Abstract: Crystalline tectosilicate ZSM-5 zeolite may be prepared which comprise substantially needle-shaped agglomerates. Tectosilicate ZSM-5 zeolite having a .sup.29 Si NMR spectrum having at least three peaks indicates the presence of Si atoms in the structure having 0, 1 or 2 T-atoms as nearest neighbors.
Type:
Grant
Filed:
May 15, 1995
Date of Patent:
July 21, 1998
Assignee:
Exxon Chemical Patents Inc.
Inventors:
Johannes Petrus Verduijn, Luc Roger Marc Martens, Johan Adriaan Martens
Abstract: A sealing system and sealing composition are provided for inflatable articles containing air under pressure. The sealing composition includes particles or particulates of three-dimensional shapes having sharp corners thereon which tend to dig into the article around the opening and wedge themselves therein. The sealing composition also includes fibers, at least some of which are fibrillated. The fibers tend to wrap around the particles and further plug the leak opening. The particles and the fibers are in a liquid carrier which also tends to form a bond of the particles and fibers in the leak opening. The particles in the composition have dimensions covering a particular range of sizes for different articles, the larger dimension being useful in larger dimension articles, such as large tires for construction machines, and the smaller dimension being useful in smaller articles such as footballs and basketballs, for example.
Abstract: A highly chemically resistant borosilicate glass which is capable of forming a seal with tungsten and has a glass transition temperature T.sub.g >570.degree. C., a coefficient of thermal expansion of between 3.95 and 4.5.times.10.sup.-6 K.sup.-1, a hydrolytic resistance in accordance with DIN 12111 in class one and a TK.sub.100 value in accordance with DIN 52326 of at least 240.degree. C. is described which has the composition (in % by weight, based on oxide) of SiO.sub.2 70 to 78, B.sub.2 O.sub.3 9 to 12, Al.sub.2 O.sub.3 1.5 to 4, Li.sub.2 O 0 to 4, Na.sub.2 O 1 to 5, K.sub.2 O 1 to 5, total of alkali metal oxides 5 to 7, MgO 0 to 3, CaO 1 to 3, BaO 0 to 2, ZnO 0 to 2, ZrO.sub.2 0.5 to 3, total of MgO+CaO+BaO+ZnO+ZrO.sub.2 6 to 10, and optionally conventional refining agents. It is preferred that the K.sub.2 O:Na.sub.2 O ratio be greater than 1 and that alkaline earth metal oxides, except for CaO, be omitted.
Abstract: A sinter-reactive lanthanum chromite powder is prepared from the lanthanum chromite precursor LaCr.sub.1-x M.sub.x O.sub.3 (Adsorbate). The powder is crystalline, has the formula LaCr.sub.1-x M.sub.x O.sub.3, where M is magnesium or calcium and x ranges from about 0.03 to 0.3, and sinters to densities higher than about 95% of theoretical density at temperature as low as 1600.degree. C. in inert or reducing atmospheres. Sintering to such high density at temperatures in the vicinity of 1600.degree. C. makes the powder particularly suited for use as interconnect material for solid oxide fuel cells.