Patent ID: 6559239
Filing Date: 2003-05-06
Classification: C08F,C08J

Abstract:
A process for the gel and/or surface postcrosslinking of a water-absorbent polymer, comprising:treating said water-absorbent polymer with a surface postcrosslinking solution, to obtain a treated water-absorbent polymer; postcrosslinking said treated water-absorbent polymer to obtain a postcrosslinked water-absorbent polymer; and drying said polymer during and after said treating and said crosslinking by raising a temperature; wherein the surface postcrosslinking solution comprises, dissolved in an inert solvent, as crosslinker a compound of formula I whereinR1, R2, R3 and R4 are each independently hydrogen, C1-C12-alkyl, C1-C12-alkenyl, C6-C12-aryl or C1-C12-alkoxy, R5 is C1-C16-alkyl, C1-C4-hydroxyalkyl, C6-C12-aryl, C1-C16-alkenyl or a group of the formula â€”(CH2)nâ€”COOH or â€”(CH2)nâ€”SO3H in the form of the acid or a respective metal salt, ammonium salt or triethanolammonium salt thereof or â€”(CH2â€”CH2â€”Oâ€”)mâ€”R6, R6 is hydrogen or C1-C16-alkyl, n is from 1 to 10, m is from 1 to 20.