Abstract: The present invention relates to abrasion-resistant granular materials which are composed of one or more inorganic pigments, one or more inorganic elements and/or compounds with a Mohs hardness of at least 7 and one or more inorganic and/or organic binders and optionally frits and/or glasses and/or inorganic fillers, and to their production and their use.

Abstract: Thick film paste composition for applying conductive patterns to automotive window glass comprising finely divided particles of metallic silver, glass frit having transition metal oxide, contained in the glass, all of the particulate solids being dispersed in an organic medium.

Abstract: Lead-free, tin phosphate glasses contain 25-50 mole percent P.sub.2 O.sub.5, 30-70% SnO, 0-15% ZnO, the mole ratio of SnO:ZnO being greater than 5:1, and an effective amount up to 25% total of at least one oxide in the indicated proportion selected from the group consisting of up to 25% R.sub.2 O, wherein R.sub.2 O consists of 0-25% Li.sub.2 O, 0-25% Na.sub.2 O, and 0-25% K.sub.2 O, up to 20% B.sub.2 O.sub.3, up to 5% Al.sub.2 O.sub.3, up to 5% SiO.sub.2, and up to 5% WO.sub.3. The glasses are particularly useful as sealing glass frits in sealing material to join component parts in electrical and electronic devices. The sealing glass material may contain mill additions to reduce the effective coefficient of thermal expansion in a seal, as well as a strength reinforcing additive having a coefficient of thermal expansion preferably below 120.times.10.sup.-7 /.degree.C.

Abstract: A new doped zirconium mixed silicate pigment has been found, having a particle size D.sub.50 of 3 .mu.m or less and a molar ratio of zirconium dioxide/silicon dioxide that deviates from the stoichiometric ratio and is in the range of 1/1.5-1/36. This new pigment is doped with 1-25% by weight of a color-providing metal oxide an exhibits great color strength as well as good thermostability. The new pigment, which has a very high particle fineness, can be used for ceramic applications and for coloring glass, but is also particularly suitable for applications outside the ceramic field, in particular as a colorant in plastics, rubber, paint, printing ink and cosmetic products. Further, a similar new doped zirconium silicate pigment has been found, which, however, has a D.sub.50 particle size that is greater than 3 .mu.m, the molar ratio of zirconium dioxide/silicon dioxide being in the range of 1/4.9-1/36. The last-mentioned pigment is very suitable to be incorporated into glass.

Abstract: The present invention relates to a process for producing an inorganic biomaterial, according to which, there can be obtained an inorganic biomaterial excellent in strength and biocompatibility, having a structure in which portions constituted by crystallized glass or crystals of calcium phosphate excellent in bioactivity are dispersed in a skeleton or matrix constituted by crystals of partially stabilized zirconia and/or alumina showing high strength. Accordingly, the inorganic biomaterial is very useful as biomaterial for artificial bones, dental implants, etc.

Abstract: Coated spinel color pigments with a core of a colored spinel, in particular CoAl.sub.2 O.sub.4, and a coating glassy layer of a silicate are described. The coating layer is essentially silicon dioxide and one or more oxides of the group of alkali metals, alkaline earth metals, and/or earth metals show a high resistance to bleeding in the presence of glass fluxes, as compared to uncoated spinels. The pigments are produced by sintering, for 0.5 to 5 hours, a powder mixture of the spinel, silicon dioxide, and at least one member chosen from the group of alkali metal halides, alkaline earth metal halides, earth metal halides and mixtures thereof as mineralizer at 900.degree. to 1,300.degree. C. The coated spinel color pigments are suitable for the production of ceramic decorations with improved contour sharpness.

Abstract: Low temperature sealing glass compositions comprising 35 to 80% by weight TeO.sub.2, 15 to 50% V.sub.2 O.sub.5 and 0.1 to 20% Nb.sub.2 O.sub.5, ZrO.sub.2 and/or ZnO.

