Abstract: A tungsten sealing glass for use in a fluorescent lamp, said glass having a composition of, by mass percent, 65-76% SiO2, 10-25% B2O3, 2-6% Al2O3, 0.5-5.8% MgO+CaO+SrO+BaO+ZnO, 3-8% Li2O+Na2O+K2O, 0.01-4% Fe2O3+CeO2, 0.1-5% TiO2, 0.1-10% TiO2+Sb2O3+PbO, and 0-2% ZrO2, wherein Na2O/(Na2O+K2O)≦0.6.

Abstract: The present invention refers to glass-ceramics consisting of the mixtures (I): ZrO2—SiO2—MeIIO, or (II) SiO2—MeIIIO2—MeIIO, wherein: MeII is chosen in the group consisting of: Ca, Ba, Mg, Zn or mixture thereof; MeIII is chosen in the group consisting of Al, B or mixtures thereof; each of the above said constituents being present in determined quantities; the invention refers also to a process for preparing the glass-ceramics above defined; porcelain stonewares and glazes containing them and their use for preparing ceramic items.

Abstract: A tungsten sealing glass for use in a fluorescent lamp has a composition of, by mass percent, 65-76% SiO2, 10-25% B2O3, 2-6% Al2O3, 0.5-5.8% MgO+CaO+SrO+BaO+ZnO, 3-8% Li2O+Na2O+K2O, 0.01-4% Fe2O3+CeO2, 0-10% TiO2+Sb2O3+PbO, and 0-2% ZrO2, where Na2O/(Na2O+K2O)≦0.6.

Abstract: The invention relates to a water-based black enamel composition capable of being deposited on a glass substrate, especially on a glass sheet, which comprises:

Abstract: Low temperature melting lead-free glass and enamel compositions are provided which have low boron content and possess high durability properties. Enamel pastes containing frits of the glass compositions are particularly useful in forming colored borders in automotive glass.

Abstract: The present invention refers to glass-ceramics consisting of the mixtures (I): ZrO2—SiO2—MeIIO, or (II) SiO2—MeIIIO2—MeIIO, wherein: MeII is chosen in the group consisting of: Ca, Ba, Mg, Zn or mixture thereof; MeIII is chosen in the group consisting of Al, B or mixtures thereof; each of the above said constituents being present in determined quantities; the invention refers also to a process for preparing the glass-ceramics above defined; porcelain stonewares and glazes containing them and their use for preparing ceramic items.

Abstract: Opaque porcelains for use with metal cores in the manufacture of PFM restorations. The porcelains exhibit a coefficient of thermal expansion (CTE) substantially equal to or slightly above the CTE of the metal to which it is applied. The porcelains exhibit a CTE equal to or up to about 1.5×10−6/° C. higher than the dental alloys to which they are applied as the opaque. The porcelains are fabricated from a mixture of two frit compositions. A high expansion, leucite containing frit is combined with a low melting glass frit to provide a porcelain having an expansion in the range of 16.9 to about 18.5×10−6/° C. in the temperature range of 25°-600° C.

Abstract: The glaze layer 2d of the spark plug 100 includes oxides of: 15 to 60 mol % of a Si component in terms of SiO2; 22 to 50 mol % of a B component in terms of B2O3; 10 to 30 mol % of a Zn component in terms of ZnO; 0.5 to 35 mol % of Ba and/or Sr components in terms of BaO or SrO; 1 mol % or less of an F component; 0.1 to 5 mol % of an Al component in terms of Al2O3; and 5 to 10 mol % in total of at least one of alkaline metal components of Na, K and Li, in terms of Na2O, K2O, and Li2, respectively, wherein Li is essential, and the amount of the Li component is 1.1 to 6 mol % in terms of Li2O.

