COLOUR-STABLE SUPERABSORBENT

摘要

Superabsorbents containing a compound of formula (I) where M represents a hydrogen atom, an ammonium ion, a monovalent metal ion or one equivalent of a divalent metal ion of groups 1, 2, 8, 9, 10, 12 or 14 of the periodic table; R1 represents OH or NR4R5, where R4 and R5 independently represent H or C1-C6-alkyl; R2 represents H or an alkyl, alkenyl, cycloalkyl or aryl group which optionally has 1, 2 or 3 substituents selected independently from C1-C6-alkyl, OH, O-C1-C6-alkyl, halogen and CF3; and R3 represents COOM, SO3M, COR4, CONR4R5 or COOR4, where M, R4 and R5 are each as defined above, or, when R2 represents aryl which is optionally substituted as indicated above, also represents H, salts thereof or mixtures of such compounds and/or salts thereof display improved stability to discoloration in storage under elevated temperatures or elevated relative humidity.