Abstract: Based on the discovery that Al.sub.2 O.sub.3 strongly retards the dissolving rate of insulating glass fibers in a synthetic lung solution, glass fibers having low alumina contents have been identified that dissolve significantly faster in lung fluid. Moreover, these glass fibers still have adequate durability for insulation pruposes and have physical properties which allow current processes to fabricate them into insulation.

Abstract: A preparation method for zircon powder, which comprises heating a feed powder mixture comprising:(1) silica and zirconia obtained by subjecting a liquid having a pH of not higher than 8 and containing silica and zirconia in a SiO.sub.2 /ZrO.sub.2 molar ratio of substantially 1/1, to liquid-removing treatment, and(2) zircon in an amount of at least 0.1% by weight based on the total amount of said silica and zirconia,at a heating rate of not higher than 5.degree. C./min from 1,200.degree. C. to a calcination temperature, and maintaining it at a calcination temperature of from 1,300.degree. to 1,700.degree. C. for from 1.0 to 24 hours.

Abstract: Improved silicon-free, continuous zirconia fibers have diameters greater than 5 micrometers and high tensile strengths. In another aspect, strong, flexible, zirconia fibers are prepared in a process involving the addition of colloidal ZrO.sub.2 particles to a fiber precursor solution.

Abstract: A process for treating a halide, e.g. fluoride, glass composition, characterized by contacting a melt of the composition (3) with dry oxygen (6). Oxygen, simply on contact with a fluoride glass melt, converts transition metals, e.g. from Fe(II) to Fe(III), from one stable state to another and thereby reduces loss at transmission wavelengths in optical fibre, e.g. the loss at 2.6 .mu.m attributabel to Fe(II).

Abstract: The invention relates to glass fiber compositions and fibers having use as a reinforcement element of cement-base products. As such, the composition is able to resist attack of strongly basic media.The fibers of the invention comprise the following constituents, in proportions by weight:SiO.sub.2 --56 to 68%,ZrO.sub.2 --14 to 17%,Na.sub.2 O--12 to 20%,K.sub.2 O--0 to 8%,Al.sub.2 O.sub.3 --1 to 9%,and wherein the sum of Na.sub.2 O and K.sub.2 O is between 14 and 22%, and wherein the sum of SiO.sub.2 and Al.sub.2 O.sub.3 is less than 70%.

Abstract: A continuous, monofilamentous, alkali-resistant glass fiber especially useful in cementitious products is conveniently prepared from a glass-forming composition comprising a magnesium silicate such as talc and a calcium carbonate such as limestone. Either the fiber itself or a strand comprising a plurality of the fiber is advantageously coated with an alkali-resistant polymer such as butadiene-styrene to provide additional alkali resistance.

Abstract: A multicomponent ceramic article which can be a fiber or particle comprises a continuous ceramic matrix phase and at least one in situ-generated discontinuous ceramic or metal phase. Particles can include shapes in the form of beads, flakes, granules, and microspheres.

Abstract: Improved dental porcelain compositions and resultant fused porcelain dental restorations are provided which exhibit enhanced strength properties as compared with conventional porcelains. The fiber-filled porcelain compositions of the invention are supplemented with zirconium oxide ceramic fibers in relatively minor amounts of less than 5% by weight. The reinforcing fibers are advantageously predominantly zirconium oxide, and have a relatively short average length of from about 1/32 to 1/4 of an inch. These fibers are normally randomly oriented and homogeneously dispersed throughout the fiber-filled porcelain composition, in order to give a reinforcing fiber network. A completed restoration in accordance with the invention would typically include a core portion formed of the fiber filled porcelain, with the outer portion of the restoration being fabricated from conventional non-fiber reinforced porcelain.

Abstract: Porous, hollow, silica-rich fibers with good alkaline tolerance are produced from hollow glass fibers of an alkali metal borosilicate glass having one or more oxides of a metal of Group IV of the Periodic Table in an amount of about 1 to about 20 weight percent of the glass composition. The hollow porous silica-rich fibers are produced by acid leaching where the hollow glass fibers have greater than 25 weight percent extractable components, less than 25 weight percent extractable components but a wall thickness of less than 15 microns, or less than 25 weight percent extractable components and a fiber diameter of less than 25 microns. In addition, heat treating can be used for hollow glass fibers having greater than 25 weight percent extractable components to enlarge the pores.

