Abstract: A glass ionomer-based fluoride applying material that is able to release 200 &mgr;g/cm2 or more, and preferably 300 &mgr;g/cm2 or more of a fluoride ion until 30 days after immersing a set material thereof in distilled water kept at 37° C., is provided, which contains a fluoroaluminosilicate glass powder, a polycarboxylic acid and water as major components, the fluoroaluminosilicate glass powder accounting for 5 to 70% by weight of the whole, preferably containing, as constitutional elements, 10 to 20% by weight of Si, 10 to 20% by weight of Al, 1 to 20% weight of F, and 5 to 30% by weight of Sr, and additionally, at least one of Na, K, Mg and Ca, and preferably containing Na in an amount of 3 to 15% by weight.

Abstract: A method is provided for manufacturing a silica glass that is substantially free of chlorine. The method includes the step of separately expelling a silicon tetrafluoride gas, a combustion gas, and a combustible gas from a burner made of silica glass, the flow velocity of the silicon tetrafluoride gas being within the range of about 9 slm/cm2 to about 20 slm/cm2. The method further includes the steps of producing minute silica glass particles by reacting the silicon tetrafluoride gas with water produced by a reaction of the combustion gas with the combustible gas, depositing the minute silica glass particles on a target, and producing the silica glass by fusing and vitrifying the minute silica glass particles deposited on the target.

Abstract: An optical glass wherein an amount of change in refractive index (&Dgr;n: difference in refractive index between a state before radiation and a state after radiation) caused by radiation of laser beam at wavelength of 351 nm having average output power of 0.43W, pulse repetition rate of 5 kHz and pulse width of 4OO ns for one hour is 5 ppm or below is provided. The optical glass comprises a fluorine ingredient and/or a titanium oxide ingredient and/or an arsenic oxide ingredient. The optical glass suffers little change in refractive index by radiation of strong light having wavelengths of 300 nm to 400 nm such as ultraviolet laser.

Abstract: A novel silica based bioactive glass composition that can be used in conjunction with a delivery agent such as a toothpaste, gel saliva, etc. having a particle size range <90 &mgr;m which will form a rapid and continuous reaction with body fluids due to the immediate and long term ionic release of Ca and P from the core silica particles, to produce a stable crystalline hydroxy carbonate apatite layer deposited onto and into the dentin tubules for the immediate and long term reduction of dentin hypersensitivity.

Abstract: The present invention is a method of making a lithography photomask and photomask blank. The method of making the lithography photomask and photomask blank includes providing a silicon oxyfluoride glass tube having an OH content less than 50 ppm. The method further includes cutting the silicon oxyfluoride glass tube, flattening the silicon oxyfluoride glass tube, and forming the flattened cut silicon oxyfluoride glass tube into a photomask blank having a planar surface. The present invention includes a glass lithography mask preform. The glass lithography mask preform is a longitudinal silicon oxyfluoride glass tube that has an OH content ≦10 ppm, a F wt. % concentration ≧0.5 wt. %.

Abstract: A glass composition is disclosed which has a high modulus of elasticity (Young's modulus) and a high rigidity (modulus of elasticity/specific gravity) and is capable of being effectively inhibited from bending or vibrating. Also disclosed is a substrate for information recording media which comprises the glass composition. The glass composition comprises the following components, in terms of mol %: 55 to 65% SiO2, 0.5 to less than 6% Al2O3, 12 to 22% Li2O, 0 to 5% Na2O, 0 to 10% TiO2, 0 to 3% ZrO2, 0 to 8% MgO, 0 to 18% CaO, and 0 to 6% SrO, provided that the content of RO (RO=MgO+CaO+SrO) is 5 to 18%.

