Abstract: This invention is directed to the production of transparent, translucent, or opaque glass-ceramic articles containing BPO.sub.4 as the predominant crystal phase by heat treating precursor glass articles consisting essentially, expressed in terms of weight percent on the oxide basis, of about:SiO.sub.2 : 10-50B.sub.2 O.sub.3 : 5-35P.sub.2 O.sub.5 : 25-75SiO.sub.2 +P.sub.2 O.sub.5 +B.sub.2 O.sub.3 : >90.

Abstract: A strong white ceramic composition and method of making the same wherein said composition is characterized by an average coefficient of thermal expansion over the range of 25.degree. C. to 500.degree. C. ("Proposed American National Standards Institute/American Dental Association Specification No. 38.1 For Porcelain-Alloy Systems") of between 14 to 16.times.10.sup.-6 /.degree.C. and a transverse strength of about 18,000 psi or even greater. The ceramic composition comprises about 40 to 60% by weight crystalline magnesium oxide particles (e.g., 74 .mu.m ) dispersed in a modified silicate glass containing at least 3% by weight of dissolved ZrO.sub.2, TiO.sub.2 or mixtures thereof and is made by firing a powdered mixture of MgO.sub.2 and modified silicate glass at about 1150.degree. C. for sufficient time to produce a fine dispersion of forsterite (Mg.sub.2 SiO.sub.4) in the continuous glass matrix phase along with the crystalline magnesia particles.

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: Glass frit compositions for use in glazes or enamels have a fiber softening point of 535.degree. C. or more and are free of cadmium, lead and arsenic and consist essentially of Bi.sub.2 O.sub.3 --B.sub.2 O.sub.3 --SiO.sub.2 with R.sub.2 O being 2-8% and RO being 0-9% by weight.

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: A composition for a dielectric ink used in a screening process including a lead-free glass frit binder, silica, and a vehicle. The dielectric composition is particularly suited for use in gas plasma display panels.

Abstract: There are described a glass composition and a magnetic head containing the same, wherein the glass composition comprises an oxide of an alkali metal or alkaline earth, and at least one non-alkali metal oxide in an amount sufficient to provide a coefficient of thermal expansion of 80-170.times.10.sup.-7 .degree. C..sup.-1, the composition featuring from 5-15 mole % Al.sub.2 O.sub.3 and an amount of a compatible glass former sufficient to insure the Al.sub.2 O.sub.3 is soluble in the composition.

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: A mixture for preparation of protective and insulating coatings on metals and metal products which sticks well to metal surfaces, is resistant to high temperatures, has good electrical properties, and provides good heat removal. The mixture includes aluminum oxide, barium oxide, boron oxide, silicon oxide, and aluminum fluoride.

Abstract: Partially crystallizing glass solders, and stripping films using them as agents to be transferred, which are sintered at temperatures below 900.degree. C. from glass powder with granulation of less than <150 .mu.m, thereafter exhibiting thermal expansion coefficients of -23.5 to 34.3.sup..multidot. 10.sup.-7.multidot. K.sup.-1, whose crystallization temperature lies below 710.degree. C. and whose crystal phase consists predominantly of h-quartz mixed crystal phase exhibiting the following composition (in weight %): 23-44 SiO.sub.2, 20-37 Al.sub.2 O.sub.3, 5.5-11 Li.sub.2 O; 3-20 B.sub.2 O.sub.3 ; 0-36 PbO; 0-1 Na.sub.2 O; 0-1.5 K.sub.2 O; 0-0.1 F; 0-4 TiO.sub.2 ; 0-3.5 MgO; 0-2 CoO, provided B.sub.2 O.sub.3 +PbO+Na.sub.2 O+K.sub.2 O+F+TiO.sub.2 is 8.5-50.0.

Abstract: A spectacle glass which is colorless in the visible spectrum range, not transmissive in the ultraviolet spectrum range below 350 nm, has a refractive index n.sub.d higher than 1.56 and an Abbe number of more than 45, and which has an extremely low density, has the following composition (in % by weight):______________________________________ 12-40 P.sub.2 O.sub.5 13-34 Al.sub.2 O.sub.3 8-30 SiO.sub.2 0-16 B.sub.2 O.sub.3 4-12 TiO.sub.2 0-4 ZrO.sub.2 2-18 CaO 0-4 MgO 0-15 Na.sub.2 O 0-11 K.sub.2 O 0-6 Li.sub.2 O 0-12 Nb.sub.2 O.sub.5 0-8 ZnO.

