CALCIUM SULFATE SUSPENSIONS INCLUDING CATIONIC STARCH, METHODS OF USING THEM, AND ARTICLES MADE THEREOF

Abstract

This disclosure relates more particularly to calcium sulfate-based suspensions useful, for example, for making gypsum boards for building construction, as well as methods for using them, for example, for making gypsum boards; in one aspect, this disclosure provides a calcium sulfate suspension composition comprising calcium sulfate basically present in the form of one or more hydrates, the calcium sulfate being present in an amount in the range of 70-99.8% w / w on a dry basis, calculated as stucco; and a cationic starch present in an amount of 0.10-10% w / w of the amount of calcium sulfate as stucco on a dry basis, the cationic starch being substituted by amine and / or ammonium groups and having a %N value in the range of 0.10% pa 2% w / w, and an RVA viscosity value of at least 100 cP at 65 °C and 16% w / w; and water, in a sufficient quantity to form a suspension; the disclosure further provides gypsum-based materials useful as building materials, for example, for use as building boards in the construction of building walls and ceilings.