Abstract: A low expansion glass comprising, all by weight, from 55 to 65% of SiO.sub.2, from 10 to 20% of Al.sub.2 O.sub.3, from 2 to 10% of B.sub.2 O.sub.3, from 3 to 10% of MgO, from 1 to 8% of CaO, from 2 to 10% of ZnO, from 0 to 4% of R.sub.2 O where R is an alkali metal atom, and from 0 to 4% of ZrO.sub.2.

Abstract: This invention relates to the production of high elastic modulus, high strength, corrosion-resistant oxynitride glass fibers for improved fiber-reinforced composites. The incorporation of nitrogen into silicon-yttrium-aluminum oxide glasses enhances the properties of bulk glass. This invention is the first demonstration that such glasses can be made into fibers. The addition of nitrogen to practically any oxide glass fiber composition will produce improvements in properties similar to those shown for the silicon-yttrium-aluminum system.

Abstract: The present invention relates to neutron-absorbent oxide or oxynitride glasses containing gadolinium and a process for their preparation.The glasses according to the invention, which incorporate silicon, aluminum, oxygen or oxygen and nitrogen, additionally contain gadolinium in a proportion of approximately 5 to 15 atom %.

Abstract: This invention is concerned with the production of glasses suitable for ophthalmic applications having refractive indices of 1.523.+-.0.004, Abbe number between 51-59, densities less than 2.43 g/cm.sup.3, transmissions at 400 nm in 2 mm thickness greater than 89%, and a UV cutoff between 310-335 nm, said glasses consisting essentially, in weight percent on the oxide basis, of:______________________________________ SiO.sub.2 49-71 Li.sub.2 O + Na.sub.2 O + K.sub.2 O 8-20 B.sub.2 O.sub.3 5-26 TiO.sub.2 1.8-6 Al.sub.2 O.sub.3 0-14 ZrO.sub.2 0-5.5 Li.sub.2 O 0-4 As.sub.2 O.sub.3 and/or Sb.sub.2 O.sub.3 0-0.7 Na.sub.2 O 0-16 Cl and/or Br 0-1 K.sub.

Abstract: This invention is directed to the preparation of haze-free photochromic glasses which darken to a comfort range, i.e., a luminous transmittance of about 40-60%, which exhibit very rapid fading, and which demonstrate excellent temperature dependence. The glasses consist essentially, in weight percent with the levels of Ag, Cu.sub.2 0, C1, and Br representing values as analyzed in the glass, of:______________________________________ Li.sub.2 O 0-2.5 P.sub.2 O.sub.5 0-25 Na.sub.2 O 0-9 SiO.sub.2 20-65 K.sub.2 O 0-17 Ag 0.115-0.145 Cs.sub.2 O 0-6 Br 0.11-0.155 Li.sub.2 O + Na.sub.2 O + K.sub.2 O + Cs.sub.2 O 8-20 B.sub.2 O.sub.3 14-23 Cu.sub.2 O 0.007-0.011 Al.sub.2 O.sub.3 5-25 Cl 0.1-0.15 ______________________________________and wherein the molar ratio alkali metal oxide: B.sub.2 0.sub.3 ranges between about 0.55-0.85, the weight ratio Ag:(C1+Br) ranges between about 0.65-0.95, and the sum of Ag+Br is at least 0.26%, when the Br content is 0.11%, and at least 0.25% when the Ag content is 0.115%.

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: Electrochemical devices use a vitreous material having a general formulaxAaR.sub.b --yNmRc--zN.sub.n Y.sub.pwherein A is Si, Ge, P, S, B, Nb, As, V, Cr or Mo; R is O, S or Se; N is Li, Na, K or Ag and Y is I, Br, Cl, F, ClO.sub.4, CF.sub.3, SO.sub.3, SCN or SO.sub.4 with the proviso that the material contain at least two salts NY. Such materials have increased cationic conductivity.

Abstract: The present invention is directed to the preparation of photochromic glasses exhibiting a darkened luminous transmittance at 40.degree. C. below 35% and a five-minute fading rate at 40.degree. C. of at least 40 units of transmittance and a darkened transmittance at 25.degree. C. below 25% and a five-minute fading rate at 25.degree. C. of at least 35 units of transmittance. The glasses consist essentially, by weight, of:______________________________________ SiO.sub.2 56-60 Al.sub.2 O.sub.3 6-9 B.sub.2 O.sub.3 18-21 Li.sub.2 O >2.5-3.5 Na.sub.2 O 0.5-2.5 K.sub.2 O 5-7 ZrO.sub.2 3.75-5 PbO 0.1-0.15 Ag >0.15-0.25 Cl 0.2-0.35 Br 0.075-0.15 CuO 0.004-0.02 CeO.sub.2 0-0.5 ______________________________________wherein the levels of Ag, Br, Cl, and CuO represent values as analyzed in the glass.

