Abstract: A silica-based coating film having a low dielectric constant not exceeding 2.5 can be formed on the surface of a substrate to serve as a planarizing layer or an interlayer insulating layer by coating the surface with a unique coating solution containing a hydrolysis-condensation product of a polyalkoxy silane compound such as tetraethoxy silane and monomethyl trimethoxy silane, which is formed by the hydrolysis of a polyalkoxy silane in the presence of a basic catalyst such as ammonia in an alcohol solvent in a relatively low concentration followed by replacement of the alcohol solvent with an aprotic polar solvent such as N-methyl pyrrolidone, followed by drying and baking at 350 to 800° C.
Abstract: An aqueous suspension comprising 15% or more, by total weight of the suspension, of at least one anionic or nonionic water-soluble polymer dispersed in an aqueous solution of an ammonium salt having a multivalent anion, wherein the weight ratio of the ammonium salt to the water is at least 0.15, a process for preparing the same, and use of the same in a variety of applications, are disclosed.
Abstract: This invention is directed to a process for the chemical stabilization of heavy metal bearing dusts and sludges. A preferred use for such process is the treatment of dust from an electric arc furnace (EAF). In the production of steel by the electric arc furnace process, a by-product thereof is the generation of EAF dust. Such dust, by virtue of the presence of such elements as cadmium, hexavalent chromium and lead, is classified as hazardous waste by U.S. Environmental Protection Agency (EPA). The present invention is directed to a process for the chemical stabilization of the inorganic EAF dust to render the hazardous constituents thereof virtually immobile. Such process is based on the pozzolanic reaction of materials containing anhydrous alumino-silicates which, in the presence of lime, water and chemicals, adsorb and/or physically entrap the heavy metals present in EAF dust into a calcium-alumino-silicate matrix.
Type:
Grant
Filed:
July 29, 1988
Date of Patent:
June 20, 1989
Assignee:
Bethlehem Steel Corporation
Inventors:
John D. Lynn, Charles E. Jablonski, Walter D. Egan