Abstract: A transparent glass which, at a thickness of 2 mm, does not transmit more than about 1% of ultraviolet radiation at a wavelength of 380 nm and exhibits a neutral gray, fixed tint bounded by apices A, B, C, D, A of the drawing, a purity no higher than 6, and a luminous transmittance between 10-16, said glass having a composition consisting essentially, expressed in terms of weight percent on the oxide basis, of______________________________________ SiO.sub.2 65-72 CaO 0-1.5 B.sub.2 O.sub.3 2-6 Al.sub.2 O.sub.3 + CaO 0.2-2.25 Na.sub.2 O 6-10 As.sub.2 O.sub.3 0-0.3 K.sub.2 O 10-16 Fe.sub.2 O.sub.3 4.8-6.2 Na.sub.2 O + K.sub.2 O 17-23 Co.sub.3 O.sub.4 0.012-0.02 K.sub.2 O:Na.sub.2 O 1.25-2.25 NiO 0.16-0.21 Al.sub.2 O.sub.3 0-2.25 ZnO 0-1.5.

Abstract: A borosilicate glass composition consisting essentially of the following components:______________________________________ SiO.sub.2 57-77 mol %, Al.sub.2 O.sub.3 0-8.5 mol %, B.sub.2 O.sub.3 4.6-23.0 mol %, ______________________________________the total amount of SiO.sub.2 +Al.sub.2 O.sub.3 +B.sub.2 O.sub.3 being from 81 to 91 mol %, ______________________________________ Li.sub.2 O 0-1.5 mol %, Na.sub.2 O 2-7.5 mol %, K.sub.2 O 2-7.5 mol %, ______________________________________the total amount of Li.sub.2 O+Na.sub.2 O+K.sub.2 O being from 7.6 to 10.6 mol %, ______________________________________ CeO.sub.2 0.7-2.0 mol %, Sb.sub.2 O.sub.3 0-0.3 mol %, As.sub.2 O.sub.3 0-0.3 mol %, TiO.sub.2 0-2.0 mol %, F.sub.2 0-2.0 mol %, ______________________________________and one or more of MgO, CaO, SrO, BaO, ZnO and PbO, in a total amount of from 0 to 7 mol %; the glass composition having a coefficient of linear expansion within the range 64.0-70.0.times.10.sup.-7 /deg.C.

Abstract: This invention is concerned with ceramic substrates for multilayer interconnection. This invention is also concerned with a raw batch for ceramic substrates which require a calcining temperature as low as 1,000.degree. C. or lower upon their production, are low in dielectric constant and have a coefficient of thermal expansion close to that of silicon and also with a process for the production of the substrates. This invention makes use of a raw batch which permits the use of a low resistance conductor such as Ag-Pd, Ag, Au or Cu and also the production of substrates by low-temperature calcination. The raw batch contains borosilicate silicate glass powder, and aluminum borate powder and at a weight ratio of 40-80 percent to 20-60 percent. The raw batch can additionally contain one or more specific oxides in particular proportions.

Abstract: A glass-ceramic composition for forming a glass-ceramic dielectric body having a dielectric constant of less than about 4.5, a firing temperature of less than about 950.degree. C. and a sintered density of greater than 95% theoretical density. The composition is formed from a mixture consisting essentially of finely divided particles of 40-50 vol. % borosilicate glass and 50-60 vol. % cordierite. The borosilicate glass comprises approximately 20-35 wt. % B.sub.2 O.sub.3 and approximately 60-75 wt. % SiO.sub.2. The exact particle size ratio of the cordierite to borosilicate glass that is used will depend on the proportions of the components, the desired fired density and the firing temperature. The mixture is fired at a temperature of less than 1000.degree. C.

Abstract: This invention provides a composite article comprising mullite bubbles dispersed in one of a glass matrix and a glass-ceramic matrix, and a method of making the same. The composite ceramic article of the present invention is useful in applications requiring a material having a low dielectric constant, low dissipation factor, thermal expansion properties compatible with silicon, and good mechanical strength. The composite ceramic article of the present invention is particularly useful as a substrate for thick film circuits, housings for integrated circuit assemblies (i.e., covers), and materials such as gyrotron windows, that require transparency to microwaves or millimeter waves, in addition to acceptable power transmission efficiencies.

