Water-absorbing polymer particles

Patent metadata

Field	Value
Publication number	US-9833766-B2
Application number	US-201515308382-A
Country	US
Kind code	B2
Filing date	May 7, 2015
Priority date	May 8, 2014
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

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.

First claim

The invention claimed is:

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 .

Assignees

• Basf Se

Inventors

• Braun Markus
• Haag Monica
• Deuerlein Stephan

Classifications

• A61L15/24

  Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives thereof {(A61L15/225 takes precedence)} · CPC title

• B01J20/267

  Cross-linked polymers · CPC title

• C08F2/10

  Aqueous solvent · CPC title

• B01J20/261 Primary

  obtained by reactions only involving carbon to carbon unsaturated bonds (macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds per se C08F) · CPC title

• A61L15/60

  Liquid-swellable gel-forming materials, e.g. super-absorbents · CPC title