Abstract: Provided herein are fluid-absorbent articles, fluid absorbent cores, and fluid-absorbent mixtures with improved properties, especially rewet performance and liquid acquisition. The fluid-absorbent article includes (A) an upper liquid-pervious sheet, (B) a lower liquid-impervious sheet, (C) a fluid-absorbent core including from 60 to 20% by weight fibrous material and from 40 to 80% by weight of at least a first type of water-absorbent polymer particles, (G) and at least a second type of water-absorbent polymer particles (H) based on the sum of water-absorbent polymer particles and fibrous material, (D) an optional acquisition-distribution layer (D) between (A) and (C), (F) other optional components, wherein the first type of water absorbent polymer particles (G) of the fluid-absorbent core (C) have a SFC of at least 20×10?7 cm3·s/g, and wherein the at least second type of water-absorbent polymer particles (H) of the fluid-absorbent core have a sphericity of at least 0.80.

Abstract: A method of pneumatically conveying superabsorbent particles, wherein the superabsorbent particles have been admixed with an aqueous wax dispersion prior to the pneumatic conveying, the wax has a glass transition temperature of at least 65° C. and, based on the untreated superabsorbent particles, from 0.020% to 0.20% by weight of wax has been used.

Abstract: Superabsorbent mixtures M comprising at least 70% by weight of superabsorbent A having a liquid absorption of 20 g/g (T20) of less than 300 s and/or a volumetric liquid absorption under pressure 0.3 psi (2.07 kPa) (VAUL) with a ? value of less than 400 s, and at least 5% by weight of superabsorbent B having a centrifuge retention capacity (CRC) of at least 30 g/g.

Abstract: An apparatus for production of pulverulent polymers having a reactor for droplet polymerization with an apparatus for dropletization of a monomer solution for the preparation of the polymer. The apparatus for dropletization has holes through which the monomer solution is introduced, an addition point for a gas above the apparatus for dropletization, at least one gas withdrawal point at the periphery of the reactor and a fluidized bed, wherein at least one of the following is fulfilled: an apparatus for increasing turbulence in the gas flow is disposed in the region of the apparatus for dropletization of the monomer solution, an apparatus for increasing turbulence in the gas flow is disposed in the region of the addition point for the gas, the addition point for gas is configured such that elevated turbulence is generated. A process for producing pulverulent polymers, in which an increase in flow turbulence in the gas flow in the region of the apparatus for dropletization also is disclosed.

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.

Abstract: Superabsorbent mixtures M comprising at least 70% by weight of superabsorbent A having a liquid absorption of 20 g/g (T20) of less than 300 s and/or a volumetric liquid absorption under pressure 0.3 psi (2.07 kPa) (VAUL) with a ? value of less than 400 s, and at least 5% by weight of superabsorbent B having a centrifuge retention capacity (CRC) of at least 30 g/g.

Abstract: The invention relates to a process for producing long-term color stable superabsorbent polymer particles, comprising polymerization of a monomer solution, drying the resulting polymer gel, optionally grinding and classifying the resulting dried polymer gel and thermally surface post-crosslinking and cooling the resulting polymer particles, wherein a thermal surface post-cross-linker and hydrogen peroxide are added to the polymer particles prior to the thermal surface post-crosslinking.

Abstract: The present invention relates to a process for producing surface-postcrosslinked water-absorbent polymer particles by coating of water-absorbent polymer particles having a content of residual monomers in the range from 0.03 to 15% by weight with at least one surface-postcrosslinker and thermal surface-postcrosslinking at temperatures in the range from 100 to 180° C.

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.

Abstract: The invention relates to a process for producing long-term color stable superabsorbent polymer particles, comprising polymerization of a monomer solution, wherein the monomer solution comprises at least 0.01% by weight of 1-hydroxyethane-1,1-diphosphonic acid or a salt thereof and at least 0.01% by weight of 2-hydroxy-2-sulfonatoacetic acid or a salt thereof.

Abstract: A method of pneumatically conveying superabsorbent particles, wherein the superabsorbent particles have been admixed with an aqueous wax dispersion prior to the pneumatic conveying, the wax has a glass transition temperature of at least 65° C. and, based on the untreated super-absorbent particles, from 0.020% to 0.20% by weight of wax has been used.