Abstract: The present invention is directed to an alkali borosilicate frit which is capable of being applied to a metal substrate by the dry powder electrostatic process at a transfer efficiency of at least 70%, has a glass transition temperature of >525.degree. C. and contains, based on the total weight of the frit:______________________________________ Oxide Wt % ______________________________________ K.sub.2 O 6 to 10 Na.sub.2 O 5.5 to 9 LiO.sub.2 0 to 4 ZrO.sub.2 0 to 4 TiO.sub.2 0 to 4 ZnO 0 to 15 B.sub.2 O.sub.3 8 to 15 SiO.sub.2 40 to 60 La.sub.2 O.sub.3 3 to 9 CaO 0 to 15 F 0 to 2 Fe.sub.2 O.sub.3 0 to 3 CoO 0 to 5 NiO 0 to 5, ______________________________________wherein the total weight of CoO plus NiO is at least 1.The present invention is also directed to enamels for self-cleaning ovens containing these frits.

Abstract: Methods for preparing a green sheet and a glass ceramic substrate are herein disclosed.

Abstract: A metal oxide dielectric dense body, comprising (I) grains having a predominant crystalline phase (a) a primary metal oxide selected from the group consisting of silicon and magnesium oxide and (b) optionally a secondary metal oxide selected from the group consisting of aluminum and zinc oxide and (II) between about 1 and about 20 atom % bismuth, vanadium, or boron oxide or combination thereof, discontinuously located at the boundaries of the crystalline grains or as inclusions in the crystalline grains, the atom %'s based on the total atoms of bismuth, vanadium, boron, silicon, magnesium, aluminum, and zinc. The dense body has a density which is at least 95% of theoretical.

Abstract: A method for improving the characteristics of fused slag material is disclosed. This improved method results in a fused slag having resistance against pulverization at the cooling process or generation of yellowish turbid water due to contact of slag lumps with rain water, this method characterized by forming a slag treatment material by rough crushing a substantially dehydrated heat-treated material containing boron, and adding that slag treatment material to molten slag.

Abstract: A thick film dielectric paste for giving fine lines and vias comprises a low permittivity borosilicate or aluminoborosilicate dielectric material of particle size less than 5 .mu.m, together with a medium. The dielectric material sinters at from 600.degree. C. to 1100.degree. C. and is preferably made by sol-gel techniques. Relatively low sintering temperatures can be combined with low permittivity.

Abstract: A low dielectric, low temperature fired glass ceramic produced by firing at about 800.degree.-950.degree. C. a mixture comprising at least one glass consisting of, by weight percent, 0 to 50% B.sub.2 O.sub.3, 35 to 65% CaO, and 10 to 65% SiO.sub.2 l , and selected from the glasses of CaO-B.sub.2 O.sub.3 -SiO.sub.2 glass system. The glass ceramic is light weight, exhibits a dielectric constant of less than about 5.2, has adequate mechanical strength and thermal conductivity, and is compatible with precious metal conductors. The glass ceramic is useful in the manufacture of integrated circuits and any other electronic or mechanical components where a glass ceramic exhibiting this particular combination of characteristics is suitable.

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: 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: An etchable core glass composition consisting essentially of the following components present in the glass in the following mole percent ranges is shown:CHART I ______________________________________ CHEMICAL COMPOSITION RANGES mole percent ______________________________________ SiO.sub.2 35-46 B.sub.2 O.sub.3 22-28 BaO + SrO + CaO + ZnO 20-32 Al.sub.2 O.sub.3 + Y.sub.2 O.sub.3 0-3.5 La.sub.2 O.sub.3 + Nd.sub.2 O.sub.3 + Sm.sub.2 O.sub.3 + CeO.sub.2 1-11 As.sub.2 O.sub.3 + Sb.sub.2 O.sub.3 0-1.5 ______________________________________A core glass for manufacturing a microchannel plate made from a glass composition having components in the glass range as defined above is also shown. The core glass has a transformation temperature in range of about 637.degree. C. to about 654.degree. C., a liquidus temperature below 1000.degree. C.