Abstract: This invention is directed to the production of transparent photochromic glasses containing silver halide crystals sensitized with copper having base compositions within the alkali metal aluminoborosilicate system wherein at least 0.025% As.sub.2 O.sub.3 and/or Sb.sub.2 O.sub.3 is present in the composition to insure that more than 50% of the copper is present in the Cu.sup.+ state. Where an oxidizing agent is added to the composition, the amount of As.sub.2 O.sub.3 and/or Sb.sub.2 O.sub.3 will be increased to reduce that agent plus insure that more than 50% of the copper is present in the Cu.sup.+ state.

Abstract: There is disclosed a barium-free Type I, Class B laboratory glass according to the standard specification set forth in ASTM E 438-80a having a linear coefficient of expansion (0.degree. to 300.degree. C., cm/cm-.degree.C..times.10.sup.-7) of about 48 to 56 and having a chemical durability, maximum titration equivalent of: 0.2N H.sub.2 SO.sub.4 /10 g of glass of 1.0 ml, the composition consisting essentially of the following ingredients in approximate percent by weight:______________________________________ Ingredient Percent ______________________________________ SiO.sub.2 70-74 B.sub.2 O.sub.3 9-13 Al.sub.2 O.sub.3 5-8 Na.sub.2 O 5-8 K.sub.2 O 0-4 CaO 0-3 MgO 0-1 ______________________________________the glass composition having an annealing point of about 550.degree. C. to 585.degree. C., a liquidus of about 1730.degree. F. to 1760.degree. F. and a Log n at the liquidus about 5.0 to 5.5.

Abstract: The present invention is concerned with the production of photochromic glass compositions consisting essentially, expressed in terms of weight percent on the oxide basis, as calculated from the batch, of______________________________________ SiO.sub.2 52-59 B.sub.2 O.sub.3 18-23 Al.sub.2 O.sub.3 6-8 Li.sub.2 O 1-2.5 Na.sub.2 O 1-3 K.sub.2 O 8-13 ZrO.sub.2 2-6 TiO.sub.2 0-3 ______________________________________and containing, as analyzed in weight percent, of ______________________________________ Ag 0.17-0.22 CuO 0.012-0.019 Cl 0.29-0.35 Br 0.06-0.12 PbO 0.1-0.15 ______________________________________exhibiting, in 0.4 mm cross section, a clear luminous transmittance in excess of 90%, a darkened luminous transmittance below about 45% at a temperature of 25.degree. C., a darkened luminous transmittance below about 57% at a temperature of 40.degree. C., and a half fading time at both temperatures of about five minutes.

Abstract: The instant invention is directed to the production of photochromic glasses having compositions consisting essentially, as analyzed in weight percent on the oxide basis, ofSiO.sub.2 --55-60Al.sub.2 O.sub.3 --9-10B.sub.2 O.sub.3 --19-20.5Li.sub.2 O--2-2.5Na.sub.2 O--2-3K.sub.2 O--6-7PbO--0.1-0.25Ag--0.1-0.15Cl--0.3-0.5Br--0.05-0.15CuO--0.0065-0.01The glasses are capable of being drawn into sheet and articles cut from the sheet simultaneously shaped and photochromic properties developed therein. The glasses display a clear luminous transmittance in excess of 90% when free from tint, a darkened luminous transmittance at 20.degree. C. below 25% when free from tint, and a fading rate at 20.degree. C. such that the glass demonstrates a faded luminous transmittance at least twice that of the darkened transmittance after a five-minute fading interval.

Abstract: A range of borosilicate glass compositions which are capable of sealing effectively to nickel iron alloys containing up to approximately 52% nickel to form a hermetic seal resistant to thermal shock breakage. The glass is in the composition range percent by weight of:SiO.sub.2 : 55-66Al.sub.2 O.sub.3 : 4.5-10Na.sub.2 O: 0-4K.sub.2 O: 3.5-7B.sub.2 O.sub.3 : 19.0-26.0TiO.sub.

Abstract: A polychromatic glass article, colored by silver, is disclosed wherein the silver occurs as an anisotropic film at the surface of lithium bromide spherulites which crystallize directly on silver nuclei from lithium silicate and lithium aluminosilicate glasses. The article is produced by sequential radiation exposures and heat treatments of the glass.

Abstract: Thermally crystallizable silicon oxynitride glasses containing substantial quantities of MgO, thermally crystallizable to fine-grained glass-ceramic products comprising forsterite, clinohumite and/or a beta-silicon nitride solid solution as the predominant crystal phase, are described.

Abstract: The instant invention is directed to the production of highly polarizing glasses, i.e., the glasses exhibit dichroic ratios up to 40 and higher, from silver-containing glasses that are characterized as being phase separable or, more preferably, as being photochromic because of the presence of silver halide particles therein, i.e., particles selected from the group of AgCl, AgBr, and AgI. The inventive method contemplates two general steps:(a) the glasses are elongated under stress such that the glass phases and/or silver halide particles are elongated and aligned in the direction of the stress; and(b) the elongated glasses are heat treated in a reducing environment at temperatures below the annealing point of the glass but above about 300.degree. C. to reduce a portion of the silver ions in the glass to metallic silver which is deposited in at least one of the glass phases and/or along the phase boundaries of the glass phases and/or deposited upon the silver halide particles.