Thin fluid absorbent core-absorbent paper

Patent metadata

Field	Value
Publication number	US-12336895-B2
Application number	US-201917048354-A
Country	US
Kind code	B2
Filing date	Apr 9, 2019
Priority date	Apr 20, 2018
Publication date	Jun 24, 2025
Grant date	Jun 24, 2025

Abstract

The present disclosure relates to fluid absorbent cores including at least one absorption layer, the layer including at least 80% by weight of water-absorbent polymer particles, 0 to 10% by weight of an adhesive and from 0 to 10% by weight of fibrous material, wherein the water-absorbent polymer particles within the absorption layer are water-absorbent polymer particles having a vortex of 40 s or less and having a roundness of 0.79 to 0.85 and/or a CRC of 38 g/g to 85 g/g.

First claim

The invention claimed is:

1. A fluid absorbent core comprising:
at least one absorption layer, the at least one absorption layer comprising at least 80% by weight of water-absorbent polymer particles,
0 to 10% by weight of an adhesive, and
from 0 to 10% by weight of fibrous material,
wherein the water-absorbent polymer particles within the at least one absorption layer are water-absorbent polymer particles having a vortex of 40 s or less and having a roundness of 0.79 to 0.85 and a centrifuge retention capacity (CRC) of 38 g/g to 85 g/g;
wherein the water-absorbent polymer particles have a free swell capacity (FSC) (1 min) of at least 25 g/g/s.

2. The fluid absorbent core according to claim 1 , comprising at least two absorption layers, an upper layer and a bottom layer, wherein at least the bottom layer comprises water-absorbent polymer particles.

3. The fluid absorbent core according to claim 2 , wherein a nonwoven material is sandwiched between the upper layer and the bottom layer.

4. The fluid absorbent core according to claim 2 , wherein a Water Pouring Time is 28 s or less and a Water Pouring Rewet 3.5 g or less measured for an absorbent core according to a water pouring test.

5. The fluid absorbent core according to claim 2 , wherein a Liquid Diffusion Length is at least 245 mm, a total strike-thru time 45 s or less and a Total Rewet 40 g or less measured for an absorbent core according to a strike-thru/rewet method.

6. The fluid absorbent core according to claim 1 , wherein the water-absorbent polymer particles have a CRC of 40 g/g to 80 g/g.

7. The fluid absorbent core according to claim 1 , wherein the water-absorbent polymer particles have a roundness of 0.80 to 0.85.

8. The fluid absorbent core according to claim 1 , wherein the water-absorbent polymer particles have an extractables content of 10 wt % or less.

9. The fluid absorbent core according to claim 1 , wherein the water-absorbent polymer particles have a volumetric absorption under load (VAUL) (τ=21 g cm −2 ) of 1000 s or less.

10. The fluid absorbent core according to claim 1 , wherein the water-absorbent polymer particles have a liquid uptake of 20 g/g (T 20 ) of 1000 s or less.

11. The fluid absorbent core according to claim 1 , wherein the water-absorbent polymer particles have a difference between a wet weight of filter papers and a dry weight of the filter papers (SAP-Rewet) (3 min) of 1.5 g or less.

12. An absorbent article, comprising:
an upper liquid-pervious sheet,
a lower liquid-impervious sheet,
a fluid absorbent core according to claim 1 , and
an optional acquisition distribution layer between the upper liquid-pervious sheet and the fluid absorbent core.

13. The fluid absorbent core according to claim 1 , wherein the water-absorbent polymer particles within the at least one absorption layer are in the form of droplet polymers.

14. Water-absorbent polymer particles having a vortex of 40 s or less and having a roundness of 0.79 to 0.85 and a centrifuge retention capacity (CRC) of 38 g/g to 85 g/g;
wherein the water-absorbent polymer particles have a free swell capacity (FSC) (1 min) of at least 25 g/g/s.

15. The water-absorbent polymer particles according to claim 14 , wherein the water-absorbent polymer particles are in the form of droplet polymers.

Assignees

• Basf Se

Inventors

• Bauer Stephan
• Baumann Katrin
• Herfert Norbert
• Duan Li Guo
• Li Le
• Liu xiao yan
• Sun Gao Min

Classifications

• A61L15/60

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

• A61L15/24

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

• A61F2013/530591

  in granules or particles · CPC title

• A61F2013/530708

  characterized by the absorbency properties · CPC title

• A61F2013/530481

  having superabsorbent materials, i.e. highly absorbent polymer gel materials · CPC title