Abstract: A thallium-containing optical glass composition which comprises the following oxides in the indicated proportions in mole %: SiO.sub.2 35-80, Tl.sub.2 O 1-30, Tl.sub.2 O+R.sub.2 O (R being an alkali metal) 1-35, ZnO 0-35, GeO.sub.2 0-30, BaO 0-25, TiO.sub.2 0-20, MgO 0-20, B.sub.2 O.sub.3 0-less than 10, ZrO.sub.2 0-2, Al.sub.2 O.sub.3 0-8, SnO 0-5, CaO 0-10, SrO 0-10, PbO 0-10, La.sub.2 O.sub.3 0-5, Bi.sub.2 O.sub.3 0-8, and Ta.sub.2 O.sub.5 0-2, and satisfies the following relations:5.ltoreq.ZnO+GeO.sub.2 +BaO+TiO.sub.2 +MgO+B.sub.2 O.sub.3 .ltoreq.40,0.1.ltoreq.ZrO.sub.2 +Al.sub.2 O.sub.3 +SnO.ltoreq.8,and0.ltoreq.CaO+SrO+PbO+La.sub.2 O.sub.3 +Bi.sub.2 O.sub.3 +Ta.sub.2 O.sub.5 .ltoreq.10.

Abstract: A cesium-containing optical glass comprising, by weight, 32-56% of SiO.sub.2, 6-25% of K.sub.2 O, 6-32% of Cs.sub.2 O, 0-30% of BaO, 0-2.5% of MgO, 5-34% of ZnO, 0-3% of ZrO.sub.2 and 0-5% of SnO.sub.2, provided that the total proportion of BaO, MgO and ZnO is 8-40% and the total proportion of ZrO.sub.2 and SnO.sub.2 is 0.2-6%. When this cesium-containing optical glass is treated in a molten bath containing potassium nitrate, the cesium ion in the glass is easily exchanged with a potassium ion and therefore, the cesium ion concentration gradually decreases radially outwardly from the central axis and the potassium ion concentration gradually increases in that direction. Thus, there is obtained a light converge-type lens in which the refractive index gradually decreases in the same direction.

Abstract: A low melting, opaque enamel frit is described, which comprises 30 to 36 wt. % of SiO.sub.2, 15 to 20 wt. % of B.sub.2 O.sub.3, 7 to 9 wt. % of Na.sub.2 O, 5 to 10 wt. % of ZrO.sub.2, 10 to 17 wt. % of TiO.sub.2, 7 to 15 wt. % of K.sub.2 O, 2 to 10 wt. % of F.sub.2 and 0.5 to 2.5 wt. % of P.sub.2 O.sub.5. The total of Na.sub.2 O and K.sub.2 O is in the range of 15 to 20 wt. % and the total of TiO.sub.2 and ZrO.sub.2 is in the range of 15 to 20 wt. %. The ZrO.sub.2 /(TiO.sub.2 +ZrO.sub.2) ratio is in the range of 0.25 to 0.5:1 and the SiO.sub.2 /B.sub.2 O.sub.3 ratio is in the range of 1.5 to 2.4:1. In addition, the Na.sub.2 O/K.sub.2 O ratio is in the range of 0.6 to 1.0:1 and the (Na.sub.2 O+K.sub.2 O)/(TiO.sub.2 +ZrO.sub.2) is in the range of 0.7 to 1.2:1.

Abstract: An acid-soluble glass used in manufacture of a flexible fiber optic bundle and a process for manufacturing a flexible fiber optic bundle using the glass. The glass has a composition expressed by mol percent comprising more than 15.0% and less than 41.0% of SiO.sub.2, more than 29.0% and less than 54.0% of B.sub.2 O.sub.3, more than 6.0% and less than 23.0% of BaO, and more than 5.0% and less than 19.0% of at least one alkali metal oxide selected from the group consisting of Na.sub.2 O, K.sub.2 O and Li.sub.2 O, the total amount of SiO.sub.2, B.sub.2 O.sub.3 and BaO being more than 71.0% and less than 80.0%.