Abstract: A strengthened high NdO.sub.3 -containing glass has the composition of, in weight percent______________________________________ SiO.sub.2 40-60 Nd.sub.2 O.sub.3 10-30 As.sub.2 O.sub.3 /Sb.sub.2 O.sub.3 0-1 B.sub.2 O.sub.3 5.15 Na.sub.2 O 3-18 ZnO 0.1-10 Li.sub.2 O 0-3 K.sub.2 O 0-3 Al.sub.2 O.sub.3 0-7 PbO 0-15 MgO 0-3 CaO 0-3 BaO 0-3 SrO 0-3 .SIGMA.V.sub.2 O.sub.5, Cr.sub.2 O.sub.3, Mn.sub.2 O.sub.3 0-7 Fe.sub.2 O.sub.3, CoO, NiO, CuO TiO.sub.2 0-5 Pr.sub.6 O.sub.11 0-1.

Abstract: Cerium-doped radiation-shielding glasses in the system of SiO.sub.2 -PbO-alkali metal oxides, with a high absorption coefficient for high-energy X-ray and/or gamma- and, respectively, neutron radiation which are resistant to discoloration and exhibit a discharge stability of >5.times.10.sup.8 rad, consist essentially of (in % by weight)______________________________________ SiO.sub.2 35-56 Na.sub.2 O K.sub.2 O 12-21 Cs.sub.2 O PbO.sub.2 24-46 CeO.sub.2 0.5-2.5 CuO + Fe.sub.2 0-0.05; ______________________________________for absorption of neutrons, the isotope Li.sup.6 can furthermore be onctained therein, and SiO.sub.2 can be substituted by B.sub.2 O.sub.3 and/or Gd.sub.2 O.sub.3 in an amount of up to 10% by weight and Gd.sub.2 O.sub.3 is present.

Abstract: A ceramic composition for forming a ceramic dielectric body having a dielectric constant of less than about 4.2. The composition is formed from a mixture of finely divided particles of 25-50 vol. % borosilicate glass and 50-75 vol. % high silica glass. The borosilicate glass comprises approximately 20-35 wt. % B.sub.2 O.sub.3 and approximately 60-80 wt. % SiO.sub.2. The high silica glass contains essentially 0.5-1 wt. % alumina, 1-5 wt. % B.sub.2 O.sub.3 and approximately 95-98 wt. % SiO.sub.2. The composition can be fired at a temperature of less than 1000.degree. C.

Abstract: A composition for making dielectric layers having low dielectric constant, the composition comprising an admixture of finely divided solids comprising lead-free amorphous borosilicate glass and cordierite glass. The dielectric layers are useful in circuits, especially multilayers circuits for high density applications.

Abstract: Gradient-index glass is produced in a sol-gel process by utilizing water or a mixture of water and alcohol. This technique is particularly suitable for production of glass bodies with a ternary system of metal alkoxides, including silicon alkoxide, an index modifying metal alkoxide, such as alkoxides of titanium and zirconium, and an additional metal alkoxide, such as an alkoxide of aluminum, boron, or germanium.

Abstract: A glass frit useful as starting material for the preparation of glass bubbles having an extremely low alkali elution, which has the following composition represented by weight percent.______________________________________ SiO.sub.2 58-75 B.sub.2 O.sub.3 11-25 Na.sub.2 O 3-12.5 ZnO 0-3 K.sub.2 O 0-3 Al.sub.2 O.sub.3 0-3 Li.sub.2 O 0-3 P.sub.2 O.sub.5 0-3 Total alkali metal oxides Sb.sub.2 O.sub.3 0-1 3-15 As.sub.2 O.sub.3 0-1 CaO 5-15 SO.sub.3 0.05-1 MgO 0-3 B.sub.2 O.sub.3 /Na.sub.2 O 1.7-4.

