Patent GB-575480-A (GB)
Title: Improvements in and relating to the manufacture of compositions
IPC: C04B26/02
Filed: 1943-06-01
Abstract: A plastic composition comprising a mixture of exfoliated vermiculite with a resinous binder in the proportion of 0.5-4 : 1 is obtained by mixing the vermiculite with a solution or suspension of the resin in a volatile liquid, evaporating the liquid, subjecting the mixture to a kneading action to ensure thorough incorporation, but insufficient to destroy the characteristics of the vermiculite, and then forming the hot mass into desired form under pressure; alternatively, the binder may be used in molten condition.  The binder may be a thermoplastic material such as a cellulose ester or ether, polyvinyl ester or acetal, polyacrylate, polystyrene or synthetic rubber; a thermosetting resin such as a phenol-formaldehyde or urea-formaldehyde resin.  Plasticisers, lubricants, colouring-agents, fillers such as cork, or other modifying materials may be added.  The compositions may be used as floor coverings, gaskets, pressure rings, crown-cap seals and insulating-materials.  According to examples, an aqueous emulsion or a solution in acetone of polyvinyl acetate is mixed, either before or after polymerization, with a plasticiser, and the vermiculite and castor oil, serving as a lubricant, are incorporated in a kneader-type mixer, the temperature being then increased, or the mixture passed between heated rolls, to remove the liquid, and the composition subsequently rolled to the desired thickness; a solution of polystyrene in benzene is mixed with a large amount of plasticiser and treated as above to produce a flexible wrapping-material resistant to water and alcohol; vermiculite is mixed with cresol-formaldehyde resin either in molten form or in solution in cresol, and the product is subjected to heat and pressure; vermiculite is mixed with a solution of cellulose acetate, and the hot masses moulded at about 140 DEG  C. under a pressure of 3000 lbs. per square inch.ALSO:A plastic composition comprising a mixture of exfoliated vermiculite with a resinous binder in the proportion of 0.5-4 : 1, is obtained by mixing the vermiculite with a solution or suspension of the resin in a volatile liquid, evaporating the liquid, subjecting the mixture to a kneading-action to ensure thorough incorporation, but insufficient to destroy the characteristics of the vermiculite, and then forming the hot mass into desired form under pressure; alternatively, the binder may be used in molten condition.  The binder may be a thermoplastic material such as a cellulose ester or ether, polyvinyl ester or acetal, polyacrylate, polystyrene, chlorinated rubber, synthetic rubber, or rubber latex; a thermosetting resin such as a phenol-formaldehyde or urea-formaldehyde resin; or a material capable of being oxidized on exposure to the air, such as a linoleum cement.  Plasticisers, lubricants, colouring-agents, fillers such as cork, or other modifying-materials may be added. The compositions may be used as floor coverings, gaskets, pressure rings, crown-cap seals, and insulating-materials. According to examples, an aqueous emulsion or a solution in acetone of polyvinyl acetate is mixed, either before or after polymerization, with a plasticiser, and the vermiculite and castor oil, serving as a lubricant, are incorporated in a kneader-type mixer, the temperature being then increased, or the mixture passed between heated rolls, to remove the liquid, and the composition subsequently rolled to the desired thickness; a solution of polystyrene in benzene is mixed with a large amount of plasticiser and treated as above to produce a flexible wrapping-material resistant to water and alcohol; vermiculite is mixed with cresol-formaldehyde resin either in molten form or in solution in cresol, and the product is subjected to heat and pressure; vermiculite is mixed with a solution of cellulose acetate, and the hot masses moulded at about 140 DEG  C. under a pressure of 3000 lbs. per square inch; vermiculite is incorporated in a mixture of oxidized linseed oil, rosin, and gum kauri, heated, extruded and then run through mixing-rolls, one of which is cooler than the other, the mass adhering to one roll from which it is scraped and calendered to a textile backing to form a floor-covering.