Dental bulk blocks for cutting machining are provided. The dental bulk block is a glass ceramic block having a structure in which crystalline phases including lithium disilicate as a main crystalline phase and lithium phosphate and at least one of cristobalite and tridymite as additional crystalline phases in an amorphous glass matrix. The dental bulk block is a functionally graded material (FGM) having gradations of size in the main crystalline phase along a depth direction thereof and having no interface at a gradation value change point at which a gradation value of size in the main crystalline phase changes. The dental bulk block is useful for the manufacture of artificial dental prostheses similar to natural teeth. Therefore, the present disclosure provides the effect of reducing the time and process of manufacturing artificial teeth protheses and increasing structural stability in teams of force distribution by functionally grading physical properties.

Disclosed is a bulk block for manufacturing a prosthesis having high aesthetics and processability required for one-day dental prosthetic materials, which is a dental composite bulk block comprising a glass ceramic matrix and a polymer, wherein the glass ceramic matrix consists of an amorphous glass matrix and a crystalline phase dispersed in the glass matrix, the crystalline phase comprises as a main crystalline phase at least one selected from a leucite crystalline phase and a lithium disilicate crystalline phase, and has an average particle diameter of 0.01-1.0 ?m, and the polymer is included in an amount of 20-40 wt % with respect to the weight of the total bulk block. The bulk block has the advantages of improved mechanical properties, being capable of preventing microleakage, exhibiting excellent aesthetics, and enabling machining.

A method for manufacturing a motor vehicle roof incorporating a glazing, in which at least one opacifying layer of ink(s), in particular at least one layer of colored ink(s), is applied by digital printing, in particular by inkjet, over at least 40% of the surface of one of the faces of at least one glass sheet, such that the composition of said ink(s) includes at least one glass frit, and where applicable one or more inorganic pigment(s), with a D90 value for the particle size distribution of less than 2 ?m, and such that the ink(s) have a viscosity of between 1 and 50 mPa.Math.s, the ink(s) further including a non-stick agent and/or a non-stick component and/or at least one non-stick agent and/or at least one non-stick layer being further applied to at least one layer of ink(s) and/or to at least one glass sheet.

A quartz glass provides an opaque quartz glass having high light-shielding property, excellent mechanical strength and excellent cleaning resistance against hydrofluoric acid. By setting the maximum width of the amorphous bubbles existing in the opaque quartz glass to an average of 3 to 15 ?m and the density to 2.15 g/cm.sup.3 or more, the mechanical strength after baking and the cleaning resistance by hydrofluoric acid are improved. The opaque quartz glass has a whiteness at a thickness of 10 mm of 75 to 90%, the reflectance of light with a wavelength of 0.24 to 2.6 ?m at a thickness of 4 mm is 60 to 85%, and the bending strength after baking is 95 MPa. In addition, a foaming agent may be mixed in the opaque quartz glass. An opaque quartz glass having cleaning resistance against acid can be obtained.

A glass-ceramic article, comprising (in mol %): 67-74% SiO.sub.2; 2-6% Al.sub.2O.sub.3; 0.5-1.5% P.sub.2O.sub.5; 18-25% Li.sub.2O; 0-1% Na.sub.2O; 0-1% K.sub.2O; 1-4% ZrO.sub.2; 0-2% CaO; and 0.001-0.5% SnO.sub.2. The glass-ceramic article is opaque, and further comprises a lithium disilicate crystalline phase, a ?-spodumene solid solution crystalline phase, a Zr-based crystalline phase, and a lithium phosphate crystalline phase. The glass-ceramic article can further comprise a fracture toughness (K.sub.IC) of from 1.0 to 3.0 MPa*m.sup.1/2, as measured by the Chevron Notch Short Bar Method, and an opacity from 60 to 97%, as measured through the glass-ceramic article with a thickness of 0.5 mm.

A lamp is provided that includes a glass tube body composed of a glass composition that includes an optical diffusive agent to increase the light diffusivity of the glass tube body. The lamp can include a glass tube body having a perimeter defined by a sidewall of the glass tube body for enclosing a hollow interior. The glass tube body is composed of a sodium silicate glass including an optically diffusive agent that is alloyed with a silicate base glass composition. The optically diffusive agent can be selected from lithium borosilicate, titanium dioxide, antimony trioxide or combinations thereof. The lamp can further include at least one light emitting diode (LED) on a substrate that provides the light source. The at least one light emitting diode (LED) that is present on the substrate is positioned within the hollow interior of the glass tube body.

A process for obtaining a material including a glass sheet, includes providing a glass sheet including a first face coated at least partly by an essentially mineral first coating, the face having at least one first zone and at least one second zone, the at least one first zone having a higher emissivity than that of the second zone, then applying, on at least one portion of the second zone, a sacrificial layer including a resin, then heat treating the coated glass sheet at a temperature of at least 550? C., during which step the sacrificial layer is removed by combustion.

A glass-ceramic article comprises: a center-volume composition comprising (on an oxide basis): 55-75 mol % SiO.sub.2; 0.2-10 mol % Al.sub.2O.sub.3; 0-5 mol % B.sub.2O.sub.3; 15-30 mol % Li.sub.2O; 0-2 mol % Na.sub.2O; 0-2 mol % K.sub.2O; 0-5 mol % MgO; 0-2 mol % ZnO; 0.2-3.0 mol % P.sub.2O.sub.5; 0.1-10 mol % ZrO.sub.2; 0-4 mol % TiO.sub.2; and 0-1.0 mol % SnO.sub.2. Lithium disilicate and either ?-spodumene or ?-quartz are the two predominant crystalline phases (by weight) of the glass-ceramic article. The glass-ceramic article further comprises tetragonal ZrO.sub.2 as a crystalline phase. The composition of the glass-ceramic article from a primary surface into a thickness of the glass-ceramic article can comprise over 10 mol % Na.sub.2O (on an oxide basis), with the mole percentage of Na.sub.2O decreasing from the primary surface towards the center-volume. The glass-ceramic article exhibits a ring-on-ring load-to-failure of at least 120 kgf, when the thickness of the glass-ceramic article is 0.3 mm to 2.0 mm.

A lamp is provided that includes a glass tube body composed of a glass composition that includes an optical diffusive agent to increase the light diffusivity of the glass tube body. The lamp can include a glass tube body having a perimeter defined by a sidewall of the glass tube body for enclosing a hollow interior. The glass tube body is composed of a sodium silicate glass including an optically diffusive agent that is alloyed with a silicate base glass composition. The optically diffusive agent can be selected from lithium borosilicate, titanium dioxide, antimony trioxide or combinations thereof. The lamp can further include at least one light emitting diode (LED) on a substrate that provides the light source. The at least one light emitting diode (LED) that is present on the substrate is positioned within the hollow interior of the glass tube body.

The invention relates to a process for the preparation of a quartz glass body comprising the process steps i.) Providing a silicon dioxide granulate, ii.) Making a glass melt from the silicon dioxide granulate in an oven, and iii.) Making a quartz glass body from at least a part of the glass melt, wherein the oven comprises a hanging sinter crucible. The invention also relates to a quartz glass body which is obtainable by this process. The invention further relates to a light guide, an illuminant and a formed body which are each obtainable by further processing the quartz glass body.