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 radiation shielding glass consisting esentially of 40.0% to 60.0% SiO.sub.2, 25.0% to 45.0% of PbO, 1.5% to 2.0% CeO.sub.2, 4.5% to 12.0% Na.sub.2 O, 2.0% to 9.0% K.sub.2 O, 0% to 5.0% B.sub.2 O.sub.3, and 0% to 10.0% BaO, Na.sub.2 O/(Na.sub.2 O+K.sub.2 O) being 0.5 to 0.8. The glass has a high radiation shielding capacity and is excellent in a resistance to browning by the gamma ray irradiation and an improved dielectric breakdown. The glass is useful for a window glass of an irradiation room of the gamma ray.

Abstract: The present invention relates to a glass/ceramic sealing system. A sealing glass having a coefficient of thermal expansion in excess of 160.times.10.sup.-7 in/in/.degree. C. is provided. The glass is useful for matched sealing of copper and copper based alloys. The glass is capable of ceramization, greatly increasing the resistance of the glass to moisture penetration and fracture due to mechanical damage. The temperature of ceramization has been designed so that a solutionized copper alloy leadframe is age hardened during ceramization. The glass has particular utility in the manufacture of electronic packages and multi-layer circuitry.

Abstract: A process for preparing a surface-darkened glass is disclosed. In the first step of this process, a specified silicate glass which contains a minor amount of antimony trioxide is provided. Thereafter, this glass is heated to a temperature of from about 350 to about 1,000 degrees Celsius while being contacted with hydrogen-containing gas. The presence of the antimony trioxide in the glass facilitates the darkening of its surface.

Abstract: A strengthened high lanthanide-containing glass has the composition of, in mole percent______________________________________ SiO.sub.2 54-75 B.sub.2 O.sub.3 5-17 Li.sub.2 O 0-4 Na.sub.2 O 3-18 K.sub.2 O 0-4 Al.sub.2 O.sub.3 0-7 PbO 0-4 MgO 0-3 CaO 0-3 SrO 0-3 BaO 0-3 ZnO 0.1-10 TiO.sub.2 0-5 Ln.sub.2 O.sub.3 3-7 V.sub.2 O.sub.5 + Cr.sub.2 O.sub.3 + Mn.sub.2 O.sub.3 0-5 Fe.sub.2 O.sub.3 + CoO + NiO + CuO As.sub.2 O.sub.3 /Sb.sub.2 O.sub.3 0-0.4 ______________________________________wherein Ln is La, Ce, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and/or Yb.

Abstract: A variable TCE composition for making dielectric layers having low dielectric constant and low dielectric loss, the composition comprising an admixture of finely divided solids comprising amorphous crystallizable glass, amorphous borosilicate frit, ceramic expansion control additive, and crystallization control additive. The dielectric layers are useful in circuits especially for high density and high frequency applications.

Abstract: Glass having ultrafine particles of CuCl and/or CuBr precipitated therein, which consists essentially of:from 10 to 70 mol % of SiO.sub.2,from 30 to 90 mol % of B.sub.2 O.sub.3,from 0.1 to 50 mol % of Li.sub.2 O+Na.sub.2 O+K.sub.2 O, andfrom 0.01 to 10 mol % of CuCl+CuBr.The glass may further contain from 0.01 to 40 mol % of Al.sub.2 O.sub.3.

Abstract: A low alkali borosilicate glass composition comprising60 to 78% by weight of SiO.sub.210 to 25% by weight of B.sub.2 O.sub.33.5 to 6.0% by weight of R.sub.2 O, wherein R.sub.2 O represents Na.sub.2 O, K.sub.2 O and/or Li.sub.2 O,2.0 to 6.5% by weight of CeO.sub.2, and0.25 to 8.0% by weight of Sb.sub.2 O.sub.3 and/or As.sub.2 O.sub.3,the percentages being based on the total weight of the glass composition. The glass composition of the invention are suitable for use as protective covers for solar cells, especially solar cells which are used in satellites.