Abstract: The glasses used for making rigid disk substrates have the following composition (in % by weight based on oxides): SiO2, 40 to 50.8; Al2O3, 5 to 20; B2O3, 0 to 5; Li2O, 0 to 10; Na2O, 0 to 12, with the proviso that Li2O+Na2O, 5 to 12; K2O, 0 to 5; MgO, 0 to 20; CaO, 0 to 6, with the proviso that MgO+CaO, 4 to 20; SrO+BaO, 0 to 10; ZrO2, 0 to 5; TiO2,0 to 5; CeO2, 0 to 1; La2O3, 0 to 10; Fe2O3, 0 to 10; Nb2O5, 0 to 10; V2O5, 0 to 15, with the proviso that TiO2+ZrO2+La2O3+Fe2O3+Nb2O5+V2O5≧18.7; As2O3+Sb2O3+F. 0,1 to 1. These glasses also fulfill the following inequality formulae (1): (E/&rgr;)·+3,500 R>38.5 and 1000 R>1  (1), wherein R represents the relaxation rate of the glass and E/&rgr; represents specific elasticity modulus of the glass measured in GPA*cm3/g.

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: Layers are patterned with a lithography method during the fabrication of integrated circuits. A mask, which may be reflective or transmissive, for carrying out the method. The photosensitive layers are exposed to radiation that is emitted by a radiation source. The radiation lies in the extreme ultraviolet region and is guided via the mask onto the photosensitive layers.

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: Novel boron-free glass compositions are described which are particularly suited for making fine diameter glass fibers for HEPA electronic clean-room filtration media using flame-attenuation or rotary glass processing.

Abstract: High purity silicon oxyfluoride glass suitable for use as a photomask substrates for photolithography applications in the VUV wavelength region below 190 nm is disclosed. The inventive silicon oxyfluoride glass is transmissive at wavelengths around 157 nm, making it particularly useful as a photomask substrate at the 157 nm wavelength region. The inventive photomask substrate is a “dry,” silicon oxyfluoride glass which exhibits very high transmittance in the vacuum ultraviolet (VUV) wavelength region while maintaining the excellent thermal and physical properties generally associated with high purity fused silica. In addition to containing fluorine and having little or no OH content, the inventive silicon oxyfluoride glass suitable for use as a photomask substrate at 157 nm is also characterized by having less than 1×1017 molecules/cm3 of molecular hydrogen and low chlorine levels.

Abstract: The present invention relates to a glass matrix which includes 4-70 wt. % SiO2, 0.5-20 wt. % Al2O3, 0-20 wt. % R2O, 0-30 wt. % R′O, 8-85 wt. % Ta2O5, 0-40 wt. % Nb2O5, and 0.01-1.0 wt. % R″2O3, where R2O+R″O is between about 2-35 wt. %, Ta2O5+Nb2O5 is between about 8-85 wt. %, R is selected from a group consisting of Li, Na, K, and combinations thereof, R′ is selected from a group consisting of Ba, Sr, Ca, Mg, Zn, Pb, and combinations thereof, and R″ is a rare earth element. The present invention also relates to use of the glass matrix in forming optic waveguides such as optic amplifiers. The present invention further relates to a transparent glass ceramic that contains pyrochlore, perovskite, or a combination thereof as its major crystal phase, and includes 4-40 wt. % SiO2, 1-15 wt. % Al2O3, 0-20 wt. % K2O, 0-12 wt. % Na2O, 0-5 wt. % Li2O, 8-85 wt. % Ta2O5, and 0-45 wt. % Nb2O5, wherein Ta2O5+Nb2O5 is at least about 20 wt.

Abstract: The invention includes methods of making lithography photomask blanks. The invention also includes lithography photomask blanks and preforms for producing lithography photomask. The method of making a lithography photomask blank includes providing a soot deposition surface, producing SiO2 soot particles and projecting the SiO2 soot particles toward the soot deposition surface. The method includes successively depositing layers of the SiO2 soot particle on the deposition surface to form a coherent SiO2 porous glass preform body comprised of successive layers of the SiO2 soot particles and dehydrating the coherent SiO2 glass preform body to remove OH from the preform body. The SiO2 is exposed to and reacted with a fluorine containing compound and consolidated into a nonporous silicon oxyfluoride glass body with parallel layers of striae.

