A glass ceramic contains the following components by wt %: 60 to 80% of SiO.sub.2; 4 to 20% of Al.sub.2O.sub.3; 0 to 15% of Li.sub.2O; more than 0 but less than or equal to 12% of Na.sub.2O; 0 to 5% of K.sub.2O; more than 0 but less than or equal to 5% of ZrO.sub.2; 0 to 5% of P.sub.2O.sub.5; and 0 to 10% of TiO.sub.2. A crystalline phase contains at least one of R.sub.2SiO.sub.3, R.sub.2Si.sub.2O.sub.5, R.sub.2TiO.sub.3, R.sub.4Ti.sub.5O.sub.12, R.sub.3PO.sub.3, RAlSi.sub.2O.sub.6, RAlSiO.sub.4O.sub.10, R.sub.2Al.sub.2Si.sub.2O.sub.8, R.sub.4Al.sub.4Si.sub.5O.sub.18, quartz and quartz solid solution. With a liquidus temperature below 1,450° C., a thermal conductivity above 2 w/m.Math.k, and a Vickers hardness above 600 kgf/mm2, the glass ceramic is applicable to portable electronic devices and optical devices.

The present application provides LAS type transparent glass-ceramics of β-quartz of composition containing a high content of zinc, articles constituted at least in part of said glass-ceramics, glasses precursors of said glass-ceramics (with a low viscosity at high temperature), and also a method of preparing said articles. Said glass-ceramics present a composition, free of arsenic oxide and antimony oxide, except for inevitable traces, expressed as percentages by weight of oxides, containing: 64.5% to 66.5% of SiO.sub.2; 19.0% to 20.6% of Al.sub.2O.sub.3; 3.0% to 3.6% of Li.sub.2O; 0 to 1% of MgO; 1.7% to 3.4% of ZnO; 2% to 3% of BaO; 0 to 3% of SrO; 0 to 1% of CaO; 2% to 4% of TiO.sub.2; 1% to 2% of ZrO.sub.2; 0 to 1% of Na.sub.2O; 0 to 1% of K.sub.2O; with Na.sub.2O+K.sub.2O+BaO+SrO+CaO≤6%; optionally up to 2% of at least one fining agent comprising SnO.sub.2; and optionally up to 2% of at least one coloring agent.

The present invention discloses a microcrystalline glass, a microcrystalline glass product, and a manufacturing method therefor. The main crystal phase of the microcrystalline glass comprises lithium silicate and a quartz crystal phase. The haze of the microcrystalline glass of the thickness of 0.55 mm is below 0.6%. The microcrystalline glass comprises the following components in percentage by weight: SiO.sub.2: 65-85%; Al.sub.2O.sub.3: 1-15%; Li.sub.2O: 5-15%; ZrO.sub.2: 0.1-10%; P.sub.2O.sub.5: 0.1-10%; K.sub.2O: 0-10%; MgO: 0-10%; ZnO: 0-10%. A four-point bending strength of the microcrystalline glass product is more than 600 Mpa.

A transparent colored glass ceramic, in particular an LAS glass ceramic, suitable for use as a cooking surface is provided. The transparent colored glass ceramic includes high-quartz solid solution (HQ s.s.) as a main crystal phase and exhibits thermal expansion of −1 to +1 ppm/Kin the range from 20° C. to 700° C. The glass ceramic has from 3.0 to 3.6 percent by weight of lithium oxide (Li.sub.2O) as constituents and either is colored with 0.003 to 0.05 percent by weight of vanadium oxide (V.sub.2O.sub.5) or is colored with 0.003 to 0.25 percent by weight of molybdenum oxide (MoO.sub.3).

Transparent, dyed cook top or hob with improved color display capability, consisting of a glass ceramic with high quartz mixed crystals as predominant crystal phase, whereby the glass-ceramic contains none of the chemical refining agents arsenic oxide and/or antimony, with transmission values of greater than 0.1% in the range of the visible light within the entire wavelength range greater than 450 nm, a light transmission in the visible of 0.8-2.5% and a transmission in the infrared at 1600 nm of 45-85%.

The present invention discloses a microcrystalline glass, a microcrystalline glass product, and a manufacturing method therefor. The main crystal phase of the microcrystalline glass comprises lithium silicate and a quartz crystal phase. The haze of the microcrystalline glass of the thickness of 0.55 mm is below 0.6%. The microcrystalline glass comprises the following components in percentage by weight: SiO.sub.2: 65-85%; Al.sub.2O.sub.3: 1-15%; Li.sub.2O: 5-15%; ZrO.sub.2: 0.1-10%; P.sub.2O.sub.5: 0.1-10%; K.sub.2O: 0-10%; MgO: 0-10%; ZnO: 0-10%. A four-point bending strength of the microcrystalline glass product is more than 600 Mpa.

The present invention relates to porous films comprising (A) from 51 wt.-% to 99.9 wt.-% based on the total weight of the film of at least one porous metal-organic framework material, the material comprising at least one at least bidentate organic compound coordinated to at least one metal ion; (B) from 0.1 wt.-% to 49 wt.-% based on the total weight of the film of at least one fibrillated fluoropolymer; and (C) 0 wt.-% to 48.9 wt.-% based on the total weight of the film of an additive component. The invention further relates to a composition for preparing such a film and its use.

A black lithium silicate glass ceramic is provided. The glass ceramic includes lithium silicate as a primary crystal phase and at least one of petalite, -quartz, -spodumene, cristobalite, and lithium phosphate as a secondary crystal phase. The glass ceramic is characterized by the color coordinates: L*: 20.0 to 40.0, a*: 1.0 to 1.0, and b*: 5.0 to 2.0. The glass ceramic may be ion exchanged. Methods for producing the glass ceramic are also provided.

The present invention discloses a glass-ceramic article and a glass-ceramic for an electric device cover plate, the glass-ceramic comprises, as a predominant crystalline phase, lithium silicate and the quartz crystalline phase, and has a composition expressed in weight percent including: SiO.sub.2: 65-85%, Al.sub.2O.sub.3: 1-15%, Li.sub.2O: 5-15%, ZrO.sub.2: 0.1-10%, P.sub.2O.sub.5: 0.1-10%, K.sub.2O: 0-10%, MgO: 0-10%, ZnO: 0-10%, and Na.sub.2O: 0-5%, wherein (SiO.sub.2+Al.sub.2O.sub.3+Li.sub.2O+ZrO.sub.2)/P.sub.2O.sub.5 is 40-90, the falling ball test height is 700 mm or more. By reasonable component design, the present invention achieves excellent mechanical properties of the glass-ceramic and the glass-ceramic article of the present invention and obtains the glass-ceramic or the glass-ceramic article suitable for electronic devices at a lower cost.

Transparent, dyed cook top or hob with improved color display capability, consisting of a glass ceramic with high quartz mixed crystals as predominant crystal phase, whereby the glass-ceramic contains none of the chemical refining agents arsenic oxide and/or antimony, with transmission values of greater than 0.1% in the range of the visible light within the entire wavelength range greater than 450 nm, a light transmission in the visible of 0.8-2.5% and a transmission in the infrared at 1600 nm of 45-85%.