Abstract: Sanitary wares having a controlled surface are disclosed which are less likely to be stained or soiled and/or possess excellent gloss. The first sanitary ware comprises a sanitary ware body and a surface glaze layer provided on the sanitary ware body, wherein the surface glaze layer has a center line average roughness Ra of less than 0.07 &mgr;m. This sanitary ware is advantageous in that stains or soils are much less likely to be adhered to the surface thereof and, even when adhered to the surface thereof, can be removed by a weak water stream. The second sanitary ware comprises a sanitary ware body and a surface glaze layer provided on the sanitary ware body, wherein the surface glaze layer has a kurtosis Rku of less than 2.70. This sanitary ware advantageously possesses excellent surface gloss.

Abstract: A lead-free glow in the dark glaze is provided for ceramic bisques. It includes Frit, Lithium Carbonate, Borax, carboxmethylceullulose and a phosphorus pigment. In some applications, Bentonite and/or Magnesium Sulfate are used. Preservatives and deflocculants may be needed in some applications.

Abstract: The present invention provides a ground coat composition for use in forming an enamel layer on sheet steel that exhibits good spot acid resistance, a satin finish, good bond, and is easy-to-clean. The composition according to the invention includes a glass component that includes a blend of from about 40% to about 70% by weight of a first glass portion including one or more alkali aluminophosphate frits, up to about 30% by weight of a second glass portion including one or more zirconia-phosphate frits, and up to about 30% by weight of a third glass portion including one or more alkali borosilicate frits.

Abstract: The present invention relates to a process for manufacturing recyclable black enamels that contain at least zinc, in which process glass forming materials comprising at least bismuth, silicon, boron and manganese are melted, at temperatures greater than about 900° C., and then a glass frit comprising at least zinc is added to the mixture obtained after this direct melting. The invention also relates to zinc-based recyclable black enamel compositions.

Abstract: Coating and filler materials for localized thermal processing of glazed ceramics and other brittle and low thermal conductivity materials. The coating materials include oxide compositions that exhibit coefficients of thermal expansion which are less than about 8×10−6/° C. and glass transition temperatures which are less than about 400° C. The filler materials include particulate oxide materials which do not substantially react during localized thermal processing of glazed ceramics and other brittle and low thermal conductivity materials. The coating and filler materials are useable together as a composite material for repairing cavities having depths greater than about 2 mm.

Abstract: A lead-free glaze that can be fired at a low temperature, a spark plug for which it is used, and a spark plug production method are provided. The lead-free glaze is for coating onto ceramic materials. This lead-free glaze contains 16-49 wt % of SiO2, 15-35 wt % of B2O3, 0-10 wt % of Al2O3 and 0-10 wt % of ZnO. A spark plug is provided that comprises coating the lead-free glaze onto the surface of an insulator and firing.

Abstract: The present invention provides a composition for use in forming an adherent, brilliant white, chemically and mechanically resistant porcelain enamel coating on aluminized steel. The composition includes a self-opacifying glass frit component which includes high levels of titanium dioxide, lithium oxide, sodium oxide, and potassium oxide. The composition is able to produce a brilliant white finish on aluminized steel in one coat without the addition of titanium oxide during milling.

Abstract: The present invention relates to glass ceramic material and its use as means for joining different types of material and as support. Said glass ceramic material comprising, on a weight percent basis, 10-35% MgO, 10-55% BaO and 25-50% SiO2 and is formed by the following steps: a) melting of glass raw material at a temperature in excess of 1450 ° C. and that the thereby formed melt is cooled rapidly to a temperature below 900° C. and thereafter to ambient temperature to form a precursor glass, b) milling of the precursor glass into a sinterable glass powder with an average particle size in the range of 1 micron to 100 microns, c) forming of the glass powder into a green body of suitable shape, with or without organic processing aids, and subjecting said green body to a thermal treatment comprising a heating stage of average heating rate not exceeding 100 ° C./minute between the temperatures of 750 ° C. and 900 ° C.

Abstract: The invention relates to a glass powder, where at least one oxidizing agent or one reducing agent is added to the glass powder. The glass powder is preferably used as dental glass powder.