Abstract: The invention relates to lamps having a glass lamp vessel (1) and to a glass suitable therefor. The relevant glass is adequately resistant to attack by electrons, is resistant to atmospheric influences and is properly workable in a gas flame. This glass contains 44-60 mole % silicon oxide; 0-7.5 mole % boron oxide; 0-6 mole % zirconium oxide; 0-7.5 mole % aluminium oxide; 5-20 mole % calcium oxide; 12.5-25 mole % barium oxide; 0-15 mole % magnesium oxide; 0-10 mole % strontium oxide; 2-8 mole % sodium oxide. The sum of the alkaline earth metals is 25-42.5 mole %.No discoloration occurs in sodium vapor discharge lamps when the lamp vessel has been made of this glass.

Abstract: Glass frits for use in glazes or enamels have fiber softening point about 535.degree.-609.degree. C. are free of lead, cadmium and zinc and consist essentially of Li.sub.2 O-B.sub.2 O.sub.3 -SiO.sub.3 plus 2-23% SnO.sub.2 +CaO and 2-23% ZrO.sub.2 +La.sub.2 O.sub.3 ; also, Al.sub.2 O.sub.3, SrO, BaO, Na.sub.2 O, F.Low expansion filler, e.g., B-eucryptite, may be used at 4 to 15% by weight of glass frit.

Abstract: A glass suitable for use as the core glass in a high numerical aperture optical fibre has a composition selected from the range of glasses which comprise(i) from 15 to 25 mole percent of soda,(ii) from 25 to 65 mole percent of silica and germania, taken together, the content of germania not exceeding 42 mole percent,(iii) up to 22.5 mole percent of boric oxide and barium oxide, taken together, the content of boric oxide not exceeding 20 mole percent, and the content of barium oxide not exceeding 12 mole percent, and(iv) from 0.01 to 1 weight percent of a redox buffering agent. The glass can be prepared by controlling the partial oxygen pressure of the melt so that it is approximately 10.sup.-5 atmospheres. An optical fibre can be produced, by using a soda-boro-silicate clad glass, and a core glass having the composition in the above range.

Abstract: A glass composition suitable for production of a fibrous wollastonite comprising, in % by weight:______________________________________ SiO.sub.2 35 to 60 CaO 30 to 55 B.sub.2 O.sub.3 1 to 30 Li.sub.2 O 0 to 4 Al.sub.2 O.sub.3 0 to 8 and Na.sub.2 O + K.sub.2 O 0 to 8 ______________________________________a method for producing said fibrous wollastonite using the glass composition, and fibrous wollastonite obtained by the method.

Abstract: The invention relates to calciumaluminosilicate glasses. The glasses contain, in weight percent, 25 to 35% silica, 27 to 35% calcium oxide, 25 to 40% alumina, 0 to 4% of alkali metal oxide selected from lithium oxide, sodium oxide and potassium oxide, and 0 to 5% of titanium oxide and a total content of lithium, sodium, potassium and titanium oxides of 0.5 to 9%. The glasses, in finely divided form, react with aqueous polycarboxylic acids and set to a solid mass; cements made from the glass and polycarboxylic acids are useful in splinting compositions.

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: There is provided a multi-component system glass fiber for optical communication which comprises a multi-component system glass for core having a composition comprising SiO.sub.2, BaO, Al.sub.2 O.sub.3, B.sub.2 O.sub.3, at least one alkali metal oxide selected from Na.sub.2 O, K.sub.2 O and Li.sub.2 O, MgO and CaO in amounts as specified in the specification and claims, and a multi-component system glass for clad layer having a composition comprising SiO.sub.2, Al.sub.2 O.sub.3, B.sub.2 O.sub.3, Na.sub.2 O, K.sub.2 O, Li.sub.2 O, at least one alkaline earth metal selected from MgO and CaO in amounts as specified in the specification and claims. The core in the glass fiber for optical communication according to the present invention shows lower optical loss and the clad layer shows high weathering resistance, and the glass fiber according to the present invention suffers from no devitrification during fiber drawing and is excellent in dimensional stability.

