Provided is a silica glass member which exhibits high optical transparency to vacuum ultraviolet light and has a low thermal expansion coefficient of 4.010.sup.7/K or less at near room temperature, particularly a silica glass member which is suitable as a photomask substrate to be used in a double patterning exposure process using an ArF excimer laser (193 nm) as a light source. The silica glass member is used in a photolithography process using a vacuum ultraviolet light source, in which the fluorine concentration is 1 wt % or more and 5 wt % or less, and the thermal expansion coefficient at from 20 C. to 50 C. is 4.010.sup.7/K or less.

Latent colorant material compositions, soda-lime-silica glass compositions, and related methods of manufacturing color-strikable glass containers. The latent colorant material compositions may be introduced into a plurality of base glass compositions having redox numbers in the range of ?40 to +20 to produce color-strikable glass compositions and color-strikable glass containers. The latent colorant material compositions introduced into the base glass compositions include a mixture of cuprous oxide (Cu.sub.2O), stannous oxide (SnO), bismuth oxide (Bi.sub.2O.sub.3), and carbon (C). After formation, the color-strikable glass containers may be heat-treated to strike red or black therein.

Latent colorant material compositions, soda-lime-silica glass compositions, and related methods of manufacturing color-strikable glass containers. The latent colorant material compositions may be introduced into a plurality of base glass compositions having redox numbers in the range of ?40 to +20 to produce color-strikable glass compositions and color-strikable glass containers. The latent colorant material compositions introduced into the base glass compositions include a mixture of cuprous oxide (Cu.sub.2O), stannous oxide (SnO), bismuth oxide (Bi.sub.2O.sub.3), and carbon (C). After formation, the color-strikable glass containers may be heat-treated to strike red or black therein.

Disclosed herein are glass-based articles having a first surface having an edge, wherein a maximum optical retardation of the first surface is at the edge and the maximum optical retardation is less than or equal to about 40 nm and wherein the optical retardation decreases from the edge toward a central region of the first surface, the central region having a boundary defined by a distance from the edge toward a center point of the first surface, wherein the distance is ? of the shortest distance from the edge to the center point.

Computer-implemented methods and apparatus are provided for predicting/estimating (i) a non-equilibrium viscosity for at least one given time point in a given temperature profile for a given glass composition, (ii) at least one temperature profile that will provide a given non-equilibrium viscosity for a given glass composition, or (iii) at least one glass composition that will provide a given non-equilibrium viscosity for a given time point in a given temperature profile. The methods and apparatus can be used to predict/estimate stress relaxation in a glass article during forming as well as compaction, stress relaxation, and/or thermal sag or thermal creep of a glass article when the article is subjected to one or more post-forming thermal treatments.

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.11.0
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.11.0
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 preparation method for transparent microcrystalline glass, and transparent microcrystalline glass and a use thereof are provided. The preparation method includes: nucleating a glass raw sheet, crystallizing the nucleated glass raw sheet, and performing heat treatment on the crystallized glass sheet to obtain microcrystalline glass having an XRD diffraction peak height H of ?870, wherein the content of lithium disilicate and petalite in the microcrystalline glass is 90-100%; the heat treatment is divided into a heating stage divided into n heating stages, a high-temperature stage divided into k high-temperature stages, and a cooling stage divided into m cooling stages; k is an integer obtained by rounding (n+k+m)/3, and 6?n+k+m?30; the maximum value of the constant temperature T.sub.Ki of the high-temperature stages is T.sub.Kmax, and T.sub.Kmax=Tg+?T.sub.2; and in the k high-temperature stages, a temperature difference between any two adjacent heat treatment stages is within the range of 5-50? C.

A glass pattern printing process may print a pattern on a front side of a glass. The glass pattern printing process may produce the pattern in a wear-resistant, acid-resistant, alkali-resistant and well-transparent form. The glass pattern printing process may be ideal for producing light-emitting tiles.

A method is provided for separating a portion from a sheet-like glass or glass ceramic element along an intended separation line to divide the element into the portion and a main part. The method includes producing filamentary damages a volume of the glass or glass ceramic element adjacently aligned along the separation line, the filamentary damages are produced by laser pulses of a laser, the glass or glass ceramic element comprises a material that is transparent for the laser pulses; displacing incidence points of the laser pulses on a surface of the glass or glass ceramic element thereof along the separation line; and subjecting the material of the glass or glass ceramic element located in a region of the portion to a phase transition so that the material contracts to detach the portion from the main part at the adjacently aligned filamentary damages along the separation line, while the main part remains intact as a whole.