Abstract: A hermetic sealing glass composition comprising an inorganic component which consists essentially of from 60 to 100 wt % of a glass powder, from 0 to 30 wt % of a filler and from 0 to 10 wt % of a pigment, wherein said glass powder consists essentially of from 30 to 45 wt % of SiO.sub.2, from 11 to 25 wt % of Al.sub.2 O.sub.3, from 11 to 25 wt % of ZnO, from 11 to 25 wt % of B.sub.2 O.sub.3, from 0.05 to 10 wt % of ZrO.sub.2, from 0.1 to 10 wt % of at least one of La.sub.2 O.sub.3, from 0.1 to 7 wt % of BaO, SrO, or CaO+MgO, from 0.1 to 7 wt % of at least one Li.sub.2 O, +Na.sub.2 or K.sub.2 O, from 0.1 to 5 wt % of at least one CeO.sub.2, +TiO.sub.2 or SnO.sub.2, from 0 to 5 wt % of PbO and from 0 to 5 wt % of at least one metal oxide selected from the group consisting of oxides of Co, Ni, Cr, Mn, Fe and Cu.

Abstract: A ceramic composition for forming a ceramic dielectric body having a dielectric constant of less than about 4.5 and a TCE of less than about 4.0 ppm/c. The composition comprises a mixture of 20-50 wt. % borosilicate glass 40-75 wt. % of a glass selected from the group consisting of glass containing 95-98 wt. % silica, titanium silicate glass and combinations thereof and sufficient amounts of gallium to inhibit the formation of crystalline forms of silica. The composition can be combined with a polymeric binder to produce an unfired green tape which is co-fireable with high conductivity metallurgies such as gold, silver and silver/palladium.

Abstract: The present invention relates to a ceramic basal layer for opacifying the metal coping of a ceramo-metallic dental reconstruction.The ceramic basal layer for opacifying the metal coping of a ceramo-metallic dental reconstruction consists of an undercoat of opaque slip produced from a glass frit high in fluxes and in particular in B.sub.2 O.sub.3, covered with an opaque layer produced from a glass frit high in opacifying metal oxides and containing approximately 30% by weight of refractory particles with a particle size of between approximately 40 microns and approximately 100 microns.

Abstract: A ceramic composition for forming a ceramic dielectric body having a dielectric constant of less than about 4.2 at 1 MHz and a linear thermal expansion coefficient of 2.5-3.0 ppm/.degree.C. from room temperature to 200.degree. C. The composition comprises a mixture of finely divided particles of 20-50 wt. % borosilicate glass, 40-75 wt. % titanium silicate glass and sufficient amounts of crystalline ceramic material to inhibit the formation of crystalline forms of silica. The composition can be used with a polymeric binder to produce an unfired green tape which is co-fireable with high conductivity metallurgies such as gold, silver and silver/palladium.

Abstract: A dielectric composition comprising an admixture of finely divided particles of(a) 65-94 wt % of a non-reducing amorphous glass comprising of 15-27% ZnO, 8-30% alkaline earth metal oxides including 7-21% BaO, 40-60% SiO.sub.2, 3-14% Al.sub.2 O.sub.3, 0-5% PbO and 0.5-5% of a metal oxide selected from ZrO.sub.2, up to 2.5% P.sub.2 O.sub.5 and mixtures thereof, the composition being crystallizable and non-reducing when fired at 850.degree.-900.degree. C.(b) 30-5 wt % of a metal oxide of Al.sub.2 O.sub.3, ZrSiO.sub.4 and mixtures thereof,(c) 1-5 wt % of a metal oxide kerf additive of CoAl.sub.2 O.sub.4, Co/CrAl.sub.2 O.sub.4, CoO, CoCr.sub.2 O.sub.4, Cr.sub.2 O.sub.3, TiO.sub.2, and mixtures thereof,where the sum of the components a and b does not exceed 35% by weight of the total particulate admixture, and(d) optionally, 1-10 wt % of either a TCE reducing additive of zircon, mullite, silica, and mixtures thereof or a TCE increasing additive of CaZrO.sub.3, quartz, .alpha.-cristobalite and mixtures thereof.

