The present invention provides an alkali-free glass sheet, which has a content of Li.sub.2O+Na.sub.2O+K.sub.2O of from 0 mol % to 0.5 mol % in a glass composition, and has a Young's modulus of 78 GPa or more, a strain point of 680° C. or more, and a liquidus temperature of 1,450° C. or less.

A transparent gahnite-spinel glass ceramic is provided. The glass ceramic includes a first crystal phase including (Mg.sub.xZn.sub.1−x)Al.sub.2O.sub.4 where x is less than 1 and a second crystal phase including tetragonal ZrO.sub.2. The glass ceramic may be ion exchanged. Methods for producing the glass ceramic are also provided.

A method of manufacturing a polarizing glass sheet includes subjecting, while heating, a glass preform sheet containing metal halide particles to down-drawing, to thereby provide a glass member having stretched metal halide particles dispersed in an aligned manner in a glass matrix, and subjecting the glass member to reduction treatment to reduce the stretched metal halide particles, to thereby provide a polarizing glass sheet. A shape of the glass preform sheet during the down-drawing satisfies a relationship of the following expression:
L.sub.1/W.sub.1≥1.0
where L.sub.1 represents a length between a portion in which a width of the glass preform sheet has changed to 0.8 times an original width and a portion in which the width of the glass preform sheet has changed to 0.2 times the original width W.sub.0, and W.sub.1 represents a length equivalent to 0.5 times the original width W.sub.0 of the glass preform sheet.

A method of manufacturing a polarizing glass sheet includes subjecting, while heating, a glass preform sheet containing metal halide particles to down-drawing, to thereby provide a glass member having stretched metal halide particles dispersed in an aligned manner in a glass matrix, and subjecting the glass member to reduction treatment to reduce the stretched metal halide particles, to thereby provide a polarizing glass sheet. A shape of the glass preform sheet during the down-drawing satisfies a relationship of the following expression:
L.sub.1/W.sub.1≥1.0
where L.sub.1 represents a length between a portion in which a width of the glass preform sheet has changed to 0.8 times an original width and a portion in which the width of the glass preform sheet has changed to 0.2 times the original width W.sub.0, and W.sub.1 represents a length equivalent to 0.5 times the original width W.sub.0 of the glass preform sheet.

The disclosure relates to a composition of biocomposite based on natural rubber containing sol-bioglass, which is used and intended for insulating layers and pads in flexible antennas which can be worn in close vicinity with regard to the human body without adversely affecting it. According to the invention, the composition of the biocomposite intended and designed for insulating layers and pads in flexible antennas based on natural rubber is filled with sol-gel derived bioglass amounting to a quantitative range starting from 8 to 50 parts by weight with regard to 100 parts by weight rubber and having following list of remaining ingredients: zinc oxide from 2.5 to 3.5, stearic acid from 1 to 2.5, bis (triethoxysilylpropyl) tetrasulfide from 4 to 6, tertiary butyl-benzothiazolyl sulfenamide from 1 to 2.5, sulfur from 1 to 3 and isopropyl-phenyl-β-phenylene diamine from 0.5 to 1.5.

The present invention relates to safe strengthened glass with a low-variation-amplitude tensile stress region, a preparation method and an application. The change curve of the compressive stress and tensile stress of the strengthened glass meets a specific function relationship; within the range of 0.45-0.85 mm, the stress distribution meets the following condition: the stress curve is within the following Log-PI function range, the upper limit Fmax of the compressive stress meets the formula (1): Fmax=b+(2*a/PI)*(w/(4*(x−c){circumflex over ( )}2+w{circumflex over ( )}2)), and the lower limit Fmin of the compressive stress meets the formula (2): Fmin=b+(2*a/PI)*(w/(4*(x−c){circumflex over ( )}2+w{circumflex over ( )}2)); or the chemically strengthened glass comprises a first stress region and a second stress region, wherein the stress range of a first subregion in the first stress region includes that the minimum value of the stress difference value of the glass thickness t in the region of 0-10 micrometers is greater than 1 Mpa; and the pressure difference value of the second stress region is smaller than that of the first stress region. The deep compressive stress region of the strengthened glass has relatively high stress, and the tensile stress region has very-low-degree variation amplitude, so that the glass has excellent mechanical strength, very high stability and very high safety.