Abstract: An improved optical glass having an index of refraction of .gtoreq.1.69, an Abbe number of .gtoreq.38, and a density of .ltoreq.3.25 g/cm.sup.3, represents a further development of another optical glass recently provided by the same inventors. The new glass has improved suitability for continuous-tank manufacture and increased acidproofness and differs from the other glass in its content of 0.5-4.0% by weight of P.sub.2 O.sub.5 ; its sum total of SiO.sub.2 +B.sub.2 O.sub.3 +Al.sub.2 O.sub.3 +P.sub.2 O.sub.5 being 38.5-41.5% by weight; and its sum total of MgO+CaO being 13-17.5% by weight. The full glass composition, e.g. is in % by weight:______________________________________ SiO.sub.2 26.0-32.5 B.sub.2 O.sub.3 6.0-12.0 Al.sub.2 O.sub.3 0-3.0 P.sub.2 O.sub.5 0.5-4.0 SiO.sub.2 + B.sub.2 O.sub.3 + Al.sub.2 O.sub.3 + P.sub.2 O.sub.5 = 38.5-41.5 Li.sub.2 O 0-5 Na.sub.2 O 0-6 K.sub.2 O 0-8 Li.sub.2 O + Na.sub.2 O + K.sub.2 O = 4.5-12.0 MgO 0-8 CaO 9-16 MgO + CaO = 13-17.

Abstract: This invention is concerned with the production of substantially transparent glass-ceramic articles containing mullite as the predominant crystal phase which can be prepared by crystallizing in situ precursor glasses capable of being melted at temperatures no higher than 1650.degree. C. The inventive articles consist essentially, in weight percent, of 1070% SiO.sub.2, 7-40% B.sub.2 O.sub.3, 14-50% Al.sub.2 O.sub.3, 0-35% RO, wherein RO consists of at least one member of the group in the indicated proportions of 015% MgO, 0-20% CaO, 0-30% SrO, 0-30% BaO, and 0-30% PbO, and 0-30% R.sub.2 O, wherein R.sub.2 O consists of at least one member of the group in the indicated proportions of 0-10% Li.sub.2 O, 0-15% Na.sub.2 O, 0-25% K.sub.2 O, 0-25% Rb.sub.2 O, and 0-25% Cs.sub.2 O, the mole ratio Al.sub.2 O.sub.3 :RO+R.sub.2 O>1.3. Where 0.01-1% Cr.sub.2 O.sub.

Abstract: An optical and ophthalmic glass having an index of refraction of .gtoreq.1.69, an Abbe number of .gtoreq.37, and a density of .ltoreq.3.30 g/cm.sup.3, consists essentially of (in % by weight):______________________________________ SiO.sub.2 18-36 B.sub.2 O.sub.3 3-18 GeO.sub.2 0-8 Al.sub.2 O.sub.3 0-6, wherein SiO.sub.2 + B.sub.2 O.sub.3 + Al.sub.2 O.sub.3 + GeO.sub.2 25-39 P.sub.2 O.sub.5 0-14, wherein SiO.sub.2 + B.sub.2 O.sub.3 + Al.sub.2 O.sub.3 + GeO.sub.2 + P.sub.2 O.sub.5 = 30-44 Li.sub.2 O 0-12 Na.sub.2 O 0-14 K.sub.2 O 0-18 Li.sub.2 O + Na.sub.2 O + K.sub.2 O = 2-18 MgO 0-15 CaO 7-25 MgO + CaO 15-32 SrO 0-13 BaO 0-17 ZnO 0-15 PbO 0-10 SrO + BaO + ZnO + PbO 0-20 TiO.sub.2 3-14 Nb.sub.2 O.sub.5 0-13 WO.sub.3 0-10 TiO.sub.2 + Nb.sub.2 O.sub.5 + WO.sub.3 = 10-21 ZrO.sub.2 0-15, La.sub.2 O.sub.3 0-20 Y.sub.2 O.sub.3 0-16 Gd.sub.2 O.sub.3 0-16 Yb.sub.2 O.sub.3 0-10 La.sub.2 O.sub.3 + Y.sub.2 O.sub.3 + Gd.sub.2 O.sub.3 + Yb.sub.2 O.sub.3 = 0-20 Ta.sub.2 O.sub.5 0-13 HfO.sub.2 0-5 SnO.sub.2 0-6.