Abstract: Fluorine-free titanium white enamel frits for enamelling steel consisting essentially of:35 to 45 parts by weight of the sum of SiO.sub.2 and ZrO.sub.2,18 to 22 parts by weight of TiO.sub.2,18 to 22 parts by weight of the sum of B.sub.2 O.sub.3 and Al.sub.2 O.sub.3,15 to 18 parts by weight of alkali metal oxides,2.5 to 4.5 parts by weight of P.sub.2 O.sub.5, and0.8 to 1.4 parts by weight alkaline earth metal oxides;with the proviso that the ratio of atomic numbers is as follows:(A+2B) to C is 0.9.+-.0.05,(lithium+0.5 magnesium) to phosphorous is 1.+-.0.1, and sodium to potassium is 1.2 to 2.6,wherein A is the sum of monovalent atoms, B is the sum of divalent atoms and C is the sum of trivalent atoms.

Abstract: Radioactive microspheres for radiation synovectomy of arthritic joints in a mammal comprises a biodegradable glass material and a beta radiation emitting radioisotope chemically dissolved in and distributed substantially uniformly throughout the glass material. The biodegradable glass material may be lithium silicate, lithium aluminosilicate, lithium aluminoborate, lithium germanate, lithium aluminogermanate, potassium silicate, potassium aluminosilicate, potassium aluminoborate, potassium germanate or potassium aluminogermanate and the beta radiation emitting radioisotope may be samarium-153, holmium-166, erbium-169, dysprosium-165, rhenium-186, rhenium-188 or yttrium-90. Method for preparing such microspheres and for carrying out radiation synovectomy of arthritic joints utilizing such microspheres are also disclosed.

Abstract: Resistive paste comprises at least one metal hexaboride and a vitreous binder suspended in an organic vehicle, and is characterized in that said vitreous binder is composed of a glass frit consisting essentially of 0.5 to 5.0 mol % of niobium oxide and the balance of alkaline earth metal borosilicate. The resistive paste may further contain at least one nitride selected from the group consisting of aluminum nitride and boron nitride, the content of aluminum nitride or boron nitride in the inorganic solid component composed of metal hexaboride, vitreous binder and aluminum or boron nitride in the paste being 5 to 30 wt %.

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 state as weight percentages: SiO.sub.2 (50 to 57%); R.sub.2 O(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: Lead-free glass frit compositions for use in vitreous coatings consisting essentially of Na.sub.2 O--ZnO--B.sub.2 O.sub.3 --SiO.sub.2 in appropriate concentrations including molar amounts of at most 17.5 mole percent of B.sub.2 O.sub.3 and at least 40 mole percent of SiO.sub.2.

Abstract: The present invention relates to a glass for making glass to metal seals. The coefficient of thermal expansion of the glass is in excess of 160.times.10.sup.-7 in/in/.degree.C. making the glass particularly useful for sealing copper and copper based alloys. The glass has particular utility in the manufacture of electronic packages and multi-layer circuitry.

Abstract: An inorganic glass having high water repellence produced by irradiating and/or implanting ions upon or into a surface of the inorganic glass, the ions are those of at least one element selected from the group consisting of(a) halogen elements selected from F, Cl, and Br, group 3A, 3B, 4A and 5B elements of the International Periodic Table selected from Al, Ti, Y, In and Bi,(b) rare gas elements selected from He, Ne, Ar, Kr and Xe, group 3A, 4A, 1B, 2B, 3B, 4B and 5B elements of the International Periodic Table selected from Sc, Cu, Zn, Ag, Cd, Sn, Sb, Au, Hg, Tl and Pb, alkali metal or alkaline earth metal elements selected from Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr and Ba, and(c) Ce, the dose of th (a), (b) and (c) ions being 5.times.10.sup.14 to 1.times.10.sup.20 ion/cm.sup.2, 5.times.10.sup.14 to 1.times.10.sup.17 ion/cm.sup.2 and 1.times.10.sup.17 to 1.times.10.sup.20 ion/cm.sup.2, respectively.