Abstract: The lead-free bismuth-containing silicate glasses, which are particularly suitable for use as funnel glass or neck glass for cathode ray tubes and as soldering glass, have the following respective compositions (in % by weight, based on oxide): SiO2 40-60; Bi2O3, 10-30; ZrO2, 0-3; Al2O3, 0.5-5; MgO, 0-6; CaO, 0.5-5; SrO, 1-15; BaO, 0-15; sum of the alkaline earth metal oxides, 2-20; ZnO, 0-2; Li2O, 0-10; Na2O, 1-10; K2O, 2-10; Cs2O, 0-3, sum of the alkali metal oxides, 5-20; CeO2, 0-8; WO3, 0.5-5; MoO3, 0-5 and Sb2O3, 0-0.6; and SiO2 30-50; Bi2O3, 20-40; ZrO2, 0-3; Al2O3, 0.5-5; MgO, 0-4; CaO, 0.5-4; SrO, 1-15; BaO, 0-15; sum of the alkaline earth metal oxides, 2-20; ZnO, 0-2; Li2O, 0-5; Na2O, 1-12; K2O, 2-15; Cs2O, 0-3, sum of the alkali metal oxides, 5-20; CeO2, 0-8; WO3, 0.5-5; MoO3, 0-5 and Sb2O3, 0-0.6.

Abstract: Low temperature melting lead-free glass and enamel compositions are provided which have low boron content and possess high durability properties. Enamel pastes containing frits of the glass compositions are particularly useful in forming colored borders in automotive glass.

Abstract: Disclosed is an insulating glass paste capable of forming an over glaze layer having a low rate of occurrence of cracks and excellent reliability. The insulating glass paste is used for forming an over glaze layer on an insulating substrate exhibits a fracture toughness strength of about 1.0 MN/m{fraction (3/2)} or more after burning.

Abstract: A ceramic enamel composition consists of an oxide frit, a bismuth silicate seed material, a pigment, and a vehicle. A preferred bismuth silicate seed material is selected from crystalline Bi12SiO20, Bi4(SiO4)3, and Bi2SiO5, and mixtures thereof. Upon firing a glass substrate coated with the enamel, components of the enamel adhere to the substrate. The glass can be formed with a die to a desired shape with reduced sticking of the coated region to the die. The ceramic enamel is particularly useful in providing a colored border around automotive glass, which enhances appearance and reduces degradation of adhesives by ultraviolet radiation.

Abstract: A sealing glass paste which comprises at least one sealing glass frit powder and an aqueous binder which comprises an aqueous solution, dispersion or emulsion of a polymeric material and a water soluble oxidant which decomposes at a temperature of below 475° C., the polymeric material burning out or decomposing at a temperature of below 475° C., in the presence of the oxidant, to leave less than 2% of residues based on the total weight of the solids content of the binder. The sealing glass pastes may be used in the assembly of cathode ray tubes. The aqueous binder system which is used results in low carbonaceous residue levels after firing and does not contain volatile organic solvents. Furthermore, using this aqueous binder system sealing glass pastes can be prepared with sealing glasses which include PbO therein.

Abstract: The present invention provides a ceramic tile and a glaze composition for use in forming the tile. The glaze composition comprises a glass component, an expansion modifier and a spodumene crystallization promoter. The spodumene crystallization promoter comprises a material that promotes the formation of beta spodumene during the firing of the glaze composition.

Abstract: A spark plug (100) includes a ground electrode (125), a firing electrode (115), an insulator core (105) having an insulator core nose (120), and an outer shell (110) surrounding the insulator core (105). The improvement includes the insulator core nose (120) including a high temperature glaze applied to an outer surface of the insulator core nose (120) and the high temperature glaze composition. The composition includes, by weight:(i) between about 72 and 84% SiO.sub.2 ;(ii) between about 10 and 20% Al.sub.2 O.sub.3 ;(iii) between about 2.0 and 2.5% K.sub.2 O;(iv) between about 0.50 and 0.65% Na.sub.2 O;(v) between about 3.0 and 5.5% CaO;(vi) between about 0.1 and 0.25% MgO; and(vii) the remainder impurities.