Abstract: Compositions useful for printing controllable adhesion conductive patterns on a printed circuit board include finely divided copper powder, a screening agent and a binder. The binder is designed to provide controllable adhesion of the copper layer formed after sintering to the substrate so that the layer can lift off the substrate in response to thermal stress. Additionally, the binder serves to promote good cohesion between the copper particles to provide good mechanical strength to the copper layer so that it can tolerate lift off without fracture.

Abstract: A ceramic composition for forming a ceramic dielectric body having a dielectric constant of less than about 4.2 at 1 MHz and a linear thermal expansion coefficient of 2.5-3.0 ppm/.degree. C. from room temperature to 200.degree. C. The composition comprises a mixture of finely divided particles of 25-50 vol. % borosilicate glass and 50-75 vol. % titanium silicate glass. The composition can be used with a polymeric binder to produce an unfired green tape which is co-fireable with high conductivity metallurgies such as gold, silver and silver/palladium.

Abstract: A composite article, such as a telescope mirror blank, comprising a solid glass body and a supporting network structure, the structure being composed of a network of interlocking struts frit sealed to one another and to the face plate. The article is characterized in that sufficient of the glass body is incorporated in particulate form in the struts to maintain an average expansion mismatch (-50.degree. C. to +50.degree. C.) between the network structure and the glass body of no more than 0.15 ppm/.degree.C.

Abstract: Glasses containing chromophores are partially struck to produce no coloring or only light coloring due to the chromophore. The glasses are colored as desired by contents of colorant ions.

Abstract: A ceramic material suitable for packaging of large scale integrated circuits is produced by the process of forming a mixture of a powdered glass ceramic material which is a glassy precursor to cordierite ceramic material, formed by the steps which are as follows:a. Mix tetragonal phase material selected from the group consisitng of zirconia or hafnia powder containing a stabilizing oxide compound selected from the group consisting of MgO, CaO and Y.sub.2 O.sub.3 and a glass frit powder or frit of a glassy precursor of cordierite glass ceramic to yield a suspension of solids. Preferably, a binder is included.b. Disperse the suspended solids to yield a dispersion of the zirconia or hafnia with the stabilizing oxide compound and the glassy precursor.c. Densify the dispersion of zirconia or hafnia with the stabilizing oxide compound and the glassy precursor by a sintering heat treatment at a temperature of about 840.degree. C.

Abstract: The invention relates to a substantially foamless sintered glass body with a decorative pattern. The glass body is made of a glass and a powder of at least one heat-resistant inorganic oxide, e.g. aluminum oxide, which is colorless or assumes a whitish color and has a refractive index different from that of the glass by at least 15%, and the glass body contains an inorganic pigment. The oxide powder amounts to 0.2-10 wt % of the glass. The glass body has, in its surfaces and sections, opaline or opaque and palely colored mottles bordered by less opaque and relatively deeply colored regions. The glass body is produced by compressively granulating a powder mixture of the glass, inorganic oxide(s) and pigment into granules not smaller than 1 mm, integrating the granules, firing the integrated granules at a temperature ranging from the softening point to the fluid point of the glass and applying a pressure to the fired material during or immediately after firing.

Abstract: The soldering enamel is composed of a basic enamel consisting of aluminium oxide and a rare earth metal oxide and/or an alkali earth metal oxide and, in the given case, some other metallic or metalloid oxide, and of a ceramic filling material. The filling material is a zirconium-rare earth oxide of perovskite crystal structure. The quantity of the filling material amounts up to 5 mass % referred to the overall quantity of enamel.

Abstract: An insulating powder for the formation of a resistant coating is disclosed which comprises a glass powder consisting of 60 to 70% by weight of ZnO, 19 to 25% by weight of B.sub.2 O.sub.3, and 10 to 16% by weight of SiO.sub.2. A composition for the formation of a resistant coating is also disclosed which comprises the powdered oxide of a platinum-family element; the powder of at least one oxide selected from the group consisting of indium oxides, tin oxides, and cadmium oxides; a glass powder capable of forming a crystalline phase on being fired; a ceramic powder; and an organic vehicle.