Abstract: The instant invention is concerned with the preparation of glass-ceramic coatings capable of being fired repeatedly to temperatures in excess of 950.degree. C. without thermal deformation and being particularly suitable for application to low carbon and titanium-stabilized stainless steels. The coatings are substantially free from alkali metal oxides and consist essentially, expressed in terms of weight percent on the oxide basis, of:______________________________________ BaO 10-60 B.sub.2 O.sub.3 5-30 SiO.sub.2 25-40 Al.sub.2 O.sub.3 0-15 CaO 0-15 MgO 10-35 ZnO 0-16 Al.sub.2 O.sub.

Abstract: A strong and biocompatible sintered phosphate of calcium ceramics are obtained by sintering a powdery material substantially consisting of phosphate of calcium having a Ca/P ratio of 1.4-1.75, e.g. apatite group and/or tricalcium phosphate, and not exceeding 15% by weight of CaO-P.sub.2 O.sub.5 frit having a Ca/P ratio of 0.2-0.75. Y.sub.2 O.sub.3 incorporation therein improves the bending strength of the ceramics. Furthermore, a P.sub.2 O.sub.5 -metal oxide frit wherein metal oxide being one or more selected from BaO, CaO, MgO, ZnO, NaO and K.sub.2 O provides a more improved bending strength. The Y.sub.2 O.sub.3 incorporation herein still improves the strength of the sintered product.

Abstract: Novel thick-film crossover dielectric inks useful in constructing multilayer circuits on suitable substrates are provided. The subject inks comprise a barium magnesium borosilicate glass powder, a pinhole reducing component comprising silicon dioxide, an alkaline earth aluminum borosilicate glass having a high softening point or mixtures thereof and a suitable organic vehicle.

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: Phosphate glass compositions are described comprising from 8 to 35 wt % P.sub.2 O.sub.5, from 8 to 48 wt % SiO.sub.2 and GeO.sub.2, provided that the GeO content is not more than 6 wt %, from 3 to 18 wt % B.sub.2 O.sub.3, from 16 to 28 wt % Al.sub.2 O.sub.3, and from 8 to 33 wt % CaO, MgO, SrO, and BaO, provided that the sum of the MgO, SrO, and BaO contents is not more than 15 wt %, andwherein the sum of the above-described oxides comprises at least 88 wt % of the total composition and the ratio of the sum of the CaO, MgO, SrO and BaO contents to the P.sub.2 O.sub.5 content ranges from 0.6/1 to 1.

Abstract: A porcelain enamel frit for sheet iron ground coat is disclosed, which contains neither fluorine nor fluorine compound, but has excellent firing property, and can be worked into sheet iron enamel having high gloss and adherence and low surface roughness. The frit consists of 100 parts of a main component and 7-42 parts of an auxiliary component, said main component consisting of 30-73 parts of SiO.sub.2 or a mixture of SiO.sub.2 and at least one of TiO.sub.2, ZrO.sub.2 and SnO.sub.2, 8-45 parts of B.sub.2 O.sub.3, and 8-41 parts of Na.sub.2 O or a mixture of Na.sub.2 O and at least one of Li.sub.2 O and K.sub.2 O, and said auxiliary component consisting of not more than 12 parts of Al.sub.2 O.sub.3, 1-22 parts of at least one of CaO, Bao, ZnO, MgO and SrO, from more than 0 part to 7 parts of MoO.sub.3 or a mixture of MoO.sub.3 and at least one of V.sub.2 O.sub.5, P.sub.2 O.sub.5 and Sb.sub.2 O.sub.3, and 0.5-10 parts of at least one of CoO, NiO, CuO, MnO.sub.2 and Fe.sub.2 O.sub.3.

Abstract: The present invention is directed to the production of glass-ceramic coatings capable of being fired repeatedly to temperatures in excess of 950.degree. C. without thermal deformation and being especially suitable for application to titanium-stabilized stainless steels. The coatings are highly crystalline, substantially free from alkali metal oxides, and consist essentially, by weight, of:______________________________________ MgO 5-35 CaO 0-35 ZnO 0-25 CaO + ZnO 10-35 Al.sub.2 O.sub.3 0-10 B.sub.2 O.sub.3 0-25 P.sub.2 O.sub.5 0-10 B.sub.2 O.sub.3 + P.sub.2 O.sub.5 4-25 SiO.sub.