Abstract: High purity silicon oxyfluoride glass suitable for use as a photomask substrates for photolithography applications in the VUV wavelength region below 190 nm is disclosed. The inventive silicon oxyfluoride glass is transmissive at wavelengths around 157 nm, making it particularly useful as a photomask substrate at the 157 nm wavelength region. The inventive photomask substrate is a “dry,” silicon oxyfluoride glass which exhibits very high transmittance in the vacuum ultraviolet (VUV) wavelength region while maintaining the excellent thermal and physical properties generally associated with high purity fused silica. In addition to containing fluorine and having little or no OH content, the inventive silicon oxyfluoride glass suitable for use as a photomask substrate at 157 nm is also characterized by having less than 1×1017 molecules/cm3 of molecular hydrogen and low chlorine levels.

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: A process for making bioactive glasses is described including preparing a reaction mixture of reactants capable of forming a sol-gel, aging the reaction mixture, near equilibrium drying a gel resulting from the reaction mixture, and heating the -near equilibrium-dried gel described. Also described are near equilibrium-dried bioactive glass compositions.

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: This invention relates to fluorescent photosensitive vitroceramics and the process for the production thereof. The fluorescent photosensitive vitroceramics according to the present invention employ fluorosilicate glass compositions including various photosensitizing metals and rare earths which impart photosensitive properties and fluorescent properties to the vitroceramic. After irradiation, the photosensitive agents control the precipitation of fine fluoride crystals which also contain rare earth ions. These rare earth ions can be made to fluoresce in a controlled manner. The inventive fluorescent photosensitive vitroceramics can be used in photographic applications, florescent displays and computer memories.

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: These glasses incorporate a combination of F and Al.sub.2 O.sub.3 to achieve even wider fluorescence and improved gain flatness. In addition, SPCVD incorporates large amounts of N into low-loss fiber whose high charge has an impact on rare earth behavior. The Surface Plasma Chemical Vapor Deposition (SPCVD) produces fiber preforms with high levels of F, Al.sub.2 O.sub.3, and N. These heavily fluorinated glasses provide much broader Er.sup.3+ emission than Type I or Type II silica for enhanced multichannel amplifiers. SPCVD successfully fluorinates silica with losses below 5 dB/km and increased Er.sup.3+ emission width.

Abstract: The invention is directed to an aluminosilicate glass containing alkaline earth metals for lamp bulbs which have molybdenum components and bulb temperatures of greater than 650.degree. C. The glass has a composition in percent by weight on oxide basis as follows: SiO.sub.2 >58-62; Al.sub.2 O.sub.3 15-17.5; B.sub.2 O.sub.3 0.2-0.7; MgO 0-<1; CaO 5.5-14; SrO 0-8; BaO 6-10; ZrO 0.05-1.0; CeO.sub.2 0-0.3; TiO.sub.2 0-0.5; Br.sup.- 0-0.6 where .SIGMA. RO 21-24; (MgO+CaO+SrO)/BaO 1.45-1.75; and an alkali metal content of <0.03% by weight and a water content of <0.02% by weight.

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: 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: The height of protrusions formed during laser texturing a glass-ceramic substrate is controlled by controlling the amount of the crystalline-phase of the substrate, to less than 70% by volume. In an embodiment, the amount of crystalline-phase is controlled by heating under controlled conditions to convert a glass substrate into the glass-ceramic substrate comprising a controlled amount of crystalline phase.

Abstract: The invention relates to fluorine-containing silica glasses, and methods of their production. The silica glass may be used for an ultraviolet light optical system in which light in a wavelength region of 200 nm or less, such as an ArF (193 nm) excimer laser, is used. The invention also relates to a projection exposure apparatus containing fluorine-containing glass of the invention.