Abstract: The invention relates to a composite body comprising a first part of ceramic material, a second part of metallic material, of ceramic material or of a mixture of metallic and ceramic material, and a third part of a melting ceramic which seals together the first and second parts, and comprises a frit of Al.sub.2 O.sub.3 and either one or more alkaline earth metal oxides or one or more rare earth metal oxides or a combination of these two oxides. According to the invention, the melting ceramic contains a filler material which occupies at least 20% and at most 50% of the volume of the melting ceramic.

Abstract: In order to produce matee precious metal decorations on carriers of ceramics and porcelain, before applying bright precious metal preparations, the carrier is first provided with a base layer composed of:(a) 50 to 80% by weight of a mixture of(aa) 50 to 80% by weight of a lead-free borosilicate glazed frit with(bb) 20 to 70% by weight of titanium dioxide powder and(b) 20 to 50% by weight of a mixture of(aa) 40 to 60% by weight of a modified alkyd resin having an oil content of 20 to 40% by weight and a solid content of 40 to 60% by weight and(bb) 40 to 60% by weight of an aromatic hydrocarbon.

Abstract: Glaze compositions for ceramic substrates such as an alumina substrate are described. In a first embodiment, the glaze composition consists of 55 to 75 mol % SiO.sub.2, 1 to 15 mol % Al.sub.2 O.sub.3, 3 to 20 mol % CaO, 1 to 13 mol % BaO and 0.1 to 5 mol % Y.sub.2 O.sub.3. In a second embodiment, the glaze composition consists essentially of 55 to 75 mol % SiO.sub.2, 1 to 15 mol % Al.sub.2 O.sub.3, 3 to 20 mol % CaO, 1 to 13 mol % BaO, 1 to 5 mol % Y.sub.2 O.sub.3, 25 mol % or less SrO, 7 mol % or less B.sub.2 O.sub.3, 2 mol % or less ZnO and 2 mol % or less MgO. In a third embodiment, the glaze composition consists essentially of 58 to 75 mol % SiO.sub.2, 2 to 15 mol % Al.sub.2 O.sub.3, 0.5 to 5 mol % La.sub.2 O.sub.3, 2 to 20 mol % CaO and 1 to 13 mol % BaO. In a fourth embodiment, the glaze composition consists essentially of 58 to 75 mol % SiO.sub.2, 2 to 15 mol % Al.sub.2 O.sub.3, 0.5 to 5 mol % La.sub.2 O.sub.

Abstract: This invention is directed to lead-free and, where desired, cadmium-free frits for glazes and enamels, said frits consisting essentially, in mole percent on the oxide basis, of______________________________________ SiO.sub.2 55-75 Na.sub.2 O 3-9 B.sub.2 O.sub.3 8-13 ZrO.sub.2 2-5 Al.sub.2 O.sub.3 0.5-3 BaO 0.5-16 ______________________________________Various inert refractory materials may be included as fillers.

Abstract: A method of preventing glaze defects occurring when using pigments which are provided by inclusion in zirconium silicate (zircon) comprises the incorporation into the glaze composition of an additive which is zirconium oxide, zirconium silicate, arsenic trioxide, antimony trioxide, ceric oxide, or a mixture thereof, or a precursor therefor in an amount sufficient to reduce or prevent glaze defects.

Abstract: An electrically stable radio frequency interference suppressing glass-type resistor seal composition forming a gas-tight seal within the center bore of a ceramic insulator is disclosed that contains borosilicate glass, barium borate glass, mullite, zirconia, carbon black, bentonite, sucrose, lithium carbonate and small, approximately equal amounts of antimony and silicon.

Abstract: A novel devitrifying frit is disclosed which has a coefficient of expansion essentially the same as that of silicon. The subject frits have a high softening temperature and excellent reheat stability which make them useful in ink formulations for forming dielectric layers in multilayer circuitry. The frits are also suitable for use as a substrate material for direct mounting of silicon chips or for use in thick film via-fill inks.

Abstract: A titanium dioxide compositon suitable for incorporation into ceramic frit, and process for preparation thereof. A clarified titanium sulfate liquor is hydrolyzed and precipitated to yield relatively large and uniform-sized hydrolysate particles which are easily separated from the acidic liquor by filtration.

