The invention relates to a super-absorbent, the surfaces of which are complexed with multivalent metal ions and which contains at least one phosphonic acid derivative, the molar ratio between multivalent metal and phosphonic acid derivative being at most 1.2/n, n being the number of phosphonic acid groups in the phosphonic acid derivative, which super-absorbent exhibits good stability against discoloration and surprisingly low caking tendency, without the usage properties of the super-absorbent being substantially impaired. Such super-absorbents can be produced by polymerizing an aqueous monomer solution that contains a) at least one ethylenically unsaturated acid-group-bearing monomer, which is optionally present at least partially as a salt, b) at least one cross-linking agent, c) at least one initiator, d) optionally one or more ethylenically unsaturated monomers that can be copolymerized with the monomers mentioned under a), e) optionally one or more water-soluble polymers. The method also comprises drying the obtained polymerizate, optionally grinding the dried polymerizate and sifting the ground polymerizate, optionally surface post-crosslinking the dried and optionally ground and sifted polymerizate, adding at least one salt of a multivalent metal, and adding at least one phosphonic acid derivative. The method is characterized in that salt of a multivalent metal and phosphonic acid derivative are added in such amounts that a molar ratio between the metal and the phosphonic acid derivative of 1.2/n is not exceeded, n being the number of phosphonic acid groups in the phosphonic acid derivative.본 발명은 표면이 다가 금속 이온으로 착화되고, 하나 이상의 포스폰산 유도체를 포함하는 초흡수체에 관한 것이며, 이때 다가 금속 및 포스폰산 유도체의 몰비는 1.2/n 이하이고, 이때 n 은 포스폰산 유도체에서 포스폰산 기의 수이고, 상기 초흡수체는 변색에 대항하여 양호한 안정도를 나타내고 놀랍게도 초흡수체의 이용 특성을 실질적으로 손상시키지 않으면서 낮은 케이킹 경향을 나타낸다. 이러한 초흡수체는 하기를 포함하는 단량체 수용액을 중합함으로써 제조될 수 있다:a)산 기를 포함하고 임의적으로는 일부 이상 염 형태로 존재하는 하나 이상의 에틸렌성 불포화 단량체,b)하나 이상의 가교제,c)하나 이상의 개시제,d)임의적으로는, 상기 a) 에 언급된 단량체와 공중