Abstract: The coatings are glass compositions which consist essentially of from 18 to 45 mol % of the alkaline oxides CaO and one or both of Na.sub.2 O and K.sub.2 O and from 5 to 22 mol % of Al.sub.2 O.sub.3, the balance being B.sub.2 O.sub.3 and SiO.sub.2 in such amounts that the molar ratio of B.sub.2 O.sub.3 : (B.sub.2 O.sub.3 +SiO.sub.2) lies in the range from 0.575:1 to 0.85:1. The molar ratio of K.sub.2 O: (K.sub.2 O+Na.sub.2 O) is from 0.4:1 to 0.6:1 and CaO is 48 to 52 mole % of the alkaline oxides.These compositions are particularly suitable for use during the heat-treatment and hot-working of titanium and its alloys.

Abstract: Volatile borates and/or fluorides are removed from the hot stack gases of a glass furnace by passing the hot stack gases up through a layer of wet pellets containing ions of an alkaline earth metal or an alkali metal. The pellets may contain solid borates and/or fluorides as part of the feed to the glass furnace, and still absorb volatile materials from the stack gases, so long as the borates and/or fluorides in the pellets are in, or are converted to a less soluble and volatile form that are the volatile materials in the stack gases. Ca(OH).sub.2 is a preferred material for converting the volatiles into an essentially nonvolatile form. Ion exchange materials, such as clay, can also be used to capture these volatiles.

Abstract: Partially devitrified porcelain compositions are provided which are comprised of a mixture, based on its oxide content, of barium oxide (BaO), magnesium oxide (MgO) or a mixture of magnesium oxide with certain other oxides (CaO,ZnO), boron trioxide (B.sub.2 O.sub.3) and slicon dioxide (SiO.sub.2). In accordance with this invention the porcelain compositions are applied to the metal core and fired to provide a partially devitrified porcelain coating on the metal core. The coating has a very low viscosity at its initial fusion point and then almost instantaneous high viscosity due to partial devitrification. The fired coating has a deformation temperature of at least 700.degree. C. and a high coefficient of thermal expansion of at least about 110.times.10.sup.-7 /.degree.C.

Abstract: Borosilicate glass frit with MgO as a major component for forming partially devitrified porcelain compositions are provided which are comprised of a mixture, based on its oxide content, of barium oxide (BaO), magnesium oxide (McO) or a mixture of magnesium oxide with certain other oxides, boron trioxide (B.sub.2 O.sub.3) and silicon dioxide (SiO.sub.2). In accordance with this invention the porcelain compositions are applied to the metal core and fired to provide a partially devitrified porcelain coating on the metal core. The coating has a very low viscosity at its initial fusion point and then almost instantaneous high viscosity due to partial devitrification. The fired coating has a deformation temperature of at least 700.degree. C. and a high coefficient of thermal expansion of at least about 110.times.10.sup.-7 /.degree.C.

Abstract: A glass enamel composition and the method of its manufacture for use in providing a decorative glass or ceramic article and which composition comprises a glass frit mixed with a nacreous pigment, the mixture being dispersed in an application medium and adapted to be applied to the surface of a glass or ceramic article and fired at a temperature whereat the glass composition fuses to form a decorative and esthetic surface on said article.

Abstract: A process for producing a photochromic glass which will exhibit a brown coloration in its darkened state without a degradation in the photochromic properties of the glass taking place. The process includes the steps of forming a batch of specified components which include tin or a tin compound and subjecting the resultant batch to a series of glass-forming steps so as to develop photochromic properties in a glass article formed from the molten batch.The invention also provides a photochromic glass having silver halide crystals and tin dispersed throughout the glass, the glass having in its darkened state a brown coloration which is described in accordance with the Hunter L,a,b, Color Scale System by the rectangular region having corners defined by the (a,b) co-ordinates: (5,1), (1,5), (12,16) and (16,12), the 1/2 OD FT of the glass being 120 seconds or less.

Abstract: Sodium resistant sealing glasses have aluminoborate glass compositions in which glass stability is improved by the incorporation of specific mixtures of modifying alkali earth oxides of calcium oxide, strontium oxide and barium oxide. These modifying alkali earth oxides are present in a total weight percent range from 15 to 40 weight percent of the glass composition.Also disclosed is the employment of the above glasses as seals in sodium-sulfur cells.

Abstract: A glaze resistor composition composed of a glass frit, molybdenum disilicide, tantalum disilicide, magnesium silicide and aluminum. This glaze resistor composition has a small temperature coefficient of resistivity, a high resistivity stability and small current noises, and can be used in a wide resistivity range.