Abstract: The present invention provides a coating layer of the coke oven having a high strength, high impact resistance and excellent smoothness to enable long term protection of the fire brick of the coke oven. Carbon adhered to the brick can be removed by spraying a coating agent with a glaze layer mainly composed of 18 to 70% by weight of SiO.sub.2 and 10 to 60% by weight of Na.sub.2 O and/or K.sub.2 O and containing one or a plurality of 2 to 14% by weight of P.sub.2 O.sub.5, 0.5 to 25% by weight of BaO, 0.5 to 25% by weight of SrO and 0.5 to 20% by weight of Fe.sub.2 O.sub.3 onto the surface of a high temperature firebrick, thereby obtaining an excellent coating layer.

Abstract: The present invention provides lead and cadmium free glass enamel compositions. In one embodiment of the invention, glass frits include from about 0.1 percent by weight to about 15 percent by weight Nb.sub.2 O.sub.5, less than about 3 percent by weight alkali metal oxides, less than about 3 percent by weight ZnO, less than about 1 percent by weight B.sub.2 O.sub.3, and precursors from which Bi.sub.2 SiO.sub.5 can be crystallized upon firing, said precursors including Bi.sub.2 O.sub.3 and SiO.sub.2. Glass frits according to the present invention preferably further include up to about 25 percent by weight of coloring oxides, such as CeO.sub.2, Co.sub.3 O.sub.4, In.sub.2 O.sub.3, SnO, Cr.sub.2 O.sub.3, CuO, Fe.sub.2 O.sub.3, MnO.sub.2, MoO.sub.3, NiO, and V.sub.2 O.sub.5. By incorporating various amounts of coloring oxides into the compositions, the degree of crystallization and the rate at which crystallization occurs upon firing of the compositions can be controlled.

Abstract: A glass frit is prepared by heating an initial glass frit in the presence of a reducing agent so as to reduce metal moiety in the glass structure of the frit and then cooling the reaction mixture. Preferably, the frit prepared is used in a method of forming electrically conducting silver tracks on enamel on glass windows, by applying to window glass an enamel composition containing the frit and on top thereof a silver composition in the shape of the tracks and firing the compositions, such that on the firing the reduced metal moiety reduces silver ions migrating through the enamel composition from the silver composition to elemental silver and thereby prevents or impairs them from interacting with the glass to form visible tracks.

Abstract: A barium/lead-free ceramic glaze includes by weight:(i) between about 44 and 50% SiO.sub.2 ;(ii) between about 7 and 13% Al.sub.2 O.sub.3 ;(iii) between about 22 and 26% B.sub.2 O.sub.3 ;(iv) between about 3 and 9% CaO;(v) between about 1 and 3% SrO;(vi) up to about 2% ZnO;(vii) between about 2 and 4% K.sub.2 O;(viii) up to about 2% Li.sub.2 O; and(ix) between about 5 and 9% Na.sub.2 O.This barium/lead-free glaze can be effectually applied to a ceramic substrate at firing temperatures on the order of 1550 to 1650.degree. F. (843 to 899.degree. C.).

Abstract: A composition which represents a new class of unleaded transparent vitreous ceramic which is described as an `Advanced or Combined Intermediate-Oxide Alkali Borosilicate. The composition comprises in combination a specially developed alkali borosilicate and a major addition selected from combinations of the group of traditionally accepted opacifiers, consisting of Zirconium, Tin, and Titanium, the said elements being present in said combination in amounts 0.5 to 43.9 wt % in terms of the Oxide form. The major addition will consist of at least two of said elements. The composition may include minor additions (.ltoreq.10 wt %) of any other element or elements which do not cause loss of transparency.

Abstract: An insulating paste comprises a glass component composed of SiO.sub.2, B.sub.2 O.sub.3 and K.sub.2 O as xSiO.sub.2 -yB.sub.2 O.sub.3 -zK.sub.2 O, where x, y and z (% by weight) fall within the area surrounded by points A (x=65, y=35, z=0), B (x=65, y=20, z=15), C (x=85, y=0, z=15) and D (x=85, y=15, z=0), and an organic vehicle. The insulating layer made of the paste has a low dielectric constant and excellent insulating properties.