Abstract: A ceramic substrate for an electrical device such as a layered circuit or an integrated circuit formed of a crystalline glass or ceramic material having a low densifying temperature such that conductor materials and circuits can be readily formed from high conductivity metals.

Abstract: Porous, silica-rich shapes have improved strength and abrasion resistance by leaching the precursor glass shape in preconditioned acid having silica ion and at least one common ion that is also present in the precursor glass shape. The precursor glass shapes have shapes such as fibers, hollow fibers, tubes, rods, beads, hollow spheres and plates and compositions having 30-75 volume percent silica and at least 10-65 volume percent nonsiliceous acid extractable components. Preconditioning of the acid solution results from a pretreatment of the acid with compounds that dissociate into the ions when added to the acid solution or with shapes, particles or fragments of glass compositions different from or similar to the glass shape to be leached so long as the glass composition has extractable material to provide the silica ion and at least one common ion.

Abstract: A process for joining components having ceramic and metallic joining surfaces provides a permanent and complete joint with ceramic surfaces despite metal-oxide layers on the metal or metal-alloy joining surfaces. A glass coating is applied to the ceramic joining surface before joining. The glass contains at least 5 to 20% by weight of Na.sub.2 O, 30 to 60% by weight of B.sub.2 O.sub.3 and 20 to 60% by weight of SiO.sub.2. The surfaces of the components to be joined are then permanently joined to each other at a specified temperature and a specified pressure.

Abstract: A sol-gel method for making gradient-index glass and a novel composition therefor, comprising at least a ternary system of metal alkoxides.

Abstract: An alkali-free composition for making a ceramic dielectric body having a dielectric constant less than 5.0, which is a mixture of finely divided particles consisting essentially of 70-85% wt. silica and 15-30% wt. zinc borate flux. This composition can be used to make green tape and multilayer devices having internal copper conductors such as multilayer capacitors and multilayer interconnects.

Abstract: The present invention relates to an improved U.V. absorbing glass composition comprising from about 75 to about 98 parts by weight of a lead oxide free base glass having dissolved therein from about 2 to about 25 parts by weight of a U.V. additive selected from the group consisting of cerium oxide, manganese oxide, iron oxide, cobalt oxide, copper oxide, vanadium oxide, molybdenum oxide, and mixtures of two or more of said oxides; and to an ink composition comprising from about 15 to about 25% by weight vehicle, from about 8 to about 16% by weight a ceramic pigment, and from about 59 to about 77% by weight of said U.V. absorbing glass composition.

Abstract: Disclosed are an adhesive for oxide ceramics, which comprises as its effective ingredient a crystallized glass mainly comprising SiO.sub.2, Al.sub.2 O.sub.3, Li.sub.2 O, MgO and/or ZnO, and TiO.sub.2 and/or ZrO.sub.2, and also a method of bonding oxide ceramics together, which comprises heating oxide ceramics to be bonded together at 1200.degree. to 1600.degree. C. with the adhesive placed between the ceramics.

Abstract: This invention is directed to the preparation of glass-ceramic materials especially suitable for use in multilayer substrates for integrated circuit packages. The inventive glass-ceramics are derived from thermally crystallizable glass which, in the form of frit, are capable of being sintered into an integral body at temperatures below 1000.degree. C. and essentially concurrently crystallized in situ to yield BPO.sub.4 as the predominant crystal phase. The inventive glass-ceramics exhibit a linear coefficient of thermal expansion between about 30-45.times.10.sup.-7 /.degree.C., a dielectric constant less than 5, and consist essentially, in weight percent, of 10-25% B.sub.2 O.sub.3, 20-40% P.sub.2 O.sub.5, and >50-65% SiO.sub.2.

