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: 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 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: 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: 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: This invention relates to photochromic glasses exhibiting refractive indices greater than 1.59, densities no higher than 3.1 g/cm.sup.3, Abbe numbers of at least 40, weight losses no greater than 0.01 mg/cm.sup.2 in the A.O. test, and which, when exposed to actinic radiation at room temperatures, darken to transmittances below 40% and fade at least 15 percentage points of transmittance after five minutes' removal from the actinic radiation.

Abstract: There are disclosed fluoroborosilicate glasses that are particularly adapted to being drawn with lead silicate core glasses to produce clad glass fibers useful in forming fiber optic bundles to be incorporated in night vision equipment. The cladding glass has a refractive index not over about 1.465 and a coefficient of thermal expansion not over about 80.times.10.sup.-7 /.degree.C. The clad fiber has a numerical aperture approximating or equal to one.

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: A sintered material for recording/reading (particularly magnetic) head slider is produced by:preparing a powdery mixture which comprises 0.5 to 6.0% by weight of at least one component selected from the component group A consisting of the following elements and compounds thereof, a garnet type compound consisting essentially of erbium oxide and aluminum oxide in amounts of 2 to 12% by weight and 0 (exclusive) to 2 (inclusive) % by weight based on the total composition, respectively, and expressed by the formula Er.sub.3 (Al,Er).sub.2 (AlO.sub.4).sub.3 through (Er,Al).sub.3 Al.sub.2 (AlO.sub.4).sub.3, and the balance being silicon carbide powder:the elements for the component group A being Ti, V, Cr, Mn, Mg, Y, Zr, Nb, Mo, Ba, La, Ce, Gd, Hf, Ta, W, Th, and Cs; andsintering the resultant mass under the application of a high pressure.Further sintering aids of Be, BeO, B and B.sub.4 C may be present. For the garnet type compound, erbium oxide may be used, preferably in combination with alumina.

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: A biocompatible glass ceramic comprises, by weight, 7-16% MgO, 20-45% CaO, 41-50% SiO.sub.2, 8-30% P.sub.2 O.sub.5, 0-5% B.sub.2 O.sub.3, 0-5% F.sub.2, and 0-10% Al.sub.2 O.sub.3, and has a crystal structure where a number of fine crystals of apatite, wollastonite, and diopside are densely dispersed and interlace with one another in a glass phase. The glass ceramic is non-porous and has an increased mechanical strength of 2,000 Kg f/cm.sup.2 without degradation of the chemical bonding with the bone of the living body. The glass ceramic contains no alkali and is chemically stable in the living body. The glass ceramic is useful for replacement materials of tooth roots and crowns as well as bones.

Abstract: High PbO-content glass in the optical range of flint and heavy flint glasses from the system SiO.sub.2 --PbO--M.sub.2 O wherein M.sub.2 O=alkali metal oxides, said glass having a minimum PbO content of 30 wt. % and a minimum M.sub.2 O content of 0.5 wt. %, are provided with enhanced chemical stability without loss of the desired optical position by replacing a portion of the SiO.sub.2 and PbO such that the glass contains 1.5-6 wt. % (TiO.sub.2 +ZrO.sub.2) and the ratio of TiO.sub.2 :ZrO.sub.2 is about 0.3-2.0.

Abstract: An aqueous solution of precursors for biologically active glass, support particles coated with the solution, support particles coated with the glass, spheroidal particles of biologically active glass, processes for making the solution, coating the support, and for making the coated support and the spheroidal glass particles. The materials that comprise the biologically active glass are useful in prosthetic devices and implants for the human body.

Abstract: An optical and ophthalmic glass with high refractive index, high Abbe number and low density, which is distinguished by good chemical stability, good crystallization behavior and capability for chemical hardening, comprises (in % by weight):SiO.sub.2 --47 to 75B.sub.2 O.sub.3 --1 to 20Al.sub.2 O.sub.3 --0 to 10P.sub.2 O.sub.5 --0 to 5Li.sub.2 O--0 to 15Na.sub.2 O--0 to 10K.sub.2 O--0 to 10CaO--0 to 20MgO--0 to 15SrO--0 to 4BaO--0 to 4ZnO--0 to 5TiO.sub.2 --1 to 15ZrO.sub.2 --0 to 8Nb.sub.2 O.sub.5 --0 to 5 andF----0 to 5.