Abstract: A sanitary ceramic glaze with improved drying and leveling properties contains a thickening amount of a hydrophobically modified hydroxyethylcellulose with a M.S. of 1.5 to 4.5 and a weight percent hydrophobic modification between 0.1 and 2.0.

Abstract: A glaze composition suitable for a thin chip substrate, for example. The glaze composition makes a low-temperature glazing possible and is superior in the electrical and chemical stability. The glaze composition can prevent even a thin substrate from warping and can easily form an extensive smooth glaze layer without deteriorating a thin glaze face. The components of the composition are 20% to 50% by weight of boron oxide, 5% to 35% by weight of aluminum oxide, and 15% to 55% by weight of at least one alkaline-earth oxide selected from the group consisting of calcium oxide, strontium oxide, magnesium oxide and barium oxide.

Abstract: The present invention relates to polyesters formed by reacting components comprising: (a) from about 20 to about 45 mol% of a diol; (b) from about 4 to about 25 mol% of a polyol; (c) from about 5 to about 25 mol% of a diacid; (d) up to 6 mol% of an ethylenically unsaturated anhydride; and (e) from about 35 to about 45 mol% of a monofunctional fatty acid, where all mole percentages are based on the total mols of (a), (b), (c), (d) and (e). Further, the present invention is directed to liquid enamel compositions comprising: (1) from about 50 to about 90 wt. % of a polyester of the present invention; (2) about 10 to about 50 wt. % of a crosslinking agent; and (3) less than about 20 wt. % of a suitable organic solvent; where all weight percentages are based on the total weight of (1), (2) and (3). The liquid enamel compositions of the present invention have a viscosity of 50 to 1,000 mPa s (cP) at room temperature.

Abstract: The present invention provides a new and improved thick film paste for use as an acid resistant overglaze. In one preferred embodiment such paste includes a glass composition comprising in weight percent from about 30% to about 60% PbO, from about 5% to about 20% ZnO, from about 2% to about 20% B.sub.2 O.sub.3, from about 4% to about 12% Al.sub.2 O.sub.3, from about 5% to about 18% SiO.sub.2, up to about 8% ZrO.sub.2, up to about 8% TiO.sub.2 and from about 9% to about 21% Nb.sub.2 O.sub.5.

Abstract: The present invention relates to a ceramic coating composition contains frit, suspending agent, binder, mica and pearlescent pigment and has a viscosity of about 10 to 50 second as measured by a Zahn cup with orifice diameter of 0.108 inch.

Abstract: A method of forming electrically conducting silver tracks on glass, by applying a silver composition comprising solids portion in a carrier medium to the glass and then firing the composition to form the tracks, wherein the solids portion contains elemental silver and/or precursor thereof and contains also elemental boron.

Abstract: A process for producing a zirconia beating opacifier is disclosed. The process comprising the steps of: (I) heat treatment of a zirconia bearing material comprising heating the zirconia bearing material in the presence of an additive to form a heat modified product having one or more phases which, when incorporated in a glaze and the glaze fired, exhibit opacifying characteristics; and (ii) cooling the heat modified product to produce a product which can be used for imparting opacity.

Abstract: A ceramic enamel composition consists of an oxide frit, a bismuth silicate seed material, a pigment, and a vehicle. A preferred bismuth silicate seed material is selected from crystalline Bi.sub.12 SiO.sub.20, Bi.sub.4 (SiO.sub.4).sub.3, and Bi.sub.2 SiO.sub.5, and mixtures thereof. Upon firing a glass substrate coated with the enamel, components of the enamel adhere to the substrate. The glass can be formed with a die to a desired shape with reduced sticking of the coated region to the die. The ceramic enamel is particularly useful in providing a colored border around automotive glass, which enhances appearance and reduces degradation of adhesives by ultraviolet radiation.