Abstract: A fluoroaluminosilicate glass powder for dental glass ionomer cement, a surface of which is treated with a fluoride in an amount of from 0.01 to 5 parts by weight based on 100 parts by weight of the glass powder, is disclosed. The fluoroaluminosilicate glass powder of the invention is improved in not only physical properties such as crushing strength but also mixing workability without impairing the inherent characteristics thereof for the dental use.

Abstract: A sealing composition suitable for sealing alumina packages for integrated circuits at a temperature below about 450.degree. C. for a short time of about 10 minutes. The composition is a mixture of 50-80 wt % vitreous PbO-B.sub.2 O.sub.3 solder glass powder having a deformation point of 350.degree. C. or less, 0-45 wt % low thermal expansion ceramic powder and 2-40 wt % zircon powder. The zircon powder is of a synthetic zircon artificially prepared to eliminate radioactive impurities such as uranium and/or thorium and contains 0.5-7 wt % Fe.sub.2 O.sub.3, MnO and/or ZnO without alkali impurities and without non-reacted zirconium oxide. The composition has an improved flowability.

Abstract: A ceramic comprises therein two or more dielectric portions having different dielectric constants formed by filling of one or more vacant spaces provided within a dielectric porcelain, a semiconductor porcelain as a precursor of said dielectric porcelain or a molded product as a precursor of said semiconductor procelain with one or more kinds of materials capable of becoming to have different dielectric constants from said dielectric porcelain and subsequent calcination.

Abstract: A method for inhibiting the formation of blisters during the firing of intermediate layers of fired multilayer electronic components comprising the sequential steps of:(1) applying to a substrate a first and second layer of finely divided particles of dielectric solids and glass dispersed in organic medium; and(2) firing the layers to effect volatilization of the organic medium therefrom, liquid phase sintering of the glass components and densification of both layers, the softening point of the glass, the particle size of the glass and the ratio of glass to dielectric solids in both layers being adjusted in such manner that when the layers are fired, the first layer is porous and the second layer is nonporous.

Abstract: A ceramic composition for a multilayer printed wiring board, consisting essentially of from 35 to 95% by weight of glass powder and from 5 to 65% by weight of refractory filler powder, said refractory filler powder being at least one member selected from the group consisting of .alpha.-quartz, corundum, zircon and zirconia and said glass powder consisting essentially of from 25 to 40% by weight of SiO.sub.2, from 4 to 15% by weight of Al.sub.2 O.sub.3, from 15 to 25% by weight of B.sub.2 O.sub.3, from 15 to 40% by weight of BaO+CaO+MgO, from 1 to 10% by weight of ZnO and from 0.5 to 5% by weight of ZrO.sub.2.

Abstract: A sealing composition suitable for sealing alumina packages for integrated circuits at a temperature below about 450.degree. C. for a short time of about 10 minutes. The composition is a mixture of 50-80 wt % vitreous solder glass powder of PbO-B.sub.2 O.sub.3 system having a deformation point of 350.degree. C. or less, 1-35 wt % zinc material powder and 1-35 wt % zircon powder. The zircon powder is of a synthetic zircon artificially prepared to eliminate radioactive impurities such as uranium and/or thorium.

Abstract: A glass glazing is provided with a coating of a colored enamel composition along one or more edges. The enamel composition includes a vitreous matrix pigment and from 2 to 5% by weight of powdered tin dioxide which preferably is an additive during a comminution step. The vitreous matrix which represents at least 75% by weight of the enamel composition includes the following constituentsSiO: 25-33 (% by weight)PbO: 47-65B.sub.2 O.sub.3 : 3-7Na.sub.2 O: 1-4K.sub.2 O: 0-2Li.sub.2 O: 0-0.8ZnO: 0.2-0.5and provides a molar ratio of SiO.sub.2 to PbO between 1.6 and 2.7. The total content of the alkaline oxide are less than 5% by weight.The linear thermal expansion coefficient of the vitreous matrix is less than the glazing to be coated.