Bulk paint and ceramic powder systems, methods of forming same, and methods of forming a flexible ceramic coating on a metal substrate are disclosed. The systems may include a ceramic composition having between 2 to 30 weight percent of an alkali metal oxide, such as K.sub.2O, Na.sub.2O, and Li.sub.2O or mixtures thereof, between 10 to 74 weight percent SiO.sub.2, and between 23 to 79 weight percent B.sub.2O.sub.3. Additives that are nonwetting with molten metals, such as boron nitride, provide durable coatings for metal processing operations. The ceramic composition may include less than 5 weight percent additional metal oxides. The bulk paint system further may include water and a cellulosic suspension agent to form a bulk paint. The ceramic powder system may be processed to form a uniform powder. The bulk paint or uniform powder may be applied to a metal substrate, such as a ferrous metal substrate, dried, and heated to form a flexible coating on the metal substrate.

A photochromic glass, comprising: (i) a glass matrix that, comprising in mol percent (mol %) based on oxides: 66 mol %≤SiO.sub.2≤75 mol %; 8 mol %≤B.sub.2O.sub.3≤13 mol %; mol %≤Al.sub.2O.sub.3≤7 mol %; 1.5 mol %≤P.sub.2O.sub.5≤6 mol %, mol %≤Na.sub.2O≤5.5 mol %; 3 mol %≤K.sub.2O≤9.5 mol %; 0 mol %≤MgO≤4 mol %; 0 mol %≤Li.sub.2O≤0.05 mol %; 0 mol %≤BaO≤0.05 mol %; 0 mol %≤CaO≤0.05 mole %; wherein the amount of (Li.sub.2O+BO+CaO≤0.1 mole %); and (ii)) a plurality of photochromic agents, comprising in mol percent (%) with respect to the glass matrix: 0.07%≤Ag≤0.15%; 0.14%≤Cl≤0.25%; 0.025%≤Br≤0.04%; 0.0065%≤CuO≤0.015%, and wherein CuO/Ag≤0.22.

A photochromic glass, comprising: (i) a glass matrix that, comprising in mol percent (mol %) based on oxides: 66 mol %≤SiO.sub.2≤75 mol %; 8 mol %≤B.sub.2O.sub.3≤13 mol %; mol %≤Al.sub.2O.sub.3≤7 mol %; 1.5 mol %≤P.sub.2O.sub.5≤6 mol %, mol %≤Na.sub.2O≤5.5 mol %; 3 mol %≤K.sub.2O≤9.5 mol %; 0 mol %≤MgO≤4 mol %; 0 mol %≤Li.sub.2O≤0.05 mol %; 0 mol %≤BaO≤0.05 mol %; 0 mol %≤CaO≤0.05 mole %; wherein the amount of (Li.sub.2O+BO+CaO≤0.1 mole %); and (ii)) a plurality of photochromic agents, comprising in mol percent (%) with respect to the glass matrix: 0.07%≤Ag≤0.15%; 0.14%≤Cl≤0.25%; 0.025%≤Br≤0.04%; 0.0065%≤CuO≤0.015%, and wherein CuO/Ag≤0.22.

An alkali-free glass substrate contains, as represented by mass % based on oxides: 54% to 68% of SiO.sub.2; 10% to 25% of Al.sub.2O.sub.3; 0.1% to 5.5% of B.sub.2O.sub.3; and 8% to 26% of MgO+CaO+SrO+BaO. The alkali-free glass substrate has β-OH of 0.15 mm.sup.−1 to 0.35 mm.sup.−1, and a Cl content of 0.15 to 0.3 mass %. A bubble growth index I of the alkali-free glass substrate given by the following formula is 320 or more: I=590.5×[β-OH]+874.1×[Cl]−5.7×[B.sub.2O.sub.3]−33.3. In the formula, [β-OH] is β-OH of the alkali-free glass substrate in mm.sup.−1, [Cl] is the Cl content of the alkali-free glass substrate in mass %, and [B.sub.2O.sub.3] is a B.sub.2O.sub.3 content of the alkali-free glass substrate in mass %.