Adducts of clay and activated mixed metal oxides

US5232627A · kind A · utility

Assignee

• THE DOW CHEMICAL COMPANY · US

Inventors

• John L. Burba, III · Angleton, US
• Arthur E. Read, Jr. · Lake Jackson, US
• Edgar F. Hoy · Kingwood, US

Key dates

• Filing date: Apr 16, 1991
• Grant date: Aug 3, 1993
• Expiry date: Apr 16, 2011

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C10N2050/01
• WIPO field: Pharmaceuticals
• WIPO sector: Chemistry

Abstract

Adducts of clay, especially of the smectite variety, most especially bentonite, are prepared with an effective amount of at least one activated mixed metal oxide or oxy-hydroxide (AHMMO) formed by dehydrating hydrotalcite or a mixture comprising magnesium oxide and aluminum oxide, or a crystalline mixed metal hydroxide conforming substantially to the formula EQU Li.sub.m D.sub.d T(OH).sub.(m+2d+3+n.a) (A.sup.n).sub.a. xH.sub.2 O where m is zero to one, D is a divalent metal, d is from zero to 4, T is a trivalent metal, A represents at least one anion or negative-valence radical of valence n, where n is 1 or more, (m+2d+3+n.a) is equal to or greater than 3, (m+d) is greater than zero, and xH.sub.2 O represents excess waters of hydration. These adducts are useful, e.g., in drilling muds and in viscosity modification of a wide variety of fluids.