Annealing treatments for modified titania-silica glasses and the glasses produced by the annealing treatments. The annealing treatments include an isothermal hold that facilitates equalization of non-uniformities in fictive temperature caused by non-uniformities in modifier concentration in the glasses. The annealing treatments may also include heating the glass to a higher temperature following the isothermal hold and holding the glass at that temperature for several hours. Glasses produced by the annealing treatments exhibit high spatial uniformity of CTE, CTE slope, and fictive temperature, including in the presence of a spatially non-uniform concentration of modifier.

A synthetic quartz glass substrate having a controlled hydrogen molecule concentration is prepared by (a) hot shaping a synthetic quartz glass ingot into a glass block, (b) slicing the glass block into a glass plate, (c) annealing the glass plate at 500-1,250 C. for 15-60 hours, (d) hydrogen doping treatment of the glass plate in a hydrogen gas atmosphere at 300-450 C. for 20-40 hours, and (e) dehydrogenation treatment of the glass plate at 200-400 C. for 5-10 hours.

To provide An Al.sub.2O.sub.3-free dental lithium silicate glass composition comprising the following components:

SiO.sub.2: 60.0 to 80.0% by weight
Li.sub.2O: 10.0 to 17.0% by weight
K.sub.2O: 0.5 to 10.0% by weight
a nucleating agent: 1.0 to 6.0% by weight
a colorant: 0.0 to 10.0% by weight, and,
a metal oxide Me(tetravalent)O.sub.2: 5.0 to 10.0% by weight.

A method for producing rare earth metal-doped quartz glass includes the steps of (a) providing a blank of the rare earth metal-doped quartz glass, and (b) homogenizing the blank by softening the blank zone by zone in a heating zone and by twisting the softened zone along a rotation axis. Some rare earth metals, however, show a discoloration of the quartz glass, which hints at an unforeseeable and undesired change in the chemical composition or possibly at an inhomogeneous distribution of the dopants. To avoid this drawback and to provide a modified method which ensures the production of rare earth metal-doped quartz glass with reproducible properties, during homogenization according to method step (b), the blank is softened under the action of an oxidizingly acting or a neutral plasma.

Annealing treatments for modified titania-silica glasses and the glasses produced by the annealing treatments. The annealing treatments include an isothermal hold that facilitates equalization of non-uniformities in fictive temperature caused by non-uniformities in modifier concentration in the glasses. The annealing treatments may also include heating the glass to a higher temperature following the isothermal hold and holding the glass at that temperature for several hours. Glasses produced by the annealing treatments exhibit high spatial uniformity of CTE, CTE slope, and fictive temperature, including in the presence of a spatially non-uniform concentration of modifier.

According to an embodiment, a cover glass includes a glass plate forming at least a portion of an electronic device, and a first coat layer deposited on a surface of the glass plate, the first coat layer at least partially including a network structure. The first coat layer includes silicon (Si), oxygen (O), and at least one impurity, and such that SiO bonds are 80% or more by weight of the first coat layer. A polysilazane-applied coat is laid over one surface of the reinforced glass plate, providing an elegant haze glass cover.

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.

The invention concerns a method for manufacturing heat treatable antireflective glass substrates by ion implantation, comprising selecting a source gas of N.sub.2, O.sub.2, or Ar, ionizing the source gas so as to form a mixture of single charge and multicharge ions of Ar, N, or O, forming a beam of single charge and multicharge ions of Ar, N, or O by accelerating with an acceleration voltage comprised between 15 kV and 60 kV and setting the ion dosage at a value comprised between 7.510.sup.16 and 7.510.sup.17 ions/cm.sup.2. The invention further concerns heat treatable and heat treated antireflective glass substrates comprising an area treated by ion implantation with a mixture of simple charge and multicharge ions according to this method.

A device for manufacturing SiO.sub.2TiO.sub.2 based glass by growing a glass ingot upon a target by a direct method. The device includes the target, comprising a thermal storage portion that accumulates heat by being preheated, and a heat insulating portion that suppresses conduction of heat from the thermal storage portion in a direction opposite to the glass ingot.

A window glass for a vehicle includes: a glass plate having a first main surface and a second main surface; a ceramic color layer, and an organic ink layer, in which the ceramic color layer is provided at least in a periphery on the first main surface of the glass plate, the organic ink layer is provided to cover at least a partial region on the ceramic color layer provided in the periphery, and a thickness of the organic ink layer is smaller than a thickness of the ceramic color layer.