| abstract |
1,146,668. Modified clay. IMPERIAL CHEMICAL INDUSTRIES Ltd. 8 July, 1966 [12 July, 1965], No. 29434/65. Heading C1A. A naturally occurring water swellable clay of base exchange capacity 20-120 milliequivalents per 100 g. clay is modified with a water soluble polymer or copolymer of vinyl pyrrolidone or a derivative thereof, generally of M.wt. 2000 to 3,000,000 and in amount 5-400% by wt. The modified clay of the invention may be used as a thickener for aqueous compositions generally in amount 0À25-10% by wt. based on the wt. of the aqueous phase. In the examples polyvinyl pyrrolidone and copolymers of vinyl pyrrolidone and vinyl acetate are used as modifiers. The clay preferably contains montmorillonite, e.g. bentonite or hectorite, in which the Ca and Mg ions may be replaced by Na. |