Abstract: This invention is related to glasses particularly useful in the fabrication of multifocal lenses for ophthalmic applications. The inventive glasses exhibit a refractive index between 1.599-1.602, an Abbe number between 40.5-41.5, a density between 2.64-2.66 g/cm.sup.3, a transmission of visible radiation at 400 nm through a thickness of 10 mm greater than 83%, a softening point between 670.degree.-680.degree. C., a birefringence upon sealing, measured as described, between -150 and +150 nm/cm, and consist essentially, expressed in terms of weight percent on the oxide basis, of:______________________________________ SiO.sub.2 52-57 K.sub.2 O 11.0-16.0 B.sub.2 O.sub.3 2.5-7.0 CaO 2-3.5 Al.sub.2 O.sub.3 0-1 ZrO.sub.2 1-1.5 Li.sub.2 O 0.3-0.8 TiO.sub.2 15.0-16.2 Na.sub.2 O 5.4-8.2 As.sub.2 O.sub.3 0.1-0.

Abstract: This specification discloses optical light-weight glass having a composition of SiO.sub.2 47--70, Li.sub.2 O 5.5-21, K.sub.2 O 2-30, Na.sub.2 O 0-30 (Li.sub.2 O+Na.sub.2 O+K.sub.2 O 21-50), TiO.sub.2 9.5-24, B.sub.2 O.sub.3 0-20, CaO 0-20, MgO+SrO+BaO+ZnO 0-4, Al.sub.2 O.sub.3 0-5 and ZrO.sub.2 +La.sub.2 O.sub.3 +Ta.sub.2 O.sub.5 +WO.sub.3 0-3, all being in % by weight, and having a refractive index (n.sub.d) of 1.58-1.65, an Abbe number (.gamma..sub.d) of 35-50 and a specific gravity of 2.69 or less. This optical glass is light in weight, high in transparency and low in dispersion, and is particularly suitable for spectacle lenses, but can also be utilized for photographic lenses.

Abstract: A sol-gel method for making gradient-index glass and a novel composition therefor, comprising at least a ternary system of metal alkoxides.

Abstract: A chemically durable porous glass of which the skeleton mainly comprises SiO.sub.2 -ZrO.sub.2 system glass having a ZrO.sub.2 content of 2 or more wt %, and a process for the production of such glass.

Abstract: Glass microbubbles having, on a weight basis, a composition consisting essentially of 70-80% SiO.sub.2, 8-15% CaO, 3-8% Na.sub.2 O, and 2-6% B.sub.2 O.sub.3, and about 0.2-1.5% SO.sub.3 and having a CaO:Na.sub.2 O ratio of 1-3.5. These microbubbles, which are made of significantly less expensive raw materials than conventional products, can also be made with a higher percent "floaters" and a lower average density. Certain substitutions can be made for at least a portion of each of the first three oxides.

Abstract: This invention provides a ceramic multi-layer circuit board wherein electroconductive patterns and ceramic insulating layers are piled alternately, characterized in that each ceramic insulating layer is a sintered product comprising one or more kinds of silica and a glass. Since the glass has a softening point lower than the melting point of the material of the electroconductive patterns, it enables sintering of the ceramic multi-layer circuit board at low temperatures. The silica is effective for reduction of the dielectric constant of each ceramic insulating layer.

Abstract: Partially crystallized ceramic articles is prepared by firing at low temperatures of 800.degree. to 1100.degree. C., a mixture consisting essentially of, (a) 40 to 50 wt. % of powdered, noncrystalline glass consisting essentially of 10 to 55 wt. % of at least one selected from the group consisting of CaO and MgO, 45 to 70 wt. % of SiO.sub.2, 0 to 30 wt. % of Al.sub.2 O.sub.3, 0 to 30% of B.sub.2 O.sub.3 and up to 10% impurities, the powder size of said glass being at least 4.0 m.sup.2 /g in terms of specific surface area measured by the BET Method; and (b) 60 to 50 wt. % of powdered Al.sub.2 O.sub.3 and the ceramic article is composed essentially of a noncrystallized glass phase, alumina and at least one of crystallized glass phase among anorthite, wollastonite, cordierite and mullite formed by partially crystallizing the glass (a).