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: A porcelain composition for dental restorations comprising a leucite crystallite phase and a glass matrix phase, wherein the leucite crystallites possess diameters not exceeding about 10 micron. Preferably, the porcelain composition has a maturing temperature from about 750.degree. to about 1050.degree. C. and a coefficient of thermal expansion from about 12.times.10.sup.-6 /.degree. C. to about 17.5.times.10.sup.-6 /.degree. C., and comprises:______________________________________ Component Amount (wt. %) ______________________________________ SiO.sub.2 57-66 Al.sub.2 O.sub.3 7-15 K.sub.2 O 7-15 Na.sub.2 O 7-12 Li.sub.2 O 0.5-3.

Abstract: The present invention relates to a process for forming glass-ceramic tiles. Fly ash containing organic material, metal contaminants, and glass forming materials is oxidized under conditions effective to combust the organic material and partially oxidize the metallic contaminants and the glass forming materials. The oxidized glass forming materials are vitrified to form a glass melt. This glass melt is then formed into tiles containing metallic contaminants.

Abstract: There is provided a belt coating material for a belt type continuous casting, which is capable of adsorbing the intermediate between a cast slab and the coating material to prevent the intermediate from remaining on the slab, and reducing the averaged heat flux during the casting to avoid an occurrence of cracking in a medium carbon steel. The belt coating material comprises: (1) a powder having a composition comprising 10 to 40 weight % of SiO.sub.2, 1 to 10 weight % of Al.sub.2 O.sub.3, 10 to 40 weight % of CaO, 10 to 30 weight % of Na.sub.2 O, 1 to 10 weight % of MgO, 10 to 20 weight % of F, and 1 to 5 weight % of LiO.sub.2, the powder being prepared by once melting the blended components, solidifying the melt, and crushing it into the powder to adjust the average grain diameter of the powder to be equal to or smaller than 10 .mu.m; (2) 0.1 to 10 weight % of graphite mixed into the powder to provide a mixture, the graphite having the same grain diameter with the powder; and (3) 0.

Abstract: The chemically prestressable glass having a low bubble count and bubble size has the following composition in mol %, based on a total amount of oxides present, SiO.sub.2 from 63.0 to 67.5 mol %, Al.sub.2 O.sub.3 from 9.5 to 12.0 mol %, Na.sub.2 O from 8.5 to 15.5 mol %, K.sub.2 O from 2.5 to 4.0 mol %, MgO from 3.0 to 9.0 mol %, sum of CaO+SrO+BaO+ZnO from 0 to 2.5 mol %, TiO.sub.2 from 0.5 to 1.5 mol %, CeO.sub.2 from 0.02 to 0.5 mol %, As.sub.2 O.sub.3 from 0.02 to 0.35 mol %, SnO.sub.2 from 0. to 1.0 mol %, and F.sub.2 from 0.05 to 2.6 mol %, wherein the molar ratio ?SiO.sub.2 !/?Al.sub.2 O.sub.3 ! is 5.3 to 6.85, the molar ratio ?Na.sub.2 O!/?K.sub.2 O! is 3.0 to 5.6, the molar ratio ?Al.sub.2 O.sub.3 !/?K.sub.2 O! is 2.8 to 3.6 and the molar ratio ?Al.sub.2 O.sub.3 !/?TiO.sub.2 +CeO.sub.2 ! is 7.6 to 18.5, but, when arsenic-free, SnO.sub.2 is from 0.02 to 1.0 mol % and F.sub.2 is from greater than 0.5 to 2.6 mol %.

Abstract: A pharmaceutical preparation, including a glass phase which is bioactive silica containing glass in the form of a paste, suspension or solution mixed in a physiologically suitable liquid or bound to a physiologically suitable vehicle, and which preparation reduces the pulpal irritation or a tooth and/or strengthens the structure of a tooth. Bioactive silica containing glass may be a material which contains only Si-oxide or Si-hydroxide and which allows the formation and movement of Si--OH-groups. Preferably, the preparation also contains calcium and phosphate sources.

