Patent ID: 6476152
Filing Date: 2002-11-05
Classification: C08F

Abstract:
Method for the preparation of a particulate, stable macroreticular polymer product with MC 30,000 to 50,000, capable of intermolecularly absorbing about 100 to 300 times its weight of water, said method comprising the steps of:(i) subjecting a polymer having aromatic groups, in a form of a 10-30% solution in chlorinated solvents(s), to a crosslinking reaction with 2,5-dichloromethyl-1,4-dimethylbenzene, to obtain an insoluble macroreticular gel; (ii) extruding and cutting said insoluble macroreticular gel to obtain discrete macroreticular gel particles of a main dimension of 3 to 5 centimeters; (iii) reacting said macroreticular gel particles, suspended in chlorinated solvent(s), with sulfonating and, optionally nitrating agents to obtain anionic macroreticular gel particles; (iv) subjecting said anionic macroreticular gel particles to a work-up procedure comprising removing solvent(s) from the macroreticular gel particles, washing the macroreticular gel particles to remove/react excess acidic agent, shrinking/dehydrating the macroreticular gel particles in an aqueous salt solution, and deodorizing the macroreticular gel particles.