Abstract: An apparatus for production of pulverulent polymers having a reactor for droplet polymerization with an apparatus for dropletization of a monomer solution for the preparation of the polymer. The apparatus for dropletization has holes through which the monomer solution is introduced, an addition point for a gas above the apparatus for dropletization, at least one gas withdrawal point at the periphery of the reactor and a fluidized bed, wherein at least one of the following is fulfilled: an apparatus for increasing turbulence in the gas flow is disposed in the region of the apparatus for dropletization of the monomer solution, an apparatus for increasing turbulence in the gas flow is disposed in the region of the addition point for the gas, the addition point for gas is configured such that elevated turbulence is generated. A process for producing pulverulent polymers, in which an increase in flow turbulence in the gas flow in the region of the apparatus for dropletization also is disclosed.

Abstract: Provided herein are fluid-absorbent articles, fluid absorbent cores, and fluid-absorbent mixtures with improved properties, especially rewet performance and liquid acquisition. The fluid-absorbent article includes (A) an upper liquid-pervious sheet, (B) a lower liquid-impervious sheet, (C) a fluid-absorbent core including from 60 to 20% by weight fibrous material and from 40 to 80% by weight of at least a first type of water-absorbent polymer particles, (G) and at least a second type of water-absorbent polymer particles (H) based on the sum of water-absorbent polymer particles and fibrous material, (D) an optional acquisition-distribution layer (D) between (A) and (C), (F) other optional components, wherein the first type of water absorbent polymer particles (G) of the fluid-absorbent core (C) have a SFC of at least 20×10?7 cm3·s/g, and wherein the at least second type of water-absorbent polymer particles (H) of the fluid-absorbent core have a sphericity of at least 0.80.

Abstract: A fluid-absorbent article includes an upper liquid-pervious layer (A), a lower liquid-impervious layer (B), a fluid-absorbent core (C) between (A) and (B) including at least 60% by weight of non-surface postcrosslinked fluid-absorbent polymer particles and not more than 40% by weight of fibrous material, based on the sum of non-surface postcrosslinked fluid-absorbent polymer particles and fibrous material. An acquisition-distribution layer (D) between (A) and (C) includes at least 90% by weight of synthetic fibers and not more than 10% by weight of cellulose based fibers, based on the sum of synthetic fibers and cellulose based fibers. The basis weight of the acquisition-distribution layer (D) is at least 70 gsm. The fluid-absorbent polymer particles have a saline flow conductivity (SFC) of less than 5×10?7 cm3s/g and an AUHL of less than 15 g/g. Preferably the acquisition-distribution layer (D) is a non-woven web including a three dimensional network of fibers.

Abstract: The present invention relates to a process for producing surface-postcrosslinked water-absorbent polymer particles by coating of water-absorbent polymer particles having a content of residual monomers in the range from 0.03 to 15% by weight with at least one surface-postcrosslinker and thermal surface-postcrosslinking at temperatures in the range from 100 to 180° C.

Abstract: The present invention relates to a process for producing surface-postcrosslinked water-absorbent polymer particles by coating of water-absorbent polymer particles having a content of residual monomers in the range from 0.03 to 15% by weight with at least one surface-postcrosslinker and thermal surface-postcrosslinking at temperatures in the range from 100 to 180° C.

Abstract: The present invention relates to a process for producing water-absorbent polymer particles by polymerizing droplets of a monomer solution comprising less than 0.3% by weight of persulfate and at least 0.05% by weight of azo initiator and thermal aftertreatment of the formed polymer particles at less than 100° C. in a fluidized bed for 60 to 300 minutes.

Abstract: The present invention relates to a process for producing surface-postcrosslinked water-absorbent polymer particles comprising polymerizing droplets of a monomer solution, wherein water-absorbent polymer particles having an average particle diameter from 420 to 700 ?m, an amount of water-absorbent polymer particles having a particle size of less than 300 ?m of less than 5% by weight and an amount of water-absorbent polymer particles having a particle size of more than 800 ?m of less than 5% by weight are coated with at least one surface-postcrosslinker and thermal surface-postcrosslinked.

Abstract: The present invention relates to a process for producing surface-postcrosslinked water-absorbent polymer particles comprising polymerizing droplets of a monomer solution, wherein water-absorbent polymer particles having an average particle diameter from 150 to 400 ???, an amount of water-absorbent polymer particles having a particle size of less than 100 ??? of less than 5% by weight and an amount of water-absorbent polymer particles having a particle size of more than 500 ??? of less than 5% by weight are coated with at least one surface-postcrosslinker and thermal surface-postcrosslinked.

Abstract: The present invention relates to a process for producing water-absorbent polymer particles by polymerizing droplets of a monomer solution comprising less than 0.3% by weight of persulfate and at least 0.05% by weight of azo initiator and thermal aftertreatment of the formed polymer particles at less than 100° C. in a fluidized bed for 60 to 300 minutes.