Abstract: The process for producing a chemically prestressed glass of very high surface quality includes subjecting an Li.sub.2 O-free starting glass from the SiO.sub.2 -Al.sub.2 O.sub.3 -M.sub.2 O-MO system which also contains TiO.sub.2, CeO.sub.2 and F.sub.2 to chemical ion exchange by immersing it in a potassium salt bath at a temperature between 350.degree. C. and 550.degree. C. and at a residence time of between 0.5 and 20 hours to form the chemically prestressed glass. In a preferred embodiment of the process, the potassium salt bath contains a potassium nitrate melt and the glass is polished after prestressing. The chemically prestressed glass is particularly useful for making hard disks.

Abstract: A silica-soda-lime glass composition suitable for making glazing. Said glass consists of 69-75 wt % SiO.sub.2, 0-3 wt % Al.sub.2 O.sub.3, 0-5 wt % B.sub.2 O.sub.3, 2-10 wt % CaO, 0-2 wt % MgO, 9-17 wt % Na.sub.2 O, 0-8 wt % K.sub.2 O, 0.2-4 wt % Fe.sub.2 O.sub.3 (total iron), and 0-0.45 wt % Se, CoO, Cr.sub.2 O.sub.3, NiO, CuO. The amount of tinting agents other than iron is at least 0.0002 wt % when the Fe.sub.2 O.sub.3 content is 1.5 wt % or less. The composition may also contain fluorine; zinc, zirconium, cerium and titanium oxides; and less than 4 wt % barium oxide; while the sum of the percentages of alkaline earth oxides is not above 10 wt %.

Abstract: The present invention relates to glass compositions suitable for the manufacture of glazings for use in the architectural field or for fitting in motor vehicles. These compositions contain the following constituents with the contents, express in weight percentages, defined by the following limits:SiO.sub.2 69 to 75%Al.sub.2 O.sub.3 0 to 3%CaO 2 to 10%MgO 0 to 2%Na.sub.2 O 9 to 17%K.sub.2 O 0 to 8%Fe.sub.2 O.sub.3 (total iron) 0.2 to 1.5%These compositions can also contain fluorine, as well as oxides of zinc, zirconium, carium, titanium and less than 4% barium oxide, the sum of the percentages of the alkaline earth oxides remaining equal to or below 10%.

Abstract: The oxyhalide rare earth doped laser glass of the present invention comprises the substitution of fluorine for oxygen in glasses having the general molar batch composition of 50% SiO.sub.2, 25% CaO, 25% Al.sub.2 O.sub.3 to improve the distribution of rare earth dopants in the glass. The general molar batch composition of the invention ranges from approximately 45-70% SiO.sub.2, 15-35% CaO, 10-25% Al.sub.2 O.sub.3, 4-15% Al.sub.2 F.sub.6, and 0.001-2% Er.sub.2 O.sub.3. This substitution of fluorine into the 2SiO.sub.2. Al.sub.2 O.sub.3. CaO glass system provides erbium doped laser glasses having a Er.sub.2 O.sub.3 batch content of 0.01 mole % Er.sub.2 O.sub.3 to 1.2 mole % Er.sub.2 O.sub.3 (500 ppm Er.sub.2 O.sub.3 to 5.68 wt. % Er.sub.2 O.sub.3) which show little to no concentration quenching and exhibit useful fluorescence lifetimes of approximately 6 milliseconds (ms) or greater.

Abstract: A novel silica based bioactive glass composition that can be used in conjunction with a delivery agent such as a toothpaste, gel saliva, etc. having a particle size range <90 .mu.m which will form a rapid and continuous reaction with body fluids due to the immediate and long term ionic release of Ca and P from the core silica particles, to produce a stable crystalline hydroxy carbonate apatite layer deposited onto and into the dentin tubules for the immediate and long term reduction of dentin hypersensitivity.