Abstract: A reinforcing inorganic fiber composed of an internal layer and a surface layer, whereinsaid internal layer is composed of an inorganic material containing silicon, either titanium or zirconium, carbon and oxygen which is(i) an amorphous material consisting substantially of Si, M, C and O, or(ii) an aggregate consisting substantially of ultrafine crystalline particles with a particle diameter of not more than 500 .ANG. of .beta.-SiC, MC, a solid solution of .beta.-SiC and MC and MC.sub.1-x, wherein M represents titanium or zirconium, and x is a number represented by 0<x<1, or(iii) a mixture of the amorphous material (i) and the aggregate (ii), andsaid surface layer is composed of an inorganic material consisting of silicon, either titanium or zirconium, and oxygen and optionally not more than 5% by weight of carbon which is(iv) an amorphous material consisting substantially of Si, M and O,(v) an aggregate composed of crystalline SiO.sub.2 and MO.sub.

Abstract: Reduced boron containing glass fibers are provided which have a refractive index similar to that of higher boron-containing glass fiber compositions. The glass fibers with a refractive index in the range of greater than 1.5495 to around 1.57 have in weight percent SiO.sub.2 - 55-56.5, CaO - 20-23, Al.sub.2 O.sub.3 14.5-15.5, B.sub.2 O.sub.3 - 5 to 5.8, R.sub.2 O - 1-1.5, wherein R is an alkali metal and F.sub.2 - 0.4 to 0.6. In addition, the glass fiber composition can have minor constituents such as TiO.sub.2 of up to around 0.6 weight percent and an MgO of up to around 0.3 weight percent and ferric oxide of up to around 0.3 weight percent. Basically, the glass fibers have a reduced content of both B.sub.2 O.sub.3 and CaO over standard glass fiber compositions such as E-glass and 621-glass and also has elevated amounts of alkali and of refractory constituents such as SiO.sub.2 and Al.sub.2 O.sub.3. The glass fibers are formed with an elevated temperature of 40.degree. to 50.degree. F. (22.degree.-28.degree.

Abstract: An improved glass composition, especially suitable for glass fiber manufacture having good fiberizing characteristics and good physical properties, and containing typically 40.0% to 65.0% silica, 4.0% to 11.0% aluminum oxide, 6.0% to 20.0% sodium oxide, 5.0% to 8.0% magnesium oxide and 6.0% to 17.0% calcium oxide, 4.0% to 12.0% ferric and ferrous oxide, and 0.0% to 7.0% potassium oxide.

Abstract: Glass fibers for insulation uses are produced by means of a centrifugal spinner which introduces glass streams into an annular attenuating blast adjacent the periphery of the spinner. An improved product quality and/or production rate as well as prolonged spinner life are obtained by selection and utilization of a novel combination of structural and operating parameters characterized in particular by a spinner diameter and peripheral speed substantially greater than conventionally employed.

Abstract: A process for treating a halide, e.g. fluoride, glass composition, characterized by contacting a melt of the composition with dry oxygen. Oxygen, simply on contact with a fluoride glass melt, converts transition metals, e.g. from Fe(II) to Fe(III), from one stable state to another and thereby reduces loss at transmission wavelengths in optical fiber, e.g. the loss at 2.7 .mu.m attributable to Fe(II).

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: Fluoroglasses, their preparation and intermediate products obtained. These glasses are characterized by containing as the forming element at least about 10% by moles of a metal fluoride or mixture of metal fluorides of the formula MF.sub.n, n being a number equal to 3 or 4, M representing a 5f transition metal when n=4 (fluoride MF.sub.4) and a 4f transition metal or yttrium when n=3 (fluoride MF.sub.3), it being understood that said glasses are free of hydrofluoric acid as the forming element.

Abstract: A water resistant, devitrification resistant glass fiber consisting essentially of SiO.sub.2, Al.sub.2 O.sub.3, CaO, MgO, B.sub.2 O.sub.3, Na.sub.2 O, and F.sub.2 and/or Fe.sub.2 O.sub.3 and/or TiO.sub.2 and/or K.sub.2 O and/or SO.sub.3 in trace amounts, said glass fiber having a delta T of at least about 365.degree. F. and a durability (% fiber weight loss at 96.degree. C.) in water for 24 hours of less than about 0.9%.