Abstract: A high strength glass-ceramic containing apatite and alkaline earth metal silicate (diopside/forsterite/akermanite) crystals having an excellent affinity for a living body and a process for producing the same are disclosed. The glass-ceramic is useful as an implant material such as an artificial dental root and an artificial bone.

Abstract: The invention is directed to a barium borosilicate glass which is free of Bi, Cd and Pb. The glass, which also contains small amounts of NiO, is especially useful as a binder for thick film resistor compositions to be used for making low end resistors.

Abstract: The invention is directed to a barium borosilicate glass which is free of Bi, Cd and Pb. The glass, which also contains small amounts of CoO, is especially useful as a binder for thick film resistor compositions to be used for making high-end resistors.

Abstract: An optical glass with the familiar optical position of n.sub.d >1.70 and v.sub.d >22, which differs from the familiar optical glasses of the optical position due to its lower density and good chemical stability, and is composed of (in percent by weight): SiO.sub.2 25-42, TiO.sub.2 15-35, B.sub.2 O.sub.3 0.5-7, BaO 3-13, CaO 1-3, Nb.sub.2 O.sub.5 1-20, GeO.sub.2 0-2, Al.sub.2 O.sub.3 0-4, Na.sub.2 O 7.5-15, Li.sub.2 O 0-9, K.sub.2 O 2-10, SrO 0-6, ZnO 0-5, ZrO.sub.2 0-3, and WO.sub.3 0-3.

Abstract: These objects have been attained by providing highly absorbent lead containing alkali metal silicate glasses for cathode ray tube image screens, having a linear absorption coefficient .mu. of >30 cm.sup.-1 (0.6 .ANG.) and with a high resistance to discoloration by X-ray and electron radiation, comprises, in weight percent:______________________________________ SiO.sub.2 20-65% P.sub.2 O.sub.5 + B.sub.2 O.sub.3 + Al.sub.2 O.sub.3 0-30% Li.sub.2 O 0-5% Na.sub.2 O 0-10% K.sub.2 O 0-15% MgO + CaO + ZnO 0-15% SrO 0-20% BaO 0-40% PbO 5-60% ZrO.sub.2 0-10% CeO.sub.2 0.1-5% Other Components 0-20%.

Abstract: A borosilicate glass composition suitable for use as an eyeglass lens, characterized by having a refractive index nd.gtoreq.1.58, an Abbe number vd.gtoreq.45, a density .rho..ltoreq.2.75 g/cm.sup.3, and an excellent aptitude for chemical hardening, consisting essentially of the following composition, in weight percent:______________________________________ SiO.sub.2 51-65 B.sub.2 O.sub.3 2-14 Al.sub.2 O.sub.3 0-5 SiO.sub.2 + B.sub.2 O.sub.3 + Al.sub.2 O.sub.3 62-73 Li.sub.2 O 4-13 Na.sub.2 O 0-4 K.sub.2 O 0-4 Li.sub.2 O + Na.sub.2 O + K.sub.2 O 7-15 CaO 1-19 MgO 0-11 CaO + MgO 6-22 TiO.sub.2 0-8 ZrO.sub.2 0-9.

Abstract: A lead-free green ceramic body useful after firing as an electrical resistor, and a method for producing such a resistor, are disclosed. The method preferably comprises the steps of preparing a uniform, finely-divided mixture by blending, by weight, substantially 69 percent of a glass frit with substantially 8 percent of AlPO.sub.4, substantially 3 percent of conductive carbon and substantially 20 percent of a phenyl lower alkyl silicone resin which is curable to form a temporary binder for the conductive carbon and the glass frit. One preferred frit consists essentially of substantially 43 percent SiO.sub.2, 20 percent B.sub.2 O.sub.3, 21 percent Na.sub.2 O, 3 percent CaO, 8 percent BaO and 5 percent Li.sub.2 O. A shape is then pressed from the mixture; the shape is heated to 450-550 degrees F. for about 30 minutes and cooled to ambient temperature. Silver paint is then applied to the cooled shape and the painted shape is fired to vitrify the frit of the resistor.