Abstract: Vitrified phosphor articles, intermediates, and methods for preparing the articles. In the methods, a combination of species are admixed. The combination of species are precursors for a glass-forming system. The glass-forming system includes precursors for a crystalline radiographic phosphor. The admixed combination of species are fired to form a melt having a single liquid. The product of the melt is molten-shaped.

Abstract: A two-phase porcelain composition for dental restorations comprising a leucite crystallite phase dispersed in a feldspathic glass matrix, a maturing temperature of from about 750.degree. to about 1050.degree. C. and a coefficient of thermal expansion of from about 12.times.10.sup.-6 /.degree.C. to about 17.5.times.10.sup.-6 /.degree.C., said porcelain composition comprising:______________________________________ Component Amount (wt. %) ______________________________________ SiO.sub.2 57-66 Al.sub.2 O.sub.3 7-15 K.sub.2 O 7-15 Na.sub.2 O 7-12 Li.sub.2 O 0.5-3 CaO 0-3 MgO 0-7 F 0-4 CeO.sub.2 0-1 ______________________________________wherein the leucite crystallites possess diameters not exceeding about 10 microns and represent from about 5 to about 65 weight percent of the two-phase porcelain composition.

Abstract: 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.

Abstract: Alkali-zinc-silicate glass ceramics and glasses are described which have a linear thermal expansion coefficient in the range from 8.0 to 18.7.times.10.sup.-6 K.sup.-1, an excellent chemical resistance and other advantageous optical properties and can be used in particular as dental material.

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: A high efficiency wavelength up-conversion transparent glass ceramics composition is provided containing a rare earth ion, which can be applied to short wavelength solid lasers, full color displays, infrared light detecting sensors, etc. The ceramic composition has the following chemical composition, in which fluoride fine crystals containing rare earth ions are preferentially precipitated:______________________________________ SiO.sub.2 10-60 mol % AlO.sub.1.5 0-40 mol % GaO.sub.1.5 0-40 mol % PbF.sub.2 5-60 mol % CdF.sub.2 0-60 mol % GeO.sub.2 0-30 mol % TiO.sub.2 0-10 mol % ZrO.sub.2 0-10 mol % ReF.sub.3 or ReO.sub.1.5 0.05-30 mol % (Re = Er, Tm, Ho, Yb, Pr, etc.).

Abstract: This invention is directed to the formation of glass-ceramic articles which exhibit a yellow coloration in visible light and fluoresce with a yellow coloration while being exposed to ultraviolet radiation. The yellow coloration is produced through the incorporation of a color package comprising 0.05-0.5% V.sub.2 O.sub.5, 0.25-5% CeO.sub.2, and 0.1-1% Tb.sub.2 O.sub.3. When the glass-ceramic articles contain tetrasilicic fluormica as the predominant crystal phase, they are eminently suitable for use as dental prosthetic materials.

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: Soda-lime-silica glass containing iron and fluorine has a high total light transmission factor while absorbing infrared radiation. This glass is useful in making glazings for automotive uses.

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: A glass-ceramic biomaterial having high strength and toughness, a family of glasses from which the glass-ceramic biomaterial can be produced, and a method of production. The material has a primary crystal phase of F-canasite and a secondary crystal phase of F-apatite. The glass family is SiO.sub.2 --CaO--Na.sub.2 O--K.sub.2 O--P.sub.2 O.sub.5 --F. The method may be a single stage heat treatment, or a two stage involving an initial nucleation and a subsequent crystallization.

Abstract: An optical glass which is a SiO.sub.2 -Nb.sub.2 O.sub.5 -R'.sub.2 O (where R' is an alkali metal element)-F system of a specific composition range exhibits optical constants of a refractive index (Nd) of about 1.52-1.67 and an Abbe number (.upsilon. d) of about 32-50, is free of PbO and has an improved light transmissivity.