Patent ID: 6914081

Claim:
A method of making a rheology-modified aqueous composition comprising admixing a material whose constituents conform to the proportions of the empirical formula M′ m M″ n (OH) (2m+3n+qa+br) (A q ) a (B r ) b .xH 2 O, where M′ represents at least one divalent metal cation selected from the group consisting of Mg, Ca, Mn, Fe, Co, Ni, Cu, and Zn and m is an amount of from greater than zero to about 8; where M″ represents at least one trivalent metal cation selected from the group consisting of Al, Ga and Fe and n is an amount of from greater than zero to about 6; where A is an anion or negative-valence radical that is monovalent or polyvalent, and a is an amount of A of valence q, provided that if A is monovalent, a is from greater than zero to about 8, and if A is polyvalent, a is from greater than zero to about 4; where B is a second anion or negative-valence radical that is monovalent or polyvalent, and where b is an amount of B of valence r and b is from zero to about 4; provided (m+n) is greater than or equal to 1; further provided qa+br cannot be greater than 2m+3n, and provided that qa cannot equal 2m+3n, and still further provided that (2m+3n+qa+br) is less than 3; where xH 2 O represents excess waters of hydration, with x being zero or more; and where the material is a calcined hydrotalcite or hydrotalcite-like compound, or mixture thereof, wherein the calcination is carried out in the presence of greater than about 1,000 ppm of sodium; with at least a day and water to form a rheology-modified aqueous composition.