Abstract: A dielectric glass and a glass ceramic obtained therefrom is provided for separating crossing conductors in multilayer thick-film circuits. The dielectric glass has a composition in mol. % between the limits of 10-25% ZnO, 7.5-25% PbO, 50-60% SiO.sub.2, and 7.5-12.5% Al.sub.2 O.sub.3. These compositions are particularly suitable for conductor patterns having silver because they are free from micropores.

Abstract: A crystallizable sealing glass composition in powered form that is a blend of a Pbo/ZnO/B.sub.2 O.sub.3 /SiO.sub.2 /BaO glass in the vitreous state and a small effective amount of finely divided zinc zirconium silicate as a nucleating agent. The zinc zirconium silicate has an average particle size of about 2 to 8 microns and is used alone, or in combination, with zirconium silicate having an average particle size of about 20 to 30 microns. The glass composition can be used to seal television picture tubes at 440.degree. C. or 460.degree. C. with excellent results, the early stages of crystallization showing large crystals and large glassy area, as well as DTA curve peaks at 15 to 25 minutes at 440.degree. C.

Abstract: Metal vaporization from precious metals is reduced by applying to the surface of the metal a flame sprayed coating comprising a refractory material and a glass.

Abstract: An improved semiconductor die bonding structure and method for electrical devices is described which utilizes a ductile foil between the semiconductor die and the base of the device package. The die is sealed to the foil with a die bonding material formed from a titania free base glass to which has been added 23.6 to 36.4 weight percent lead titanate powder to give a glass plus ceramic mixture consisting essentially of (by weight percent) 2.5-10.7% GeO.sub.2, 0-2.3% SiO.sub.2, 58.6-78.5% PbO, 0-5.3% PbF.sub.2, 7-13% B.sub.2 O.sub.3, 2.5-6.9% Al.sub.2 O.sub.3, 0-5.3% ZnO, 0.4-2.3% V.sub.2 O.sub.5, 0-5.3% CdO, and 6.2-9.6% TiO.sub.2. The ductile foil is bonded to the ceramic package base directly without intermediate layers or alternatively by means of an improved foil bonding glass material consisting essentially of (by weight percent) 10-15% SiO.sub.2, 45-55% PbO, 8-12% ZnO, 2-5% Al.sub.2 O.sub.3, and 25-30% B.sub.2 O.sub.3.

Abstract: There are obtained metal effect glazes having broad displays of colors, which also can be employed for rapid firing conditions by treating 75-95% of a base glaze made of 20-55% PbO, 0.1-10% Na.sub.2 O, 1-15% CaO, 1-18% Al.sub.2 O.sub.3, and 8-81% SiO.sub.2 with 5-25% of a color body made of 10-80% MnO.sub.2, 1-20% Cu, 0.1-50% TiO.sub.2, and 0.01-20% NiO.

Abstract: A biologically active glass and class-ceramic composition useful for making surgical and dental implants comprising, by mol %,:______________________________________ SiO.sub.2 35.about.60 B.sub.2 O.sub.3 5.about.15 Na.sub.2 O 10.about. 30 CaO 5.about. 40 TiO.sub.2 0.5.about. 10 P.sub.2 O.sub.5 0.about. 15 K.sub.2 O 0.about. 20 Li.sub.2 O 0.about. 10 MgO 0.about. 5 Al.sub.2 O.sub.3 + ZrO.sub.2 + Nb.sub.2 O.sub.5 0.about. 8 La.sub.2 O.sub.3 + Ta.sub.2 O.sub.5 + Y.sub.2 O.sub.3 0.about.8 and F.sub.2 0.about.15.

Abstract: A terminal assembly includes a ferrule and a terminal pin disposed in spaced relationship to the ferrule. First layers made from a first ceramic insulating material are disposed in spaced relationship to each other in the space between the terminal pin and the ferrule. The layers are primarily polycrystalline but partially amorphous. Second layers made from a second ceramic insulating material are disposed in spaced relationship to each other in the space between the terminal pin and the ferrule and between the first layers. The second layers are fused to the terminal pin and the ferrule and the first layers. The second layers are primarily amorphous but partially polycrystalline. Layers of a third insulating material having relatively high characteristics of electrical insulation and having a lower melting temperature than the first and second layers may be respectively disposed at the opposite ends of the terminal assembly.