Abstract: The instant invention is directed to the production of highly crystalline glass-ceramic articles demonstrating high intrinsic mechanical strength and toughness containing crystals of canasite and/or agrellite and/or fedorite as the predominant crystal phase. The articles have overall compositions consisting essentially, expressed in terms of weight percent on the oxide basis, of about______________________________________ SiO.sub.2 45-75 CaO 8-30 F 3.5-12 Na.sub.2 O 3-15 K.sub.2 O 0-20 Na.sub.2 O + K.sub.2 O 5-25 B.sub.2 O.sub.3 0-6 Al.sub.2 O.sub.3 0-7 ZrO.sub.

Abstract: Glass microspheres and other glass elements based on B.sub.2 O.sub.3, BaO, SiO.sub.2 and TiO.sub.2 have an improved combination of crushing strength, index of refraction, and, especially in some formulations, chemical resistance. The microspheres are especially adapted for use as retroreflective elements in pavement markings.

Abstract: Alkali-resistant glass fibres for use as reinforcement in cementitious products are formed from a composition comprising, in weight percentages:______________________________________ SiO.sub.2 55 to 75% R.sub.2 O 11 to 23% ZrO.sub.2 6 to 22% Cr.sub.2 O.sub.3 0.1 to 1% Al.sub.2 O.sub.3 0.1 to 7% Rare earth oxides + TiO.sub.2 0.5 to 16% ______________________________________where R.sub.2 O is any one or more of Na.sub.2 O, K.sub.2 O or Li.sub.2 O, the content of TiO.sub.2 does not exceed 10%, and the total of the components recited above amounts to at least 88% by weight of the glass, the glass having been melted under non-oxidizing conditions such that all or a substantial proportion of the chromium in the glass is in the trivalent state.Cementitious products incorporating such fibres, e.g. in a proportion of 3 to 6 weight %, can be made using a Magnani-type asbestos cement machine or by a "spray-up" method.

Abstract: The incorporation of an additive selected from the group consisting of sodium carbonate, sodium hydroxide and boric acid into a glass batch pellet comprising uncalcined colemanite imparts to the pellets improved strength when heated to 1100.degree. F. (593.degree. C.).

Abstract: Alkali-resistant glass fibres, in the form of continuous-filament for use as reinforcement in cementitious products, or in the form of glass wool, are given enhanced alkali resistance by the incorporation of ThO.sub.2. The fibres are formed from a glass composition comprising, in weight percentages:______________________________________ SiO.sub.2 50 to 75% ThO.sub.2 + ZrO.sub.2 5 to 30% with ThO.sub.2 at least 0.4% R.sub.2 O 0 to 25% R'O 0 to 40% R.sub.2 O + R'O 10 to 40% Rare earth oxides 0 to 20% ______________________________________the content of ThO.sub.2 being at least 1% when the content of ZrO.sub.2 is less than 6% but not exceeding 9.5% when ZrO.sub.2 exceeds 8%, where R.sub.2 O represents Na.sub.2 O, K.sub.2 O or LiO.sub.2, with K.sub.2 O not exceeding 10% and Li.sub.2 O not exceeding 5% and R'O represents one or more of MgO, CaO, SrO, BaO, ZnO and MnO.

Abstract: A flux composition for ceramic color, containing no harmful heavy metal such as lead, cadmium, chromium, etc. is provided.The flux composition consists mainly of 30 to 45% of SiO.sub.2, 0 to 5% of TiO.sub.2, 4 to 10% of ZrO.sub.2, 13 to 18% of B.sub.2 O.sub.3, 18 to 23% of ZnO, 0 to 3% of CaO, 12 to 15% of the total of two or three kinds of R.sub.2 O selected from Na.sub.2 O, K.sub.2 O and Li.sub.2 O, 4 to 10% of fluorine and 0 to 5% of tin oxide (% being all by weight).The composition uses no lead which has been indispensable for lower melting glasses, and exhibits superior performances difficult to afford according to conventional lower melting lead-free fluxes.