Abstract: A potassium fluoro-borate glass, including silica and optionally alumina, containing at least 20 mole % potassium computed as K.sub.2 (O,F.sub.2), and wherein there are more fluorine atoms in the glass than oxygen atoms. The range of compositions includes low refractive index glasses, some with refractive indices less than that of silica, and high coefficient of thermal expansion glasses, some with coefficients matching those of aluminum, copper and brass.

Abstract: Disclosed are various ceramic frits which have a unique combination of low solubility, low-melting temperature, and freedom from lead oxide. They are formed from selected compositions in the alkali--ZnO--Al.sub.2 O.sub.3 --B.sub.2 O.sub.3 --P.sub.2 O.sub.5 --SiO.sub.2 --TiO.sub.2 --F system.

Abstract: This invention is directed to glazes exhibiting a strong yellow-to-brown coloration or a bright red color which are stable at temperatures of 700.degree.-950.degree. C., the latter glazes being stable in non-oxidizing or inert environments. Both glazes utilize frits consisting essentially, in weight percent on the oxide basis as calculated from the batch, of______________________________________ SiO.sub.2 35-47 B.sub.2 O.sub.3 5.5-9 BaO 24-42 TiO.sub.2 1.5-4 ZrO.sub.2 6-10 Li.sub.2 O 1-5 MgO 0-5 CaO 0-4 SrO 0-8 ZnO 0-10 Bi.sub.2 O.sub.3 0-8 SrO + MgO + CaO + ZnO + Bi.sub.2 O.sub.3 0-10 ______________________________________The yellow-to-brown coloration is produced through the addition of 0.5-10% by weight Fe.sub.2 O.sub.3 and 0-4% TiO.sub.2. The red coloration is produced through the addition of 2-10% cadmium sulfoselenide.

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.

Abstract: Aluminum metaphosphate optical fibers are disclosed. In a specific embodiment, aluminum metaphosphate, doped with from 10 to 30 mole percent of diboron trioxide, is found to yield an optical fiber which combines the desirable properties of both high numerical aperture and low material dispersion. The fiber is nonhygroscopic and has a high melting temperature. The index of refraction of the glass may be lowered by doping with silicon dioxide. Consequently, a graded fiber may be made by increasing the concentration of silicon oxide from the core to the cladding.

Abstract: The instant invention is directed to glasses manifesting solar transmissions (350-2100 nm) through a 2.54 mm thick sheet in excess of 90% which can be prepared from conventional glass batch materials containing up to 0.1% iron, expressed as Fe.sub.2 O.sub.3, as impurities. The inventive glasses consist essentially, expressed in weight percent on the oxide basis as calculated from the batch, of______________________________________ Al.sub.2 O.sub.3 7-13 B.sub.2 O.sub.3 7-10 Na.sub.2 O 6-11 K.sub.2 O 2-7 CaO 2-7 TiO.sub.2 0.1-1 As.sub.2 O.sub.3 0-1 Sb.sub.2 O.sub.3 0-1 SiO.sub.2 Balance ______________________________________Part of the batch materials is added in the form of nitrates in a sufficient amount to virtually completely oxidize all the tramp iron present to the Fe.sup.+3 state.

Abstract: Low alkali, high phosphate and high Al.sub.2 O.sub.3 content glasses are described which are highly suitable for optical colored and filter glasses. They exhibit a glass transformation temperature Tg>450.degree. C. and have the following composition, in percent by weight:______________________________________ P.sub.2 O.sub.5 71.0-76.0 SiO.sub.2 0.25-2.5 B.sub.2 O.sub.3 2.4-3.75 Al.sub.2 O.sub.3 8.6-11.6 R.sub.2 O (alkali oxide) 1.25-6.5 CaO 0.5-1.65 MgO 2.0-3.5 Refining Agent 0.2-0.6 CeO.sub.2 0.1-0.4 F' 0.2-0.4 and CuO 1.0-10.0.

Abstract: What is disclosed is a method of preparing carbon-containing monolithic glassy ceramics from organosilsesquioxanes, metal oxides and metal alkoxides through pyrolysis of their gels. Also disclosed are certain gel compositions used in the method and the glassy ceramics.