 0 to 5%CaO: 5 to 10%MgO: 0 to 5%Na.sub.2 O+K.sub.2 O: 13 to 18%B.sub.2 O.sub.3 : 2 to 12%F: 0 to 1.5%P.sub.2 O.sub.

Abstract: A thick film conductor composition adapted to be bonded to an aluminum nitride substrate is provided which comprises a sufficient amount of conductive metallic material to render the conductor composition electrically conductive when bonded to the substrate, a glass frit binder for the metallic material capable of being bonded to the substrate, and a lithium containing compound capable of reacting with the substrate upon heating so as to aid in adherently bonding the conductor composition to the aluminum nitride substrate. A thick film conductor bonded onto the surface of an aluminum nitride substrate as well as a method of producing the same are also provided.

Abstract: An enamel frit for producing an acid-resistant enamelled steel in a single coating comprising at least about 40% of silicon atoms, 50% of silicon atoms and boron atoms, where the proportion of the boron atoms should not fall below 6.5%, 63% of silicon atoms, boron atoms and sodium atoms, where the proportion of the sodium atoms should not fall below 7.5%, each relative to the overall total of the non-oxygen atoms in the frit, the proportion of the remaining non-oxygen atoms being less than about 37%, and 1.0 to 1.2% of cobalt atoms. In addition, there are (1) x fluorine atoms with 1%.ltoreq.x.ltoreq.11% and at least y lithium atoms and at most 2y lithium atoms with y=(15/x)+5 being present, the proportion of lithium atoms being from about 6.3% to 20% relative to the overall total of the non-oxygen atoms in the frit, or (2) y lithium atoms with 6.3%<y.ltoreq.

Abstract: The invention relates to a glass which is transparent to UV radiation and which, for a thickness of 1 mm and the wavelength of 253.7 nm has a transmission of at least 75%, a linear coefficient of thermal expansion of 3.8.times.10.sup.-6 to 4.5.times.10.sup.-6 K.sup.-1 in the temperature range from 20.degree. to 300.degree. C. and a hydrolytic resistance of <120 .mu.g of Na.sub.2 O/g according to DIN 12 111. The new glass has the synthesis composition, calculated on an oxide basis, of______________________________________ SiO.sub.2 64 to 66.5 percent by weight B.sub.2 O.sub.3 20 to 22.5 percent by weight Al.sub.2 O.sub.3 4 to 6 percent by weight Li.sub.2 O 0.4 to 1 percent by weight Na.sub.2 O 1.0 to 3.5 percent by weight K.sub.2 O 1.0 to 2.5 percent by weight CaO 0.35 to 0.8 percent by weight BaO 0.5 to 2.0 percent by weight F.sup.- 0.5 to 2.0 percent by weight .SIGMA. Li.sub.2 O + Na.sub.2 O + K.sub.2 O 3.8 to 5.5 percent by weight .SIGMA. CaO + BaO 1.0 to 2.5 percent by weight one or more 0.2 to 2.