| 摘要 |
A composition of matter comprising anionic clay having the general formula <?in-line-formulae description="In-line Formulae" end="lead"?>[M<SUP>2+</SUP><SUB>1-x</SUB>M<SUP>3+</SUP><SUB>x</SUB>(OH)<SUB>2</SUB>]<SUP>x+</SUP>(x/n)A<SUP>n-</SUP>.yH<SUB>2</SUB>O (I) <?in-line-formulae description="In-line Formulae" end="tail"?> <?in-line-formulae description="In-line Formulae" end="lead"?>or <?in-line-formulae description="In-line Formulae" end="tail"?> <?in-line-formulae description="In-line Formulae" end="lead"?>[M<SUP>1+</SUP>M<SUP>3+</SUP><SUB>2</SUB>(OH)<SUB>6</SUB>]<SUP>1+</SUP>(1/n)A<SUP>n-</SUP>.yH<SUB>2</SUB>O; (II) <?in-line-formulae description="In-line Formulae" end="tail"?> where M<SUP>1+</SUP> is a mono-valent metal; M<SUP>2+</SUP> is a divalent metal; and M<SUP>3+</SUP> is a trivalent metal; A is an inorganic or organic anion, chosen such that the rule of charge neutrality is obeyed; n is an integer; x is any rational number between 0 and 1; and y is any rational number between 0 and 10; where the anionic clay is in the form of particles having a volume weighted mean particle size diameter of less than 500 nm. Stable colloidal dispersions comprise such anionic clay particles having a volume weighted mean particle size diameter of less than 500 nm dispersed in a liquid medium. Method for preparing such stable colloidal dispersion of anionic clay particles comprises simultaneously bringing together salt solutions of M<SUP>2+</SUP> and M<SUP>3+</SUP> metals, or of M<SUP>1+</SUP> and M<SUP>3+</SUP> metals, and a base in a high shear mixing zone within a liquid dispersion medium in a particle precipitation vessel, and precipitating anionic clay particles having a volume weighted mean particle size diameter of less than 500 nm.
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