ORGANOPHILIC CLAY AND THIXTROPIC POLYESTER COMPOSITION CONTAINING SAME

摘要

Organophilic clays and thixotropic cross-linkable polyester compositions containing the same are provided comprising an unsaturated polyester and an unsaturated aromatic monomer such as styrene having dispersed therein an organophilic clay gellant comprising the reaction product of a smectite-type clay having a cation exchange capacity of at least 75 milliequivalents per 100 grams of clay and a methyl benzyl dialkyl ammonium compound or a dibenzyl dialkyl ammonium compound, said alkyl groups comprising long chain alkyl radicals having from 8 to 20 carbon atoms, wherein at least 5% of said long chains contain 8 to 14 carbon atoms and preferably at least 20% have 12 carbon atoms, the amount of said ammonium compound reacted with said clay being from 100 to 130 milliequivalents per 100 grams of clay based on 100% active clay. The polyester commpositions are prepared by a pregel method in which the organophilic clay gellant is mixed with the unsaturated aromatic monomer under high shear to form a pregel and the pregel is then combined with an unsaturated polyester to form the thixotropic compositions.