The present invention generally relates to a process for preparing an aqueous monomer solution comprising: (i) preparing an aqueous monomer solution comprising an at least partially neutralized, monoethylenically unsaturated monomer (α1) containing a carboxylic acid group and at least one crosslinker (α3)； (Ii) optionally adding fine particles of a water-absorbing polymer to said aqueous monomer solution； (Iii) adding at least one component of a polymerization initiator system or a polymerization initiator system comprising two or more components to the aqueous monomer solution； (iv) reducing the oxygen content of the aqueous monomer solution； (v) filling the polymerization reactor with the aqueous monomer solution； (vi) polymerizing the monomer of the aqueous monomer solution in the polymerization reactor； (Iii) releasing a polymer gel strand out of the polymerization reactor, and optionally pulverizing the polymer gel, thereby obtaining polymer gel particles； (Iii) drying the polymer gel particles； (ix) milling the dried polymer gel particles to thereby obtain a particulate water-absorbing polymer particle； (x) arranging the milled water-absorbent polymer particles in size order； And (xi) treating the surface of the water-absorbing polymer particles arranged in the milling and size order； Here, the gel particles obtained in process step (ⅶ) by process step (ⅷ) is filled with the surface of the belt material of the belt drier in the position L 0, and later dried while further through the belt dryer, in which the belt material is Absorbing polymer particles before contact with the gel particles. The present invention also relates to a process for producing water-absorbing polymer particles, a composite material, a composite material obtainable by such a process, a composite material obtainable by such a process, a chemical product and the use of the water- .본 발명은 일반적으로 (i) 카르복실산기를 함유하는 적어도 부분적으로 중화된, 모노에틸렌계 불포화 단량체 (α1) 및 적어도 하나의 가교제 (α3)를 포함하는 수성 단량체 용액을 제조하는 단계； (
