The present invention relates to alumina flakes having a defined thickness and particle size distribution and to their use in varnishes, paints, automotive coatings, printing inks, masterbatches, plastics and cosmetic formulations and as substrate for effect pigments.

Various embodiments disclosed relate to an abrasive article (10). The abrasive article (10 includes a backing (12) defining a major surface. The abrasive article (10) includes an abrasive layer including a plurality of tetrahedral abrasive particles (16) attached to the backing (12). The tetrahedral abrasive particles (16) include four faces joined by six edges terminating at four vertices (40, 42, 44, 46). Each one of the four faces contacts three of the four faces, and a major portion of the tetrahedral abrasive particles (16) have at least one of the vertices (40, 42, 44, 46) oriented in substantially a same direction.

A supported catalyst, its method of preparation and use in hydrogenation methods, which catalyst contains an oxide substrate that is for the most part calcined aluminum and an active phase that contains nickel, with the nickel content between 5 and 65% by weight in relation to the total mass of the catalyst, with the active phase not containing a metal from group VIB, the nickel particles having a diameter that is less than or equal to 20 nm, the catalyst having a median mesopore diameter of between 14 nm and 30 nm, a median macropore diameter of between 50 and 200 nm, a mesopore volume that is measured by mercury porosimetry that is greater than or equal to 0.40 mL/g, and a total pore volume that is measured by mercury porosimetry that is greater than or equal to 0.42 mL/g.

Sintering is an important issue in creating crystalline metal oxides with high porosity and surface area, especially in the case of high-temperature materials such as metal aluminates. Herein we report a rationally designed synthesis of metal aluminates that diminishes the surface area loss due to sintering. Metal aluminate (e.g. MeAl.sub.2O.sub.4or MeAlO.sub.3Me=Mg, Mn, Fe, Ni, Co, Cu, La, or Ce; or mixture thereof) supported on -Al.sub.2O.sub.3 with ultralarge mesopores (up to 30 nm) was synthesized through microwave-assisted peptization of boehmite nanoparticles and their self-assembly in the presence of a triblock copolymer (Pluronic P123) and metal nitrates, followed by co-condensation and thermal treatment. The resulting materials showed the surface area up to about 410 m.sup.2.Math.g.sup.1, porosity up to about 2.5 cm.sup.3.Math.g.sup.1, and very good thermal stability. The observed enhancement in their thermomechanical resistance is associated with the faster formation of the metal aluminate phases. The nanometer scale path diffusion and highly defective interface of -alumina facilitate the counter diffusion of Me.sup.X+ and Al.sup.3+ species and further formation of the metal aluminate phase.

The present invention relates to a process for conducting endothermic gas phase or gas-solid reactions, wherein the endothermic reaction is conducted in a production phase in a first reactor zone, the production zone, which is at least partly filled with solid particles, where the solid particles are in the form of a fixed bed, of a moving bed and in sections/or in the form of a fluidized bed, and the product-containing gas stream is drawn off from the production zone in the region of the highest temperature level plus/minus 200 K and the product-containing gas stream is guided through a second reactor zone, the heat recycling zone, which at least partly comprises a fixed bed, where the heat from the product-containing gas stream is stored in the fixed bed, and, in the subsequent purge step, a purge gas is guided through the production zone and the heat recycling zone in the same flow direction, and, in a heating zone disposed between the production zone and the heat recycling zone, the heat required for the endothermic reaction is introduced into the product-containing gas stream and into the purge stream or into the purge stream, and then, in a regeneration phase, a gas is passed through the two reactor zones in the reverse flow direction and the production zone is heated up; the present invention further relates to a structured reactor comprising three zones, a production zone containing solid particles, a heating zone and a heat recycling zone containing a fixed bed, wherein the solid particles and the fixed bed consist of different materials.

The present invention provides alumina hydrate particles, a flame retardant and a resin composition that are each for an electric wire/cable covering material improvable in flame retardancy and mechanical properties while the covering material keeps acid resistance; such an electric wire/cable; and producing methods thereof. The alumina hydrate particles of the present invention for electric wire/cable covering material have an average particle size of 0.5 to 2.5 m, and having a primary particle variation R of 24% or less, the variation R being represented by the following expression: primary particle variation R=standard deviation (m) of major axis diameters of the primary particles/average value (m) of the major axis diameters of the primary particles100.

The invention provides highly reactive nano-sized alumina particle compositions, including alumina compositions with a BET surface areas on the order of 2000 m.sup.2/g. Also disclosed are impregnated alumina supports comprising materials that are metal oxides or carbonates. Methods for the synthesis and fabrication of these compositions are provided, along methods for the use of these compositions as sorbents.

An abrasive grain is disclosed and may include a body. The body may define a length (l), a height (h), and a width (w). In a particular aspect, the length is greater than or equal to the height and the height is greater than or equal to the width. Further, in a particular aspect, the body may include a primary aspect ratio defined by the ratio of length:height of at least about 2:1. The body may also include an upright orientation probability of at least about 50%.

The present invention relates to alumina flakes having a defined thickness and particle size distribution and to their use in varnishes, paints, automotive coatings printing inks, masterbatches, plastics and cosmetic formulations and as substrate for effect pigments. and organic dyes.

The present invention relates to alumina flakes having a defined thickness and particle size distribution and to their use in varnishes, paints, automotive coatings printing inks, masterbatches, plastics and cosmetic formulations and as substrate for effect pigments. and organic dyes.