Abstract: Dentures, dental glazes or coatings, reconstructive jacket-crowns and inlays and restorative constructions over metal or preformed alumina substrates are fabricated from a dental porcelain frit prepared by a gel route.

Abstract: Acid and alkali oxides are smelted for an extended period of time at a first elevated temperature above their melting temperatures. The smelted mixture is then quenched in water and fritted. The fritted mixture is then disposed between a pair of members which are to be hermetically sealed relative to each other. The fritted mixture is then at least partially fused in an oxygen atmosphere at a second temperature below the first temperature for a relatively short period of time. The at least partially fused mixture is then rapidly cooled in air. In this way, the mixture is provided with a partially amorphous state and a partially crystalline state. The crystals in the mixture are disposed primarily at the borders of at least a particular one of the members to be sealed.The mixture hermetically seals the two members, is resistant to acids and alkalis and inhibits the propagation of cracks.

Abstract: Thick film dielectric compositions suitable for screen-printing comprising a substituted perovskite, an inorganic dopant, and a low temperature-devitrifiable frit or glass. Upon firing the dielectric composition is highly hermetic.

Abstract: Thick film dielectric compositions suitable for screen-printing comprising a perovskite, a bismuth-substituted pyrochlore, and a low temperature melting-devitrifiable glass. Upon firing the dielectric composition is highly hermetic.

Abstract: Acid and alkali oxides are smelted for an extended period of time at a first elevated temperature above their melting temperatures. The smelted mixture is then quenched in water and fritted. The fritted mixture is then disposed between a pair of members which are to be hermetically sealed relative to each other. The fritted mixture is then at least partially fused in an oxygen atmosphere at a second temperature below the first temperature for a relatively short period of time. The at least partially fused mixture is then rapidly cooled in air. In this way, the mixture is provided with a partially amorphous state and a partially crystalline state. The crystals in the mixture are disposed primarily at the borders of at least a particular one of the members to be sealed.The mixture hermetically seals the two members, is resistant to acids and alkalis and inhibits the propagation of cracks.

Abstract: A vitreous enamel resistor material comprising a mixture of a vitreous glass frit, an insulating material containing an oxide of zirconium, and a conductive phase of fine particles of tin oxide. The insulating material is selected from the group consisting of zirconia (ZrO.sub.2), calcium zirconate (CaZrO.sub.2), barium zirconate (BaZrO.sub.3) and strontium zirconate (SrZrO.sub.3), and the conductive phase may also contain an additive such as tantalum oxide. An electrical resistor is made from the resistor material by applying the material to a substrate and firing the coated substrate to a temperature at which the glass softens. Upon cooling, the substrate has on the surface thereof a film of glass and insulating material having the particles of the conductive phase embedded therein and dispersed therethroughout. The resistor material provides a resistor having relatively high resistivity as well as rugged physical characteristics.

Abstract: There is disclosed an integral vitreous article composed of an opaque portion encased within a thin surface layer of transparent, colored glass. The article has a uniform chemical composition of an alkaline aluminosilicate nature, the opaque portion contains light scattering particles of a titaniferous nature, and the surface layer contains a titania coupled colorant. The article may be produced by simultaneously forming an article and quenching its surface whereby differential heat extraction produces the transparent surface layer.

Abstract: A buffered glass ionomer cement for dental use, including in combination, a mixture of a fine particle, 5-10 microns, powder consisting essentially by weight of______________________________________ silica 20-30% boron oxide 1-10% aluminum oxide 10-20% aluminum fluoride 1-10% calcium fluoride 30-40% phosphorus pentoxide .[.1-5%.]..Iadd.1-10%.Iaddend. ammonium fluoride .[.1-10%.]..Iadd.1-5%.Iaddend. ______________________________________plus five to twenty percent of the weight of the above of zinc oxide and zero to ten percent of titanium dioxide, anda liquid component comprising, by weight polyacrylic acid of low molecular weight, 40% solution in water--100-80% by weight, d-tartaric acid--0-20%. The powder and the liquid component are mixed together in a ratio of from 1:1 to 5:3 by weight.