Superabsorbent polymer with high permeability
AssigneeStockhausen GmbH & Co. KG
InventorsScott Smith, Mark Joy, Whei-Neen Hsu, Markus Frank
Life of this patent
Estimating the term…
Abstract
The invention relates to absorptive, crosslinked polymers which are based on partly neutralized, monoethylenically unsaturated monomers carrying acid groups, and have improved properties, in particular in respect of their capacity for transportation of liquids in the swollen state, and which has a high gel bed permeability and high centrifuge retention capacity.
Claims16
1-82. (canceled)
A superabsorbent polymer composition comprising a polymer consisting essentially of:
- a) from about 55 to about 99.9 wt. % of polymerizable unsaturated acid group containing monomers;
- b) from about 0.001 to about 5.0 wt. % based on the weight of a) of internal crosslinking agent;
- said superabsorbent polymer composition further comprising
- c) from about 0.001 to about 5.0 wt. % based on dry polymer powder weight of surface crosslinking agent applied to the particle surface;
- d) from about 0.01% to about 5 wt. % based on dry polymer powder weight of a penetration modifier added immediately before, during or immediately after the surface crosslinking step;
- e) from 0 to about 5 wt. % based on dry polymer powder weight of a multivalent metal salt on the particle surface;
- f) from about 0.01 to 10 wt % based on dry polymer powder weight of a water-soluble polymer including a polyvinyl portion;
- and
- g) from about 0.01 to about 5 wt % based on dry polymer powder weight of an insoluble, inorganic phosphate powder wherein the composition has a degree of neutralization of more than about 25%;
- and a gel bed permeability of at least about [54000e−0.18x+75]×10−9 cm2 where x is the numeric value of centrifuge retention capacity.
A water insoluble, slightly cross-linked, partially neutralized, superabsorbent polymer composition comprising a polymer consisting essentially of a polymerizable unsaturated acid group containing monomers and an internal crosslinking agent, and the superabsorbent polymer further comprising a penetration modifier;
- an insoluble inorganic phosphate powder, and water-soluble polymer including a polyvinyl portion, wherein the superabsorbent polymer has a gel bed permeability of at least about [54000e−0.18x+75]×10−9 cm2. where x is the numeric value of centrifuge retention capacity.
A superabsorbent polymer composition comprising a polymer consisting essentially of:
- a) from about 55 to about 99.9 wt. % of polymerizable unsaturated acid group containing monomers;
- b) from about 0.001 to about 5.0 wt. % based on the weight of a) of internal crosslinking agent;
- said superabsorbent polymer composition further comprising
- c) from about 0.001 to about 5.0 wt. % based on dry polymer powder weight of surface crosslinking agent applied to the particle surface;
- d) from about 0.01% to about 5 wt. % based on dry polymer powder weight of a penetration modifier added immediately before, during or immediately after the surface crosslinking step;
- e) from 0 to about 5 wt. % based on dry polymer powder weight of a multivalent metal salt on the surface;
- f) from 0 to about 30 wt % based on dry polymer powder weight of a from 0 to about 30 wt. % of water-soluble polymer including a polyvinyl portion;
- and
- g) from about 0.01 to about 5 wt % based on dry polymer powder weight of an insoluble, inorganic phosphate powder wherein the composition has, a degree of neutralization of more than about 25%;
- having the characteristics of centrifuge retention capacity from about 30 to about 36 g/g, and a gel bed permeability of about [54000e−0.18x+75]×10−9 cm2 or more where x is the numeric value of centrifuge retention capacity.
Dependencies are inferred from the claim text.