Water-absorbing Polymeric Particles with Optimized Size Distribution

The patent optimizes the particle size distribution parameters by controlling the average particle diameter within a specific range (150-425 μm) and defining the proportion of fine particles (≤300 μm) to be at least 20% by weight. This parameter optimization resolves the contradiction by identifying the optimal balance point where particles are small enough for ultrathin articles but maintain sufficient SFC through the specific size distribution composition.

The patent creates a composite particle size distribution system combining fine particles (≤300 μm) for high SFC and fluid transportation with coarser particles (>300 μm) for structural integrity and absorbency. This composite approach allows the material to exhibit both high flow conductivity from fine particles and adequate absorption capacity from the mixed size distribution, resolving the contradiction between particle size reduction and SFC maintenance.

The patent applies partial crosslinking rather than extensive crosslinking, with the postcrosslinker content specifically controlled to be 0.01-0.5% by weight based on base polymer. This partial action approach provides sufficient crosslinking to improve SFC and fluid transportation while avoiding excessive crosslinking that would overly reduce CRC, thus resolving the contradiction between improving flow conductivity and maintaining absorption capacity.

The patent optimizes the postcrosslinking parameters by controlling the postcrosslinker content within a narrow range (0.01-0.5% by weight) and the degree of postcrosslinking to achieve specific performance targets (SFC ≥ 80×10⁻⁷ cm³s/g, CRC ≥ 26 g/g). This precise parameter control resolves the contradiction by identifying the optimal crosslinking level that balances SFC improvement with CRC preservation.

The patent applies controlled postcrosslinking with postcrosslinker content limited to 0.01-0.5% by weight, which is sufficient to improve SFC but not excessive enough to severely compromise CRC. This partial postcrosslinking approach resolves the contradiction by providing just enough crosslinking to enhance fluid transportation while preserving adequate absorption capacity.

The patent uses postcrosslinking as a secondary modification step that copies and enhances the crosslinking structure initiated during base polymer formation, rather than relying solely on extensive internal crosslinking. This allows for fine-tuned control over the crosslinking density to balance SFC and CRC performance.