Abstract: A refractory fiber composition and method for making refractory fiber from the composition. The refractory fiber composition includes kaolin clay as a source of alumina and silica to which is added zircon.

Abstract: Glass fibers having suitable properties for reinforcing electrical laminates have a defined viscosity-liquidus relationship, a low coefficient of thermal expansion, a high elastic modulus, and a low dielectric constant.

Abstract: A composition for forming a high temperature, acid and alkali resistant refractory fiber. The compositional formulation, by weight, is 56-76% silica, 12-33% alumina, and 3-22% zirconia. These fibers are chemically resistant in both acidic and alkaline environments even when heat treated to temperatures exceeding 500.degree. F. (260.degree. C.) in such environments.

Abstract: A composition for forming a high temperature, alkali resistant refractory fiber. The compositional formulation, by weight, is 46-52% silica, 32-38% alumina, 13-18% zirconia with a silica to zirconia ratio in the range from 2.6 to 3.8. These fibers have a maximum service temperature in the range of 2550.degree. F. (1400.degree. C.) to 2650.degree. F. (1455.degree. C.) and exhibit better shrinkage resistance than similarly rated commercially available refractory fiber.

Abstract: Novel glass fibers are described which contain 58 to 60 percent SiO.sub.2, 11 to 13 percent Al.sub.2 O.sub.3, 21 to 23 percent CaO, 2 to 4 percent MgO and 1 to 5 percent TiO.sub.2. The fibers also have a seed count of 5 seeds or less per cc of glass and an electrical leakage value of 2.8 nanoamperes or less as measured by a test described in the specification.

Abstract: Glass fibers are disclosed, the fibers being formed of a glass composition containing the following ingredients in the weight percentages indicated below:SiO.sub.2 : 25 to 54%Al.sub.2 O.sub.3 : 20 to 40%MgO: 24 to 40%ZrO.sub.2 : 1 to 5%P.sub.2 O.sub.5 : 0 to 10%TiO.sub.2 : 0 to 10%B.sub.2 O.sub.3 : 0 to 10%F: 0 to 5%Cr.sub.2 O.sub.3 : 0 to 2%It is disclosed that the sum of 2MgO+Al.sub.2 O.sub.3 is equal at least to 70% of the composition. The use of such fibers in cementitious products is disclosed.

Abstract: A devitrification resistant, sulfuric acid resistant and water resistant glass fiber consisting essentially of SiO.sub.2, Al.sub.2 O.sub.3, CaO, MgO, Na.sub.2 O and/or K.sub.2 O, B.sub.2 O.sub.3, and optionally Fe.sub.2 O.sub.3, and/or TiO.sub.2 and/or F.sub.2, said glass fiber having delta T of at least about 395.degree. F. and a durability (% fiber weight loss at 96.degree. C.) in water for 24 hours of less than about 1.6% and in 10% H.sub.2 SO.sub.4 for 24 hours of less than about 1.1%.

Abstract: A partly hydrolyzed gelled polysiloxane mass is contacted with a solution of dopant metal compounds which diffuse therein under thermally controlled condition; alternatively, a partly hydrolyzed gelled polysiloxane mass containing distributed therein dopant metal compounds is contacted with a solvent into which said dopant metal compounds will partly diffuse under thermally controlled conditions.

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 glass composition which can be drawn into continuous filaments at a temperature of 1050.degree. C. or below, without risk of devitrification (crystallization), comprises by weight:______________________________________ % ______________________________________ SiO.sub.2 49-55 Al.sub.2 O.sub.3 2-4 B.sub.2 O.sub.3 7-10 Na.sub.2 O 14-18 K.sub.2 O 0.5-3 CaO 8-12 ZnO 1-4.5 ZrO.sub.2 1-7.5 ______________________________________and has a 1000-poise viscosity temperature not greater than 1050.degree. C. and a liquidus temperature at least 20.degree. C. below the 1000-poise viscosity temperature.

Abstract: An optical fiber of the graded index type consisting of a glass having predominantly the composition 60-70 mole % SiO.sub.2, 15-30 mole % alkali metal oxides, and 10 to 15 mole % MgO in combination with at least one oxide selected from the group formed by CaO, SrO, BaO and ZnO. The impurity content of the fiber is less than 0.01 ppm. In the fiber the MgO content increases from the axis of the fiber to the circumference of the fiber. The oxide or the other oxides, having cations which can be exchanged for the magnesium cation, decrease to a corresponding extent in this direction.

