US Patent 7147629 Disposable diaper

A disposable diaper has an absorbent core. The core contains therein hydrophilic fibers of 30–70 wt % and super-absorbent polymer particles of 70–30 wt %. Of the super-absorbent particles, first super-absorbent polymer particles having a relatively long liquid-absorbing duration lying in a middle zone of the core as viewed in a transverse direction as well as in a thickness direction of the core to form a polymer phase and second super-absorbent polymer particles having a relatively short liquid-absorbing duration lying in the core above, below and laterally outside the polymer phase to form a mixture phase containing therein the hydrophilic fibers mixed therewith.