Water-absorbing polymer particles
Crosslinked polymer particles having a) a proportion of particles having a particle size of 150 to 300 μm of at least 20% by weight, b) a free swell rate of the entirety of the polymer particles FSR overall of at least 0.25 g/g·s, c) a difference ΔFSR of at least 0.15, d) a centrifuge retention capacity CRC of at least 25.0 g/g, and e) a permeability of the swollen gel bed SFC of at least 90×10 −7 cm 3 ·s/g are disclosed.
1. Water-absorbing polymer particles formed from crosslinked polymer chains comprising predominantly polymerized units of at least partly neutralized acrylic acid, characterized by
a) a proportion of particles having a particle size of 150 to 300 μm of at least 20% by weight,
b) a free swell rate of the totality of the polymer particles FSR overall of at least 0.25 g/g·s,
c) a difference ΔFSR of at least 0.15, where ΔFSR is defined as
ΔFSR=FSR 150-300 μm −FSR overall
in which FSR 150-300 μm represents the free swell rate of the polymer particles having a particle size of 150 to 300 μm,
d) a centrifuge retention capacity CRC of at least 25.0 g/g, and
e) a permeability of the swollen gel bed SFC of at least 90×10 −7 cm 3 ·s/g.
2. Polymer particles according to claim 1 , characterized by a proportion of particles having a particle size of 150 to 300 μm of at least 25% by weight.
3. Polymer particles according to claim 1 , characterized by a proportion of particles having a particle size of 150 to 300 μm of at most 80% by weight.
4. Polymer particles according to claim 1 , characterized by a proportion of particles having a particle size of less than 150 μm of at most 5% by weight.
5. Polymer particles according to claim 1 , characterized by a proportion of particles having a particle size of more than 710 μm of at most 5% by weight.
6. Polymer particles according to claim 1 , characterized by a free swell rate of the entirety of the polymer particles FSR overall of at least 0.26 g/g·s.
7. Polymer particles according to claim 1 , characterized by a free swell rate of the polymer particles having a particle size of 150 to 300 μm FSR 150-300 μm of at least 0.35 g/g·s.
8. Polymer particles according to claim 1 , characterized by a free swell rate of the polymer particles having a particle size of 150 to 300 μm FSR 150-300 μm of at least 0.40 g/g·s.
9. Polymer particles according to claim 1 , characterized by a centrifuge retention capacity CRC of at least 26.0 g/g.
10. Polymer particles according to claim 1 , characterized by a permeability of the swollen gel bed SFC of at least 100×10 −7 cm 3 ·s/g.
11. A hygiene article comprising water-absorbing polymer particles according to claim 1 .