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: Continuous inorganic fibers consisting substantially of Si, Ti and C and optionally of O, said fibers being composed of (1) an amorphous material consisting substantially of Si, Ti and C and optionally of O, or (2) an aggregate consisting substantially of ultrafine crystalline particles of .beta.-SiC, TiC, a solid solution of .beta.-SiC and TiC and TiC.sub.1-x wherein 0<x<1 and having a particle diameter of not more than 500 A, in which amorphous SiO.sub.2 and TiO.sub.2 sometimes exist in the neighborhood of these ultrafine crystalline particles, or (3) a mixture of said amorphous material (1) and said aggregate (2) of ultrafine crystalline particles. The aforesaid continuous inorganic fibers can be produced by the following steps: a first step of preparing a semi-inorganic block copolymer comprising polycarbosilane blocks having a main chain skeleton composed mainly of carbosilane units of the formula --Si-CH.sub.

Abstract: Fiberizable glass compositions are disclosed. The glass compositions are boron-free wool glasses which are useful as insulation. The glass batch used to prepare these glass compositions contains high amounts of iron oxide.

Abstract: A glass batch, and a fiberizable glass composition, comprising 2 percent B.sub.2 O.sub.3 is disclosed. The glass fibers have improved dry strength and water durability and have a surface boron concentration, in weight percent, of about 2.5.

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: A process is described for making a doped-silica ingot useful in the manufacture of optical fibers. At least a silicon compound and a titanium compound are decomposed in the flame of the induction plasma burner in the presence of a determined supply of hydrogen and are reacted with the oxygen contained in the burner feed gas and/or in the vector gas to form SiO.sub.2 and H.sub.2 O against a heat-stable support. As a result silica and titanium oxide are deposited on the support in the form of a homogeneous vitreous mass exhibiting a selected concentration of hydroxyl groups between 10 and 50 parts per million. Fluorine-doped silica is deposited radially in the same way on the resulting ingot. The resulting semifinished product is a cylinder consisting of a titanium-doped silica core, whose TiO.sub.2 concentration by weight is about 0.1 to 8%, covered by a sheath of fluorine-doped silica, whose fluorine concentration is about 0.1 to 3%.

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: Continuous inorganic fibers consisting substantially of Si, Ti and C and optionally of O, said fibers being composed of (1) an amorphous material consisting substantially of Si, Ti and C and optionally of O, or (2) an aggregate consisting substantially of ultrafine crystalline particles of .beta.-SiC, TiC, a solid solution of .beta.-SiC and TiC and TiC.sub.1-x wherein 0<x<1 and having a particle diameter of not more than 500 A, in which amorphous SiO.sub.2 and TiO.sub.2 sometimes exist in the neighborhood of these ultrafine crystalline particles, or (3) a mixture of said amorphous material (1) and said aggregate (2) of ultrafine crystalline particles. The aforesaid continuous inorganic fibers can be produced by the following steps: a first step of preparing a semi-inorganic block copolymer comprising polycarbosilane blocks having a main chain skeleton composed mainly of carbosilane units of the formula --Si--CH.sub.

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: Method for the production of mineral fibers resistant to alkaline media which are to be used for the micro-reinforcement of cement-, lime- and/or plaster-bound or bituminous binders or building materials. The starting material is a mixture of extrusive rocks with an addition of 4 to 6 weight percent of ZrO.sub.2, based on the end product, in a composition that is readily fusible and easy to process into fibers of high mechanical strength and resistance to alkaline media. The mixture is fused at a temperature between 1350.degree. and 1500.degree. C. and is then processed into fibers 10 to 20 .mu.m in diameter.

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.

Abstract: An asbestos-free intumescent thermal protection coating consisting essently of from 0.5 to 1.5 weight percent of a ceramic fiber that comprises from 40 to 50 weight percent of Al.sub.2 O.sub.3, 50 to 60 weight percent of SiO.sub.2, from 0.5 to 1 weight percent of Fe.sub.2 O.sub.3, and from 1.2 to 2 weight percent of TiO.sub.2, the fiber having the dimensions of less than 3.2 millimeters in length and from 0.8 to 1.2 micrometers in diameter and from 98.5 to 99.5 weight percent of a polysulfide-epoxide binder. The binder may include a filler.