Abstract: Disclosed herein is a glass composition for insulation which comprises SiO.sub.2 and at least one of B.sub.2 O.sub.3 or K.sub.2 O in a ratio falling within the region enclosed by lines passing through point A (65, 35, 0), point B (65, 20, 15), point C (85, 0, 15) and point D (85, 15, 0) on a composition diagram for the ternary system of SiO.sub.2, B.sub.2 O.sub.3 and K.sub.2 O. The glass composition can additionally contain at least one member selected from the group consisting of Al.sub.2 O.sub.3, La.sub.2 O.sub.3, CaO, Ta.sub.2 O.sub.5 and Nd.sub.2 O.sub.3 in an amount less than 25 parts by weight for 100 parts by weight of the major constituents.

Abstract: Alkaline-earth lanthanoborate sealing-glass compositions containing CaO, La.sub.2 O.sub.3, B.sub.2 O.sub.3, TiO.sub.2 and Al.sub.2 O.sub.3 in various combinations of mole-% are provided. These sealing-glass compositions are useful for forming hermetic glass-to-metal seals with titanium and titanium alloys that have a high aqueous durability for component or device applications requiring exposure to moisture, water or body fluids. Particular applications of the titanium sealing-glass compositions include forming glass-to-metal seals for lithium batteries and implanted biomedical devices (e.g. batteries, pacemakers, defibrillators, pumps).

Abstract: An interference pigment comprising a platelet-shaped substrate coated with titanium dioxide and additionally oxidic compounds of copper and manganese, whereby the pigment powder color is dark gray.

Abstract: A lead-free ceramic glaze comprising, by weight:(i) between about 27 and 35% SiO.sub.2 ;(ii) between about 9 and 15% Al.sub.2 O.sub.3 ;(iii) between about 26 and 34% B.sub.2 O.sub.3 ;(iv) between about 4 and 9% BaO;(v) up to about 2.5% CaO;(vi) between about 3 and 8% SrO;(vii) between about 6 and 12% ZnO;(viii) up to about 1% K.sub.2 O;(ix) between about 1 and 4% Li.sub.2 O;(x) between about 1.5 and 3% Na.sub.2 O; and(xi) balance of minor impurities.Also disclosed are ceramic substrates spray coated with such composition and a method for making a lead-free glaze to a ceramic substrate using lower firing temperatures, on the order of 1550.degree. to 1650.degree. F. (843.degree. to 899.degree. C.).

Abstract: Barium lanthanoborate sealing-glass compositions are provided comprising various combinations (in terms of mole-%) of boron oxide (B.sub.2 O.sub.3), barium oxide (BaO), lanthanum oxide (La.sub.2 O.sub.3), and at least one other oxide selected from the group consisting of aluminum oxide (Al.sub.2 O.sub.3), calcium oxide (CaO), lithium oxide (Li.sub.2 O), sodium oxide (Na.sub.2 O), silicon dioxide (SiO.sub.2), or titanium dioxide (TiO.sub.2). These sealing-glass compositions are useful for forming hermetic glass-to-metal seals with titanium and titanium alloys having an improved aqueous durability and favorable sealing characteristics. Examples of the sealing-glass compositions are provided having coefficients of thermal expansion about that of titanium or titanium alloys, and with sealing temperatures less than about 900.degree. C., and generally about 700.degree.-800.degree. C.

Abstract: An article of manufacture comprising a glass substrate having a thermal expansion of less than 5.0.multidot.10.sup.-6 /K and, coated thereon, a lead- and cadmium-free glaze comprising, in percent by weight, the following components:______________________________________ Li.sub.2 O 0-12 MgO 0-10 CaO 3-18 B.sub.2 O.sub.3 5-25 Al.sub.2 O.sub.3 3-18 Na.sub.2 O 3-18 K.sub.2 O 3-18 BaO 0-12 SiO.sub.2 25-55 TiO.sub.2 0-5 ZrO.sub.2 0-<3 ______________________________________with up to 30% by weight of a pigment stable at the baking temperature.

