Anionically modified organophilic clays and their preparation

A process for preparing an organophilic clay gellant which comprises:

• a. preparing an aqueous slurry of smectite-type clay having a cation exchange capacity of at least 75 milliequivalents per 100 grams of clay, said clay ranging from about 1 to about 80% by weight of slurry;
• b. heating the slurry to a temperature between 20.degree. C. and 100.degree. C.;
• c. adding from about 5 to 100 milliequivalents of an organic anion per 100 grams of clay, 100% active clay basis and an organic cation compound, wherein said organic cation has the formula:
• ##STR10## wherein R.sub.1 is selected from the group consisting of a .beta.,.gamma.-unsaturated alkyl group having less than 7 aliphatic carbon atoms, a hydroxyalkyl group having 2 to 6 aliphatic carbon atoms, and mixtures thereof;
• R.sub.2 is a long chain alkyl group having 12 to 60 carbon atoms;
• R.sub.3 and R.sub.4 are individually selected from the group consisting of a .beta.,.gamma.-unsaturated alkyl group having less than 7 aliphatic carbon atoms, a hydroxyalkyl group having 2 to 6 aliphatic carbon atoms, an aralkyl group having 1 to 22 carbon atoms in the alkyl portion, an alkyl group having from 1 to 22 carbon atoms and mixtures thereof;
• X is selected from a group consisting of phosphorous and nitrogen;
• said organic cation compound is used in a sufficient amount to at least satisfy the cation exchange capacity of the smectite-type clay and the cationic activity of the organic anion while agitating the reaction solution;
• and
• d. reacting the mixture for a sufficient time to form a reaction product comprising an organic cation-organic anion complex which is intercalated with the smectite-type clay and the cation exchange sites of the smectite-type clay are substituted with the organic cation.