Abstract: Compositions and methods for planarizing or polishing a NiP, glass, ceramic or Glass-ceramic surface in the manufacture of a computer memory disk. The polishing compositions described herein comprise (a) a liquid carrier, preferably water; (b) an abrasive; (c) purified clay; and optional additives, such as (d) a chemical accelerator or oxidizing agent; and (e) a complexing or coupling agent capable of chemically or ionically complexing with, or coupling to, the NiP, glass, ceramic, and/or glass-ceramic material removed during the polishing process. The complexing or coupling agent carries away the metal, glass, ceramic and/or glass-ceramic particles removed during polishing, to prevent the separated particles from returning to the surface from which they were removed. Also disclosed are methods of planarizing or polishing a NiP, glass, ceramic and/or glass-ceramic surface comprising contacting the surface with the compositions.

Abstract: A fiber-reinforced sealing article disposed between an upper sand mold portion (cope) and lower sand mold portion (drag) to fill in, or correct irregularities in green sand molds. In casting metal shapes in a sand/binder mold, the cope and/or drag mold portions include sand compositions that are not perfectly planar surrounding the mold cavity, leaving one or more areas where the cope and drag are not in contact or otherwise provide a seal surrounding the mold cavity. The fiber-reinforced clay-containing article described herein is disposed between the cope and drag to seal the mold in one or more locations surrounding the mold cavity. The composition described herein is capable of shaping by hand, like modeling clay; and the article is preferably in the form of a continuous rope that is flexible, remains hydrated, and can be cut or broken to a desired length and disposed in area(s) where the cope and drag do not make good mating contact.

Abstract: Concentrated suspensions of smectite clays are obtained as either relatively “thin” or highly shear-thinning slurries that are easy to pump, by adding one or more of certain cationic polymers whose weight average molecular weight, Mw, is 50,000 or higher. It was found during the course of the invention that a cationic polymer with an Mw of 10,000 did not work, while the same polymer with a bimodal Mw of 50,000 and 30,000 worked satisfactorily. To achieve the full advantage of the present invention, the cationic polymer preferably has 1 to 10 milliequivalents of cationic charge per gram of the polymer, and more preferably 5 to 10 milliequivalents of cationic charge per gram of the polymer, and most preferably 6 to 8 milliequivalents of cationic charge per gram of the polymer.