Abstract: Lead-free glass frits having the following composition in weight percent:______________________________________ ZnO 25-35 SiO.sub.2 10-17 ZrO.sub.2 0-2 Al.sub.2 O.sub.3 0-4 Na.sub.2 O 8-12 B.sub.2 O.sub.3 20-30 Bi.sub.2 O.sub.3 6-25 F.sup.-1 1-5 ______________________________________are useful in the formulation of ceramic enamel compositions.

Abstract: An all-ceramic dental restoration comprising a ceramic core over and at least one coating thereon of a porcelain composition having a maturing temperature of from about 850.degree. to about 1050.degree. C. and a coefficient of thermal expansion of from about 4.0 to about 13 (room temperature to 500.degree. C.) parts per million per .degree.C. comprising:______________________________________ Component Amount (Wt. %) ______________________________________ SiO.sub.2 69-75 Al.sub.2 O.sub.3 4.0-9.5 Na.sub.2 O 5-10 K.sub.2 O 0-4 CaO 0-1.5 MgO 0-6 B.sub.2 O.sub.

Abstract: An on-glaze low expansion glass flux composition suitable for coating onto a glazed surface which is essentially free from lead and cadmium and comprises, in mole percent, SiO.sub.2 : 35 to 75%, Bi.sub.2 O.sub.3 : 4 to 12%, Al.sub.2 O.sub.3 : 2 to 12%, B.sub.2 O.sub.3 : 18 to 35%, at least one of Li.sub.2 O, Na.sub.2 O, K.sub.2 O : 0 to 12% (in total), and certain other optional ingredients with the provisos that BaO is not contained in an amount of more than 2 mole percent, the total amount of Bi.sub.2 O.sub.3 +B.sub.2 O.sub.3 +Li.sub.2 O,Na.sub.2 O and K.sub.2 O is in the range of from 25 to 45 mole percent, the total amount of Li.sub.2 O, Na.sub.2 O and K.sub.2 O is in the range of up to 10 percent by weight except when the only alkali metal oxide present is Li.sub.2 O, and the composition has a coefficient of thermal expansion in the range of from 4.0 to 7.0.times.10.sup.-6 /.degree.C.

Abstract: Lead-free glass frits having the following composition in weight percent:______________________________________ ZnO 25-35 SiO.sub.2 10-17 ZrO.sub.2 0-2 Al.sub.2 O.sub.3 0-4 Na.sub.2 O 8-12 B.sub.2 O.sub.3 20-30 Bi.sub.2 O.sub.3 6-25 F.sup.-1 1-5 ______________________________________are useful in the formulation of ceramic enamel compositions.

Abstract: A lead-free ceramic glaze comprising, by weight:(i) between about 27 and 35% SiO.sub.2 ;(ii) between about 9 and 15% Al.sub.2 O.sub.3 ;(iii) between about 26 and 34% B.sub.2 O.sub.3 ;(iv) between about 4 and 9% BaO;(v) up to about 2.5% CaO;(vi) between about 3 and 8% SrO;(vii) between about 6 and 12% ZnO;(viii) up to about 1% K.sub.2 O;(ix) between about 1 and 4% Li.sub.2 O;(x) between about 1.5 and 3% Na.sub.2 O; and(xi) balance of minor impurities.Also disclosed are ceramic substrates spray coated with such composition and a method for making a lead-free glaze to a ceramic substrate using lower firing temperatures, on the order of 1550.degree. to 1650.degree. F. (843.degree. to 899.degree. C.).

Abstract: A dental porcelain material free of yellow coloring or opacification upon firing is produced. A powder mixture is prepared by adding 0.1 to 2.0 wt % of antimony trioxide and 0.01 to 5 wt % of nitric acid or its salt or salt, to a porcelain starting material. The powder mixture is heat-treated at a temperature not lower than the softening temperature of the powder mixture to produce a fused mass which is pulverized and water-washed. 0.01 to 5 wt % of nitric acid or its salt or salts may be added again during the pulverizing step.